Systems and methods for treating ammonia

Abstract

The present disclosure provides a catalyst, a method for making the catalyst, and a method for producing hydrogen and nitrogen using the catalyst for ammonia decomposition. The catalyst may include an electrically conductive support having one or more metal oxide layers adjacent to the support and at least one active metal adjacent to the layers. Methods for depositing, drying, and heat-treating the metal oxides and active metals are disclosed. A method for using the catalyst may include contacting ammonia with the catalyst in a reactor. The catalyst may be configured to be heated to a target temperature in less than about 60 minutes by passing an electric current through the catalyst. A method for using the catalyst may include contacting the catalyst with ammonia at about 450-700°C to produce a reformate stream at a conversion efficiency greater than about 70%.

Description

[Technical Field]

[0001] cross reference This application is a continuation of U.S. Patent Application No. 18 / 065,915, filed December 14, 2022, which in turn claims priority to U.S. Patent Application No. 18 / 475,917, filed September 27, 2023, which claims the benefit of U.S. Provisional Application No. 63 / 418,251, filed October 21, 2022, and U.S. Provisional Application No. 63 / 427,245, filed November 22, 2022, each of which is incorporated herein by reference in its entirety for all purposes. This application also claims priority to U.S. Patent Application No. 18 / 066,163, filed December 14, 2022, which in turn claims the benefit of U.S. Provisional Application No. 63 / 418,249, filed October 21, 2022, and U.S. Provisional Application No. 63 / 427,286, filed November 22, 2022, each of which is incorporated herein by reference in its entirety for all purposes. This application also claims the benefit of U.S. Provisional Application No. 63 / 519,742, filed August 15, 2023, U.S. Provisional Application No. 63 / 427,540, filed November 23, 2022, and U.S. Provisional Application No. 63 / 432,805, filed December 15, 2022, each of which is incorporated herein by reference in its entirety for all purposes. [Background technology]

[0002] Various systems can be operated using a fuel source. A fuel source can have a specific energy corresponding to the amount of energy stored or extractable per unit mass of fuel. A fuel source can be provided to various systems to enable such systems to generate energy and / or deliver power (e.g., for mobility or transportation purposes).

[0003] Ammonia is an attractive alternative energy fuel source, particularly because it contains no carbon. Ammonia can be burned in internal combustion engines, but a supplemental fuel (e.g., hydrogen) is often required to provide acceptable combustion characteristics. Ammonia can also be used as a hydrogen carrier and can undergo catalytic oxidation to produce nitrogen and hydrogen (which can then be used to power a fuel cell). However, many alternative fuels (including ammonia) have similar limitations in that they have lower energy density or conversion efficiency than traditional fossil fuels, creating some reluctance in the market to transition to cleaner power plants. Summary of the Invention

[0004] Hydrogen can be utilized as a clean energy source to power various systems. Hydrogen can offer distinct advantages over other types of fuels, such as diesel, gasoline, or jet fuel, which have a specific energy of approximately 45 megajoules per kilogram (MJ / kg) (heat), or lithium-ion batteries, which have a specific energy of approximately 0.95 MJ / kg (electrical). In contrast, hydrogen has a specific energy (heat) of over 140 MJ / kg. Thus, 1 kg of hydrogen can provide the same amount of energy as approximately 3 kg of gasoline or kerosene. Hydrogen as a fuel source can therefore help reduce the amount of fuel (by mass) required to provide an equivalent amount of energy as other conventional fuel sources. Furthermore, systems that use hydrogen as a fuel source (e.g., as a combustion reactant) generally produce harmless or non-toxic by-products, such as water, while producing minimal or near-zero harmful emissions, such as carbon dioxide or nitrous oxide emissions, thereby reducing the environmental impact of various systems (e.g., transportation) that use hydrogen as a fuel source.

[0005] Various limitations of conventional catalysts used to extract hydrogen from ammonia (e.g., through an ammonia decomposition process or reaction) are recognized herein. Ammonia decomposition may also be referred to as ammonia dehydrogenation, ammonia cracking, ammonia reforming, ammonia splitting, ammonia decomposition, ammonia stripping, ammonia conversion, or ammonia dissociation. Ammonia decomposition can be a highly structure-dependent reaction, and using conventional catalyst manufacturing methods, the ability to control the morphology and / or physical or chemical properties of the active metal nanoparticles used to decompose the ammonia molecule may be limited. Therefore, efficient use of active metal nanoparticles is difficult, and conventional catalysts often contain increased active metal nanoparticle content. Furthermore, the nanoparticles may not be highly dispersed, which can reduce the efficiency of the catalyst. Conventional catalysts may also exhibit low heat transfer rates, which are undesirable for endothermic ammonia decomposition reactions. Conventional catalysts may also lack stability at high temperatures, in the presence of impurities in industrial-grade ammonia, or under mechanical perturbation, and may not be able to withstand harsh reaction conditions or maintain the physical and chemical properties necessary to efficiently crack ammonia. Some conventional catalysts may include bead, extrudate, or pellet-type catalyst supports; however, when catalyst materials are compressed into these form factors, the interior material of the pellets may not be fully utilized, which can be wasteful and inefficient. As used herein, the morphology of an active metal nanoparticle support may correspond to the size, shape, aspect ratio, pore structure, pore size, pore shape, pore volume, pore density, pore size distribution, grain structure, grain size, grain shape, crystalline structure, flake size, or layered structure of one or more active metal nanoparticles. As used herein, the physical or chemical properties of the active metal nanoparticles may include the size, size distribution, aspect ratio, facet distribution, Arrhenius acidity or basicity, Lewis acidity or basicity, or hydrophilicity or hydrophobicity of one or more active metal nanoparticles.

[0006] The present disclosure provides systems and methods for addressing at least the above-described shortcomings of conventional catalysts. Some aspects of the present disclosure are directed to improved catalytic materials, related systems and methods for producing such improved catalytic materials, and methods for using such improved catalytic materials. The improved catalytic materials may exhibit improved morphology and / or physical or chemical properties for the active metal nanoparticles used to promote the decomposition of ammonia. The physical or chemical properties may include the surface chemistry or properties of one or more active metal nanoparticles. The improved catalytic materials may also exhibit improved levels of dispersion of the active metal nanoparticles. The improved catalytic materials may further maintain favorable physical and chemical properties under harsh reaction conditions and may exhibit high thermal stability and improved heat transfer rates, enabling an efficient endothermic ammonia decomposition reaction.

[0007] The present disclosure further provides methods for producing catalysts that include improved material composition, active metal nanoparticle morphology, surface chemistry or properties, and / or support-metal interactions. The production methods disclosed herein can be implemented to produce catalytic materials with high thermal stability and improved heat transfer properties. Catalytic materials produced using the disclosed methods can be used to efficiently decompose ammonia at lower reaction temperatures for longer durations compared to conventional catalysts, and can extract greater amounts of hydrogen per unit weight or volume of ammonia while reducing or eliminating the need for expensive and difficult-to-obtain active metals (e.g., low or no content of ruthenium or platinum group metals).

[0008] The present disclosure further provides one or more catalysts for treating ammonia. The one or more catalysts may include, for example, modified pore structures and active metal nanoparticle morphologies and / or surface chemistries or properties. The catalytic materials of the present disclosure may have high thermal stability and improved heat transfer properties. The catalytic materials may be used to efficiently decompose ammonia at lower reaction temperatures and may extract greater amounts of hydrogen per unit weight or volume of ammonia while using lower concentrations of active metals. In some cases, more hydrogen may be produced when the same amount of catalytic material is used. In some cases, hydrogen may be produced at lower reaction temperatures.

[0009] In some aspects, the present disclosure is directed to a method for reforming ammonia, the method comprising: providing a reactor comprising a catalyst, the catalyst in electrical communication with a pair of electrodes, the catalyst comprising a conductive support, the conductive support comprising a resistivity greater than about 50 microohm-centimeters (ohm-cm) and less than about 100 ohm-cm; applying a voltage across the pair of electrodes, thereby passing an electric current through the catalyst, to heat at least a portion of the catalyst from a first temperature to a second temperature in a period of less than about 60 minutes, the second temperature being greater than about 200°C and less than about 700°C; and contacting ammonia (NH) with the catalyst to produce hydrogen (H) and nitrogen (N) at an ammonia conversion efficiency of greater than about 70%.

[0010] In some cases, the ammonia contacts the catalyst and the reactor produces hydrogen and nitrogen with an ammonia conversion efficiency of greater than about 90%.

[0011] In some cases, the ammonia is greater than about 1,000 milliliters and less than about 100,000 milliliters of NH3 (ml) per milliliter of catalyst per hour. NH3 hr -1 mL 触媒 -1 ) contact with the catalyst at a GHSV of 1000 ppm.

[0012] In some embodiments, the catalyst is heated from the first temperature to the second temperature in less than about 30 minutes.

[0013] In some cases, the first temperature is ambient temperature.

[0014] In some cases, the first temperature is about 25°C.

[0015] In some cases, the conductive support has a resistance greater than about 1 ohm.

[0016] In some cases, the current passes between the electrodes and through the catalyst at a distance greater than about 1 centimeter (cm) and less than about 10 meters.

[0017] In some cases, the combined resistance of the catalyst and electrode is greater than about 0.1 ohms and less than about 100 ohms.

[0018] In some cases, the resistivity is the resistance of the catalyst multiplied by the cross-sectional area of ​​the catalyst divided by the distance that the current passes between the electrodes and through the catalyst.

[0019] In some cases, the resistivity of the conductive support is at a temperature greater than about 15°C and less than about 30°C.

[0020] In some embodiments, the current comprises a power per gram of catalyst greater than about 5 watts per gram (W / g) and less than about 500 W / g.

[0021] In some cases, the period begins based on current beginning to pass through the catalyst.

[0022] In some embodiments, the catalyst is a monolith.

[0023] In some cases, the catalyst comprises beads, pellets, or powder configured to form an electrical circuit between the electrodes.

[0024] In some cases, the conductive support comprises a ceramic material.

[0025] In some embodiments, the conductive support comprises silicon carbide (SiC), silicon (Si), or germanium (Ge).

[0026] In some cases, the conductive support comprises a carbon-based material.

[0027] In some cases, the carbon-based material includes graphite or amorphous carbon.

[0028] In some cases, the conductive support includes NiCrAl, FeCrAl, NiFeCrAl, or NiCr.

[0029] In some cases, the conductive support comprises a dopant comprising phosphorus (P), nitrogen (N), or boron (B).

[0030] In some embodiments, the catalyst further comprises a layer adjacent to the conductive support.

[0031] In some cases, the conductive support comprises SiC and the layer comprises alumina (Al2O3).

[0032] In some cases, the Al2O3 comprises alpha alumina, theta alumina, or gamma alumina.

[0033] In some embodiments, the catalyst further comprises an active metal adjacent to the layer comprising Al2O3.

[0034] In some cases, the active metal includes Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Pd, Mo, or Cu.

[0035] In some embodiments, the active metal comprises Ru.

[0036] In some cases, the concentration of Ru is greater than about 0.5 wt % and less than about 3 wt % based on the total weight of the catalyst, including the support and layer.

[0037] In some embodiments, a first electrode of the pair of electrodes is positioned proximate a first side of the reactor and a second electrode of the pair of electrodes is positioned proximate a second side of the reactor, the first side and the second side being positioned substantially opposite one another.

[0038] In some cases, a pair of electrodes are adjacent to each other and close to the sides of the reactor.

[0039] In some embodiments, the voltage between the electrodes is reduced or stopped based on the catalyst reaching a second temperature.

[0040] In some cases, the reactor is heated by combustion.

[0041] In some cases, the reactor is heated electrically in addition to heating the catalyst by passing an electric current through the catalyst.

[0042] In some cases, the reactor further comprises a second catalyst.

[0043] In some cases, a second catalyst is mixed with the catalyst.

[0044] In some cases, the reactor includes at least two zones, a first zone including a catalyst and a second zone including a second catalyst.

[0045] In some cases, the voltage is provided by a battery.

[0046] In some cases, the voltage is provided from an electrical grid.

[0047] In some embodiments, power is generated by providing H2 to a fuel cell.

[0048] In some cases, the fuel cell includes a proton exchange membrane fuel cell (PEMFC), a solid oxide fuel cell (SOFC), a molten carbonate fuel cell (MCFC), an alkaline fuel cell (AFC), an alkaline membrane fuel cell (AMFC), or a phosphoric acid fuel cell (PAFC).

[0049] In some cases, electricity is produced by providing hydrogen to one or more combustion engines or turbines.

[0050] In some embodiments, the catalyst is heated to a second temperature, greater than about 600° C. and less than about 700° C., for a period of less than 10 minutes, and contacting NH with the catalyst produces H and N at an ammonia conversion efficiency of greater than about 95%.

[0051] In some aspects, the present disclosure provides a method for producing a catalyst for ammonia decomposition, the catalyst comprising an electrically conductive support, the electrically conductive support comprising a resistivity greater than about 50 microohm-cm and less than about 100 ohm-cm, the method comprising: (a) immersing the electrically conductive support in a slurry comprising (i) a binder and (ii) alumina to deposit a layer comprising alumina in, on, or adjacent to the electrically conductive support; (b) removing the catalyst comprising the electrically conductive support and the layer from the slurry; and (c) removing the catalyst comprising the electrically conductive support and the layer. (d) heat-treating the catalyst comprising the conductive support and the layer in a non-reducing atmosphere at a temperature greater than about 200°C and less than about 1400°C; (e) immersing the catalyst comprising the conductive support and the layer in a solution comprising an active metal precursor to deposit the active metal precursor in, on, or adjacent to the layer; and (f) heat-treating the catalyst comprising the conductive support, the layer, and the active metal precursor in a non-oxidizing atmosphere at a temperature greater than about 200°C and less than about 1300°C to convert the active metal precursor to the active metal.

[0052] In some embodiments, the slurry comprises a pH greater than about 0.1 and less than about 3.

[0053] In some cases, the catalyst is a monolith.

[0054] In some cases, the binder is an alumina-derived sol-gel.

[0055] In some cases, the binder includes boehmite, bayerite, or gibbsite.

[0056] In some cases, the binder is a hydrocarbon-based binder.

[0057] In some cases, the hydrocarbon binder comprises polyvinyl alcohol (PVA), polyethylene glycol (PEG), polyurethane (PUR), or polyethyleneimine (PEI).

[0058] In some embodiments, the conductive support is immersed in the slurry for a period of more than about 1 second and less than about 10 minutes.

[0059] In some cases, the period begins based on the conductive support being fully immersed below the surface of the slurry.

[0060] In some cases, the drying in (c) includes blowing air onto the catalyst including the conductive support and the layer.

[0061] In some cases, the drying in (c) includes passing a flame or combustion product gases adjacent to or over the catalyst including the conductive support and layer.

[0062] In some cases, the non-reducing atmosphere includes air, O2, N2, CO2, Ar, He, Kr, or Xe.

[0063] In some cases, the non-oxidizing atmosphere includes at least one of N2, H2, Ar, NH3, CO, CO2, He, Kr, and Xe.

[0064] In some embodiments, the alumina comprises alpha alumina, theta alumina, or gamma alumina.

[0065] In some cases, the active metal precursor is Ru(NO)(NO3)3, Ru(NO3)3, RuCl3, Ru3(CO) 12 , ruthenium(III) chloride hexaammoniumide Ru(NH3)6Cl3, cyclohexadiene ruthenium tricarbonyl ((CHD)Ru(CO)3), butadiene ruthenium tricarbonyl ((BD)Ru(CO)3), or dimethylbutadiene ruthenium tricarbonyl ((DMBD)Ru(CO)3).

[0066] In some embodiments, the active metal comprises ruthenium (Ru).

[0067] In some cases, the concentration of Ru comprises greater than about 0.5 wt % and less than about 3 wt % based on the total weight of the catalyst including the semiconductor support and layer.

[0068] In some embodiments, the solids in the slurry include a binder and an alumina powder, and the concentration of solids comprises greater than about 20% by weight and less than about 60% by weight based on the total weight of the slurry.

[0069] In some cases, the conductive support comprises a ceramic material.

[0070] In some cases, the conductive support comprises silicon carbide (SiC), silicon (Si), or germanium (Ge).

[0071] In some cases, the conductive support comprises a carbon-based material.

[0072] In some cases, the carbon-based material includes graphite or amorphous carbon.

[0073] In some cases, the conductive support comprises NiCrAl, FeCrAl, NiFeCrAl, or NiCr.

[0074] In some cases, the conductive support comprises a dopant comprising phosphorus (P), nitrogen (N), or boron (B).

[0075] In some aspects, the present disclosure is directed to a catalyst for ammonia decomposition, the catalyst comprising: an electrically conductive support comprising a resistivity greater than about 50 microohm-cm and less than about 100 ohm-cm; a layer in, on, or adjacent to the electrically conductive support, the layer comprising alumina, zirconia, iron oxide, magnesium oxide, manganese oxide, nickel oxide, silicon dioxide, titanium dioxide, vanadium dioxide, or zinc oxide; and an active metal adjacent to the layer, the active metal comprising Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu.

[0076] In some embodiments, the catalyst is a monolith.

[0077] In some embodiments, the conductive support comprises SiC, the layer comprises alumina, and the active metal comprises Ru.

[0078] In some cases, the alumina includes alpha alumina, theta alumina, or gamma alumina.

[0079] In some cases, the concentration of Ru comprises greater than about 0.5 wt % and less than about 3 wt % based on the total weight of the catalyst, including the support and layer.

[0080] In some cases, the conductive support comprises a ceramic material.

[0081] In some cases, the conductive support comprises silicon carbide (SiC), silicon (Si), or germanium (Ge).

[0082] In some cases, the conductive support comprises a carbon-based material.

[0083] In some cases, the carbon-based material includes graphite or amorphous carbon.

[0084] In some cases, the conductive support comprises NiCrAl, FeCrAl, NiFeCrAl, or NiCr.

[0085] In some cases, the conductive support comprises a dopant comprising phosphorus (P), nitrogen (N), or boron (B).

[0086] In some aspects, the disclosure relates to a method for ammonia decomposition, the method comprising: (a) providing a catalyst comprising an electrically conductive support, the electrically conductive support comprising a resistivity greater than about 50 microohm-cm and less than about 100 ohm-cm; a layer adjacent to the electrically conductive support, the layer comprising alumina, zirconia, iron oxide, magnesium oxide, manganese oxide, nickel oxide, silicon dioxide, titanium dioxide, vanadium dioxide, or zinc oxide; and an active metal adjacent to the layer, the active metal comprising Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu; and (b) contacting the catalyst with ammonia at a temperature of about 450° C. to about 700° C. to produce a reformate stream comprising hydrogen and nitrogen at an ammonia conversion efficiency greater than about 70%.

[0087] In some cases, the catalyst is in electrical communication with a pair of electrodes, and passing an electric current through the catalyst heats the catalyst.

[0088] In some cases, the ammonia is contacted over the catalyst at a temperature of from about 450°C to about 700°C at a space velocity of from about 1 to about 50 liters per hour per gram of catalyst.

[0089] In some cases, the ammonia is contacted over the catalyst at a temperature of from about 450° C. to about 700° C. and a gas hourly space velocity (GHSV) of from about 1 to about 50 liters per gram of catalyst per hour.

[0090] In some cases, contacting the catalyst with ammonia to produce the reformed stream is an autothermal reforming process, such that at least a portion of the reformed stream provides heat for the autothermal reforming process.

[0091] In some cases, at least a portion of the reforming stream is converted by (1) combustion to produce heat or (2) conversion of hydrogen to electricity to produce heat, thereby providing heat for the autothermal reforming process.

[0092] In some embodiments, undecomposed ammonia in the reformate stream is removed by an ammonia filter.

[0093] In some embodiments, the ammonia filter comprises an adsorber, a membrane separation module, or an ammonia scrubber.

[0094] In some cases, a pressure swing adsorption (PSA) module is used to remove nitrogen from the reformate stream.

[0095] In some cases, ammonia is directed to a first reformer containing a catalyst to produce a reformate stream, the reformate stream is combusted in a fired heater to heat a second reformer, additional ammonia is directed to the second reformer to produce additional hydrogen for the reformate stream, and a first portion of the reformate stream is combusted to heat the second reformer.

[0096] In some cases, the first reformer is heated using at least one of an electric heater or combustion of the reformate stream.

[0097] In some cases, the method includes directing ammonia at an ammonia flow rate to a reformer to generate a reformed stream; combusting a first portion of the reformed stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformed stream in a hydro-processing module; and performing, at least in part, one or more of: (i) varying the ammonia flow rate; (ii) varying a percentage of the reformed stream that is the first portion of the reformed stream; (iii) varying a percentage of the reformed stream that is the second portion of the reformed stream; or (iv) varying the oxygen flow rate based at least in part on the stimulus.

[0098] In some embodiments, a method includes directing ammonia at an ammonia flow rate to a reformer to produce a reformed stream; combusting a first portion of the reformed stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformed stream in a hydrogen-processing module; measuring a temperature in the reformer or fired heater; and, based at least in part on the measured temperature being outside a target temperature range of the reformer or fired heater, performing one or more of: (i) varying the ammonia flow rate; (ii) varying the oxygen flow rate; (iii) varying a percentage of the reformed stream that is the second portion of the reformed stream; (iv) varying a percentage of the reformed stream that is the first portion of the reformed stream; or (v) varying a percentage of the reformed stream directed out of the fired heater.

[0099] In some aspects, the present disclosure is directed to a method for reforming ammonia, the method comprising: contacting a gas comprising ammonia in a reactor containing a catalyst at a temperature in a range of about 400°C to about 700°C to produce a reformate stream comprising hydrogen (H) and nitrogen (N) at an ammonia conversion efficiency of at least about 70%, wherein the catalyst comprises an electrically conductive support, the electrically conductive support comprising a resistivity greater than about 50 microohm-centimeters (mohm-cm) and less than about 100 ohm-cm, the catalyst being in electrical communication with a pair of electrodes; and applying a voltage across the pair of electrodes, thereby passing an electric current through the catalyst, to heat at least a portion of the catalyst from a first temperature to a second temperature in a period of less than about 60 minutes, wherein the second temperature is greater than about 200°C and less than about 700°C.

[0100] In some embodiments, ammonia produces hydrogen and nitrogen with an ammonia conversion efficiency of greater than about 90%.

[0101] In some embodiments, the ammonia contacts the catalyst at a space velocity of greater than about 1000 milliliters and less than about 100,000 milliliters of NH3 per milliliter of catalyst per hour.

[0102] In some embodiments, the catalyst is heated from the first temperature to the second temperature in less than about 30 minutes.

[0103] In some embodiments, the first temperature is ambient temperature.

[0104] In some embodiments, the first temperature is about 25°C.

[0105] In some embodiments, the conductive support has a resistance greater than about 1 ohm.

[0106] In some embodiments, the current passes between the electrodes and through the catalyst at a distance greater than about 1 centimeter (cm) and less than about 10 meters.

[0107] In some embodiments, the combined resistance of the catalyst and electrode is greater than about 0.1 ohms and less than about 100 ohms.

[0108] In some embodiments, the resistivity is the resistance of the catalyst multiplied by the cross-sectional area of ​​the catalyst divided by the distance that the current passes between the electrodes and through the catalyst.

[0109] In some embodiments, the resistivity of the conductive support is at a temperature greater than about 15°C and less than about 30°C.

[0110] In some embodiments, the current comprises a power per gram of catalyst greater than about 5 watts per gram (W / g) and less than about 500 W / g.

[0111] In some embodiments, the period begins when current begins to pass through the catalyst.

[0112] In some embodiments, the catalyst is a monolith.

[0113] In some embodiments, the catalyst comprises beads, pellets, or powder configured to form an electrical circuit between the electrodes.

[0114] In some embodiments, the conductive support comprises a ceramic material.

[0115] In some embodiments, the conductive support comprises silicon carbide (SiC), silicon (Si), or germanium (Ge).

[0116] In some embodiments, the conductive support comprises a carbon-based material.

[0117] In some embodiments, the carbon-based material comprises graphite or amorphous carbon.

[0118] In some embodiments, the conductive support comprises NiCrAl, FeCrAl, NiFeCrAl, or NiCr.

[0119] In some embodiments, the conductive support comprises a dopant comprising phosphorus (P), nitrogen (N), or boron (B).

[0120] In some embodiments, the catalyst further comprises a layer adjacent to the conductive support.

[0121] In some embodiments, the conductive support comprises SiC and the layer comprises alumina (Al2O3).

[0122] In some embodiments, Al2O3 comprises alpha-alumina, theta-alumina, or gamma-alumina.

[0123] In some embodiments, the catalyst further comprises an active metal adjacent to the layer comprising Al2O3.

[0124] In some embodiments, the active metal comprises Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Pd, Mo, or Cu.

[0125] In some embodiments, the active metal comprises Ru.

[0126] In some embodiments, the concentration of Ru is greater than about 0.5 wt % and less than about 3 wt % based on the total weight of the catalyst, including the support and layer.

[0127] In some embodiments, a first electrode of the pair of electrodes is positioned proximate a first side of the reactor and a second electrode of the pair of electrodes is positioned proximate a second side of the reactor, the first side and the second side being positioned substantially opposite one another.

[0128] In some embodiments, a pair of electrodes are adjacent to each other and proximate to a side of the reactor.

[0129] In some embodiments, the method further includes reducing the voltage between the electrodes or ceasing application of the voltage based on the catalyst reaching the second temperature.

[0130] In some embodiments, the method further comprises heating the reactor by combustion.

[0131] In some embodiments, the method further comprises electrically heating the reactor in addition to heating the catalyst by passing an electric current through the catalyst.

[0132] In some embodiments, the reactor further comprises a second catalyst.

[0133] In some embodiments, a second catalyst is mixed with the catalyst.

[0134] In some embodiments, the reactor comprises at least two zones, a first zone comprising a catalyst and a second zone comprising a second catalyst.

[0135] In some embodiments, the voltage is provided by a battery.

[0136] In some embodiments, the voltage is provided from an electrical grid.

[0137] In some embodiments, the method further includes generating electrical power by providing H2 to a fuel cell.

[0138] In some embodiments, the fuel cell comprises a proton exchange membrane fuel cell (PEMFC), a solid oxide fuel cell (SOFC), a molten carbonate fuel cell (MCFC), an alkaline fuel cell (AFC), an alkaline membrane fuel cell (AMFC), or a phosphoric acid fuel cell (PAFC).

[0139] In some embodiments, the method further includes generating electrical power by providing the hydrogen to one or more combustion engines or turbines.

[0140] In some embodiments, the catalyst is heated to a second temperature, greater than about 600° C. and less than about 700° C., for a period of less than 30 minutes, and contacting NH with the catalyst produces H and N at an ammonia conversion efficiency of greater than about 95%.

[0141] In some aspects, the present disclosure provides a method of making a catalyst for ammonia decomposition, wherein the catalyst comprises an electrically conductive support, the electrically conductive support comprising a resistivity greater than about 50 micro-ohm-cm and less than about 100 ohm-cm, and the method comprises:

[0142] (a) immersing a conductive support in a slurry comprising (i) a binder and (ii) alumina (Al2O3) to deposit a layer comprising alumina adjacent to the conductive support;

[0143] (b) removing the conductive support and catalyst containing layer from the slurry;

[0144] (c) drying the catalyst including the conductive support and layer;

[0145] (d) heat treating the catalyst comprising the conductive support and layer in a non-reducing atmosphere at a temperature greater than about 200°C and less than about 1400°C;

[0146] (e) immersing the catalyst comprising the conductive support and the layer in a solution comprising an active metal precursor to deposit the active metal precursor adjacent to the layer;

[0147] (f) heat-treating the catalyst comprising the conductive support, the layer, and the active metal precursor in a non-oxidizing atmosphere at a temperature greater than about 200°C and less than about 1300°C to convert the active metal precursor to the active metal.

[0148] In some embodiments, the slurry comprises a pH greater than about 0.1 and less than about 3.

[0149] In some embodiments, the catalyst is a monolith.

[0150] In some embodiments, the binder is an alumina-derived sol-gel.

[0151] In some embodiments, the binder comprises boehmite, bayerite, or gibbsite.

[0152] In some embodiments, the binder is a hydrocarbon-based binder.

[0153] In some embodiments, the hydrocarbon binder comprises polyvinyl alcohol (PVA), polyethylene glycol (PEG), polyurethane (PUR), or polyethyleneimine (PEI).

[0154] In some embodiments, the conductive support is immersed in the slurry for a period of more than about 1 second and less than about 10 minutes.

[0155] In some embodiments, the period begins based on the conductive support being fully immersed below the surface of the slurry.

[0156] In some embodiments, drying comprises blowing air onto the catalyst comprising the conductive support and the layer.

[0157] In some embodiments, drying comprises passing a flame or combustion product gases adjacent to or over the catalyst comprising the conductive support and layer.

[0158] In some embodiments, the non-reducing atmosphere comprises air, O 2 , N 2 , CO 2 , Ar, He, Kr, or Xe.

[0159] In some embodiments, the non-oxidizing atmosphere includes N2, H2, Ar, NH3, CO, CO2, He, Kr, and Xe.

[0160] In some embodiments, the alumina comprises alpha alumina, theta alumina, or gamma alumina.

[0161] In some embodiments, the active metal precursor is Ru(NO)(NO3)3, Ru(NO3)3, RuCl3, Ru3(CO) 12 , ruthenium(III) chloride hexaammoniumide Ru(NH3)6Cl3, cyclohexadiene ruthenium tricarbonyl ((CHD)Ru(CO)3), butadiene ruthenium tricarbonyl ((BD)Ru(CO)3), or dimethylbutadiene ruthenium tricarbonyl ((DMBD)Ru(CO)3).

[0162] In some embodiments, the active metal comprises ruthenium (Ru).

[0163] In some embodiments, the concentration of Ru is greater than about 0.5 wt % and less than about 3 wt % based on the total weight of the catalyst, including the conductive support and layer.

[0164] In some embodiments, the solids in the slurry include a binder and alumina, and the concentration of solids comprises greater than about 20% and less than about 60% by weight based on the total weight of the slurry.

[0165] In some embodiments, the conductive support comprises a ceramic material.

[0166] In some embodiments, the conductive support comprises silicon carbide (SiC), silicon (Si), or germanium (Ge).

[0167] In some embodiments, the conductive support comprises a carbon-based material.

[0168] In some embodiments, the carbon-based material comprises graphite or amorphous carbon.

[0169] In some embodiments, the conductive support comprises NiCrAl, FeCrAl, NiFeCrAl, or NiCr.

[0170] In some embodiments, the conductive support comprises a dopant comprising phosphorus (P), nitrogen (N), or boron (B).

[0171] In some aspects, the present disclosure is directed to a catalyst for ammonia decomposition, the catalyst comprising: an electrically conductive support comprising a resistivity greater than about 50 microohm-cm and less than about 100 ohm-cm; a layer adjacent to the electrically conductive support, the layer comprising alumina, zirconia, iron oxide, magnesium oxide, manganese oxide, nickel oxide, silicon dioxide, titanium dioxide, vanadium dioxide, or zinc oxide; and an active metal adjacent to the layer, the active metal comprising Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu.

[0172] In some embodiments, the catalyst is a monolith.

[0173] In some embodiments, the conductive support comprises SiC, the layer comprises alumina, and the active metal comprises Ru.

[0174] In some embodiments, the alumina comprises alpha alumina, theta alumina, or gamma alumina.

[0175] In some embodiments, the concentration of Ru comprises greater than about 0.5 wt % and less than about 3 wt % based on the total weight of the catalyst, including the support and layer.

[0176] In some embodiments, the conductive support comprises a ceramic material.

[0177] In some embodiments, the conductive support comprises silicon carbide (SiC), silicon (Si), or germanium (Ge).

[0178] In some embodiments, the conductive support comprises a carbon-based material.

[0179] In some embodiments, the carbon-based material comprises graphite or amorphous carbon.

[0180] In some embodiments, the conductive support comprises NiCrAl, FeCrAl, NiFeCrAl, or NiCr.

[0181] In some embodiments, the conductive support comprises a dopant comprising phosphorus (P), nitrogen (N), or boron (B).

[0182] In some aspects, the present disclosure provides a method for ammonia decomposition, comprising: The present invention relates to a method for producing a reformate stream comprising hydrogen and nitrogen at an ammonia conversion efficiency of at least about 70%, the method comprising contacting an ammonia-containing gas over a catalyst at a temperature in the range of about 400°C to about 700°C to produce a reformate stream comprising hydrogen and nitrogen at an ammonia conversion efficiency of at least about 70%, the catalyst comprising: an electrically conductive support comprising a resistivity greater than about 50 microohm-cm and less than about 100 ohm-cm; a layer adjacent to the electrically conductive support, the layer comprising alumina, zirconia, iron oxide, magnesium oxide, manganese oxide, nickel oxide, silicon dioxide, titanium dioxide, vanadium dioxide, or zinc oxide; and an active metal adjacent to the layer, the active metal comprising Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu.

[0183] In some embodiments, the catalyst is in electrical communication with a pair of electrodes, and passing an electric current through the catalyst heats the catalyst.

[0184] In some embodiments, ammonia is contacted over the catalyst at a temperature of from about 450° C. to about 700° C. and at a space velocity of from about 1 to about 50 liters per hour per gram of catalyst.

[0185] In some embodiments, ammonia is contacted over the catalyst at a temperature of about 450° C. to about 700° C. and a gas hourly space velocity (GHSV) of about 1 to about 50 liters per mL of catalyst per hour.

[0186] In some embodiments, contacting the catalyst with ammonia to produce a reformed stream is an autothermal reforming process, such that at least a portion of the reformed stream provides heat for the autothermal reforming process.

[0187] In some embodiments, at least a portion of the reforming stream is converted by (1) combustion to produce heat, or (2) hydrogen-to-electricity conversion to produce heat, thereby providing heat for the autothermal reforming process.

[0188] In some embodiments, undecomposed ammonia in the reformate stream is removed by an ammonia filter.

[0189] In some embodiments, the ammonia filter comprises an adsorber, a membrane separation module, or an ammonia scrubber.

[0190] In some embodiments, a pressure swing adsorption (PSA) module is used to remove nitrogen from the reformate stream.

[0191] In some embodiments, the method further includes directing ammonia to a first reformer including a catalyst to produce a reformate stream; combusting the reformate stream in a fired heater to heat a second reformer; and directing additional ammonia to the second reformer to produce additional hydrogen for the reformate stream, wherein a first portion of the reformate stream is combusted to heat the second reformer.

[0192] In some embodiments, the first reformer is heated using at least one of an electric heater or combustion of the reformate stream.

[0193] In some embodiments, the method includes directing ammonia at an ammonia flow rate to a reformer to generate a reformate stream; combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydro-processing module; and, based at least in part on the stimulus, (i) Varying the ammonia flow rate; (ii) varying the percentage of the reformate stream that is the first portion of the reformate stream; (iii) varying the percentage of the reformate stream that is the second portion of the reformate stream; or (iv) varying the oxygen flow rate.

[0194] In some embodiments, a method includes directing ammonia to a reformer at an ammonia flow rate to produce a reformate stream; combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydrogen-processing module; measuring a temperature in the reformer or fired heater; and based, at least in part, on the measured temperature being outside a target temperature range of the reformer or fired heater: (i) Varying the ammonia flow rate; (ii) varying the oxygen flow rate; (iii) varying the percentage of the reformate stream, which is the second portion of the reformate stream; (iv) varying the percentage of the reformate stream that is the first portion of the reformate stream; or (v) varying the percentage of the reformate stream that is directed out from the fired heater.

[0195] In some aspects, the present disclosure is directed to a catalyst for ammonia decomposition, the catalyst comprising: a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, or carbon nanotubes; a layer adjacent to the support, the layer comprising the support material doped with at least one oxide of an alkali metal, an alkaline earth metal, or a rare earth metal; and one or more active metal particles adjacent to the layer, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu, wherein the concentration of the active metal particles is at least about 0.1 wt. % and no more than about 15 wt. %.

[0196] In some embodiments, the support comprises zirconium and oxygen.

[0197] In some embodiments, the layer comprises Ce.

[0198] In some embodiments, the layer comprises a tetragonal network of zirconium, cerium, and oxygen.

[0199] In some embodiments, the layer comprises at least about 0.1 mmol / g up to about 10 mmol / g of oxygen vacancies.

[0200] In some embodiments, the layer comprises an acid site density of at least about 10 μmol / g up to about 1000 μmol / g.

[0201] In some embodiments, the layer comprises Ce 3+ ions and Ce 4+ ions, including Ce 3+ Ion pair Ce4+ The ratio of the ions is at least about 0.1:1 and not more than about 1:1.

[0202] In some embodiments, the layer comprises one or more promoters, and the molar ratio of the one or more promoters to Ce in the support is at least about 1:2 and not more than about 10:1.

[0203] In some embodiments, the layer comprises one or more promoters selected from alkali metals and alkaline earth metals, and the one or more promoters are co-impregnated with Ce.

[0204] In some embodiments, the active metal particles comprise ruthenium (Ru).

[0205] In some embodiments, the concentration of Ru is at least about 0.5 wt % and no more than about 10 wt %.

[0206] In some embodiments, the one or more active metal particles comprise nanoparticles of elemental Ru.

[0207] In some embodiments, at least one of the carriers or layers comprises one or more promoters, including at least one of K, Cs, or Rb.

[0208] In some embodiments, the layer comprises oxide nanoparticles of at least one of Ce, K, Cs, and Rb.

[0209] In some embodiments, the layer includes annealed nanoparticles of at least one of Ce, K, Cs, and Rb.

[0210] In some aspects, the present disclosure provides a method of producing a catalyst for ammonia decomposition, comprising: (a) providing a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, and carbon nanotubes, or precursors thereof; (b) depositing a layer adjacent to the support to form a doped support, the layer comprising at least one of an alkali metal oxide or precursor thereof, an alkaline earth metal oxide or precursor thereof, or a rare earth metal oxide or precursor thereof; (c) depositing a precursor of one or more active metal particles adjacent to the layer, wherein the one or more active metal particles comprise at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu, and wherein a concentration of the active metal particles is at least 0.1 wt. % and not more than about 15 wt. %; (d) maintaining the doped support at a temperature of at least about 200°C and not more than about 1000°C in an atmosphere comprising hydrogen for a duration of at least about 0.1 hours and not more than about 168 hours.

[0211] In some embodiments, (b) further comprises maintaining the doped support at a temperature of at least about 20° C. and not more than about 150° C. in a vacuum or in an atmosphere comprising air or an inert gas below an absolute pressure of about 5 bar for a duration of at least about 0.1 hours and not more than about 168 hours.

[0212] In some embodiments, (b) further comprises maintaining the doped support at a temperature of at least about 600°C and not more than about 1300°C for a duration of at least about 0.1 hours and not more than about 168 hours in a non-reducing atmosphere comprising at least one of air, N2, CO2, Ar, He, Kr, or Xe.

[0213] In some embodiments, (b) further comprises maintaining the doped support at a temperature of at least about 600°C and not more than about 1300°C for a duration of at least about 0.1 hours and not more than about 168 hours in an inert, oxygen-free, or non-oxidizing atmosphere comprising at least one of N2, H2, Ar, NH3, CO, CO2, He, Kr, or Xe.

[0214] In some embodiments, the support comprises zirconium and oxygen.

[0215] In some embodiments, the layer comprises Ce.

[0216] In some embodiments, the layer comprises a tetragonal network of zirconium, cerium, and oxygen.

[0217] In some embodiments, the catalyst comprises at least about 0.1 mmol / g up to about 10 mmol / g of oxygen vacancies.

[0218] In some embodiments, the catalyst comprises an acid site density of at least about 10 μmol / g up to about 1000 μmol / g.

[0219] In some embodiments, the layer comprises Ce 3+ ions and Ce 4+ ions, including Ce 3+ Ion pair Ce 4+ The ratio of the ions is at least about 0.1:1 and not more than about 1:1.

[0220] In some embodiments, the layer comprises one or more promoters, and the molar ratio of the one or more promoters to Ce in the support is at least about 1:2 and not more than about 10:1.

[0221] In some embodiments, (b) further comprises incorporating one or more promoters selected from alkali metals and alkaline earth metals, wherein the one or more promoters are co-impregnated with Ce.

[0222] In some embodiments, the molar ratio of promoter to active metal is at least about 1:2 and not more than about 10:1.

[0223] In some embodiments, one or more promoters or promoter precursors comprise at least one of K, Cs, or Rb.

[0224] In some embodiments, the one or more active metal particles comprise Ru, and the concentration of Ru is at least about 0.5 wt % and no more than about 10 wt %.

[0225] In some embodiments, the precursor of one or more active metal particles is Ru(NO)(NO), Ru(NO), RuCl, or Ru(CO). 12 It includes at least one of the following:

[0226] In some embodiments, the support or precursor thereof comprises a bead or pellet, the bead or pellet having a diameter of (i) at least about 0.1 mm and not more than about 10 mm, or (ii) at least about 50 mm. 2 / g and approximately 500m 2 / g or less.

[0227] In some aspects, the present disclosure is directed to a method for ammonia decomposition, comprising contacting a gas comprising ammonia over a catalyst at a temperature in the range of about 400° C. to about 700° C. to produce a reformate stream comprising hydrogen and nitrogen with an ammonia conversion efficiency of at least about 70% and not more than about 99.9%, wherein the catalyst comprises: a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, or carbon nanotubes; a layer adjacent to the support, the layer comprising a support material doped with at least one oxide of an alkali metal, an alkaline earth metal, or a rare earth metal; and one or more active metal particles deposited adjacent to the layer, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu, wherein the concentration of the active metal particles is at least about 0.1% by weight and not more than about 15% by weight.

[0228] In some embodiments, the catalyst is contacted with ammonia at a space velocity of at least about 1 liter per hour per gram of catalyst and no greater than about 100 liters per hour per gram of catalyst.

[0229] In some embodiments, the method further includes generating electricity by providing hydrogen produced by the catalyst to at least one fuel cell, wherein the at least one fuel cell comprises a proton exchange membrane fuel cell (PEMFC), a solid oxide fuel cell (SOFC), a molten carbonate fuel cell (MCFC), an alkaline fuel cell (AFC), an alkaline membrane fuel cell (AMFC), or a phosphoric acid fuel cell (PAFC).

[0230] In some embodiments, the method further includes providing the catalytically produced hydrogen to one or more combustion engines or turbines.

[0231] In some embodiments, the present disclosure is directed to a system configured to reform ammonia using the method of embodiment 123.

[0232] In some embodiments, contacting the catalyst with ammonia to produce a reformed stream is an autothermal reforming process, such that at least a portion of the reformed stream provides heat for the autothermal reforming process.

[0233] In some embodiments, at least a portion of the reforming stream is at least one of: (1) combusted to produce heat; or (2) converted by hydrogen-to-electricity conversion to produce heat, thereby providing heat for the autothermal reforming process.

[0234] In some embodiments, undecomposed ammonia in the reformate stream is removed by an ammonia filter.

[0235] In some embodiments, the ammonia filter comprises at least one of an adsorber, a membrane separation module, or an ammonia scrubber.

[0236] In some embodiments, a pressure swing adsorption (PSA) module is used to remove nitrogen from the reformate stream.

[0237] In some embodiments, (b) includes directing ammonia to a first reformer to produce a reformate stream, and the method includes combusting the reformate stream in a fired heater to heat a second reformer, and directing additional ammonia to the second reformer to produce additional hydrogen for the reformate stream, and a first portion of the reformate stream is combusted to heat the second reformer.

[0238] In some embodiments, the first reformer is heated using at least one of an electric heater or combustion of the reformate stream.

[0239] In some embodiments, (b) includes directing ammonia at an ammonia flow rate to a reformer to produce a reformate stream, and the method includes combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydro-processing module; and, based at least in part on the stimulus, (i) Varying the ammonia flow rate; (ii) varying the percentage of the reformate stream that is the first portion of the reformate stream; (iii) varying the percentage of the reformate stream that is the second portion of the reformate stream; or (iv) varying the oxygen flow rate.

[0240] In some embodiments, (b) includes directing ammonia to a reformer at an ammonia flow rate to produce a reformate stream, and the method includes combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydrogen-processing module; measuring a temperature in the reformer or fired heater; and, based at least in part on the measured temperature being outside a target temperature range of the reformer or fired heater: (i) Varying the ammonia flow rate; (ii) varying the oxygen flow rate; (iii) varying the percentage of the reformate stream, which is the second portion of the reformate stream; (iv) varying the percentage of the reformate stream that is the first portion of the reformate stream; or (v) varying the percentage of the reformate stream that is directed out from the fired heater.

[0241] In some aspects, the present disclosure is directed to a catalyst for ammonia decomposition, the catalyst comprising: a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, and carbon nanotubes; a layer adjacent to the support, the layer comprising the support material doped with at least one oxide of an alkali metal, an alkaline earth metal, or a rare earth metal; and one or more active metal particles adjacent to the layer, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu, wherein the concentration of the active metal particles is at least about 0.1 and no more than about 15 wt.%.

[0242] In some embodiments, the support comprises aluminum and oxygen.

[0243] In some embodiments, the layer comprises at least one of theta-alumina (θ-alumina) or gamma-alumina (γ-alumina).

[0244] In some embodiments, the layer comprises a perovskite phase.

[0245] In some embodiments, the layer comprises La at a concentration of at least about 0.1 and not more than about 50 mol %.

[0246] In some embodiments, the layer comprises La and Ce, and the molar ratio of La to Ce is at least about 10:90 and not more than about 90:10.

[0247] In some embodiments, at least one of the carrier or layers further comprises a promoter comprising at least one of K, Cs, or Rb.

[0248] In some embodiments, the molar ratio of promoter to active metal particles is at least about 1:2 and not more than about 10:1.

[0249] In some embodiments, the active metal particles comprise ruthenium (Ru).

[0250] In some embodiments, the concentration of Ru is at least about 0.5 and no more than about 10% by weight.

[0251] In some embodiments, the layer comprises nanoparticles of elemental Ru.

[0252] In some embodiments, the layer comprises oxide nanoparticles of at least one of La, Ce, K, Cs, or Rb.

[0253] In some embodiments, the layer comprises annealed nanoparticles of at least one of La, Ce, K, Cs, or Rb.

[0254] In some aspects, the present disclosure provides a method of producing a catalyst for ammonia decomposition, comprising:

[0255] (a) providing a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, or carbon nanotubes, or precursors thereof; (b) depositing a layer adjacent to the support comprising at least one of an alkali metal oxide or precursor thereof, an alkaline earth metal oxide or precursor thereof, or a rare earth metal oxide or precursor thereof to form a doped support; (c) depositing a precursor of one or more active metal particles adjacent to the layer, wherein the one or more active metal particles comprise at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu, and wherein a concentration of the active metal particles is at least about 0.1 wt. % and not more than about 15 wt. %; (d) maintaining the doped support at a temperature of at least about 200°C and not more than about 1300°C in an atmosphere comprising hydrogen for a duration of at least about 0.1 hours and not more than about 168 hours.

[0256] In some embodiments, (b) further comprises maintaining the doped support at a temperature of at least about 20° C. and not more than about 150° C. in a vacuum or in an inert, oxygen-free, or non-oxidizing atmosphere below an absolute pressure of 5 bar for a duration of at least about 0.1 hours and not more than about 168 hours.

[0257] In some embodiments, (b) further comprises maintaining the doped support at a temperature of at least about 300° C. and not more than about 1300° C. for a duration of at least about 0.1 hours and not more than about 168 hours in a non-reducing atmosphere comprising at least one of air, N, CO, Ar, He, Kr, or Xe.

[0258] In some embodiments, (b) further comprises maintaining the doped support at a temperature of at least about 300° C. and not more than about 1300° C. in an inert, oxygen-free, or non-oxidizing atmosphere comprising at least one of N, H, Ar, NH, CO, CO, He, Kr, or Xe for a duration of at least about 0.1 hours and not more than about 168 hours.

[0259] In some embodiments, the support comprises aluminum and oxygen.

[0260] In some embodiments, the layer comprises at least one of theta alumina (θ-alumina) or gamma alumina (γ-alumina).

[0261] In some embodiments, the layer comprises a perovskite phase.

[0262] In some embodiments, the layer comprises La at a concentration of at least about 0.1 and not more than about 50 mol %.

[0263] In some embodiments, the layer comprises La and Ce, and the molar ratio of La to Ce is at least about 10:90 and not more than about 90:10.

[0264] In some embodiments, the layer comprises depositing one or more promoters or promoter precursors, wherein the one or more promoters or promoter precursors comprise at least one of K, Cs, or Rb.

[0265] In some embodiments, the layer further comprises a molar ratio of one or more promoters or promoter precursors to one or more active metal particles comprising at least about 1:2 and not more than about 10:1.

[0266] In some embodiments, the one or more active metal particles further comprise ruthenium (Ru).

[0267] In some embodiments, the concentration of Ru comprises at least about 0.5 wt % and no more than about 10 wt %.

[0268] In some embodiments, (c) the precursor of the one or more active metal particles is Ru(NO)(NO3)3, Ru(NO3)3, RuCl3, Ru3(CO) 12 , Ru(NH3)6Cl3 (ruthenium(III) chloride hexaammoniumide), (CHD)Ru(CO)3 (cyclohexadiene ruthenium tricarbonyl), (BD)Ru(CO)3 (butadiene ruthenium tricarbonyl), or (DMBD)Ru(CO)3 (dimethylbutadiene ruthenium tricarbonyl).

[0269] In some embodiments, (a) the support or precursor thereof comprises a bead or pellet, and the bead or pellet has a diameter of (i) at least about 0.1 mm and not more than about 10 mm, or (ii) at least about 50 mm. 2 / g and approximately 500m 2 / g or less.

[0270] In some aspects, the disclosure provides a method for ammonia decomposition comprising contacting an ammonia-containing gas over a catalyst at a temperature in the range of about 400° C. to about 700° C. to produce a reformate stream comprising hydrogen and nitrogen with an ammonia conversion efficiency of at least about 70% and not more than about 99.9%, wherein the catalyst comprises: a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, and carbon nanotubes; a layer adjacent to the support, the layer comprising a support material doped with an oxide of at least one of an alkali metal, an alkaline earth metal, and a rare earth metal; and one or more active metal particles adjacent to the layer, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu, wherein the concentration of the active metal particles is at least about 0.1 and not more than about 15 wt.%; (b) contacting the catalyst with ammonia at a temperature of at least about 400°C and no more than about 700°C to produce a reformate stream comprising hydrogen and nitrogen at an ammonia conversion efficiency of at least about 70% and up to about 99.9%.

[0271] In some embodiments, ammonia is contacted over the catalyst at a space velocity of at least about 1 liter per gram of catalyst per hour and no greater than about 100 liters per hour.

[0272] In some embodiments, the method further includes generating electricity by providing hydrogen produced by the catalyst to at least one fuel cell, wherein the at least one fuel cell comprises a proton exchange membrane fuel cell (PEMFC), a solid oxide fuel cell (SOFC), a molten carbonate fuel cell (MCFC), an alkaline fuel cell (AFC), an alkaline membrane fuel cell (AMFC), or a phosphoric acid fuel cell (PAFC).

[0273] In some embodiments, the method further includes generating power or electricity by providing the hydrogen produced by the catalyst to one or more combustion engines or turbines.

[0274] In some embodiments, the system is configured to reform ammonia using the method of embodiment 168.

[0275] In some embodiments, contacting the catalyst with ammonia to produce a reformed stream is an autothermal reforming process, such that at least a portion of the reformed stream provides heat for the autothermal reforming process.

[0276] In some embodiments, at least a portion of the reforming stream is at least one of: (1) combusted to produce heat; or (2) converted by hydrogen-to-electricity conversion to produce heat, thereby providing heat for the autothermal reforming process.

[0277] In some embodiments, undecomposed ammonia in the reformate stream is removed by an ammonia filter.

[0278] In some embodiments, the ammonia filter comprises at least one of an adsorber, a membrane separation module, or an ammonia scrubber.

[0279] In some embodiments, a pressure swing adsorption (PSA) module is used to remove nitrogen from the reformate stream.

[0280] In some embodiments, (b) includes directing ammonia to a first reformer to produce a reformate stream, and the method includes combusting the reformate stream in a fired heater to heat a second reformer, and directing additional ammonia to the second reformer to produce additional hydrogen for the reformate stream, and a first portion of the reformate stream is combusted to heat the second reformer.

[0281] In some embodiments, the first reformer is heated using at least one of an electric heater or combustion of the reformate stream.

[0282] In some embodiments, (b) includes directing ammonia at an ammonia flow rate to a reformer to produce a reformate stream, and the method includes combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydro-processing module; and, based at least in part on the stimulus, (i) varying the ammonia flow rate; (ii) varying the percentage of the reformate stream that is the first portion of the reformate stream; (iii) varying the percentage of the reformate stream that is the second portion of the reformate stream; or (iv) varying the oxygen flow rate.

[0283] In some embodiments, (b) includes directing ammonia to a reformer at an ammonia flow rate to produce a reformate stream, and the method includes combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydrogen-processing module; measuring a temperature in the reformer or fired heater; and, based at least in part on the measured temperature being outside a target temperature range of the reformer or fired heater: (i) varying the ammonia flow rate; (ii) varying the oxygen flow rate; (iii) varying the percentage of the reformate stream, which is the second portion of the reformate stream; (iv) varying the percentage of the reformate stream that is the first portion of the reformate stream; or (v) varying the percentage of the reformate stream that is directed out from the fired heater.

[0284] In some aspects, the present disclosure is directed to a catalyst for ammonia decomposition, the catalyst comprising: a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, and carbon nanotubes; a layer adjacent to the support, the layer comprising the support material doped with at least one oxide of an alkaline earth metal, Zn, Fe, or Mn; and one or more active metal particles in, on, or adjacent to the layer, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, and Pd.

[0285] In some embodiments, the support comprises aluminum and oxygen.

[0286] In some embodiments, at least one of the support or layers comprises at least one of alpha-alumina (α-alumina), theta-alumina (θ-alumina), or gamma-alumina (γ-alumina).

[0287] In some embodiments, the layer comprises a spinel phase.

[0288] In some embodiments, the concentration of the one or more active metal particles ranges from about 0.1 wt % to about 15 wt % based on the weight of the catalyst.

[0289] In some embodiments, the layer comprises at least one of Mg, Ca, Sr, Ba, Zn, Fe, or Mn, wherein the concentration of the at least one of Mg, Ca, Sr, Ba, Zn, Fe, or Mn is in the range of about 0.1 mol% to about 80 mol%.

[0290] In some embodiments, the supports and layers comprise modified supports comprising an ASTM D7084 (Determination of Bulk Crush Strength of Catalysts and Catalyst Supports) crush strength of at least about 4000 psi (peak stress).

[0291] In some embodiments, the one or more active metal particles comprise ruthenium (Ru).

[0292] In some embodiments, the concentration of Ru ranges from about 0.5 to about 10 wt %.

[0293] In some embodiments, the one or more active metal particles comprise Ru nanoparticles.

[0294] In some embodiments, the layer comprises oxide nanoparticles comprising at least one of Mg, Ca, Sr, Ba, Zn, Fe, or Mn.

[0295] In some embodiments, the layer comprises annealed nanoparticles comprising at least one of Mg, Ca, Sr, Ba, Zn, Fe, or Mn.

[0296] In some embodiments, the catalyst comprises an ASTM D7084 crush strength of at least about 400 psi (peak stress).

[0297] In some embodiments, the catalyst is substantially free of promoters.

[0298] In some embodiments, the catalyst is substantially free of support surface modifiers.

[0299] In some aspects, the present disclosure provides a method of producing a catalyst for ammonia decomposition, comprising: (a) providing a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, and carbon nanotubes, or precursors thereof; (b) depositing at least one of an alkaline earth metal oxide or precursor thereof, an iron oxide or precursor thereof, a manganese oxide or precursor thereof, or a zinc oxide or precursor thereof to form a layer in, on, or adjacent to the support such that the support comprises a doped support comprising the layer and the support; (c) depositing an oxide or precursor of one or more active metal particles adjacent to the doped support, wherein the one or more active metal particles comprise at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu, and wherein the concentration of the one or more active metal particles is in the range of about 0.1 to about 15 wt. %; (d) maintaining the doped support at a temperature of about 300°C to about 1300°C for a duration of about 0.1 to about 168 hours in an atmosphere comprising hydrogen.

[0300] In some embodiments, the support comprises aluminum and oxygen.

[0301] In some embodiments, the layer comprises at least one of alpha-alumina (α-alumina), theta-alumina (θ-alumina), or gamma-alumina (γ-alumina).

[0302] In some embodiments, the layer comprises a spinel phase.

[0303] In some embodiments, the alkaline earth metal comprises at least one of Mg, Ca, Sr, or Ba, and the concentration of the oxide of at least one of Mg, Ca, Sr, Ba, Zn, Fe, or Mn is in the range of about 0.1 to about 80 mol%.

[0304] In some embodiments, the carrier and layer comprise a modified carrier comprising an ASTM D7084 crush strength of at least about 4000 psi (peak stress).

[0305] In some embodiments, the one or more active metal particles comprise ruthenium (Ru).

[0306] In some embodiments, the precursor of Ru is Ru(NO)(NO3)3, Ru(NO3)3, RuCl3, or Ru3(CO) 12 It includes at least one of the following:

[0307] In some embodiments, the concentration of Ru ranges from about 0.5 to about 10 wt %.

[0308] In some embodiments, (b) further comprises maintaining the doped support at a temperature of about 20° C. to about 150° C. in a vacuum or in an inert or non-oxidizing atmosphere for a duration of about 0.1 hours to about 168 hours, wherein the pressure of the non-oxidizing atmosphere ranges from about 0.1 bar absolute to about 5 bar absolute.

[0309] In some embodiments, (b) further comprises maintaining the doped support at a temperature between about 300°C and about 1300°C for a duration between about 0.1 hours and about 168 hours in a non-reducing atmosphere comprising at least one member from the group of air, O2, N2, CO2, Ar, He, Kr, or Xe.

[0310] In some embodiments, (b) further comprises maintaining the doped support at a temperature of about 300°C to about 1300°C for a duration of about 0.1 hours to about 168 hours in an inert, oxygen-free, or non-oxidizing atmosphere, the atmosphere comprising at least one member of the group: N2, CO2, CO, H2, Ar, He, Kr, or Xe.

[0311] In some embodiments, the catalyst comprises an ASTM D7084 crush strength of at least about 400 psi (peak stress).

[0312] In some embodiments, the method does not include adding a promoter to the catalyst.

[0313] In some embodiments, the method does not include adding a support surface modifier to the catalyst.

[0314] In some embodiments, the support or precursor thereof comprises beads or pellets, the beads or pellets having a diameter of (i) about 0.1 to about 10 millimeters (mm), or (ii) about 50 to about 1200 mm. 2 / g of surface area per unit mass.

[0315] In some aspects, the present disclosure is directed to a method for ammonia decomposition, comprising contacting a gas comprising ammonia over a catalyst at a temperature in the range of about 400° C. to about 700° C. to produce a reformate stream comprising hydrogen and nitrogen with an ammonia conversion efficiency of at least about 70% and no greater than about 99.9%, wherein the catalyst comprises: a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, or carbon nanotubes; a layer adjacent to the support, the layer comprising a support material doped with at least one oxide of an alkaline earth metal, Zn, Fe, or Mn; and one or more active metal particles adjacent to the layer, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu, wherein a concentration of the one or more active metal particles is in the range of at least about 0.1% to about 15% by weight.

[0316] In some embodiments, ammonia is contacted over the catalyst at a temperature of from about 450° C. to about 700° C. and at a space velocity of from about 1 to about 50 liters per hour per gram of catalyst.

[0317] In some embodiments, ammonia is contacted over the catalyst at a temperature of about 450° C. to about 700° C. and a gas hourly space velocity (GHSV) of about 1 to about 50 liters per mL of catalyst per hour.

[0318] In some embodiments, the method further includes contacting the catalyst with ammonia to produce a reformed stream, wherein the reformed stream is an autothermal reforming process, such that at least a portion of the reformed stream provides heat for the autothermal reforming process.

[0319] In some embodiments, at least a portion of the reforming stream is at least one of: (1) combusted to produce heat; or (2) converted by hydrogen-to-electricity conversion to produce heat, thereby providing heat for the autothermal reforming process.

[0320] In some embodiments, undecomposed ammonia in the reformate stream is removed by an ammonia filter.

[0321] In some embodiments, the ammonia filter comprises at least one of an adsorber, a membrane separation module, or an ammonia scrubber.

[0322] In some embodiments, a pressure swing adsorption (PSA) module is used to remove nitrogen from the reformate stream.

[0323] In some embodiments, the method further includes generating electricity by directing the hydrogen to at least one fuel cell, wherein the at least one fuel cell comprises a proton exchange membrane fuel cell (PEMFC), a solid oxide fuel cell (SOFC), a molten carbonate fuel cell (MCFC), an alkaline fuel cell (AFC), an alkaline membrane fuel cell (AMFC), or a phosphoric acid fuel cell (PAFC).

[0324] In some embodiments, the method further includes directing the hydrogen to one or more combustion engines or turbines.

[0325] In some embodiments, the method further includes directing the hydrogen to one or more fuel cells, combustion engines, or turbines to produce electricity and / or motive power.

[0326] In some embodiments, the catalyst is substantially free of promoters or support surface modifiers.

[0327] In some embodiments, the system is configured to reform ammonia using the method of embodiment 210.

[0328] In some embodiments, (b) includes directing ammonia to a first reformer to produce a reformate stream, and the method includes combusting the reformate stream in a fired heater to heat a second reformer, and directing additional ammonia to the second reformer to produce additional hydrogen for the reformate stream, and a first portion of the reformate stream is combusted to heat the second reformer.

[0329] In some embodiments, the first reformer is heated using at least one of an electric heater or combustion of the reformate stream.

[0330] In some embodiments, (b) includes directing ammonia at an ammonia flow rate to a reformer to produce a reformate stream, and the method includes combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydro-processing module; and, based at least in part on the stimulus, (i) varying the ammonia flow rate; (ii) varying the percentage of the reformate stream that is the first portion of the reformate stream; (iii) varying the percentage of the reformate stream that is the second portion of the reformate stream; or (iv) varying the oxygen flow rate.

[0331] In some embodiments, (b) includes directing ammonia to a reformer at an ammonia flow rate to produce a reformate stream, and the method includes combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydrogen-processing module; measuring a temperature in the reformer or fired heater; and, based at least in part on the measured temperature being outside a target temperature range of the reformer or fired heater: (i) Varying the ammonia flow rate; (ii) varying the oxygen flow rate; (iii) varying the percentage of the reformate stream, which is the second portion of the reformate stream; (iv) varying the percentage of the reformate stream that is the first portion of the reformate stream; or (v) varying the percentage of the reformate stream that is directed out from the fired heater.

[0332] In some aspects, the present disclosure provides a catalyst comprising a support comprising alumina and a layer adjacent to the support, the layer being doped with an oxide of a rare earth metal, the rare earth metal comprising at least one of lanthanum (La) or cerium (Ce);

[0333] a layer comprising a mixed oxide of aluminum and a rare earth metal, the concentration of the rare earth metal being at least about 1 and not more than about 15 mol % relative to the layer and the support, and the layer being free of a perovskite phase;

[0334] and one or more active metals adjacent to the layer, wherein the one or more active metals comprise at least one of ruthenium (Ru), platinum (Pt), or palladium (Pd), and wherein a concentration of the one or more active metals is at least about 0.1 and no more than about 10 wt. % based on the weight of the catalyst.

[0335] In some embodiments, the layer comprises theta alumina (θ-alumina) or gamma alumina (γ-alumina).

[0336] In some embodiments, the layer comprises a rare earth metal in a concentration of about 10 mol % or less relative to the layer and support.

[0337] In some cases, the layer comprises a rare earth metal in a concentration of about 2 to about 8 mol % relative to the layer and support.

[0338] In some cases, the layer comprises a rare earth metal in a concentration of about 3 to about 7 mol % relative to the layer and support.

[0339] In some cases, the layer comprises a rare earth metal in a concentration of about 4 to about 6 mol % relative to the layer and support.

[0340] In some embodiments, the rare earth metal is lanthanum (La).

[0341] In some cases, the rare earth metal is cerium (Ce).

[0342] In some cases, the concentration of the one or more active metals is at least about 0.5 and no more than about 8 wt. % based on the weight of the catalyst.

[0343] In some embodiments, the concentration of the one or more active metals is at least about 0.5 and no more than about 3 wt. % based on the weight of the catalyst.

[0344] In some cases, one or more active metals are nanoparticles.

[0345] In some embodiments, the nanoparticles comprise a reduced form of one or more active metals after contacting the layer with a gas comprising hydrogen (H) at a temperature ranging from about 300° C. to about 800° C. for at least 1 hour and not more than 40 hours.

[0346] In some embodiments, the one or more active metals include Ru.

[0347] In some embodiments, the concentration of Ru is about 5% by weight or less.

[0348] In some cases, the layer does not include a perovskite phase.

[0349] In some embodiments, the catalyst is free of alkali metals and alkaline earth metals.

[0350] In some aspects, the present disclosure provides a method of producing a catalyst, comprising:

[0351] (a) forming a support comprising at least one of theta-alumina (θ-alumina) or gamma-alumina (γ-alumina) using at least Al2O3 or a precursor thereof; and (ii) producing a layer comprising mixed oxides of aluminum and lanthanum or aluminum and cerium using a rare earth metal comprising at least one of La2O3 or a precursor thereof, or CeO2 or a precursor thereof, wherein the concentration of the rare earth metal is at least about 1 and not more than about 15 mol% of the layer and the support; (b) depositing at least one precursor of one or more active metals adjacent to the layer, wherein the one or more active metals comprise at least one of ruthenium (Ru), platinum (Pt), or palladium (Pd), and wherein a concentration of the one or more active metals is at least about 0.1 wt. % and no more than about 10 wt. % based on the weight of the catalyst; (c) contacting the catalyst with a gas comprising hydrogen (H) at a temperature in the range of about 300°C to about 800°C for at least 1 hour and not more than 40 hours to reduce at least one precursor of the one or more active metals to the elemental state without converting the phase to form a perovskite phase.

[0352] In some cases, (a) further comprises maintaining the support at a temperature of at least about 300°C and about 800°C for a duration of at least about 0.1 hours and not more than about 168 hours in a non-reducing atmosphere comprising at least one of air, nitrogen (N), carbon dioxide (CO), argon (Ar), helium (He), krypton (Kr), or xenon (Xe).

[0353] In some cases, the layer comprises a rare earth metal in a concentration of about 10 mol % or less relative to the layer and support, and the catalyst comprises one or more active metals in a concentration of about 8 wt % or less relative to the weight of the catalyst.

[0354] In some cases, one or more active metals are nanoparticles.

[0355] In some embodiments, the one or more active metals comprise Ru, the precursor of the one or more active metals comprises ruthenium nitrosyl nitrate (Ru(NO)(NO)), and the concentration of Ru is about 5 wt. % or less based on the weight of the catalyst.

[0356] In some embodiments, incipient wetness impregnation is used to form the layer using a rare earth metal precursor.

[0357] In some embodiments, incipient wetness impregnation is used to deposit at least one precursor of one or more active metals.

[0358] In some cases, the Al2O3 or precursor thereof comprises beads or pellets, the beads or pellets having a diameter of (i) about 0.1 millimeters (mm) to about 10 mm, or (ii) about 50 mm. 2 / g~about 500m 2 / g of surface area per unit mass.

[0359] In some cases, the catalyst is free of alkali metals and alkaline earth metals.

[0360] In some aspects, the present disclosure provides a method for ammonia decomposition, comprising contacting a gas comprising ammonia over a catalyst at a temperature in the range of about 450° C. to about 700° C. to produce a reformate stream comprising hydrogen and nitrogen at an ammonia conversion efficiency of about 70% to about 99.9%, wherein the catalyst:

[0361] a support comprising alumina; and a layer adjacent to the support, the layer comprising a support doped with an oxide of a rare earth metal, the rare earth metal comprising at least one of lanthanum (La) or cerium (Ce), the layer comprising a mixed oxide of aluminum and the rare earth metal, the concentration of the rare earth metal being at least about 1 and not more than about 15 mol % relative to the layer and the support;

[0362] and one or more active metals adjacent to the layer, wherein the one or more active metals comprise at least one of ruthenium (Ru), platinum (Pt), or palladium (Pd), and wherein a concentration of the one or more active metals is at least about 0.1 and no more than about 15 wt. % based on the weight of the catalyst, wherein the catalyst does not comprise an alkali metal or an alkaline earth metal.

[0363] In some cases, the layer comprises theta alumina (θ-alumina) or gamma alumina (γ-alumina).

[0364] In some cases, the layer comprises a rare earth metal in a concentration of about 10 mol % or less relative to the layer and the support.

[0365] In some embodiments, the rare earth metal is La.

[0366] In some cases, the rare earth metal is Ce.

[0367] In some cases, one or more active metals are nanoparticles.

[0368] In some embodiments, the nanoparticles comprise a reduced form of one or more active metals after the layer is contacted with a gas comprising hydrogen (H) at a temperature in the range of about 300°C to about 800°C for at least 1 hour and not more than 40 hours.

[0369] In some embodiments, the one or more active metals include Ru, and the concentration of Ru is about 5 wt % or less.

[0370] In some cases, the layer does not include a perovskite phase.

[0371] In some cases, the ammonia-containing gas is contacted over the catalyst at a space velocity of less than or equal to about 100 liters per hour per gram of catalyst.

[0372] In some cases, the method includes generating electricity by providing the generated hydrogen to one or more fuel cells.

[0373] In some cases, the method includes contacting a gas comprising ammonia over a catalyst to produce a reformed stream, the reformed stream being an autothermal reforming process, such that at least a portion of the reformed stream provides heat for the autothermal reforming process.

[0374] In some embodiments, at least a portion of the reforming stream is at least one of: (1) combusted to produce heat; or (2) converted by hydrogen-to-electricity conversion to produce heat, thereby providing heat for the autothermal reforming process.

[0375] In some cases, the method includes contacting a gas containing ammonia over a catalyst including directing the ammonia to a first reformer to produce a reformed stream, the method includes combusting the reformed stream to heat a second reformer, and directing additional ammonia to the second reformer to produce an additional reformed stream, wherein the first portion of the reformed stream, the additional reformed stream, or a combination thereof, is combusted to heat the second reformer.

[0376] In some cases, the first reformer is heated using at least one of an electric heater or combustion of the reformate stream.

[0377] In some cases, the method includes contacting a gas comprising ammonia over a catalyst including directing ammonia to a reformer at an ammonia flow rate to produce a reformate stream, the method further comprising combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer, and processing a second portion of the reformate stream in a hydroprocessing module, and, based at least in part on the stimulus, i. Varying the ammonia flow rate; ii. varying the percentage of the reformate stream that is the first portion of the reformate stream; iii. Varying the percentage of the reformate stream that is the second portion of the reformate stream; or iv. varying the oxygen flow rate.

[0378] In some cases, the stimulus is x. A change in the amount of hydrogen used by the hydrogen processing module; y. Reformer temperature outside the target temperature range, or z. Including changes in the amount or concentration of ammonia in the reformate stream.

[0379] In some embodiments, the hydrogen processing module comprises a fuel cell, which provides anode off-gas containing hydrogen to the fired heater.

[0380] In some cases, the method includes contacting a gas comprising ammonia over a catalyst including directing ammonia to a reformer at an ammonia flow rate to produce a reformate stream, the method further comprising combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydro-processing module; measuring a temperature in the reformer or fired heater; and based, at least in part, on the measured temperature being outside a target temperature range of the reformer or fired heater: i. Varying the ammonia flow rate; ii. Varying the oxygen flow rate; iii. Varying the percentage of the reformate stream that is the second portion of the reformate stream; iv. Varying the percentage of the reformate stream that is the first portion of the reformate stream; or v. varying the percentage of the reformate stream that is directed out from the fired heater.

[0381] In some cases, the hydrogen processing module comprises a fuel cell, which provides anode off-gas containing hydrogen to the fired heater.

[0382] Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in the art from the following detailed description, wherein only illustrative embodiments of the present disclosure are shown and described. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the present disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. Incorporation by Reference

[0383] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. To the extent that the publications and patents or patent applications incorporated by reference conflict with the disclosure contained in the specification, the present specification is intended to supersede and / or take precedence over any such conflicting content. [Brief explanation of the drawings]

[0384] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings (also referred to herein as "figures"), of which:

[0385] [Figure 1] 1 illustrates a schematic diagram of an exemplary system for processing ammonia to produce hydrogen fuel, according to some embodiments of the present disclosure. [Figure 2] 1A and 1B illustrate schematically an exemplary method of hydrogen storage using liquid chemicals, according to some embodiments of the present disclosure. [Figure 3] 1 illustrates a schematic diagram of an exemplary hydrogen extraction reformer including a heterogeneous catalyst according to some embodiments of the present disclosure. [Figure 4] 1A and 1B illustrate schematically an exemplary process for modifying and enhancing a catalyst support according to some embodiments of the present disclosure. [Figure 5] 1A and 1B illustrate schematically an exemplary process for processing precursor materials according to some embodiments of the present disclosure. [Figure 6A] 10A-10C illustrate a schematic diagram of the effect of catalyst reduction on ammonia conversion efficiency according to some embodiments. [Figure 6B] 10A-10C illustrate schematically the effect of heat treatment of a catalyst on hydrogen generation or production rate, according to some embodiments. [Figure 6C]1A-1C are schematic diagrams illustrating the effect of active metal promotion of a catalyst on ammonia conversion efficiency, according to some embodiments. [Figure 6D] 10A-10C schematically illustrate the effect of catalyst doping on ammonia conversion efficiency, according to some embodiments. [Figure 6E] 10A-10C schematically illustrate the effect of catalyst doping on ammonia conversion efficiency, according to some embodiments. [Figure 7] 1A and 1B illustrate schematically a computer system that is programmed or otherwise configured to perform the methods provided herein, according to some embodiments of the present disclosure. [Figure 8] 1 illustrates a comparison of ammonia conversion efficiencies using various catalysts synthesized using alumina supports of different sizes, according to some embodiments. [Figure 9] Examples of some of the approaches incorporated herein for producing mixed carriers are provided. [Figure 10] 1 illustrates the effect of metal oxide on the ammonia conversion efficiency of catalysts prepared with composite supports. [Figure 11] 1 shows the mechanical strength (crush strength) of selected supports, modified supports, and catalysts according to some embodiments. [Figure 12] 1 illustrates a comparison of catalysts prepared using different alumina supports with and without the addition of rare earth metals, according to some embodiments. [Figure 13] 1 illustrates the benefit of minimizing the amount of solvent during the wet impregnation procedure. [Figure 14] 1 illustrates the effect of impregnation solution volume on the conversion efficiency of various catalysts, according to some embodiments. [Figure 15] 1 illustrates a schematic methodology for preparing catalysts by oxidizing the surface of a silicon carbide monolith and depositing other metals and metal oxides onto the silicon dioxide surface. [Figure 16] Photographs are presented showing the appearance of silicon carbide supports subjected to electro-oxidation by resistive (Joule) heating. [Figure 17]1 is a plot illustrating a comparison of ammonia conversion efficiencies of various catalysts with different surface treatments. [Figure 18] 1 is a plot illustrating a comparison of ammonia conversion efficiencies of various catalysts having various surface treatments and washcoat applications, according to some embodiments of the present disclosure. [Figure 19] 1 is a plot illustrating a comparison of ammonia conversion efficiencies of a series of catalysts using a washcoat to form a layer of alpha-alumina or gamma-alumina on the surface of a monolith, according to some embodiments of the present disclosure. [Figure 20] 1 is a plot illustrating a comparison of ammonia conversion efficiencies of a series of catalysts using various active metal loadings and reduction temperatures, according to some embodiments of the present disclosure. [Figure 21] 1 is a plot illustrating a comparison of ammonia conversion efficiencies of a series of catalysts brought to operating temperature by Joule heating or by heating in a furnace, according to some embodiments of the present disclosure. [Figure 22] 1 is a plot illustrating the rapid heat-up and high ammonia conversion efficiency obtained for a Joule heated catalyst according to some embodiments of the present disclosure. [Figure 23] 1 is a plot illustrating a comparison of ammonia conversion efficiencies of two joule heated catalysts aged over several heating and cooling cycles, according to some embodiments of the present disclosure. [Figure 24] 1 illustrates a comparison of ammonia conversion efficiencies of various catalysts synthesized via reduction at different temperatures, according to some embodiments. [Figure 25] 1 illustrates a comparison of ammonia conversion efficiencies of various catalysts synthesized using different gamma- and theta-alumina supports, according to some embodiments. [Figure 26] 1 illustrates a comparison of ammonia conversion efficiencies of various catalysts synthesized using different ruthenium precursors, according to some embodiments. [Figure 27]1 illustrates a comparison of ammonia conversion efficiencies of various exemplary catalysts produced using different combinations of materials and production methods, according to some embodiments. [Figure 28] 1 illustrates a comparison of ammonia conversion efficiencies of various catalysts synthesized with different La and Ce ratios, according to some embodiments. [Figure 29] 1 illustrates a comparison of ammonia conversion efficiency of various catalysts with different La:Ce molar ratios, and the variation in ammonia conversion efficiency based on changes in Ce content, according to some embodiments. [Figure 30] 1 illustrates a comparison of ammonia conversion efficiencies of various catalysts with different La:Ce molar ratios, and the variation in ammonia conversion efficiency based on different operating temperatures, according to some embodiments. [Figure 31] 1 illustrates the effect of impregnation solution volume on ammonia conversion efficiency for catalysts containing different amounts of rare earth metals, according to some embodiments. [Figure 32] 1 illustrates the effect of impregnation solution volume on ammonia conversion efficiency for catalysts containing different amounts of rare earth metals, according to some embodiments. [Figure 33] 1 illustrates the ammonia conversion efficiency of catalysts containing various amounts of metal oxide on alumina, according to some embodiments, compared to the conversion rates of other previously disclosed alumina-supported catalysts. [Figure 34] 1 illustrates the effect of metal ratio on ammonia conversion efficiency of catalysts prepared with composite supports. [Figure 35] 1 shows the effect of metal ratio on the ammonia conversion efficiency of Ru catalysts prepared using composite supports. [Figure 36] We provide examples of some strategies contemplated herein for improving the ammonia conversion efficiency of Ru, according to some embodiments. [Figure 37] 1 shows a comparison of hydrogen production rates between catalysts of the present disclosure and conventional catalysts, according to some embodiments. [Figure 38] 34 shows a table describing the conditions under which the catalysts shown in FIG. 33 were tested, according to some embodiments. [Figure 39] 1 shows ammonia conversion efficiency of various catalysts as a function of temperature, according to some embodiments. [Figure 40] 1 shows powder X-ray diffraction (pXRD) spectra of supports containing various amounts of ceria along with zirconia, according to some embodiments. [Figure 41] 1 shows pXRD spectra of supports containing various amounts of ceria along with zirconia, according to some embodiments. [Figure 42] 1 shows the electron binding energy of electrons in the 3P3 / 2 orbital of ruthenium provided on a support, measured using X-ray photoelectron spectroscopy (XPS), according to some embodiments. [Figure 43] 1 shows the Ce3+ / Ce4+ ratio determined using XPS, according to some embodiments. [Figure 44] 1 shows pXRD spectra of supports and catalysts annealed at various temperatures, according to some embodiments. [Figure 45] Same as above. [Figure 46] 1 shows the ammonia conversion efficiency of catalysts annealed at various temperatures, according to some embodiments. [Figure 47] 1 shows ammonia conversion efficiency of various catalysts as a function of temperature, according to some embodiments. [Figure 48] 1 shows pXRD spectra of a support and a catalyst, respectively, according to some embodiments. [Figure 49] Same as above. [Figure 50] 1 shows the ammonia conversion efficiency of various catalysts, according to some embodiments. [Figure 51] 1 shows the ammonia conversion efficiency of various catalysts where the potassium impregnation step was sequenced between each catalyst, according to some embodiments. [Figure 52] 1 shows the electron binding energy of electrons in the 3P3 / 2 orbital of ruthenium provided on a support, measured using X-ray photoelectron spectroscopy (XPS), according to some embodiments. [Figure 53]FIG. 1 is a block diagram illustrating an ammonia reforming system according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0386] While various embodiments of the present invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed. It should be understood that any of the embodiments, configurations, and / or components described with reference to a particular figure may be combined with other embodiments, configurations, and / or components described with reference to other figures.

[0387] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well (and vice versa), unless the context clearly indicates otherwise. For example, "a," "an," and "the" can be interpreted as "one or more."

[0388] This disclosure may be divided into sections using headings, which should not be construed as limiting the disclosure but are present solely for purposes of organization and clarity.

[0389] Whenever the terms "at least," "at least about," "greater than," "greater than about," "greater than or equal to," or "greater than or equal to about" precede the first number in a series of two or more numbers, the term "at least," "at least about," "greater than," "greater than about," "greater than or equal to," or "greater than or equal to about" applies to each and every number in the series. For example, 1, 2, or 3 or more is equivalent to 1 or more, 2 or more, or 3 or more.

[0390] Whenever the term "no more than," "about less than," "no more than about," "not more than," "about less than," "less than," "about less than," "less than or equal to," or "about less than or equal to about" precedes a first number in a series of two or more numbers, the term "not more than," "about less than," "no more than about," "not more than," "about less than," "less than," or "about less than or equal to about" applies to each and every number in the series. For example, 3, 2, or 1 or less is equivalent to 3 or less, 2 or less, or 1 or less.

[0391] The terms "at least one" and "one or more" may be used interchangeably. The phrases "at least one of A and B" and "at least one of A or B" may be interpreted to mean at least A, at least B, or at least A and B (i.e., a set that includes A and B, which may include one or more additional elements). The term "A and / or B" may be interpreted to mean A only, B only, or both A and B.

[0392] The phrases "at least about A, B, and C" and "at least about A, B, or C" can be interpreted to mean at least about A, at least about B, or at least about C. The phrases "up to about A, B, and C" and "up to about A, B, or C" can be interpreted to mean up to about A, up to about B, or up to about C.

[0393] The expression "between about A and B, C and D, and E and F" can be interpreted as meaning between about A and about B, between about C and about D, and between about E and about F. The expression "between about A and B, C and D, or E and about F" can be interpreted as meaning between about A and about B, between about C and about D, or between about E and about F.

[0394] The expression "about A to B, C to D, or E to F" can be interpreted as meaning about A to about B, about C to about D, or about E to about F. The expression "about A to B, C to D, or E to about F" can be interpreted as meaning about A to about B, about C to about D, or about E to about F.

[0395] The terms "substantially free" and "essentially free" are used interchangeably herein to mean that a described entity may have a relatively small amount of an item that it is "essentially free of." This small amount may be passively present or may be intentionally added. The threshold for what constitutes "essentially free" depends on the described entity and may range from an undetectable amount to a trace amount, to less than about 0.01%, 0.05%, 0.1%, 0.5%, 1%, or 5%. The threshold amount may be low enough that it does not interfere with the essential properties of the described entity. Similarly, when a method "does not involve" adding a substance, it is used herein to mean that a significant amount of the substance is not added, but may be present, for example, as an impurity or not added in a quantity sufficient to interfere with the essential properties of the entity being made.

[0396] The terms "decompose," "dissociate," "reform," "crack," "dehydrogenate," "split," "stripping," "convert," "break down," and grammatical variations thereof may be construed interchangeably. For example, the expression "ammonia decomposition" may be interchangeable with "ammonia dissociation," "ammonia reforming," "ammonia cracking," "ammonia dehydrogenation," "ammonia splitting," "ammonia stripping," "ammonia conversion," "ammonia break down," etc.

[0397] The term "reformer" refers to a containment vessel in which an ammonia decomposition catalyst is located and in which the ammonia decomposition reaction occurs. The term "reformer" may be used interchangeably with other commonly used chemical and chemical industry terms, such as "cracker," "cracking unit," "reactor," "reaction unit," "reforming unit," "dehydrogenator," "dehydrogenation unit," "dissociator," "dissociator unit," "stripper," "stripping unit," "splitter," "splitting unit," "cracker," "cracking," "converter," "conversion unit," "breaker," "breaker unit," "breaking unit," "breakdown unit," or "breakdown unit."

[0398] The terms "ammonia conversion" and "ammonia conversion efficiency," and grammatical variations thereof, may be interpreted as the percentage of ammonia that is converted to hydrogen and nitrogen and may be interpreted interchangeably. For example, 90% "ammonia conversion" or "ammonia conversion efficiency" may represent that 90% of the ammonia is converted to hydrogen and nitrogen.

[0399] The term "turnover frequency" refers to the normalized ammonia consumption or hydrogen production (amount) per unit catalyst per unit time. アンモニア又は水素 amount 触媒 -1 time -1 ) can be interpreted as the forward reaction rate of ammonia decomposition, measured as either アンモニア若しくは水素 is mmol アンモニア若しくは水素 , mol アンモニア若しくは水素 , g アンモニア若しくは水素 , or mL アンモニア若しくは水素 It can be measured as: 触媒 is g 触媒 , g 活性金属 , g 表面活性金属 , g 活性部位 , mol 触媒 , mol 活性金属 , mol 表面活性金属 , or mol活性部位 Time may be measured in seconds, minutes, hours, or days.

[0400] In some cases, the term "turnover frequency" refers to the normalized ammonia consumption or hydrogen production (amount) per unit catalyst per unit time. アンモニア又は水素 amount 触媒 -1 time -1 ) can be interpreted as the net reaction rate of ammonia decomposition (i.e., forward reaction minus reverse reaction). アンモニア若しくは水素 is mmol アンモニア若しくは水素 , mol アンモニア若しくは水素 , g アンモニア若しくは水素 , or mL アンモニア若しくは水素 It can be measured as: 触媒 is g 触媒 , g 活性金属 , g 表面活性金属 , g 活性部位 , mol 触媒 , mol 活性金属 , mol 表面活性金属 , or mol 活性部位 Time may be measured in seconds, minutes, hours, or days.

[0401] The terms "production rate" and "consumption rate" may be interpreted as the production or consumption of an element, compound, or species involved in a reaction, measured as net rate = forward reaction - reverse reaction. The units of "production rate" and "consumption rate" are quantities. アンモニア又は水素 amount 触媒 -1 time -1 It can be. アンモニア若しくは水素 is mmol アンモニア若しくは水素 , mol アンモニア若しくは水素 , g アンモニア若しくは水素 , or mL アンモニア若しくは水素 It can be measured as: 触媒 is g 触媒 , g 活性金属 , g 表面活性金属 , g 活性部位 , mol 触媒 , mol 活性金属 , mol 表面活性金属 , or mol 活性部位Time may be measured in seconds, minutes, hours, or days.

[0402] The term "space velocity" may be defined as the volumetric flow rate of the feed gas (e.g., ammonia) relative to the mass of catalyst material, and is expressed in units of liters (or milliliters) of gas per hour per gram of catalyst, e.g., L hr -1 g -1 , L ガス hr -1 g 触媒 -1 , L NH3 hr -1 g 触媒 -1 , L アンモニア hr -1 g 触媒 -1 , mL hr -1 g -1 , mL ガス hr -1 g 触媒 -1 , mL NH3 hr -1 g 触媒 -1 , or mL アンモニア hr -1 g 触媒 -1 The term "gas hourly space velocity" or GHSV may be defined as the volumetric flow rate of a feed gas (e.g., ammonia) relative to the volume of catalyst material, and may be expressed in units of liters (or milliliters) of gas per milliliter of catalyst per hour, e.g., L hr -1 mL -1 , L ガス hr -1 mL 触媒 -1 , L NH3 hr -1 mL 触媒 -1 , L アンモニア hr -1 mL 触媒 -1 , mL hr -1 mL -1 , mL ガス hr -1 mL 触媒 -1 , mLNH3 hr -1 mL 触媒 -1 , or mL アンモニア hr -1 mL 触媒 -1 It can be expressed as:

[0403] The term "autothermal reforming" may be interpreted as a condition in which the ammonia decomposition reaction (2NH3 → N2 + 3H2, an endothermic reaction) is heated by a hydrogen combustion reaction (2H2 + O2 → 2H2O, an exothermic reaction) that uses at least a portion of the hydrogen produced by the ammonia decomposition reaction itself.

[0404] In some cases, the term "autothermal reforming" may be interpreted as a condition in which the ammonia decomposition reaction is heated by a hydrogen combustion reaction using at least a portion of the hydrogen produced by the ammonia decomposition reaction itself, electrical heating, or a combination of both (which may result in an overall positive electrical and / or chemical energy output). For example, when "autothermal reforming" is carried out using a hydrogen combustion reaction and / or electrical heating, the hydrogen produced from the ammonia decomposition reaction may be sufficient to provide electrical energy to power the hydrogen combustion reaction with combustion fuel and / or for electrical heating via a hydrogen-to-electricity conversion device (e.g., fuel cell, combustion engine, etc.).

[0405] In some cases, the hydrogen provided for the hydrogen combustion reaction and / or electrical heating may or may not use hydrogen from the ammonia decomposition reaction (e.g., hydrogen may be provided by a separate hydrogen source, electricity may be provided from a battery or the electrical grid, etc.).

[0406] In this disclosure, the term "support" may refer to a base support, a composite support, a modified support, or a doped support, as described herein.

[0407] In some cases, a "base support" may comprise a relatively inert, thermally stable, and mechanically robust material onto which compounds may be deposited or impregnated to impart catalytic activity. In some cases, the base support material may comprise a powder, which may be processed into a more useful form for practical use. In some cases, the base support material may comprise a monolith, or pre-fabricated beads, pellets, rods, or other engineered particle shapes. In some cases, the base support material may comprise low thermal and / or electrical resistivity. In some cases, the base support material may comprise high thermal and / or electrical resistivity. In some cases, the base support may be heat-treated (e.g., calcined) prior to use, but may not be chemically treated.

[0408] In some cases, a "composite support" may include a base support impregnated with a significant amount of at least one other compound or material such that the at least one other compound or material comprises more than about 30% (by mole, mass, or volume) of the composite support. A composite support may include a washcoated (immersed in a washcoat slurry) monolith.

[0409] In some cases, a "modified support" may include a support or washcoated monolith that has been treated with an element or compound in a process to improve its porosity and / or its surface properties. A modified support may include a base support or washcoated monolith that has been treated with an acid or base, a liquid, or a gas to improve or modify its pore properties. A modified support may include a base support or washcoated monolith that has been impregnated with a support surface modifier or a precursor thereof and heat-treated to form improved or modified crystalline structures or phases on the surface of the support. These crystalline structures may include one or more of perovskite, triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, and cubic phases. In some cases, incorporation of a support surface modifier may include the formation of an amorphous surface phase.

[0410] In some embodiments, a "doped support" may refer to a base support, a composite support, or a modified support that has been treated with elements or compounds in a process for producing a catalyst based on the support. A doped support may be impregnated with one or more metals or metal compounds to improve its properties as a catalyst. A doped support may include a washcoated monolith impregnated with one or more metals or metal compounds to improve its properties as a catalyst. In some cases, a doped support may include additional elements and / or compounds to modify its thermal and / or electrical resistance properties.

[0411] In this disclosure, the term "adjacent" may be interpreted interchangeably with "in," "on," "against," "next to," "near," "proximal to," "in contact with," "in contact with," "in physical contact with," or "touching." Thus, the phrase "adjacent to the support" may be understood to mean "in the support," "on the support," "next to the support," "in contact with the support," etc. The use of "adjacent" removes dependency on the orientation or perspective of the support and is intended to indicate, for example, that a material may be deposited on, within, and throughout a porous or non-porous support material, substrate, or monolith structure.

[0412] In this disclosure, the term "resistivity" may be defined as the resistance of a catalyst, support material, or support monolith multiplied by the cross-sectional area of ​​the catalyst, support material, or support monolith divided by the distance that the current passes between the electrodes and through the catalyst, support material, or support monolith. The resistance of a catalyst, support material, or support monolith, and therefore its resistivity, may be measured at a temperature of at least about 15°C up to and including about 30°C. The resistance of an electrode may be measured at a temperature of at least about 15°C up to and including about 30°C.

[0413] In this disclosure, designations are used to distinguish catalysts by indicating the use of certain active metals, promoters, and dopants, along with information related to their concentrations and heat treatment conditions. These designations are in the format of xA / P-HT2-mD-S HT1 or xA-P / mD-S HT1. In these designations, "x" represents the weight percent of active metal "A," "P" represents promoter "P," and "m" represents the mol percent of dopant "D" incorporated onto support "S." The component preceding the slash (" / ") may be considered supported by the component following the slash. "HT1" and "HT2" indicate first and second heat treatment steps applied to the support or doped support before the active metal is applied to the catalyst. If "x" is missing from a catalyst designation, this may indicate that the catalyst contains 1 wt. % of active metal "A." If "m" is missing from a catalyst designation, this may indicate that the catalyst contains 1 mol. % of dopant "D." If "HT2" is missing from the designation, this may indicate that the catalyst was prepared without a second heat treatment step before incorporating the active metal. If any of "A," "P," or "D" is missing, this may indicate that the component it represents was not used. As an example, "5Ru / K-A700-Ce-ZrO2C900" may indicate that the catalyst comprises 5 wt. % Ru on a modified ZrO2 support containing K and 1 mol. % Ce, which was calcined at 900°C after incorporating Ce and annealed at 700°C after incorporating K. As a further example, "Ru-K / 5Ce-ZrO2A600" may indicate that the catalyst comprises 1 wt. % Ru and K deposited on a modified ZrO2 support containing 5 mol. % Ce, which was annealed at 600°C after incorporating Ce.

[0414] The examples described herein are provided as embodiments to demonstrate the effectiveness of the disclosed catalyst compositions and methods of preparation. Each of these catalysts was prepared according to the detailed preparation methods described herein.

[0415] In one aspect, the present disclosure provides a method of making a catalyst for ammonia processing or decomposition, the method comprising: (a) providing a catalyst support; (b) thermally, chemically, physically, or electrochemically treating the catalyst support to modify pore characteristics of the catalyst support; (c) depositing a composite support material on the catalyst support, the composite support material comprising a morphology or surface chemistry or properties; and (d) depositing one or more active metals on at least one of the composite support material and the catalyst support, the one or more active metals comprising one or more nanoparticles configured to conform to the morphology or surface chemistry or properties of the composite support material upon thermal or chemical treatment, thereby improving one or more active sites on the nanoparticles for ammonia processing or decomposition.

[0416] In some cases, the morphology includes pore structure, pore size, pore shape, pore volume, pore density, pore size distribution, grain structure, particle size, grain shape, crystalline structure, flake size, or layered structure. In some cases, the surface chemistry or property includes elemental composition, Arrhenius acidity or basicity, Lewis acidity or basicity, surface hydroxyl group density, or hydrophilicity or hydrophobicity. In some cases, thermally, chemically, physically, or electrochemically treating the catalyst support includes subjecting the catalyst support to one or more thermal, chemical, physical, or electrochemical processes or treatments to improve one or more pores or surface chemistry or properties of the catalyst support. In some cases, improving one or more pores includes (i) modifying one or more pore sizes, (ii) modifying the pore volume of the catalyst support, (iii) modifying the pore size distribution, or (iv) modifying the pore density of the catalyst support. In some cases, improving the surface chemistry or properties includes modifying (i) the Arrhenius acidity or basicity, (ii) the Lewis acidity or basicity, (iii) the surface hydroxyl group density, or (iv) the hydrophilicity or hydrophobicity of the surface.

[0417] In some cases, the composite support material is deposited using physical vapor deposition or chemical vapor deposition. In some cases, the morphology or surface chemistry or properties of the composite support material are matched to the morphology or surface chemistry or properties of the catalyst support. In some cases, the one or more active metals are deposited using physical vapor deposition or chemical vapor deposition. In some cases, the method may further include thermally or chemically activating the one or more active metals. In some cases, thermally, physically, chemically, or electrochemically activating the one or more active metals induces the growth of one or more nanoparticles of the active metals. In some cases, the one or more nanoparticles are configured to grow in a manner that matches the morphology or surface chemistry or properties of the composite support material upon thermal, physical, electrochemical, or chemical activation. In some cases, the method may further include combining the catalyst with one or more promoters to modify or improve the morphology, active sites, electron density, Arrhenius acidity or basicity, Lewis acidity or basicity, or electronic state of the catalyst.

[0418] In some cases, the one or more promoters include sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba). In some cases, the one or more active metals include ruthenium (Ru), nickel (Ni), rhodium (Rh), iridium (Ir), cobalt (Co), molybdenum (Mo), iron (Fe), platinum (Pt), chromium (Cr), palladium (Pd), or copper (Cu). In some cases, the catalyst support comprises aluminum oxide (Al2O3), magnesium oxide (MgO), cerium dioxide (CeO2), silicon dioxide (SiO2), yttrium oxide (YO3), zirconium oxide (ZrO2), one or more zeolites, titanium dioxide (TiO2), lanthanum oxide (La2O3), chromium oxide (Cr2O3), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), iron oxide (FeO, Fe2O3, Fe3O4), manganese oxide (MnO), or zinc oxide (ZnO). In some cases, the composite support material comprises a carbon-based material, a boron-based material, or a metal oxide. In some cases, the carbon-based material comprises graphite, activated carbon (AC), one or more carbon nanotubes (CNTs), one or more carbon nanofibers (CNFs), graphene oxide (GO), one or more carbon nanoribbons, or reduced graphene oxide (rGO). In some cases, the boron-based material comprises hexagonal boron nitride (hBN), boron nitride nanotubes (BNNTs), or boron nitride nanosheets (BNNSs). In some cases, the metal oxide comprises aluminum oxide (Al2O3), titanium dioxide (TiO2), magnesium oxide (MgO), strontium oxide (SrO), barium oxide (BaO), lanthanum oxide (La2O3), cerium dioxide (CeO2), yttrium oxide (YO3), one or more CeO2 nanotubes, nanorods, or nanocubes, mesoporous silica, zirconium dioxide (ZrO2), chromium oxide (Cr2O3), or calcium oxide (CaO).In some cases, the composite support material may include yttria-stabilized zirconia (YSZ), hydrotalcite (MgAl-LDO), metal-organic frameworks (MOFs) (e.g., MIL-101), zeolitic imidazolate frameworks (ZIFs), alkali amides (NaNH, Ca(NH), Mg(NH), inorganic electrides (e.g., C), halloysite nanotubes (HNTs), ABO perovskite, ABO spinel, mesoporous silicates (e.g., MCM-4), or any combination thereof.

[0419] In some cases, the method may further include thermally, physically, chemically, or electrochemically treating the surface of the catalyst support material to improve the pore structure or surface chemistry or properties of the catalyst support material. In some cases, one or more ammonia molecules are configured to bind or attach to one or more active sites on the active metal for decomposition of the one or more ammonia molecules. In some cases, the location, orientation, and / or density of the one or more active sites are determined at least in part based on the morphology and / or surface chemistry or properties. In some cases, the catalyst support includes beads, pellets, powder, thin film, monolith, foam, reformer wall, heating element, one or more wires, mesh, textured or corrugated plate, or form factor of a porous solid material. In some cases, the pore properties include pore structure, pore size, pore size distribution, pore shape, pore volume, or pore density. In some cases, the method may include modifying the pore density of the catalyst support. In some cases, the method may include increasing the pore density of the catalyst support.

[0420] In another embodiment, the present disclosure provides a catalyst for ammonia processing, the catalyst comprising: a catalyst support comprising one or more modified pore properties produced by thermal, physical, chemical, or electrochemical treatment of the catalyst support; a composite support material provided on the catalyst support, the composite support material comprising a morphology or surface chemistry or properties; and one or more active metals provided on or incorporated into at least one of the composite support material and the catalyst support, the one or more active metals comprising one or more nanoparticles configured to conform to the morphology or surface chemistry or properties of the composite support material upon thermal, physical, chemical, or electrochemical activation, thereby improving one or more active sites on the nanoparticles for the processing or decomposition of ammonia.

[0421] In some cases, the composite support material is deposited using physical vapor deposition or chemical vapor deposition. In some cases, the morphology or surface chemistry or properties of the composite support material are matched to the morphology or surface chemistry or properties of the catalyst support. In some cases, the one or more active metals are deposited using physical vapor deposition or chemical vapor deposition. In some cases, the one or more active metals are configured to match the morphology or surface chemistry or properties of the composite support material when thermally or chemically activated. In some cases, the one or more active metals are configured to grow when thermally, physically, chemically, or electrochemically activated. In some cases, the one or more nanoparticles are configured to grow while matching the morphology or surface chemistry or properties of the composite support material.

[0422] In some cases, the morphology or surface chemistry or properties are created or improved by thermally, physically, chemically, or electrochemically treating the surface of the catalyst support material. In some cases, one or more active metal nanoparticles include one or more active sites configured to attach or bind one or more ammonia molecules for decomposition of the one or more ammonia molecules. In some cases, the location, orientation, or density of the one or more active sites is determined at least in part based on the morphology or surface chemistry or properties. In some cases, the catalyst support includes a form factor of beads, pellets, powder, thin film, monolith, foam, reformer wall, heating element, wire, mesh, textured or corrugated plate, or porous solid material.

[0423] Reformer In one aspect, the present disclosure provides a system for processing a source material. The system may include one or more reformers. The one or more reformers may include one or more catalysts. The one or more catalysts may be used to process the source material. The one or more catalysts may be modified to improve processing of the source material. The source material may include, for example, ammonia (NH). The source material may be processed to produce a fuel source. The fuel source may include, for example, hydrogen and / or nitrogen. The fuel source may be provided to one or more hydrogen fuel cells, which may be configured to generate electrical energy using the fuel source. Such electrical energy may be used to power various systems, vehicles, and / or devices.

[0424] FIG. 1 schematically illustrates a block diagram of an exemplary method for processing a source material to produce electrical energy. A source material 110 may be provided to a reformer 120. The source material 110 may include a compound containing one or more hydrogen molecules. The compound may be, for example, ammonia or NH3. In some cases, the compound may be a hydrocarbon C x H y , substituted hydrocarbon C x H y A z(where A is at least one non-metallic element other than carbon and hydrogen, and z is any integer greater than zero), or another hydrogen gas (e.g., borane) that can release hydrogen when exposed to a catalyst. The source material 110 may be provided to the reformer 120. The source material 110 may be in a gaseous state and / or a liquid state. The reformer 120 may be designed or configured to process the source material 110 using one or more catalysts 121 to extract, produce, or release the fuel source 130 from the source material 110. In some cases, processing the source material 110 may include heating the one or more catalysts 121 to extract, produce, or release the fuel source 130 from the source material 110. The fuel source 130 may include, but may not be limited to, hydrogen and / or nitrogen. The fuel source 130 may be provided to one or more fuel cells or one or more combustion engines for the production of electrical energy or mechanical work. Such electrical energy may be used to power various systems, vehicles, and / or devices, including, for example, land, air, or underwater vehicles.

[0425] In some cases, the fuel source 130 may be provided to various chemical or industrial processes, including, but not limited to, steel or iron processing, combustion engines, combustion turbines, hydrogen storage, hydrogen for chemical processes, hydrogen fueling stations, etc. In some cases, the fuel source 130 may be supplied to a combustion engine or combustion turbine as a pilot, auxiliary, or primary fuel.

[0426] As described above, one or more fuel cells may be used to generate electrical energy from a fuel source 130, which may include, but may not be limited to, hydrogen and / or nitrogen. In some cases, one or more fuel cells may generate electricity through an electrochemical reaction between a fuel. The fuel may include hydrogen and / or nitrogen in the fuel source 130. The electricity generated by the fuel cell may be used to power one or more systems, vehicles, or devices. In some cases, excess electricity generated by the fuel cell may be stored in one or more energy storage units (e.g., batteries) for future use. In some optional cases, a fuel cell may be provided as part of a larger fuel cell system. A fuel cell system may include an electrolysis module. Electrolysis of a by-product (e.g., water) of one or more fuel cells may allow the by-product to be removed through decomposition of the by-product into one or more constituent elements (e.g., oxygen and / or hydrogen). Electrolysis of the by-product may also produce another fuel (e.g., hydrogen) for the fuel cell.

[0427] As described above, one or more combustion engines may be used to generate electrical energy or mechanical work from a fuel source 130, which may include, but may not be limited to, hydrogen and / or nitrogen. In some cases, the one or more combustion engines may generate mechanical work through the combustion of one or more fuels. The mechanical work can be converted to electrical energy by one or more generators. The fuel may include hydrogen and / or nitrogen in the fuel source 130. The electricity or mechanical work generated by the combustion engine may be used to power one or more systems, vehicles, or devices. In some cases, excess electricity or mechanical work generated by the combustion engine may be stored in one or more energy storage units (e.g., batteries) for future use. In some optional cases, the combustion engine may be provided as part of a larger engine or power generation system. The combustion engine system may include a combustion chamber. Electrolysis of by-products (e.g., water) of one or more combustion engines may allow the by-products to be removed through decomposition of the by-products into one or more constituent elements (e.g., oxygen and / or hydrogen). Electrolysis of the by-products can also produce other fuels (e.g., hydrogen) for combustion engines.

[0428] FIG. 2 schematically illustrates an exemplary method of hydrogen storage using liquid chemicals, according to some embodiments. Hydrogen can be stored using one or more liquid chemicals, whether produced by electrolysis of renewable energy or through hydrocarbon reforming. In some cases, the one or more liquid chemicals can include, for example, ammonia, liquid organic hydrogen carriers (LOHCs), formic acid (HCOOH), or methanol (CHOH). Hydrogen can be stored in a hydrogen-rich or hydrogen-depleted form. The one or more liquid chemicals containing hydrogen can be processed as described elsewhere herein to release the hydrogen stored in the liquid chemicals. Once released, the hydrogen can be used to generate electricity (e.g., stationary or portable power generation) or provided to a hydrogen fueling station or hydrogen distribution facility.

[0429] In some cases, ammonia can be used as a hydrogen carrier. The hydrogen carrier can include a fluid or liquid chemical that can be used to store hydrogen. The use of ammonia as an energy carrier provides the benefits of hydrogen fuel (e.g., high volumetric energy density) when ammonia is decomposed into hydrogen, while taking advantage of (a) the greater volumetric density of ammonia compared to both gaseous and liquid hydrogen, and (b) the ability to transport ammonia at standard temperatures and pressures without the need for complex, highly pressurized storage vessels such as those typically used to store and transport hydrogen.

[0430] In some cases, hydrogenation can be used to store hydrogen in one or more fluid or liquid chemicals (e.g., ammonia). Hydrogenation can refer to the treatment of a material or substance with molecular hydrogen (H2) to add one or more pairs of hydrogen atoms to various constituent compounds (e.g., one or more unsaturated compounds) that make up the material or substance. Hydrogenation can be carried out using a catalyst that can allow the reaction to occur under normal temperature and / or pressure conditions. In some cases, the Haber-Bosch process (an artificial nitrogen fixation process) can be used to produce ammonia. This process can be used to convert atmospheric nitrogen (N2) to ammonia (NH3) by reaction with hydrogen (e.g., H2 produced or obtained by electrolysis) using a metal catalyst under various reaction temperatures and pressures.

number

[0431] As described above, the Haber-Bosch process can be used to produce ammonia, which can be used as a hydrogen carrier. Using ammonia as a hydrogen carrier may offer several benefits, including easy storage and convenient transportation at relatively standard conditions (0.8 MPa and 20°C in the liquid state). Ammonia also has a relatively high hydrogen content (17.7% by weight, 120 grams of H2 per liter of liquid ammonia). Furthermore, ammonia production using the Haber-Bosch process can be powered by renewable energy sources (e.g., photovoltaics or solar thermal), making the production process environmentally safe and benign, as N2 is the only byproduct and there are no additional CO2 emissions. Once ammonia is produced, it can be processed (e.g., catalytically decomposed) to release hydrogen through a dehydrogenation process. The released hydrogen can then be provided to one or more fuel cells, such as a proton exchange membrane fuel cell (PEMFC) with a proton-conducting polymer electrolyte membrane, a polymer electrolyte membrane (PEM) fuel cell, a solid oxide fuel cell (SOFC), or one or more combustion engines with one or more combustion chambers. PEMFCs can have relatively low operating temperatures and / or pressure ranges (e.g., approximately 50-100°C). Proton exchange membrane fuel cells can be used to convert the chemical energy released during the electrochemical reaction of hydrogen and oxygen into electrical energy, as opposed to the direct combustion of hydrogen and oxygen gases to produce thermal energy. PEMFCs can operate on the opposite principle to PEM electrolysis, which produces and consumes electricity. Combustion engines can generate mechanical work or electricity through the combustion of (i) hydrogen and oxygen gases, or (ii) hydrogen, ammonia, and oxygen gases. The methods and systems disclosed herein can be implemented to achieve thermally efficient hydrogen production and can be extended for application in high-energy density power systems.

[0432] FIG. 3 schematically illustrates a hydrogen extraction reformer 300 for extracting hydrogen from ammonia. Extraction of hydrogen from ammonia can be achieved using one or more catalysts 340. The one or more catalysts 340 can include a heterogeneous catalyst. The heterogeneous catalyst can include a catalyst having a phase that is different from the phase of the reactants 310 (e.g., NH) or products 320 and / or 330 (N and / or H). The one or more catalysts 340 can include a plurality of metal nanoparticles 350 incorporated in, on, or within a support material 360 (e.g., a composite support and / or catalyst support described elsewhere herein). Impregnation of the metal nanoparticles 350 into, on, or within the support material 360 can lower the activation energy barrier for the ammonia decomposition reaction, thereby enabling the one or more catalysts 340 to efficiently crack or decompose ammonia at a lower reaction temperature.

[0433] 4 schematically illustrates various types of modifications and / or treatments to improve catalytic materials that can be used to crack ammonia. The catalyst can include, for example, aluminum, boron, calcium, carbon, chromium, cobalt, copper, iron, gallium, germanium, indium, lanthanum, lithium, magnesium, manganese, molybdenum, nickel, niobium, palladium, platinum, potassium, rhenium, rhodium, silicon, sodium, thallium, tin, titanium, tungsten, vanadium, zinc, and / or zirconium, or any metal alloy containing at least two metals or metalloids selected from, for example, Ni / Cr-a, Ni / Cr-a / Fe-b, Ni / Cr-a / Fe-b / Vc, or Ni / Cr-a / Fe-b / Vc / Al-d, where a, b, c, and d each range from 0 to 100. The surface of the catalyst may be treated (e.g., by etching, alloying, overloading, leaching, and / or one or more acid treatments) to increase the surface area and surface properties of the catalytic material. The catalyst may also be subjected to a catalyst coating operation (e.g., by impregnation, physical vapor deposition (PVD), or chemical vapor deposition (CVD)) and / or one or more heat treatment operations. In some cases, the treated catalytic material may include a catalyst-coated material that includes one or more electrical resistive catalysts.

[0434] Process and pore improvements FIG. 5 schematically illustrates an exemplary process for modifying and enhancing a catalyst support. A catalyst support may be provided. The catalyst support may include any one or more metals (e.g., aluminum), non-metals, and / or metalloids. In some cases, the pores of the catalyst support material may be modified. Modifying the pores may include, for example, modifying the pore size, pore density, pore volume, or the location or distribution of pores throughout the area or volume of the catalyst support material. The pores may be modified chemically (e.g., using corrosive gases or liquid chemicals to selectively etch pores) or physically (e.g., using one or more heat treatments under various gases). In some cases, the heat treatment may change the phase or state of the catalyst support material, which may also change the pore size of the catalyst support material. In some cases, the pore size may be modified differently for different types of reactions or different types of performance characteristics. In some cases, the heat treatment may involve exposing the catalyst support material to one or more reactive gases. In some cases, the reactive gas may include a gas containing one or more of nitrogen (e.g., NO, NO, N2O, NH3, HCN), sulfur (e.g., H2S, SO2), chlorine (e.g., Cl2, HCl), carbon (e.g., CO, CO2, acetylene, and other hydrocarbons), fluorine, or a gas generated from a plasma (e.g., ozone).

[0435] Metal foam catalyst In some cases, the catalyst may include one or more metal foam catalysts. The one or more catalysts may include, for example, modified metal foam catalysts. The catalyst material may be subjected to or may undergo one or more improvements and / or treatments as shown and described elsewhere herein. In some cases, the catalyst may include nickel chromium aluminum (NiCrAl) foam, magnesium aluminum (MgAl) foam, aluminum cerium lanthanum (AlCeLa) foam, or cerium zirconium (CeZr) foam.

[0436] In some cases, at least one of the first catalyst and the second catalyst can include a metal foam catalyst. The metal foam catalyst can include nickel, iron, chromium, and / or aluminum. In some cases, the metal foam catalyst can include one or more alloys including nickel, iron, chromium, aluminum, magnesium, zirconium, cerium, cobalt, copper, molybdenum, or lanthanum.

[0437] In some cases, the metal foam catalyst may include one or more powder, bead, pellet, or monolithic catalyst catalyst coatings. The catalyst coating may include a metal material, a promoter material, a dopant material, and / or a support material. The metal material may include, for example, ruthenium, nickel, rhodium, rhenium, iridium, cobalt, molybdenum, iron, platinum, chromium, palladium, manganese, tungsten, vanadium, and / or copper. The promoter material may include, for example, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, and / or barium. In some cases, the dopant may include, for example, magnesium, cerium, lanthanum, or other rare earth metals. In some cases, the support material may include, for example, at least one of Al2O3, alumina, MgO, magnesia, CeO2, ceria, SiO2, silica, TiO2, titania, Y2O3, yttria, ZrO2, zirconia, SiC, carborundum, silicon nitride (SiN, Si3N4), nierite, MgAl2O4, spinel, CaAl2O4, krotite, dmitryivanovite, CoAl2O4, cobalt aluminate, hexagonal boron nitride (hBN), one or more boron nitride nanotubes (BNNTs), hexagonal boron nitride carbon (hBCN), one or more boron nitride carbon nanotubes (BCNNTs), and / or one or more carbon nanotubes. In some cases, the support material may include, for example, zinc aluminate (ZnAlO), gahnite, ferrous aluminate (FeAlO), hercynite, manganese aluminate (MnAlO), galaxite, magnesium ferrous aluminate ((MgFe)AlO), pleonast, calcium oxide (CaO), lime, quicklime, calcium hydroxide (Ca(OH)), slaked lime, calcium carbonate (CaCO), calcite, barium oxide (BaO), baria, barium carbonate (BaCO), strontium oxide (SrO), strontia, ferrous oxide (FeO), ferric oxide (FeO), zinc oxide (ZnO), or manganese oxide (MnO). x O y , Mgx O y , Ce x O y , Si x O y , Ti x O y , Y x O y , Zr x O y , B x N y , Si x C y , Si x N y and / or C. In some cases, the catalytic coating may include one or more ruthenium-based precursors. The one or more ruthenium-based precursors may be soluble metal salts, such as RuCl, Ru(NO)(NO), or Ru(CO). 12 In any of the embodiments described herein, the metal foam catalyst may have an apparent electrical resistivity of at least about 8 microohm-meters (μΩm).

[0438] In some cases, the metal foam catalyst may be treated using one or more of etching, alloying, leaching, or acid treatment to increase the surface area of ​​the metal foam catalyst. In some cases, the metal foam catalyst may be heat treated. In some cases, the metal foam catalyst may be coated using physical vapor deposition (PVD) and / or chemical vapor deposition (CVD) processes.

[0439] Catalysts based on modified supports In some cases, the metal foam catalyst may be treated using one or more of etching, alloying, leaching, or acid treatment to increase the surface area of ​​the metal foam catalyst. In some cases, the metal foam catalyst may be heat treated. In some cases, the metal foam catalyst may be coated using physical vapor deposition (PVD) and / or chemical vapor deposition (CVD) processes. In some embodiments, the one or more ammonia decomposition catalysts may include a metal material, a promoter material, a dopant material, and / or a support material. In some cases, the metal material may include, for example, at least one of nickel, rhodium, rhenium, iridium, cobalt, molybdenum, iron, platinum, chromium, palladium, manganese, tungsten, vanadium, zinc, and / or copper. In some cases, the promoter material may include, for example, at least one of sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, and / or barium. In some cases, the support material may include, for example, Al. x O y , Mg x O y , Ce x O y , Si x O y , Ti x O y , Y x O y , Zr x O y , B x N y , Si x C y , Si x N yand / or C. In some cases, the support material may include, for example, at least one of Al2O3, alumina, MgO, magnesia, CeO2, ceria, SiO2, silica, SiC, carborundum, TiO2, titania, Y2O3, yttria, ZrO2, zirconia, SiN, Si3N4, nierite, MgAl2O4, spinel, CaAl2O4, krotite, domitriivanovite, CoAl2O4, hexagonal boron nitride (hBN), one or more boron nitride nanotubes (BNNTs), hexagonal boron nitride carbon (hBCN), one or more boron nitride carbon nanotubes (BCNNTs), and / or one or more carbon nanotubes.

[0440] Active Metal Nanoparticles One or more nanoparticles can be used to decompose ammonia. The one or more nanoparticles can include an active metal configured to decompose or facilitate the decomposition of ammonia. In some cases, the active metal nanoparticles can include, for example, ruthenium (Ru), platinum (Pt), palladium (Pd), iron (Fe), nickel (Ni), vanadium (V), molybdenum (Mo), cobalt (Co), chromium (Cr), copper (Cu), or zinc (Zn). The nanoparticles can include one or more binding sites (also referred to herein as active sites) for ammonia to attach to. The binding sites can be determined based on the shape, morphology, and / or surface chemistry or properties of the active metal nanoparticles. As described elsewhere herein, the morphology of the active metal nanoparticles can correspond to the size, shape, pore structure, pore size, pore shape, pore volume, pore density, pore size distribution, grain structure, particle size, grain shape, crystalline structure, flake size, or layered structure of the one or more active metal nanoparticles. As described elsewhere herein, the physical or chemical properties of the active metal nanoparticles may include the Arrhenius acidity or basicity, Lewis acidity or basicity, electron density, electronic state, or hydrophilicity or hydrophobicity of one or more active metal nanoparticles. One or more ammonia particles may be attached to binding sites of the active metal nanoparticles. The active metal nanoparticles may be configured to cleave the nitrogen-hydrogen (NH) bond of ammonia. The morphology and / or surface chemistry or properties of the active metal nanoparticles may enhance ammonia adsorption, NH bond decomposition (or cleavage), and hydrogen and / or nitrogen desorption.

[0441] form The morphology of nanoparticles can be modified. Morphology can include the structure, size, aspect ratio, facet distribution, and / or shape of the nanoparticles. In some cases, morphology can include grain structure, particle size, and / or grain boundaries. In some cases, morphology can correspond to the size, shape, pore structure, pore size, pore shape, pore volume, pore density, pore size distribution, grain structure, particle size, grain shape, crystalline structure, flake size, or layered structure of one or more active metal nanoparticles. The morphology of nanoparticles can be customized or altered to modify the location and / or availability of active sites at the molecular level. The binding or active sites of the nanoparticles can be defined or determined based in part on the morphology of the nanoparticles.

[0442] surface chemistry The chemical and / or physical properties of the nanoparticles can be modified. The chemical and / or physical properties can include, for example, the surface chemistry or properties of the one or more active metal nanoparticles. The physical and / or chemical properties of the active metal nanoparticles can include, for example, the Arrhenius acidity or basicity, Lewis acidity or basicity, electron density, electronic state, or hydrophilicity or hydrophobicity of the one or more active metal nanoparticles. The surface chemistry or properties of the nanoparticles can be customized or altered to modify the location and / or availability of active sites at the molecular level. The binding or active sites of the nanoparticles can be defined or determined based in part on the surface chemistry or properties of the nanoparticles.

[0443] form factor In some embodiments, the catalyst support material may comprise a porous material. In some cases, the catalyst support material may comprise a two-dimensional material. In some embodiments, the catalyst may be provided as a coating on beads or pellets. This may solve the problem of compressing a powder catalyst into a bead or pellet form but not being able to use all of the catalyst material within the body of the bead or pellet. In some cases, the catalyst may be provided as a coating on a powder. In some cases, the catalyst may be provided as a mesh, textured, or corrugated sheet, or as a coating on such structures. In some cases, the catalyst may be provided as a coating on a porous monolith or solid foam material. The coating may be modified with a predetermined amount of catalytic material to ensure that at least a threshold amount of catalytic material is used. The threshold amount may be, for example, at least about 75, 80, 85, 90, 95, or 99% by weight or volume. A plurality of beads or pellets containing the catalytic material coating may be used in combination with at least one reformer for decomposing or cracking ammonia to produce hydrogen.

[0444] Preparation of modified or composite carriers In some embodiments, the surface of the catalyst support may be modified or coated. In some cases, a catalyst support material containing modified pore characteristics may be coated with an intermediate layer that can act as a substrate for the growth of one or more active metals or active metal particles. When active metal nanoparticles are provided on the intermediate layer, the intermediate layer can be used to change or influence the morphology of the active metal nanoparticles. In some cases, the intermediate layer may include a composite support material. The composite support material may be deposited on the catalyst support material using vapor deposition (e.g., chemical vapor deposition or physical vapor deposition). In some cases, the composite support material may be deposited on the catalyst support material by sputtering.

[0445] The composite support material may include morphology and physical or chemical properties (e.g., surface chemistry). The morphology and / or physical or chemical properties of the composite support material layer may be used to change or influence the morphology and physical or chemical properties of the active metal nanoparticles deposited on the composite support material. In some cases, the active metal nanoparticles may grow while adapting to the morphology and physical or chemical properties of the composite support material layer.

[0446] In some cases, the catalyst support material may have morphology and physical or chemical properties (e.g., surface chemistry). The morphology and / or physical or chemical properties of the catalyst support material layer may be used to change or influence the morphology and physical or chemical properties of the active metal nanoparticles deposited on the catalyst support material or composite support material. In some cases, the active metal nanoparticles may grow to conform to the morphology and physical or chemical properties of the catalyst support material and / or composite support material layer.

[0447] In some cases, the catalyst support may include one or more properties or characteristics that can be improved or modified using one or more physical or chemical processes. The one or more properties or characteristics may include, for example, the morphology or surface chemistry or properties of the catalyst support. Morphology may include pore structure, pore size, pore shape, pore volume, pore density, pore size distribution, grain structure, particle size, grain shape, crystalline structure, flake size, or layer structure. Surface chemistry or properties may include Arrhenius acidity or basicity, Lewis acidity or basicity, surface hydroxyl group density, or hydrophilicity or hydrophobicity. In some cases, the morphology or surface chemistry or properties of the composite support material may be matched to the morphology or surface chemistry or properties of the catalyst support. In some cases, the morphology or surface chemistry or properties of the active metal nanoparticles may be matched to the morphology or surface chemistry or properties of the catalyst support material and / or composite support material. In some cases, the morphology or surface chemistry or properties of the composite support material may be matched to the morphology or surface chemistry or properties of the catalyst support material.

[0448] In some cases, CVD can be used to deposit a composite support material comprising boron nitride onto a catalyst support. A thin layer of the composite support material can be deposited onto a surface layer of the catalyst support. CVD can be used to create a network of composite support material on an existing catalyst support and / or within one or more pores of the catalyst support material. In some cases, the composite support material can include various metal oxides (e.g., titanium oxide, or one or more other two-dimensional (2D) or three-dimensional (3D) materials).

[0449] Depositing a composite support material as an additional layer on a catalyst support can be advantageous compared to using a powder form of the composite support material, as the powder form can be difficult to use in a reformer due to the resulting pressure drop. Compressing the powder into a pellet form can solve the pressure drop problem, but the composite support material within the body of the pellet may not be fully utilized, which is wasteful and inefficient. In some cases, powder can refer to a granular material that includes a majority of particles with characteristic dimensions less than 1 mm in size. In some cases, the aspect ratio can be at least about 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, or 45:1. In some cases, the aspect ratio can be about 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, or 50:1 or less. In some cases, the majority can be at least about 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, or 99 weight, volume, or count percent. In some embodiments, the majority can be at least about 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, or 99 weight, volume, or count percent or less.

[0450] Preparation of high surface area composite supports In some cases, this may involve the use of a preformed mixed metal, mixed metal oxide, or composite support. In some cases, this may require the preparation of a composite support, including the formation of an M / S, or M1-M2 / S, mixed metal alloy, mixed metal oxide, or mixed metal nitride layer adjacent to the support material, where M1 and M2 represent different metals and S represents the predominant metal in the support. In some embodiments, M, or M1 and M2, may comprise at least one alkaline earth metal. In some embodiments, M, or M1 and M2, may comprise at least one transition metal. In some embodiments, M, or M1 and M2, may comprise at least one rare earth metal. In some embodiments, M, or M1 and M2, may comprise a spinel-forming metal. In some cases, M1 and M2 may comprise metals selected from different groups selected from those listed herein (e.g., M1 may be an alkaline earth metal and M2 may be a transition metal). In some cases, the mixed metal alloy layer is formed during the heat treatment process. In some cases, the heat treatment process may include at least one of drying, firing, annealing, or nitriding.

[0451] Various techniques can be used to form or deposit the M or M1 M2 layer on the support, as described herein. For this approach, it may be useful to deposit as much material as necessary to form the desired alloy with the support metal, but it may also be possible to form a protective barrier of the deposited metal, metal precursor, or metal oxide that resists further processing to produce a high-surface-area composite support. In some cases, it may be convenient and practical to use wet impregnation or incipient wetness techniques to deposit the metal oxide or precursor on the support surface. In some cases, it may be beneficial to use the correct molar concentration of the precursor solution to achieve this and not overload the support to reduce or eliminate the formation of free metal, metal oxide, or metal nitride particles comprising M or a mixture of M1 and M2 on the layer during subsequent heat treatment steps.

[0452] In some cases, the target may be for the doped or composite support to contain about 50 mol % of the additive metal, which would result in a molar ratio of about 1:1 for S and M if only one metal were deposited on the support. If two metals are deposited, a molar ratio of about 1:1 for S and (M1 and M2) may be the target, although the molar or mass ratio of M1 and M2 (e.g., about 75:25) may depend on the desired composition of the alloy. In some cases, the target may be for the doped support to contain about 50 wt % of the additive metal, which would result in a molar ratio of about 1:1 for S and M if only one metal were deposited on the support. If two metals are deposited, a molar ratio of about 1:1 for S to (M1 and M2) may be the target, although the molar or mass ratio of M1 to M2 (e.g., about 75:25) may depend on the desired composition of the alloy. When the amount of M, or M1 and M2, used is stoichiometric with the metals in the original support, it is possible to form a layer on the support that includes a mixed metal allylic, mixed metal oxide, or mixed metal nitride with effectively undetectable free metal particles, metal oxides, or metal nitrides of M, or M1 and M2.

[0453] etching Once the composite support is prepared, it can undergo further processing to modify its properties for improved catalytic performance (e.g., activity, selectivity, surface morphology). The production of high-surface-area composite supports can involve the preferential removal of one or more metals using an etching process. Various techniques can be employed, such as photochemical, electrochemical, laser, plasma, low-energy ion, and wet chemical etching. Wet chemical etching is a relatively simple and economical technique that can be suitable for small-scale laboratory and large-scale industrial processes. Wet etching solutions can be selected to preferentially remove one or more of the metals from the support or modified support, creating or enlarging gaps, holes, and pores, and to create or increase heterogeneity on the surface (e.g., areas of increased yield or basicity, and / or electron surplus or electron deficiency). The choice of solution can also depend on the composition of the metals desired to remain on the composite support and whether the solution can reduce or oxidize the metal species, dissolve it, or whether it remains inert or forms a protective layer that resists further chemical reaction and material removal.

[0454] In some cases, the wet etching solution may include an alkaline aqueous solution such as LiOH, NaOH, KOH, NH, tetramethylammonium hydroxide, and combinations thereof. In some cases, the wet etching solution may include an acidic aqueous solution such as HPO, HSO, HCl, HNO, HF, HClO, acetic acid, formic acid, citric acid, oxalic acid, boric acid, tetrafluoroboric acid, and combinations thereof. In some cases, the wet etching solution may include an aqueous solution of a reducible or chelating species such as FeCl, CuCl, SnCl, CuSO, NaHSO, NaCl, NaCO, NaNO, CrO, HO, potassium sodium tartrate, KNaCHO, sodium 3-nitrobenzenesulfonate, and combinations thereof. In some cases, the wet etching solution may include solubility improving additives such as gluconates, polyalcohols, amines, flow agents, leveling agents, and complexing agents, and combinations thereof.

[0455] The choice of etching solution may depend on the composition of the material to be removed and the desired removal rate. In some cases, a combination of nitric acid, phosphoric acid, and acetic acid has been found to allow for relatively slow but highly controllable removal of aluminum and / or aluminum oxide from composite materials. In some cases, the use of aqueous NaOH, KOH, or NH3 solutions allows for much faster but less controllable removal of aluminum and / or aluminum oxide from composite materials. In some cases, the material removal rate may also be increased by increasing the temperature, the concentration of the active ingredient in the solution, agitation of the solution, and the use of additional agents as described herein. In some cases, the etching process may be performed under elevated pressure when the temperature approaches or exceeds the boiling point of the solution under atmospheric conditions. In some cases, the use of an autoclave may allow any or all of the temperature, pressure, duration, or concentration of the etching solution to be reduced.

[0456] In some cases, the concentration of the acid or base solution may be at least about 0.01, 0.05, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, or 19.5 M. In some cases, the concentration of the acid or base solution may be about 0.05, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, or 20 M or less. In some cases, the concentration of the acid or base solution can be in the range of about 0.01 to about 20, 0.1 to 19, 0.5 to 18, 1 to 17, 2 to 16, 3 to 15, 4 to 14, 5 to 13, 5 to 12, 5 to 11, 5 to 10, 6 to 12, 6 to 11, 6 to 10, 6 to 9, 6 to 8, 6 to 7, 7 to 12, 7 to 11, 7 to 10, 7 to 9, 7 to 8, 8 to 12, 8 to 11, 8 to 10, 8 to 9, 9 to 12, 9 to 11, 9 to 10, 10 to 12, 10 to 11, or 11 to 12 M.

[0457] In some cases, the temperature of the etching solution can be at least about 10, 15, 20, 25, 30, 25, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, or 290°C. In some cases, the temperature of the etching solution can be less than or equal to about 15, 20, 25, 30, 25, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300°C. In some cases, the temperature of the etching solution is about 10 to about 300, 20 to 250, 30 to 200, 40 to 150, 40 to 140, 40 to 130, 40 to 120, 40 to 110, 40 to 100, 40 to 90, 40 to 80, 40 to 70, 40 to 60, 40 to 50, 50 to 150, 50 to 140 0, 50-130, 50-120, 50-110, 50-100, 50-90, 50-80, 50-70, 50-60, 60-150, 60-140, 60-130, 60-120, 60-110, 60-100, 60-90, 60-80, 60-70, 70-150, 70-140, 70 ~130, 70~120, 70~110, 70~100, 70~90, 70~80, 80~150, 80~140, 80~130, 80~120, 80~110, 80~100, 80~90, 90~150, 90~140, 90~130, 90~120, 80~110, 90~100, 1 The temperature may be in the range of 00 to 150, 100 to 140, 100 to 130, 100 to 120, 100 to 110, 110 to 150, 110 to 140, 110 to 130, 110 to 120, 120 to 150, 120 to 140, 120 to 130, 130 to 150, 130 to 140, or 140 to 150°C.

[0458] In some cases, the composite support may be immersed in the etching solution for at least about 0.5, 1, 2, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80, 84, 88, 92, 96, 108, 120, 132, 144, 156, 168, 192, 216, 240, 266, 290, or 312 hours. In some cases, the composite support may be immersed in the etching solution for about 1, 2, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80, 84, 88, 92, 96, 108, 120, 132, 144, 156, 168, 192, 216, 240, 266, 290, 312, or 336 hours or less.In some cases, the composite carrier may be from about 0.5 to about 336, 1 to 168, 2 to 144, 24 to 96, 24 to 84, 24 to 72, 24 to 68, 24 to 64, 24 to 60, 24 to 56, 24 to 52, 24 to 48, 24 to 44, 24 to 40, 24 to 36, 24 to 32, 24 to 28, 28 to 96, 28 to 84, 28 to 72, 28 to 68, 28 to 64, 28 to 60, 28 to 56, 28 to 52, 28 to 48 , 28~44, 28~40, 28~36, 28~32, 32~96, 32~84, 32~72, 32~68, 32~64, 32~60, 32~56, 32~52, 32~48, 32~44, 32~40, 32~36, 36~96, 36~84, 36~72, 36~68, 36~64, 36~60, 36~56, 36~52, 36~48, 36~44, 36~40, 40~96, 40~84, 40~72, 40~68, 40~64, 40~60, 40~56, 40~52, 40~48, 40~44, 44~96, 44~84, 44~72, 442~68, 44~64, 44~60, 44~56, 44~52, 44~48, 48~96, 48~84, 48~72, 48~68, 48~64, 48~60, 48~56, 48~52, 52~96, 52~84, 52~72, 52~68, The etching solution may be immersed for a duration ranging from 52 to 64, 52 to 60, 52 to 56, 56 to 96, 56 to 84, 56 to 72, 56 to 68, 56 to 64, 56 to 60, 60 to 96, 60 to 84, 60 to 72, 60 to 68, 60 to 64, 64 to 96, 64 to 84, 64 to 72, 64 to 68, 68 to 96, 68 to 84, 68 to 72, 72 to 96, 72 to 84, or 84 to 96 hours.

[0459] In some cases, the composite substrate can be immersed in the etching solution at a pressure of at least about 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, or 45 bar absolute pressure. In some cases, the composite substrate can be immersed in the etching solution at a pressure of no more than about 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, or 50 bar absolute pressure. In some cases, the composite carrier may be from about 1 to about 10, 1 to 9, 1 to 8, 1 to 7, 1 to 6, 1 to 5, 1 to 4.5, 1 to 4, 1 to 3.5, 1 to 3, 1 to 2.5, 1 to 2, 1 to 1.5, 1.5 to 10, 1.5 to 9, 1.5 to 8, 1.5 to 7, 1.5 to 6, 1.5 to 5, 1.5 to 4.5, 1.5 to 4, 1. 5~3.5, 1.5~3, 1.5~2.5, 1.5~2, 2~10, 2~9, 2~8, 2~7, 2~6, 2~5, 2~4.5, 2~4, 2~3.5, 2~3, 2~2.5, 2.5~10, 2.5~9, 2.5~8, 2.5~7, 2.5~6, 2.5~5, 2.5~4.5, 2.5~4, 2.5~3 .5, 2.5-3, 3-10, 3-9, 3-8, 3-7, 3-6, 3-5, 3-4.5, 3-4, 3-3.5, 3.5-10, 3.5-9, 3.5-8, 3.5-7, 3.5-6, 3.5-5, 3.5-4.5, 3.5-4, 4-10, 4-9, 4-8, 4-7, 4-6, 4-5, 4-4.5, The etching solution may be immersed at a pressure in the range of 4.5-10, 4.5-9, 4.5-8, 4.5-7, 4.5-6, 4.5-5, 5-10, 5-9, 5-8, 5-7, 5-6, 6-10, 6-9, 6-8, 6-7, 7-10, 7-9, 7-8, 8-10, 8-9, or 9-10 bar absolute.

[0460] Active metal addition One or more active metals can be deposited on the catalyst support material or composite support material. The active metals can be deposited using a variety of methods, including, for example, CVD, PVD, sol-gel, and wet impregnation. The active metals can be deposited as active metal nanoparticles on the composite support and also within one or more modified pores of the catalyst support material. This can facilitate the decomposition of any ammonia molecules that penetrate the pores of the catalyst support. The deposition of active metal nanoparticles on the composite support can also be referred to herein as impregnation of the composite support with one or more active metal nanoparticles.

[0461] Once deposited on or within the catalyst support material and / or composite support material, the active metal nanoparticles may grow according to the morphology and / or physical or chemical properties of the composite support material. In some cases, the composite support material may include hexagonal particles. The active metal nanoparticles may grow while maintaining a particle shape corresponding to the particle shape of the composite support material. In some cases, the active metal nanoparticles may grow while maintaining a hexagonal particle shape. The composite support material may provide a 2D structure or platform for the active metal nanoparticle growth. The active metal nanoparticles may grow while conforming to the structure of the composite support material. In some cases, the composite support material may include boron nitride. The active metal nanoparticles may grow while maintaining the hexagonal morphology of the composite support material. In some cases, the catalyst may undergo one or more heat treatments under vacuum (i.e., below atmospheric pressure) and / or in the presence of various gases, such as hydrogen gas or ambient air. Such heat treatments can be used to thermally activate active metal nanoparticles incorporated into the composite support structure and promote a change in the morphology and / or physical or chemical properties of the active metal nanoparticles to match those of the materials or particles (e.g., atoms or molecules) that make up the composite support.

[0462] Use of promoters with active metals In some cases, the composite material and / or one or more active metal nanoparticles incorporated therein can be promoted (e.g., Group 1 or Group 2 metals) to alter the electronic state or electron density of the active metal nanoparticles. As described above, the active metal nanoparticles can include, for example, ruthenium, cobalt, or molybdenum. In some cases, the modified electronic state or electron density can promote the elimination of recombined nitrogen and / or the cleavage of N-H bonds during the ammonia decomposition reaction.

[0463] The methods and processes disclosed herein for producing composite catalysts can be implemented to produce catalysts with one or more desirable properties or performance characteristics (e.g., efficient hydrogen production). The catalysts can lower the activation energy barrier for the ammonia decomposition reaction, promoting the reaction at lower temperatures while increasing throughput and improving the efficient utilization of precious metals. The disclosed methods and processes can be adapted and scaled for economical mass production of high-performance, high-efficiency catalysts.

[0464] FIG. 5 illustrates an exemplary method for synthesizing one or more active metal nanoparticles. In some cases, the active metal nanoparticles can be produced from a precursor material (e.g., a precursor material containing Ru, Co, or Mo). The active metal nanoparticles can be promoted with one or more alkali metals. The promoter can include one or more substances (e.g., cocatalysts) that can be added to increase ammonia conversion efficiency or selectivity. The one or more active metal nanoparticles can undergo one or more heat treatments to thermally activate the active metal nanoparticles so that they undergo growth and changes in morphology or physical / chemical properties to reflect the morphology and / or physical or chemical properties of the composite support material in or on which they are deposited. The systems and methods described herein can be used to control the morphology, surface chemistry, and / or dispersion of the active metal nanoparticles and to control the interaction between the active metal nanoparticles and the composite support or catalyst support. The systems and methods of the present disclosure can also be used to modify one or more active sites on the active metal nanoparticles to disintegrate and decompose or crack one or more ammonia molecules.

[0465] The improved catalysts described herein may exhibit improved ammonia decomposition performance and increased ammonia conversion efficiency. The ammonia conversion efficiency of the improved catalysts may be a function of reaction temperature. In some cases, the ammonia conversion efficiency may include at least about 90% at a reaction temperature of about 500°C. In some cases, the ammonia conversion efficiency may be greater than about 70% and less than about 99% at a reaction temperature ranging from about 450°C to about 600°C.

[0466] Thermal and chemical treatment of the carrier In some embodiments, the catalyst preparation method may include heat treatment under a reactive gas. Such heat treatment may be used to modify the porosity of the support for improved mass transfer. Such heat treatment may also be used to modify one or more properties of the support (e.g., the chemical composition, basicity, or acidity of the support) for better surface modification results.

[0467] In some embodiments, the catalyst production method can include a surface modification and coating step. The surface modification and coating step can include an interlayer deposition by PVD or CVD. PVD or CVD can be used to coat the support geometry with a thin, uniform layer of functional material. The coating layer can have a thickness ranging from at least about 1 nanometer to about 30,000 nanometers (30 microns). The functional material can serve as a substrate for nanoparticle growth. In some cases, the morphology and / or physical or chemical properties of the functional material can affect the growth and / or morphology or surface chemistry of the nanoparticles.

[0468] In some embodiments, the catalyst preparation method can include impregnation of active metal nanoparticles. Impregnation can include precursor impregnation by vacuum deposition or incipient wetness impregnation. This can allow for control of precursor adhesion on the functional material.

[0469] In some embodiments, catalyst preparation methods can include promoting thermal, physical, chemical, or electrochemical activation. Promotion can include electron density modification and impregnation of promoter materials (e.g., alkali metals and / or alkaline earth metals) in active metal and / or composite support materials to promote modification or improvement of catalyst morphology or active sites. Thermal and / or chemical activation can also be used to modify the morphology of active metal nanoparticles in a reducing environment (e.g., an environment containing hydrogen gas) or in the presence of one or more noble gases.

[0470] FIG. 6A schematically illustrates the effect of reduction of a Ru-alumina catalyst on ammonia conversion efficiency according to some examples of the present disclosure. The catalysts of the present disclosure can be doped, promoted, and / or heat-treated in an appropriate manner to improve catalytic performance and ammonia conversion efficiency. Compared to bare sample catalysts (i.e., catalysts that have not undergone doping, promotion, and / or heat treatment), doped, promoted, and heat-treated catalysts can exhibit higher ammonia conversion efficiencies. Higher temperatures or treatment times can result in better catalytic performance. For example, bare sample catalysts can exhibit an ammonia conversion efficiency of up to about 30% at a temperature of about 500°C. Surprisingly, doped, promoted, and heat-treated catalysts at 700°C can exhibit an ammonia conversion efficiency of at least about 60% or greater at a temperature of about 500°C. Unexpectedly, doped, promoted, and heat-treated catalysts at 900°C can exhibit an ammonia conversion efficiency of at least about 80% or greater at a temperature of about 500°C.

[0471] Examples of the effect of reduction temperature and duration on hydrogen generation or production rate, according to some embodiments, are described herein. In some cases, catalytic performance can be improved by about two-fold or more with higher temperature and / or longer duration heat treatment under H. Referring to FIG. 6B, approximately 125 mmol H2 g 触媒 -1 h -1 Presented herein is a base Ru-alumina catalyst 601 without dopant or heat treatment that can have a hydrogen production rate that can be up to (mmol of hydrogen per gram of catalyst material per hour). The base catalyst can be treated with a dopant ("X") before Ru is deposited 602, which can produce approximately 150 mmol of hydrogen per gram of catalyst material per hour. H2 g 触媒 -1 h -1 Treatment in an NH3 atmosphere can improve the base catalyst, producing a hydrogen production rate of about 150 mmol H2 g 触媒 -1 h -1Alternatively, the base catalyst may be heat treated in a H atmosphere at 700° C. for 20 hours 606, or 40 hours 608, or at 900° C. for 9 hours 610, to produce hydrogen at rates of about 175, 200, and 250 mmol / L, respectively. H2 g 触媒 -1 h -1 It can be increased to

[0472] FIG. 6C schematically illustrates the effect of catalyst active metal promotion on ammonia conversion efficiency according to some embodiments of the present disclosure. The catalysts of the present disclosure can be promoted with one or more alkali metals. In some cases, cesium may be one of the most effective promoters for X-Al2O3 catalysts. However, in some cases, excessive promoter incorporation may decrease catalytic performance and hydrogen production or generation rate. Therefore, there is an optimal promoter amount for a catalyst material. The catalysts of the present disclosure may be appropriately doped, promoted, and / or heat-treated to optimize catalytic performance and hydrogen production or generation rate.

[0473] In some embodiments, the catalyst may be free of alkali metals or alkaline earth metals. In some embodiments, the catalyst may be essentially free of alkali metals or alkaline earth metals. In some embodiments, the catalyst may be promoter-free. In some embodiments, the catalyst may be essentially promoter-free.

[0474] In some cases, bare sample catalysts may exhibit ammonia conversion efficiencies of up to about 20% at temperatures of about 500° C. Potassium-promoted catalysts may exhibit ammonia conversion efficiencies of at least about 60% or greater at temperatures of about 500° C. Cesium-promoted catalysts may exhibit ammonia conversion efficiencies of at least about 85% or greater at temperatures of about 500° C.

[0475] 6D schematically illustrates the effect of doping-based Ru-ammonia catalysts on ammonia conversion efficiency and hydrogen production or generation rate, according to some embodiments. Surprisingly, catalysts containing more effective levels of promoter relative to active metal content can exhibit ammonia conversion efficiencies of at least about 85% or greater at temperatures of about 500° C. Meanwhile, catalysts with lower or higher promoter levels can have reduced ammonia conversion efficiencies (e.g., about 20% to about 60% or less).

[0476] Examples of the effects of promoter concentration and active metal to promoter molar ratio on some Ru-alumina catalysts are described herein. Compared to the base Ru-alumina catalyst, the inclusion of a promoter at a 1:1 molar ratio of active metal to promoter improved catalyst performance compared to the same catalyst without a promoter. As the promoter concentration increases to a more effective molar ratio of active metal to promoter (e.g., 1:3), catalyst performance continues to improve. However, further increases in promoter concentration unexpectedly reduce catalyst performance below baseline levels. Surprisingly, when a more effective molar ratio of active metal to promoter is used, additional heat treatment can further improve catalyst performance.

[0477] Referring to FIG. 6E, the base Ru-alumina catalyst 611, without promoter or heat treatment, is shown, which has a yield of about 175 mmol H2 g 触媒 -1 h -1 The base catalyst exhibits the following hydrogen production rate, 612: When doped with a promoter (Cs) to reach a 1:1 molar ratio of Ru and Cs, the hydrogen production rate increases up to about 300 mmol / L. H2 g 触媒 -1 h -1 612. The base catalyst can be doped with higher concentrations of promoters to reach a 1:3 Ru and Cs molar ratio 613, and when subjected to additional heat treatment 615, the Ru and Cs molar ratios can be increased to approximately 460 and 500 mmol, respectively. H2 g 触媒-1 h -1 Further increasing the promoter concentration to a molar ratio of Ru and Cs of 1:6 can result in a hydrogen production rate of about 100 mmol H2 g 触媒 -1 h -1 This significantly reduced the number of cases to 614.

[0478] material In any of the embodiments described herein, the catalyst support material may include, for example, a metal oxide-based support having one or more micropores or mesopores. In some cases, the support material may include, for example, aluminum (Al), iron (Fe), carbon (C), silicon (Si), titanium (Ti), tantalum (Ta), platinum (Pt), palladium (Pd), nickel (Ni), nickel-chromium (Ni-Cr), Nicralloy (Ni-Cr-Al), Fecralloy (Fe-Cr-Al-Y), field metal (In-Bi-Sn)-based metal foam, monolith, or engineered sheet, foil, or mesh design. In some embodiments, the catalyst support material may include one or more of aluminum oxide (Al2O3), alumina, magnesium oxide (MgO), magnesia, magnesium aluminate (MgAl2O4), spinel, cerium dioxide (CeO2), ceria, silicon dioxide (SiO2), silica, silicon carbide (SiC), carborundum, yttrium oxide (YO3), yttria, one or more zeolites (e.g., MFI zeolite, MCM-41 zeolite, Y-type zeolite, X-type zeolite), titanium dioxide (TiO2), titania, zirconium dioxide (ZrO2), zirconia, lanthanum oxide (La2O3), lanthanum, chromium oxide (Cr2O3), or chromia. In some cases, the catalyst support material may include one or more of Al x O y , Mg x O y , Ce x O y , Si x O y , Y x O y , Ti x Oy , Zr x O y , La x O y , or Cr x O y may include one or more of:

[0479] In any of the cases described herein, the composite coating material may include a carbon-based material, a boron-based material, or a metal oxide. The carbon-based material may include, for example, activated carbon (AC), one or more carbon nanotubes (CNTs), carbon nanofibers (CNFs), graphene oxide (GO), graphite, one or more carbon nanoribbons, or reduced graphene oxide (rGO). The boron-based material may include, for example, hexagonal boron nitride (hBN), boron nitride nanotubes (BNNTs), hexagonal boron nitride carbon (hBCN), boron nitride carbon nanotubes (BCNNTs), boron nitride nanosheets (BNNSs), or boron nitride carbon nanosheets (BCNNSs). The metal oxide may include, for example, TiO2, titania, MgO, magnesia, magnesium aluminate (MgAl2O4), spinel, La2O3, lanthanum, CeO2, ceria, Y2O3, yttria, one or more CeO2 nanotubes, nanorods, or nanocubes, mesoporous silica (e.g., KIT-6), ZrO2, or zirconia. The metal oxide may include, for example, strontium oxide (SrO), strontium aluminate (SrAlO), barium oxide (BaO), barium aluminate (BaAlO), zinc aluminate (ZnAlO), gahnite, ferrous aluminate (FeAlO), hercynite, manganese aluminate (MnAlO), galaxite, magnesium ferrous aluminate ((MgFe)AlO), pleonast, calcium oxide (CaO), lime, quicklime, calcium hydroxide (Ca(OH)), slaked lime, calcium carbonate (CaCO), calcite, ferrous oxide (FeO), iron oxide (ZnO), or manganese oxide (MnO).

[0480] In any of the embodiments described herein, the active metal or active metal nanoparticles may include, for example, ruthenium (Ru), nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), molybdenum (Mo), zinc (Zn), iridium (Ir), rhenium (Re), platinum (Pt), or palladium (Pd). One or more active metals may be produced from one or more precursor materials. Precursor materials include, for example, ruthenium chloride (RuCl), ruthenium nitrosyl nitrate (Ru(NO)(NO)), triruthenium dodecacarbonyl (Ru(CO)), and the like. 12 ), ruthenium acetylacetonate (Ru(AcAc)3), ruthenium nitrate (Ru(NO3)3), ruthenium hexamine chloride (Ru(NH3)6Cl3), cyclohexadiene ruthenium tricarbonyl ((CHD)Ru(CO)3), butadiene ruthenium tricarbonyl ((BD)Ru(CO)3), or dimethylbutadiene ruthenium tricarbonyl ((DMBD)Ru(CO)3), cobalt chloride (CoCl2), iron acetylacetonate (Fe(AcAc)2), copper nitrate (Cu(NO3)2), nickel nitrate (Ni(NO3)2), manganese nitrate (Mn(NO3)2), zinc sulfate (ZnSO4), cobalt molybdate (CoMoO4), chromium hexacarbonyl (Cr(CO)6), or ammonium molybdate ((NH4)6Mo7O 24 ).

[0481] As noted above, in some cases, one or more promoters or promoter materials can be used to modify or improve the electron density of the active metal nanoparticles and / or composite support material. In any of the embodiments described herein, the one or more promoters or promoter materials can include, for example, cesium (Cs), rubidium (Rb), potassium (K), sodium (Na), barium (Ba), strontium (Sr), calcium (Ca), or magnesium (Mg). In some cases, excessive concentrations of promoter material can reduce catalytic performance and ammonia conversion efficiency (i.e., a more efficient and / or effective amount of doping material is present). As noted above, one or more promoters can be added to the catalysts of the present disclosure in appropriate amounts or relative concentrations to improve catalytic performance and ammonia conversion efficiency.

[0482] In some cases, one or more layers of a composite material can be coated onto a catalyst support material. The composite material can include one or more layers of boron nitride or boron carbon nitride. The one or more layers can have a thickness of up to about 10 nanometers.

[0483] In some embodiments, a catalyst support, including a layer of composite material deposited thereon, can be impregnated with one or more active metal nanoparticles. In some cases, active metal nanoparticles can be deposited on the composite layer, and the morphology of the active metal nanoparticles can be modified by treating the nanoparticles with one or more heat treatment methods. In some cases, the nanoparticles can have a size ranging from about 1 nanometer to about 100 nanometers. In some cases, the dispersion of the nanoparticles can range from about 5% to about 80%. In some cases, the dispersion of the nanoparticles can range from about 10% to about 60%. As used herein, dispersion can refer to the total number of atoms comprising the catalyst, or the number of active metal atoms exposed on the surface of the active metal nanoparticles relative to the surface area or volume of the catalyst. The active metal atoms exposed on the surface of the catalyst can bind to one or more ammonia molecules using one or more active sites (also referred to herein as binding sites) of the active metal nanoparticles. As described elsewhere herein, the active sites or binding sites of the active metal nanoparticles may be improved by subjecting the active metal nanoparticles to one or more heat treatments that allow the active metal nanoparticles to assume the form of the particles that make up the composite layer.

[0484] In some embodiments, the improved catalysts disclosed herein may have hydrogen production rates that are comparable to or higher than the hydrogen production rates of conventional base transition metal catalysts. In some cases, the improved catalysts disclosed herein may have hydrogen production rates that are higher than conventional ruthenium catalysts. The hydrogen production rate (which may be based on the active metal content of the improved catalyst) may be at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more times greater than the hydrogen production rate of conventional catalysts. In some cases, the improved catalysts may be capable of producing hydrogen at temperatures of at least about 200° C. and at rates of about 100 liters (L) per milliliter (mL) of catalyst per hour. NH3 hr -1 mL 触媒 -1 ) can exhibit ammonia to hydrogen conversion efficiencies of at least about 70%.

[0485] In some cases, the improved catalyst is heated at a temperature of at least about 200° C. and at a rate of about 160 liters (L) per gram of catalyst per hour. NH3 hr -1 g 触媒 -1 In some embodiments, the improved catalyst may exhibit ammonia to hydrogen conversion efficiency of at least about 70% at space velocities below about 700° C. and at least about 1, 2, 4, 6, 8, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, or 90 L. NH3 hr -1 mL 触媒 -1 In some embodiments, the improved catalyst may exhibit ammonia to hydrogen conversion efficiency of at least about 90% at a GHSV of about 700° C. or less and at up to about 2, 4, 6, 8, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, or 100 L. NH3 hr -1 mL catalyst -1 At a GHSV of 1000 MPa, the conversion efficiency of ammonia to hydrogen can be at least about 90%.

[0486] In some cases, the improved catalysts are oxidized at 450°C and at a flow rate of about 10 liters (L) per gram of catalyst per hour. ガス hr -1 g 触媒 -1 ), and at space velocities below 450°C and at least about 1, 2, 4, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 26, 28, 30, 35, 40, 45, or 50 liters (L) per gram of catalyst per hour. ガス hr -1 g 触媒 -1), and up to about 2, 4, 6, 8, 10, 12, 14, 15, 16, 18, 20, 22, 24, 25, 26, 28, 30, 35, 40, 45, or 50 liters (L) per gram of catalyst per hour at 450°C. ガス hr -1 g 触媒 -1 ) can exhibit ammonia to hydrogen conversion efficiency of at least about 90%.

[0487] In some cases, the improved catalyst is heated at a temperature of at least about 490° C. and at a rate of about 16 liters (L) per gram of catalyst per hour. ガス hr -1 g 触媒 -1 ) or about 10 liters per milliliter of catalyst per hour (L ガス hr -1 mL 触媒 -1 ), and at a gas hourly space velocity (GHSV) below 100°C, the improved catalysts may exhibit ammonia to hydrogen conversion efficiency of at least about 90%. In some cases, the improved catalysts may exhibit a lower nitrogen desorption activation energy than conventional ruthenium catalysts. In some cases, the improved catalysts may exhibit ammonia to hydrogen conversion efficiency of at least about 90% at a gas hourly space velocity (GHSV) below 100°C, and at a nitrogen desorption activation energy below 100°C, the improved catalysts may exhibit ammonia to hydrogen conversion efficiency of at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 20, 22, 24, 26, 28, 30, 35, 40, 45, or 50 L. gガス hr -1 g 触媒 -1 In some cases, the improved catalysts may exhibit ammonia to hydrogen conversion efficiencies of at least about 90% at space velocities of at least about 490° C. and at up to about 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, or 50 L. ガス hr -1 g 触媒 -1In some cases, the improved catalysts may exhibit ammonia to hydrogen conversion efficiencies of at least about 90% at a space velocity of at least about 490° C. and at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 20, 22, 24, 26, 28, 30, 35, 40, 45, or 50 L. ガス hr -1 mL 触媒 -1 In some cases, the improved catalysts may exhibit ammonia to hydrogen conversion efficiency of at least about 90% at a GHSV of at least about 490° C. and at a maximum of about 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, or 50 L. ガス hr -1 mL 触媒 -1 At a GHSV of 1000 MPa, the conversion efficiency of ammonia to hydrogen can be at least about 90%.

[0488] In some cases, the improved catalyst is prepared by subjecting the catalyst to a temperature of at least about 450° C. and a reaction time of about 1 to about 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, 5 to 40, 5 to 35, 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 10, 10 to 40, 10 to 35, 10 to 30, 10 to 25, 10 to 20, 10 to 15, 15 to 40, 15 to 35, 15 to 30, 15 to 25, 15 to 20, 20 to 40, 20 to 35, 20 to 30, or 20 to 25 L. ガス hr -1 g 触媒 -1 In some cases, the improved catalysts can produce hydrogen and nitrogen at an ammonia conversion efficiency of about 70% to about 99% at a space velocity of at least about 490°C and at a temperature of 1 to about 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, 5 to 40, 5 to 35, 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 10, 10 to 40, 10 to 35, 10 to 30, 10 to 25, 10 to 20, 10 to 15, 15 to 40, 15 to 35, 15 to 30, 15 to 25, 15 to 20, 20 to 40, 20 to 35, 20 to 30, or 20 to 25 L. ガス hr -1 mL触媒 -1 At a GHSV of 1000 MPa, the conversion efficiency of ammonia to hydrogen can be at least about 90%.

[0489] In some cases, the improved catalysts may exhibit nitrogen desorption activation energies that are comparable to or lower than those of conventional base transition metal catalysts, and in some cases, the improved catalysts may exhibit nitrogen desorption activation energies that are lower than those of conventional ruthenium catalysts.

[0490] In some cases, the improved catalyst is a catalyst having a temperature of at least about 200°C and a temperature of about 1-160, 1-150, 1-140, 1-130, 1-120, 1-110, 1-100, 1-90, 1-80, 1-70, 1-60, 1-50, 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10, 5-160, 5-150, 5-140, 5-130, 5-120, 5-110, 5-100, 5-90, 5-80, 5-70, 5-60, 5-50, 5-45, 5-40, 5-35, 5-30, 5 ~25, 5~20, 5~15, 5~10, 10~160, 10~150, 10~140, 10~130, 10~120, 10~110, 10~100, 10~90, 10~80, 10~70, 10~60, 10~50, 10~45, 10~40, 10~35, 10~30, 10~25, 10~20, 10~15, 15~50, 15~40, 15~35, 15~30, 15~25, 15~20, 20~50, 20~40, 20~35, 20~30, 20~25, 25~50, 25~45, 25~35, or 25~30L NH3 hr -1 g 触媒 -1In some cases, the improved catalysts can produce hydrogen and nitrogen at an ammonia conversion efficiency of about 70% to about 99% at a space velocity of at least about 200°C and at a temperature of about 1 to about 100, 1 to 90, 1 to 80, 1 to 70, 1 to 60, 1 to 50, 1 to 45, 1 to 40, 1 to 35, 1 to 30, 1 to 25, 1 to 20, 1 to 15, 1 to 10, 5 to 100, 5 to 90, 5 to 80, 5 to 70, 5 to 60, 5 to 50, 5 to 45, 5 to 40, 5 to 35, 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 5 ~10, 10~100, 10~90, 10~80, 10~70, 10~60, 10~50, 10~45, 10~40, 10~35, 10~30, 10~25, 10~20, 10~15, 15~50, 15~40, 15~35, 15~30, 15~25, 15~20, 20~50, 20~40, 20~35, 20~30, 20~25, 25~50, 25~45, 25~35, or 25~30L NH3 hr -1 mL 触媒 -1 At a GHSV of 1000 MPa, the conversion efficiency of ammonia to hydrogen can be at least about 90%.

[0491] In some cases, the improved catalyst has a conversion efficiency of about 70 to about 99% and a conversion efficiency of about 1 to 160 L at a temperature of at least about 200, 225, 250, 275, 300, 235, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, or 675°C. NH3 hr -1 g 触媒 -1 In some cases, the improved catalyst may exhibit a conversion efficiency of about 70 to about 99% and a space velocity of about 1 to 160 L at temperatures up to about 225, 250, 275, 300, 235, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, or 700°C. NH3 hr -1 g 触媒 -1In some cases, the improved catalysts may exhibit space velocities of about 200 to about 700, 200 to 650, 200 to 600, 200 to 550, 200 to 500, 200 to 450, 200 to 400, 250 to 700, 250 to 650, 250 to 600, 250 to 550, 250 to 500, 250 to 450, 300 to 700, 300 to 650, 300 to 600, 400 to At temperatures of 550, 300-500, 350-700, 350-650, 350-600, 350-550, 400-700, 400-650, 400-600, 450-700, 450-650, 450-600, 500-700, 550-650, 600-700, or 650-700°C, a conversion efficiency of about 70 to about 99% and a volume of about 1 to 160L NH3 hr -1 g 触媒 -1 can show the space velocity of

[0492] In some cases, the improved catalyst has a conversion efficiency of about 70 to about 99% and a conversion efficiency of about 1 to 100 L at a temperature of at least about 200, 225, 250, 275, 300, 235, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, or 675°C. NH3 hr -1 mL 触媒 -1 In some cases, the improved catalyst may exhibit a GHSV of about 70 to about 99% conversion efficiency and a GHSV of about 1 to 100 L at temperatures up to about 225, 250, 275, 300, 235, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, or 700° C. NH3 hr -1 mL 触媒 -1In some cases, the improved catalysts may exhibit a GHSV of about 200 to about 700, 200 to 650, 200 to 600, 200 to 550, 200 to 500, 200 to 450, 200 to 400, 250 to 700, 250 to 650, 250 to 600, 250 to 550, 250 to 500, 250 to 450, 300 to 700, 300 to 650, 300 to 600, 400 to At temperatures of 550, 300-500, 350-700, 350-650, 350-600, 350-550, 400-700, 400-650, 400-600, 450-700, 450-650, 450-600, 500-700, 550-650, 600-700, or 650-700°C, a conversion efficiency of about 70 to about 99% and a volume of about 1 to 100L NH3 hr -1 mL 触媒 -1 The GHSV can be shown.

[0493] Reformer and power system using improved catalysts The catalysts of the present disclosure can be adapted for use in various power systems (e.g., one or more reformers) for decomposing or cracking ammonia to produce hydrogen. The power system may include, for example, one or more reformers capable of performing catalytic decomposition or cracking of ammonia to extract and / or produce hydrogen. Such reformers may be operated using thermal energy. In some cases, the power system may include a combustor that generates thermal energy to drive the operation of the reformer. In some cases, the thermal energy may be generated from the combustion of chemical compounds (e.g., hydrogen or hydrocarbons). In some cases, the reformer may include an outlet configured to direct one or more fluids (e.g., ammonia, nitrogen, and / or hydrogen) to another system or subsystem. In some cases, the outlet may be configured to direct hydrogen gas produced by the reformer to one or more fuel cells and / or one or more combustion mechanisms. In some cases, the outlet may be configured to direct at least a portion of the hydrogen gas produced by the reformer to one or more combustors to generate thermal energy that can be used to power or heat the reformer (e.g., for autothermal heating or self-heating). In some cases, the outlet may be configured to direct the hydrogen, nitrogen, and / or ammonia to at least one other reformer (e.g., to combust the hydrogen to heat the at least one other reformer).

[0494] Use of the produced hydrogen in fuel cells or engines Hydrogen produced using the improved catalysts of the present disclosure can be provided to one or more fuel cells or proton exchange membrane fuel cells (PEMFCs) to generate electrical energy. Hydrogen produced using the improved catalysts of the present disclosure can also be provided to one or more combustion engines to generate mechanical work or mechanical energy. Hydrogen produced and / or extracted using a reformer can be provided to one or more fuel cells or one or more combustion engines, which can generate electrical energy or mechanical work to power one or more systems, subsystems, or devices that require electrical or mechanical energy to operate. In some cases, at least a portion of the partially produced and / or extracted hydrogen and nitrogen and residual ammonia mixture from the reformer can be provided to one or more other reformers to enable a continuous reforming process. The partially produced and / or extracted hydrogen and nitrogen and residual ammonia can be part of a partially cracked ammonia stream. The partially cracked ammonia stream can be produced using a reformer having an ammonia conversion efficiency of less than 100% (i.e., less than 100% of the ammonia is converted to hydrogen and nitrogen). The partially cracked stream may be sent to one or more downstream reformers to minimize waste and maximize the amount of ammonia that can be cracked or decomposed. In some cases, hydrogen produced and / or extracted using the reformer is provided to one or more other reformers. In such cases, the one or more other reformers may be configured to combust the hydrogen to generate additional thermal energy. Such additional thermal energy is used to heat the one or more other reformers to facilitate further catalytic decomposition or cracking of the ammonia and extract and / or produce additional hydrogen.

[0495] Resistive heating of catalysts in reformers. In some cases, the one or more reformers may be configured to directly heat the improved catalyst using resistive heating (e.g., by passing an electric current through the catalyst itself or through a catalyst support). In such cases, the one or more reformers may include one or more electrodes for passing an electric current through the catalyst to heat the catalyst (e.g., by resistive heating or Joule heating). The one or more electrodes may include, for example, one or more metal (e.g., copper, steel, titanium, or carbon) electrodes. In other cases, the one or more reformers may be configured to heat the improved catalyst by burning hydrogen. The improved catalyst may be configured to decompose ammonia into hydrogen and / or nitrogen when heated by combustion or resistive heating.

[0496] In some cases, one or more reformers may include one or more conductive springs. The one or more conductive springs may be provided adjacent to the improved catalyst disclosed herein. In some cases, the one or more conductive springs may be provided at the opposite end of the catalyst. The one or more conductive springs may be in physical, electrical, and / or thermal communication with the catalyst, the catalyst bed, and / or one or more electrodes used to implement direct resistive heating of the catalyst. The one or more conductive springs may be configured to reduce thermal stress on the catalyst when the catalyst undergoes thermal cycling. The one or more conductive springs may be configured to accommodate thermal expansion during catalyst heating and thermal contraction during catalyst cooling. The one or more conductive springs may reduce and / or redistribute mechanical loads on the catalyst bed so that the catalyst bed can withstand multiple thermal cycles without breaking or destroying. In some cases, the one or more springs may be configured to reduce thermal stress on the catalyst due to thermal expansion or contraction of the catalyst during one or more thermal cycling procedures. The one or more springs may include, for example, stainless steel, titanium, or steel springs. The use of one or more conductive springs can enable one or more reformers to reduce or minimize thermal stress on the catalyst bed during rapid temperature changes, providing fast start-up capabilities.

[0497] Conductive catalyst In some embodiments, one or more reformers may include an electrically conductive (i.e., non-insulating) catalyst. In some cases, the electrically conductive catalyst may include at least one of an electrically conductive (i.e., non-insulating) support or an electrically conductive coating, layer, or particle within, on, or adjacent to the surface of the support. In some cases, the electrically conductive catalyst may be brought to a minimum target operating temperature using resistive (Joule) heating. In some cases, the electrically conductive catalyst may be maintained at a target operating temperature or range by Joule heating. In some cases, the electrically conductive catalyst may be brought to a minimum operating temperature by an internal or external heat source (e.g., electric heating element, induction heating, combustion gases, or heat exchanger). In some cases, the electrically conductive catalyst may be maintained at a target operating temperature or range by an internal or external heat source (e.g., electric heating element, induction heating, combustion gases, or heat exchanger).

[0498] In some embodiments, the conductive catalyst may comprise one or more monolithic structures or substrate forms. In some embodiments, the monolithic structures and / or substrates may be formed by at least one of extrusion, 3D printing, or additive manufacturing. In some cases, the monolithic structures may be formed from flat, folded, crimped, corrugated, or textured sheets, wires, tubes, or various engineered shapes and forms. In some cases, the monolithic structures may be constructed from alternating combinations of flat sheets and folded, crimped, corrugated, or textured sheets. In some cases, the monolithic structures may resemble at least one concentric spiral in cross section. In some cases, the thickness of the flat, corrugated, or textured sheet may include about 0.02 to about 0.2, 0.02 to 0.15, 0.02 to 0.1, 0.02 to 0.05, 0.03 to 0.15, 0.03 to 0.1, 0.03 to 0.05, 0.05 to 0.15, or 0.05 to 0.1 mm.

[0499] In some cases, the monolith structure may include tubes or channels having a honeycomb cell cross-section. In some cases, the cells of the honeycomb monolith structure may be circular, triangular, square, rectangular, pentagonal, hexagonal, or more complex geometric shapes. In some cases, the wall thickness of the cells within the honeycomb monolith structure may include about 0.02 to about 0.2, 0.02 to 0.15, 0.02 to 0.1, 0.02 to 0.05, 0.03 to 0.15, 0.03 to 0.1, 0.03 to 0.05, 0.05 to 0.15, or 0.05 to 0.1 mm. In some cases, the cell dimensions are such that the cell density (cm) is about 5 to about 100, 10 to 100, 20 to 100, 20 to 80, 20 to 60, 25 to 100, 25 to 75, 25 to 50, 40 to 100, 40 to 80, 50 to 100, 50 to 75, or 60 to 100 cells per square centimeter. -1 ) may be possible.

[0500] In some cases, the electrically heated catalyst may include the form of particles (e.g., powder, beads, pellets, or other engineered designs) configured to form an electrical circuit between a pair of electrodes. In some cases, the engineered design may be, for example, at least one of a sphere, a cube, a hollow cube, a solid cylinder, a hollow cylinder, a four-hole cylinder, a single ring, a cross-web, a grooved cylinder, a Pall ring, an interlocking saddle, or a Berle saddle. Other, more attractive designs of catalyst particles may also be suitable. In some cases, the electrically conductive catalyst may include one or more beds of particles (e.g., a packed bed and / or a fluidized bed).

[0501] In some cases, one or more monolith structures and / or beds may be connected in electrical communication with each other. In some cases, one or more monolith structures and / or catalyst beds may be connected to separate or different electrical circuits. In some cases, one or more monolith structures and / or beds may be connected to the same power source. In some cases, one or more monolith structures and / or beds may be connected to separate or different power sources. In some cases, one or more monolith structures and / or beds may be in electrical communication with a single temperature controller device. In some cases, one or more monolith structures and / or beds may be in electrical communication with multiple temperature control devices. In some cases, one or more monolith structures and / or beds may be heated together, simultaneously, or separately in a stepwise manner. In some cases, one or more monolith structures and / or beds may be controlled to the same or similar minimum and / or target operating temperatures or temperature ranges. In some cases, one or more monolith structures and / or beds may be controlled to different minimum and / or target operating temperatures or temperature ranges. In some cases, one or more monolith structures and / or beds may be located in one section or section of the reformer or in separate sections or sections of the reformer. In some cases, one or more monolith structures and / or beds may be located in the same zone or different zones of the reformer. In some cases, the zones within the reformer may be defined by the expected or intended composition of gases, operating temperature, operating temperature range, catalyst composition and / or shape factor, type of heating, electrical circuitry, or control system used.

[0502] In some embodiments, the monolith structure and / or catalyst particles may include a support made of at least one ceramic, metal, or hybrid material. In some embodiments, the support may include one or more ceramic materials (e.g., at least one of silicon carbide, silicon, or germanium). In some cases, the support may include a complex perovskite ceramic material. In some cases, the support may include carbon or a carbon-based material (e.g., at least one of graphite, graphene, amorphous carbon, or graphite oxide). In some cases, the support may include one or more metals or metal alloys (e.g., at least one of Ni, Cr, Fe, Al, NiCrAl, FeCrAl, NiFeCrAl, and NiCr). In some cases, the support may include a non-stoichiometric, non-conductive compound to increase the concentration of conductive elements. In some cases, the support may include a conductive polymer. In some cases, the support may include a metal foam. In some cases, the conductive coating may include carbon (graphite, graphene, nanoparticles, or nanotubes), certain conductive metal oxides, or conductive ceramic materials. In some cases, the carrier or coating may include one or more dopants (e.g., at least one of B, N, and P) to modify the conductivity or resistivity properties.

[0503] Electrical properties of catalysts and supports For effective and efficient resistive (or Joule) heating, the conductive catalyst, support material, or support monolith must have suitable electrical properties. If the resistivity is too low (or the conductivity is too high), the applied voltage will result in high current flow through the catalyst, support material, or support monolith, which can lead to overheating, melting, and degradation. If the resistivity is too high (or the conductivity is too low), very high voltages will be required to provide the necessary current, but it may be difficult for the current to flow through a sufficient volume of the catalyst, support material, or support monolith to heat the catalyst uniformly. Significantly uneven heating of the catalyst, support material, or support monolith can lead to the creation of hot spots, where the catalyst, support material, or support monolith is exposed to excessive temperatures and more rapid decomposition, and / or cold spots, where the catalyst, support material, or support monolith cannot reach the minimum temperature required to deliver the required ammonia conversion efficiency. Significantly uneven heating of the catalyst, support material, or support monolith can reduce overall ammonia conversion efficiency or cause unpredictable catalyst behavior, reducing the ability of the control system to maintain the performance necessary to produce enough hydrogen to meet power demands. Significantly uneven heating of the catalyst, support material, or support monolith can also shorten the useful life of the catalyst, support material, or support monolith and increase backpressure within the reformer due to thermally induced stress fracture and structural breakdown into smaller particles or powder.

[0504] Electrical resistivity of catalyst and support In some cases, the electrically conductive catalyst, support material, or support monolith may comprise a resistivity of at least about 10, 25, 50, 100, 200, 300, 400, 500, 1000, 2000, 3000, 4000, 5000, 10000, 20000, 30000, 40000, 50000, 100000, or 500000 microohm-cm (μΩ.cm). In some cases, the conductive catalyst, support material, or support monolith may include a resistivity of less than or equal to about 10, 25, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 5000, 10000, 20000, 30000, 40000, 50000, 100000, 500000, or 1,000,000 microohm-cm (μΩ-cm). In some cases, the conductive catalyst, support material, or support monolith may have a molecular weight of about 10 to about 1,000,000, 10 to 500,000, 10 to 100,000, 10 to 50,000, 10 to 10,000, 10 to 5,000, 10 to 1,000, 50 to 1,000,000, 50 to 500,000, 50 to 100,000, 50 to 50,000, 50 to 10,000, 50 to 5000, 50-1000, 100-1,000,000, 100-500,000, 100-100,000, 100-50,000, 100-10,000, 100-5000, 500-1,000,000, 500-500,000, 500-100,000, 500-50,000, 500-10,000, 500-5000, 1000-1,000,000 , 1000~500000, 1000~100000, 1000~50000, 1000~10000, 1000~50000, 1000~10000, 1000~5000, 5000~1000000, 5000~500000, 5000~100000, 5000~50000, 5000~10000, 10000~1000000 , 10,000 to 500,000, 10,000 to 100,000, 10,000 to 50,000, 50,000 to 1,000,000, 50,000 to 500,000, 50,000 to 100,000, 100,000 to 1,000,000, 100,000 to 500,000, or 500,000 to 1,000,000 microohm-cm (μΩ.cm).

[0505] In some cases, the conductive catalyst, support material, or support monolith may include a resistivity of at least about 0.1, 0.5, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, or 140 ohm-cm (Ω.cm). In some cases, the conductive catalyst, support material, or support monolith may include a resistivity of no more than about 0.5, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, or 150 ohm-cm (μΩ-cm). In some cases, the conductive catalyst, support material, or support monolith may have a molecular weight of about 0.1 to about 150, 0.1 to 100, 0.1 to 50, 0.1 to 10, 0.5 to 150, 0.5 to 100, 0.5 to 50, 0.5 to 10, 1 to 150, 1 to 100, 1 to 50, 1 to 10, 2 to 50, 2 to 10, 3 to 50, 3 to 10, 4 to 50, 4 to 10, 5 to 150, 5 to 100, 5 to 50, 5 to 40, 5 to 30, 5 to 20, 5 to 10, 10 to 150, 10 The resistivity may be between 100, 10 and 50, 10 and 40, 10 and 30, 10 and 20, 20 and 150, 20 and 100, 20 and 50, 30 and 150, 30 and 100, 30 and 60, 40 and 150, 40 and 100, 40 and 80, 50 and 150, 50 and 100, 60 and 150, 60 and 100, 70 and 150, 70 and 100, 80 and 150, 80 and 100, 90 and 150, 90 and 100, or 100 and 150 ohm.cm (μΩ-cm).

[0506] Electrical resistance of catalyst and support When connected in electrical communication with an applied voltage, an electrically conductive catalyst, support material, or support monolith may present a resistance to the flow of electrical current.

[0507] In some cases, the resistance of the conductive catalyst, support material, or support monolith may include at least about 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, or 90 ohms (Ω). In some cases, the resistance of the conductive catalyst, support material, or support monolith may include no more than about 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 90, or 100 ohms (Ω). In some cases, the resistance of the conductive catalyst, support material, or support monolith may be from about 0.01 to about 100, 0.01 to 50, 0.01 to 10, 0.05 to 100, 0.05 to 50, 0.05 to 10, 0.1 to 100, 0.1 to 50, 0.1 to 10, 0.5 to 100, 0.5 to 50, 0.5 to 10, 1 to 100, 1 to 50, 1 to 10, 5 to 100, 5 to 50, 5 to 40, 5 to 30, 5 to 20, 5 to 10, 10 to 100, 10 to 90, 10 to 80, 10 to 70, 10 to 60, 10 to 50, 10 to 40, 10 to 30, 10 to 20, 15 to 100, 15 to 50, 1 The resistance may include 5 to 40, 15 to 30, 15 to 20, 20 to 100, 20 to 80, 20 to 60, 20 to 50, 20 to 40, 20 to 30, 25 to 100, 25 to 90, 25 to 80, 25 to 70, 25 to 60, 25 to 50, 30 to 100, 30 to 90, 30 to 80, 30 to 70, 30 to 80, 30 to 50, 35 to 100, 35 to 90, 35 to 80, 35 to 70, 35 to 60, 40 to 100, 40 to 90, 40 to 80, 40 to 70, 40 to 60, 45 to 100, 45 to 90, 45 to 80, 50 to 100, 50 to 90, 50 to 80, or 50 to 70 ohms (Ω).

[0508] When connected in electrical communication with an electrode, the conductive catalyst, support material, or support monolith, and electrode may present a combined resistance to the flow of electrical current due to an applied voltage.

[0509] In some cases, the combined resistance of the electrodes and conductive catalyst, support material, or support monolith may include at least about 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 90, 100, 110, 120, 130, or 140 ohms (Ω). In some cases, the combined resistance of the electrodes and conductive catalyst, support material, or support monolith may include no more than about 0.05, 0.1, 0.5, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 90, 100, 110, 120, 130, 140, or 150 ohms (Ω). In some cases, the combined resistance of the electrode and conductive catalyst, support material, or support monolith is about 0.01 to about 150, 0.05 to 120, 0.1 to 110, 0.1 to 100, 0.1 to 90, 0.1 to 80, 0.1 to 70, 0.1 to 65, 0.1 to 60, 0.1 to 55, 0.1 to 50, 0.1 to 45, 0.1 to 40, 0.1 to 35, 0.1 to 30, 0.1 to 25, 0.1 to 20, 0.1 to 15, 0. 1~10, 0.1~5, 0.1~1, 0.5~110, 0.5~100, 0.5~90, 0.5~80, 0.5~70, 0.5~65, 0.5~60, 0.5~55, 0.5~50, 0.5~45, 0.5~40, 0.5~35, 0.5~30, 0.5~25, 0.5~20, 0.5~15, 0.5~10, 0.5~5, 0.5~1, 1~110, 1~100, 1~90, 1~80, 1~70, 1-65, 1-60, 1-55, 1-50, 1-45, 1-40, 1-35, 1-30, 1-25, 1-20, 1-15, 1-10, 1-5, 5-110, 5-100, 5-90, 5-80, 5-70, 5-65, 5-60, 5-55, 5-50, 5-45, 5-40, 5-35, 5-30, 5-25, 5-20, 5-15, 5-10, 10-110, 10-100, 10-90, 10-80, 10-70, 10-65, 10-60, 10-55, 10-50, 10-45, 10-40, 10-35, 10-30, 10-25, 10-20, 10-15, 15-110, 15-100, 15-90, 15-80, 15-70, 15-65, 15-60, 15-55, 15-50, 15-45, 15-40, 15-35, 15-30, 15-25, 15-20, 20-110, 20-100,20~90, 20~80, 20~70, 20~65, 20~60, 20~55, 20~50, 20~45, 20~40, 20~35, 20~30, 20~25, 25~110, 25~100, 25~90, 25~80, 25~70, 25~65, 25~60, 25~55, 25~50, 25~45, 25~40, 25~35, 25~30, 30~110, 30~ 100, 30-90, 30-80, 30-70, 30-65, 30-60, 30-55, 30-50, 30-45, 30-40, 30-35, 35-110, 35-100, 35-90, 35-80, 35-70, 35-65, 35-60, 35-55, 35-50, 35-45, 35-40, 40-110, 40-100, 40-90, 40-80, 40-70 , 40~65, 40~60, 40~55, 40~50, 40~45, 45~110, 45~100, 45~90, 45~80, 45~70, 45~65, 45~60, 45~55, 45~50, 50~110, 50~100, 50~90, 50~80, 50~70, 50~65, 50~60, 50~55, 55~110, 55~100, 55~90, 55~80 , 55 to 70, 55 to 65, 55 to 60, 60 to 100, 60 to 110, 60 to 90, 60 to 80, 60 to 70, 60 to 65, 65 to 110, 65 to 100, 65 to 90, 65 to 80, 65 to 70, 70 to 110, 70 to 100, 70 to 90, 70 to 80, 80 to 110, 80 to 90, 90 to 110, 90 to 100, or 100 to 110 ohms (Ω).

[0510] Power supply to catalyst The conductive catalyst, support material, or support monolith requires a direct electrical supply to provide the power necessary to raise the temperature of the catalyst to the minimum required to achieve good ammonia conversion efficiency. In some cases, the power may be delivered in the form of direct current or alternating current. In some cases, the power may be provided by at least one of a battery, a fuel cell, a generator, an engine, a turbine, a capacitor, a flywheel, or an electrical grid. In some cases, the power may be supplemented or replaced by heat from the combustion of a gas (e.g., H2 or NH3).

[0511] In some cases, the power required may be related to the resistivity, specific heat capacity, and size (mass or volume) of the catalyst, support material, or support monolith. In some cases, the power required may be related to the target temperature to be achieved (desired ammonia conversion efficiency), the start temperature (e.g., ambient environment, or any temperature below the target temperature). In some cases, the power required may be related to the desired rate at which the target temperature is reached, or the time period from when power is turned on (when current begins to pass through the catalyst, support material, or support monolith) to when the target temperature is reached. In some cases, the power required may depend on the presence, condition, and / or composition of electrically insulating and / or thermally insulating materials adjacent to the electrically conductive catalyst, support material, or support monolith, or adjacent to the interior and / or exterior surfaces of the reformer.

[0512] In some cases, the power provided to the conductive catalyst, support material, or monolith support may include at least about 1, 5, 10, 20, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, or 900 Watts per gram of catalyst (W / g). In some cases, the power provided to the conductive catalyst, support material, or monolith support may include no more than about 5, 10, 20, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, or 1000 Watts per gram of catalyst (W / g). In some cases, the power provided to the conductive catalyst, support material, or monolith support may be from about 1 to about 1000, 1 to 900, 1 to 800, 1 to 700, 1 to 600, 1 to 500, 1 to 400, 1 to 300, 1 to 200, 1 to 100, 5 to 1000, 5 to 900, 5 to 800, 5 to 700, 5 to 600, 5 to 500, 5 to 450, 5 to 400, 5 to 350, 5 to 300, 5 to 250, 5 to 200, 5-150, 5-100, 5-50, 5-20, 10-1000, 10-900, 10-800, 10-700, 10-600, 10-500, 10-450, 10-400, 10-350, 10-300, 10-250, 10-200, 10-150, 10-100, 10-50, 20-1000, 20-900, 20-800, 20-700, 20-600, 20-500, 20-450, 2 0-400, 20-350, 20-300, 20-250, 20-200, 20-150, 20-100, 20-50, 50-1000, 50-900, 50-800, 50-700, 50-600, 50-500, 50-450, 50-400, 50-350, 50-300, 50-250, 50-200, 50-150, 50-100, 100-1000, 100-900, 100-800, 100- 700, 100-600, 100-500, 100-450, 100-400, 100-350, 100-300, 100-250, 100-200, 100-150, 150-1000, 150-900, 150-800, 150-700, 150-600, 150-500, 150-450, 150-400, 150-350, 150-300, 150-250, 150-200, 200-1000,200~900, 200~800, 200~700, 200~600, 200~500, 200~450, 200~400, 200~350, 200~300, 200~250, 250~1000, 250~900, 250~800, 250~700, 250~600, 250~500, 250~450 , 250~400, 250~350, 250~300, 300~1000, 300~900, 300~800, 300~700, 300~600, 300~500, 300~450, 300~400, 300~350, 350~1000, 350~900, 350~800, 350~700, 350~6 00, 350-500, 350-450, 350-400, 400-1000, 400-900, 400-800, 400-700, 400-600, 400-500, 400-450, 450-1000, 450-900, 450-800, 450-700, 450-600, 450-500, 500 The watts (W / g) may be up to 1000, 500 to 900, 500 to 800, 500 to 700, 500 to 600, 600 to 1000, 600 to 900, 600 to 800, 600 to 700, 700 to 1000, 700 to 900, 700 to 800, 800 to 1000, 800 to 900, or 900 to 1000.

[0513] Catalyst temperature and heating time In some embodiments, the electrically conductive catalyst, support material, or monolith may require heating from a first temperature to a second temperature to achieve a desired ammonia conversion efficiency. In some embodiments, the first temperature may be the ambient temperature of the surrounding environment. In some embodiments, the electrically conductive catalyst, support material, or monolith may be utilized as a start catalyst or in a start reformer in an ammonia conversion or hydrogen production system. In some embodiments, the electrically conductive catalyst, support material, or monolith may be utilized as a fast start catalyst or in a fast start reformer in an ammonia conversion or hydrogen production system. In some embodiments, the electrically conductive catalyst, support material, or monolith may be utilized as a catalyst or in a reformer to produce hydrogen for use in a combustion-heated reactor and / or a hydrogen fuel cell in an ammonia conversion or hydrogen production system. In some embodiments, the electrically conductive catalyst, support material, or monolith may be utilized as a catalyst in a combustion-heated reformer in an ammonia conversion or hydrogen production system. In some cases, at least a portion of the catalyst, support material, or support monolith must reach a second temperature to achieve a desired ammonia conversion efficiency. In some cases, it may be necessary for at least a portion of the catalyst to reach a second temperature within a defined time period, beginning with the current beginning to pass through the catalyst.

[0514] In some cases, the first temperature may include at least about -40, -35, -30, -25, -20, -15, -10, -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, or 650°C. In some cases, the first temperature may include less than or equal to about -35, -30, -25, -20, -15, -10, -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, or 700°C. In some cases, the first temperature is between about -40 and about 40, -35 and 40, -30 and 40, -25 and 40, -20 and 40, -15 and 40, -10 and 40, -10 and 35, -10 and 30, -10 and 25, -5 and 40, -5 and 35, -5 and 30, -5 and 25, 0 and 40, 0 and 35, 0 and 30, 0 and 25, 5 and 50, 5 and 45, 5 ~40, 5~35, 5~30, 5~25, 10~50, 10~45, 10~40, 10~35, 10~30, 10~25, 15~50, 15~45, 15~40, 15~35, 15~30, 15~25, 20~50, 20~45, 20~40, 20~35, 20~30, 20~25, 25~100, 25~60, 25~50 , 25~40, 30~100, 30~75, 30~50, 30~40, 40~100, 40~60, 40~50, 50~150, 50~100, 100~200, 100~150, 150~300, 150~250, 150~200, 200~400, 200~350, 200~300, 200~250, 250~400 , 250 to 350, 250 to 300, 300 to 500, 300 to 450, 300 to 400, 300 to 350, 350 to 550, 350 to 500, 350 to 450, 350 to 400, 400 to 600, 400 to 550, 400 to 500, 400 to 450, 450 to 650, 450 to 550, or 450 to 500°C.

[0515] In some cases, the second temperature can include at least about 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, or 850° C. In some cases, the second temperature can include no more than about 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, or 900° C. In some cases, the second temperature is between about 100 and about 800, 150 and 750, 200 and 700, 200 and 600, 200 and 500, 200 and 400, 300 and 800, 300 and 700, 300 and 600, 300 and 500, 300 and 400, 400 and 800, 400 and 700, 400 and 600, 400 and 500, 500 and 900, 500 and 800, 500 and 700, 500 and 650, 500 and 600, 500 and 550, 550 and 900, The temperature may include 0, 550-750, 550-700, 550-650, 550-600, 600-900, 600-800, 600-750, 600-700, 600-650, 650-900, 650-850, 650-800, 650-750, 650-700, 700-900, 700-850, 700-800, 700-750, 750-900, 750-850, 750-800, 800-900, 800-850, or 850-900°C.

[0516] In some cases, it may not be necessary for the entire mass, volume, or measurable surface of the catalyst, support material, or support monolith to reach the second temperature to achieve the desired ammonia conversion efficiency. In some cases, the desired ammonia conversion efficiency (e.g., about 70% to about 99%) may be achieved when only a portion of the catalyst, support material, or support monolith reaches the second temperature.

[0517] In some cases, a desired ammonia conversion efficiency (e.g., about 70% to about 99%) can be achieved when a portion comprising at least about 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 99% of the mass of the catalyst, support material, or support monolith reaches the second temperature. In some cases, a desired ammonia conversion efficiency can be achieved when a portion comprising no more than about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, or 100% of the mass of the catalyst, support material, or support monolith reaches the second temperature. In some cases, the desired ammonia conversion efficiency is about 1 to about 100, 1 to 99, 1 to 95, 1 to 90, 1 to 80, 1 to 70, 1 to 60, 1 to 50, 1 to 40, 1 to 30, 1 to 20, 1 to 10, 5 to 100, 5 to 99, 5 to 95, 5 to 90, 5 to 80, 5 to 70, 5 to 60, 5 to 50, 5 to 60, 5 to 75, 5 to 80, 5 to 80, 5 to 90, 5 to 90, 5 to 10 ... ~40, 5~30, 5~20, 5~10, 10~100, 10~99, 10~95, 10~90, 10~80, 10~70, 10~60, 10~50, 10~40, 10~30, 10~20, 20~100, 20~99, 20~95, 20~90, 20~80, 20~70, 20~60, 20~50, 20~40, 20~30, 30 ~100, 30~99, 30~95, 30~90, 30~80, 30~70, 30~60, 30~50, 30~40, 40~100, 40~99, 40~95, 40~90, 40~80, 40~70, 40~60, 40~50, 50~100, 50~99, 50~95, 50~90, 50~80, 50~70, 50~60, 60~1 This can be achieved when a portion including 00, 60-99, 60-95, 60-90, 60-80, 60-70, 70-100, 70-99, 70-95, 70-90, 70-80, 80-100, 80-99, 80-95, 80-90, 90-100, 90-99, 90-95, 95-100, or 95-99% reaches the second temperature.

[0518] In some cases, a desired ammonia conversion efficiency (e.g., about 70% to about 99%) can be achieved when a portion comprising at least about 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 99% of the volume of the catalyst, support material, or support monolith reaches the second temperature. In some cases, a desired ammonia conversion efficiency can be achieved when a portion comprising no more than about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, or 100% of the volume of the catalyst, support material, or support monolith reaches the second temperature. In some cases, the desired ammonia conversion efficiency is about 1 to about 100, 1 to 99, 1 to 95, 1 to 90, 1 to 80, 1 to 70, 1 to 60, 1 to 50, 1 to 40, 1 to 30, 1 to 20, 1 to 10, 5 to 100, 5 to 99, 5 to 95, 5 to 90, 5 to 80, 5 to 70, 5 to 60, 5 to 50, 5 to 60, 5 to 70, 5 to 80, 5 to 90, 5 to 90, 5 to 10 ... ~40, 5~30, 5~20, 5~10, 10~100, 10~99, 10~95, 10~90, 10~80, 10~70, 10~60, 10~50, 10~40, 10~30, 10~20, 20~100, 20~99, 20~95, 20~90, 20~80, 20~70, 20~60, 20~50, 20~40, 20~30, 30 ~100, 30~99, 30~95, 30~90, 30~80, 30~70, 30~60, 30~50, 30~40, 40~100, 40~99, 40~95, 40~90, 40~80, 40~70, 40~60, 40~50, 50~100, 50~99, 50~95, 50~90, 50~80, 50~70, 50~60, 60~1 This can be achieved when a portion including 00, 60-99, 60-95, 60-90, 60-80, 60-70, 70-100, 70-99, 70-95, 70-90, 70-80, 80-100, 80-99, 80-95, 80-90, 90-100, 90-99, 90-95, 95-100, or 95-99% reaches the second temperature.

[0519] In some cases, a desired ammonia conversion efficiency (e.g., about 70% to about 99%) can be achieved when a portion comprising at least about 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 99% of the measurable surface of the catalyst, support material, or support monolith reaches the second temperature. In some cases, a desired ammonia conversion efficiency can be achieved when a portion comprising no more than about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, or 100% of the measurable surface of the catalyst, support material, or support monolith reaches the second temperature. In some cases, the desired ammonia conversion efficiency is about 1 to about 100, 1 to 99, 1 to 95, 1 to 90, 1 to 80, 1 to 70, 1 to 60, 1 to 50, 1 to 40, 1 to 30, 1 to 20, 1 to 10, 5 to 100, 5 to 99, 5 to 95, 5 to 90, 5 to 80, 5 to 70, 5 to 60, 5 to 80, 5 to 95, 5 to 10 ... 50, 5-40, 5-30, 5-20, 5-10, 10-100, 10-99, 10-95, 10-90, 10-80, 10-70, 10-60, 10-50, 10-40, 10-30, 10-20, 20-100, 20-99, 20-95, 20-90, 20-80, 20-70, 20-60, 20-50, 20-40, 20-30 , 30~100, 30~99, 30~95, 30~90, 30~80, 30~70, 30~60, 30~50, 30~40, 40~100, 40~99, 40~95, 40~90, 40~80, 40~70, 40~60, 40~50, 50~100, 50~99, 50~95, 50~90, 50~80, 50~70, 50~60, 60 This may be achieved when a portion including ∼100, 60 to 99, 60 to 95, 60 to 90, 60 to 80, 60 to 70, 70 to 100, 70 to 99, 70 to 95, 70 to 90, 70 to 80, 80 to 100, 80 to 99, 80 to 95, 80 to 90, 90 to 100, 90 to 99, 90 to 95, 95 to 100, or 95 to 99% reaches the second temperature.

[0520] In some embodiments, the ammonia conversion efficiency when at least a portion of the catalyst, support material, or support monolith reaches the second temperature may include at least about 50, 55, 60, 65, 70, 75, 80, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, 99.6, 99.7, 99.8, or 99.9%. In some embodiments, the ammonia conversion efficiency when at least a portion of the catalyst, support material, or support monolith reaches the second temperature can include less than or equal to about 55, 60, 65, 70, 75, 80, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, 99.6, 99.7, 99.8, 99.9, or 100%.

[0521] In some embodiments, the ammonia conversion efficiency when at least a portion of the catalyst, support material, or support monolith reaches the second temperature is about 50 to about 100, 50 to 99, 55 to 95, 50 to 90, 60 to 99, 60 to 100, 60 to 99.9, 60 to 95, 60 to 90, 65 to 100, 65 to 99.9, 65 to 99, 65 to 95, 65 to 90, 70 to 100, 70 to 99.9, 70 to 99, 70 to 98, 70 to 97, 70 to 96, 70 to 95, 70 to 94, 70 to 93, 70 to 92, 70 to 91, 70 to 90, 75 to 100, 50 to 99.9, 75 to 99, 75 to 98, 75 to 97 75~96, 75~95, 75~94, 75~93, 75~92, 75~91, 75~90, 80~100, 80~99.9, 80~99, 80~98, 80~97, 80~96, 80~95, 80~94, 80~93, 80~92, 80~91, 80~90, 85~100, 85~99.9, 85~99, 85~98, 85~97 85~96, 85~95, 85~94, 85~93, 85~92, 85~91, 85~90, 90~100, 90~99.9, 90~99.8, 90~99.7, 90~99.6, 90~99.5, 90~99, 90~98, 90~97 90~96, 90~95, 91~100, 91~99.9, 91~99.5, 91~99, 91~98, 91~97, 91~96, 91~95, 92~100, 92~99.9, 92~99.5, 92~99, 92~98, 92~97, 92~96, 92~95, 93~100, 93 95-100, 95-99.9, 95-99.8, 95-99.7, 95-99.6, 95-99.5, 95-99, or 95-98%.

[0522] In some cases, the time period during which the temperature of at least a portion of the electrically conductive catalyst, support material, or support monolith is increased from a first temperature to a second temperature may comprise at least about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, 45, 50, or 55 minutes. In some cases, the time for increasing the temperature of at least a portion of the electrically conductive catalyst, support material, or support monolith from a first temperature to a second temperature may comprise about 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, 45, 50, 55, or 60 minutes or less.

[0523] In some cases, the time for which the temperature of at least a portion of the conductive catalyst, support material, or support monolith is increased from a first temperature to a second temperature is about 0.1 to 60, 0.5 to 55, 1 to 50, 1 to 40, 1 to 30, 1 to 20, 1 to 10, 2 to 50, 2 to 40, 2 to 30, 2 to 20, 2 to 10, 3 to 50, 3 to 40, 3 to 30, 3 to 20, 3 to 10, 4 to 50, 4 to 40, 4 to 30, 4 to 20, 4 to 10, 5 to 50, 5 to 40, 5 to 30, 5 to 20, 5 to 10, 6 to 50, 6 to 40, 6 to 30, 6 to 20, 6 to 10, 7 to 50, 7 to 40, The time period may include 7 to 30, 7 to 20, 7 to 10, 8 to 50, 8 to 40, 8 to 30, 8 to 20, 8 to 10, 9 to 50, 9 to 40, 9 to 30, 9 to 20, 9 to 10, 10 to 50, 10 to 40, 10 to 30, 10 to 25, 1 to 20, 10 to 15, 15 to 50, 15 to 40, 15 to 30, 15 to 25, 15 to 20, 20 to 50, 20 to 45, 20 to 40, 20 to 35, 20 to 30, 20 to 25, 25 to 50, 25 to 45, 25 to 40, 25 to 35, 25 to 30, 30 to 60, 30 to 55, 30 to 50, 30 to 45, 30 to 40, or 30 to 35 minutes.

[0524] In some cases, the current is at least about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 225, 250, 275, 300, 400, 500, 600, 700, 800, 900, 1000 , 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, or 19000 cm, travelling between the electrodes and through the catalyst. In some cases, the current is about 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 225, 250, 275, 300, 400, 500, 600, 700, 800, 900, 1000, 1500, 200 The catalyst travels between the electrodes over a distance of 0, 2500, 3000, 3500, 4000, 4500, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, or 20000 cm or less.

[0525] In some cases, the current is from about 0.1 to about 20,000, 0.1 to 15,000, 0.1 to 10,000, 0.1 to 5,000, 0.5 to about 20,000, 0.5 to 15,000, 0.5 to 10,000, 0.5 to 5,000, 1 to about 20,000, 1 to 15,000, 1 to 10,000, 1 to 5,000, 1 to 4,000, 1 to 3,000, 1 to 2,000, 1 to 1,000, 2 to about 20,000, 2 to 15,000, 2 to 10,000 , 2-5000, 2-4000, 2-3000, 2-2000, 2-1000, 5-approx. 20000, 5-15000, 5-10000, 5-5000, 5-4000, 5-3000, 5-2000, 5-1000, 5-500, 10-approx. 20000, 10-15000, 10-10000, 10-5000, 10-4000, 10-3000, 10-2000, 10-1000, 10-500, 10 ~100, 15~15000, 15~10000, 15~5000, 15~4000, 15~3000, 15~2000, 15~1000, 15~500, 15~100, 20~10000, 20~5000, 20~4000, 20~3000, 20~2000, 20~1000, 20~500, 20~100, 30~10000, 30~5000, 30~4000, 30~3000, 30~200 It travels between the electrodes and through the catalyst over a distance of 0, 30-1000, 30-500, 30-100, 50-10000, 50-5000, 50-4000, 50-3000, 50-2000, 50-1000, 50-500, 50-100, 100-10000, 100-5000, 100-4000, 100-3000, 100-2000, 100-1000, or 100-500 cm.

[0526] In some embodiments, the conductive catalyst can be heated to a temperature of about 600-700°C by passing an electric current through the catalyst in about 10 minutes or less and can decompose NH to produce H and N with a conversion efficiency of at least about 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.9%. In some embodiments, the conductive catalyst can be heated to a temperature of about 550-650°C by passing an electric current through the catalyst in about 10 minutes or less and can decompose NH to produce H and N with a conversion efficiency of at least about 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.9%. In some embodiments, the conductive catalyst can be heated to a temperature of about 500-600°C by passing an electric current through the catalyst in about 10 minutes or less and can decompose NH3 to produce H2 and N2 with a conversion efficiency of at least about 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.9%. In some embodiments, the conductive catalyst can be heated to a temperature of about 450-550°C by passing an electric current through the catalyst in about 10 minutes or less and decompose NH3 to produce H2 and N2 with a conversion efficiency of at least about 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 99.9%.

[0527] Hybrid Heating System In some cases, improved catalysts can be hybrid heated within the reformer. Such hybrid heating can improve heat transfer while minimizing heat loss and increasing start-up time. Hybrid heating designs can also reduce the weight and volume of the reformer and improve the thermal management characteristics of the system while providing an improved heat source for ammonia conversion.

[0528] In some cases, the improved catalyst may be heated using one or more heat sources. In some cases, the one or more heat sources may include two or more heat sources or heating units. In some cases, the two or more heat sources may be the same or similar. In some cases, the two or more heat sources may be different. For example, a first heat source may be configured for Joule heating and a second heat source may be configured for combustion.

[0529] In some cases, the improved catalyst can be heated using multiple heating units. The multiple heating units can include a first heating unit configured to heat at least a first portion of the catalyst by burning hydrogen and a second heating unit configured to heat at least a second portion of the catalyst using electrical heating. As used herein, the term "electrical heating" generally refers to heating performed at least in part by passing electrons through a material (e.g., a conduit). The conduit can be a resistive load. In some examples, electrical heating can include Joule heating (i.e., heating according to Ohm's law). Joule heating, also known as resistive heating, resistance heating, or ohmic heating, can include passing an electric current through a material (e.g., an electrical resistor, a catalyst, a catalytic material, or a catalyst bed) to generate heat or thermal energy. In some cases, when the catalyst is heated using multiple heating units, hydrogen can be produced from a feed material including ammonia using the catalyst. In some cases, the first and second portions can be the same portion of the catalyst. In other cases, the first and second portions can be different portions of the catalyst. In some cases, the first portion and the second portion may overlap or partially overlap.

[0530] In some cases, the first heating unit of the reformer may be configured to heat the first portion of the catalyst based on combustion of hydrogen gas produced using the second reformer. In some cases, the first heating unit may be configured to heat the first portion of the catalyst based on combustion of (i) one or more fuel cells in fluid communication with the reformer, or (ii) unconsumed hydrogen gas from the second reformer. In some cases, the second heating unit may be configured to heat the second portion of the catalyst by passing an electric current through the second portion of the catalyst. In some cases, the first portion of the catalyst and the second portion of the catalyst may be contiguous (i.e., physically connected). In some cases, the first portion of the catalyst and the second portion of the catalyst may be separated by a third portion of the catalyst. The third portion of the catalyst may be located between the first and second portions of the catalyst. In some cases, the first and second portions of the catalyst may be in thermal communication with each other (e.g., either directly or indirectly via the third portion of the catalyst). In other cases, the first and second portions of the catalyst may not or need not be in thermal communication with each other.

[0531] In some cases, the heat load distribution between the first heating unit and the second heating unit may be adjustable to increase ammonia conversion efficiency and / or improve the thermal efficiency of the reformer. The heat load distribution may include a heating power ratio corresponding to the ratio between the heating power of the first heating unit and the heating power of the second heating unit. The heating power of the first heating unit and the second heating unit may be adjusted to achieve desired ammonia conversion efficiency and thermal efficiency. In some cases, the system may further include a controller or processor configured to control operation of the first heating unit and the second heating unit to adjust the heat load distribution within the reformer module. In some cases, such adjustment of the heat load distribution may be performed in real time based on one or more sensor measurements (e.g., temperature measurements) or based on reformer performance (e.g., ammonia conversion efficiency and / or reformer thermal efficiency). In some cases, one or more heating units having two or more heating zones may be used to control the power and heat distribution within one or more heating units. In some cases, the system may include multiple heating units. The multiple heating units may include at least two or more heating units. In some cases, the heat load distribution among the at least two or more heating units may be adjustable to increase ammonia conversion efficiency and improve thermal reforming efficiency of the reformer. In some cases, each of the at least two or more heating units may have one or more heating zones within the reformer, allowing for continuous heat distribution within one or more regions within the reformer. In some cases, the at least two or more heating units may be configured to heat different zones within the reformer. In some cases, the at least two or more heating units may be configured to heat one or more of the same zones within the reformer.

[0532] Catalyst and reformer system configuration In some embodiments, the catalyst is housed within a reformer unit. The reformer unit may be designed in a variety of shapes (typically cylindrical) but may have at least two sides (a first side and a second side) that are substantially or essentially opposite one another. For example, in some embodiments, the at least two sides are configured to allow an electric current to flow through the catalyst. In some embodiments, the reformer includes at least a pair of electrodes, including a first electrode and a second electrode. In some cases, the first electrode of the pair of electrodes may be positioned proximate to the first side of the reactor. In some cases, the second electrode of the pair of electrodes may be positioned proximate to the second side of the reactor. In some embodiments, the second electrode of the pair of electrodes may be positioned substantially opposite from the first side. For example, in some embodiments, the first and second electrodes of the pair of electrodes are configured to allow an electric current to flow through the catalyst. In some cases, the electrodes of the pair may be adjacent to one another and proximate to the sides of the reactor. In some embodiments, a voltage may be applied between or across the electrodes to effect a temperature change of the catalyst. In some embodiments, the voltage between or across the electrodes may be reduced or removed based on or based on the catalyst reaching a second temperature. In some cases, the controller may stop applying the voltage between or across the electrodes based on the catalyst reaching the second temperature. In some embodiments, the voltage is provided from at least one of a battery, a fuel cell, a solar panel, a wind turbine, a capacitor, a transformer, or an electrical distribution grid or meshwork.

[0533] In some cases, the reformer may be heated by combustion. In some cases, the reformer may be electrically heated separately from the catalyst. In some cases, the reformer may be electrically heated in addition to the catalyst. In some cases, the reformer may include a second catalyst. In some cases, the second catalyst may have the same composition and / or shape factor as the (first) catalyst. In some cases, the second catalyst may have a different composition and / or shape factor than the (first) catalyst. In some cases, the second catalyst is in at least one of physical, thermal, electrical, or fluid contact with the (first) catalyst. In some cases, the second catalyst is not in physical, thermal, electrical, or fluid contact with the (first) catalyst. In some cases, the second catalyst may be at least partially mixed with the (first) catalyst. In some embodiments, the reformer includes at least two zones, where the first zone includes the (first) catalyst and the second zone includes the second catalyst.

[0534] Computer Systems The present invention provides computer systems (e.g., controllers, computing devices, and / or computers) programmed to implement the methods of the present invention. Figure 7 shows a computer system 701 programmed or configured to control the systems disclosed herein. The computer system 701 can control various aspects of the systems disclosed in this disclosure. The computer system 701 can be a user's electronic device or a computer system located remotely relative to the electronic device. The electronic device can be a mobile electronic device.

[0535] The computer system 701 may include a central processing unit (CPU, herein "processor" and "computer processor") 702, which may be a single-core or multi-core processor, or multiple processors for parallel processing. The computer system 701 may also include memory or memory locations 703 (e.g., random access memory, read-only memory, flash memory), an electronic storage unit 704 (e.g., hard disk), a communication interface 705 (e.g., network adapter) for communicating with one or more other systems, and peripheral devices 706, such as cache, other memory, data storage, and / or an electronic display adapter. The memory 703, storage unit 704, interface 705, and peripheral devices 706 communicate with the CPU 702 via a communication bus (solid lines), e.g., a motherboard. The storage unit 704 may be a data storage unit (or data repository) for storing data. The computer system 701 may be operatively coupled to a computer network ("network") 707 with the aid of the communication interface 705. Network 707 may be the Internet, an Internet and / or extranet, or an intranet and / or extranet in communication with the Internet. Network 707, in some cases, is a telecommunications network and / or a data network. Network 707 may include one or more computer servers, thereby enabling distributed computing, such as cloud computing. Network 707, in some cases, may implement a peer-to-peer network with the help of computer system 701, thereby allowing devices associated with computer system 701 to act as clients or servers.

[0536] The CPU 702 may execute a series of machine-readable instructions, which may be embodied in a program or software. The instructions may be stored in a memory location, such as the memory 703. The instructions may be directed to the CPU 702, which may then be programmed or configured to perform the methods of the present disclosure. Examples of operations performed by the CPU 702 may include fetch, decode, execute, and write-back.

[0537] The CPU 702 may be part of a circuit, for example, an integrated circuit. One or more other components of the system 701 may be included in the circuit. In some cases, the circuit is an application specific integrated circuit (ASIC).

[0538] The storage unit 704 can store files, such as drivers, libraries, and saved programs. The storage unit 704 can store user data, such as user settings and user programs. The computer system 701 may, in some cases, include one or more additional data storage units located external to the computer system 701, for example, on a remote server that communicates with the computer system 701 via an intranet or the Internet.

[0539] Computer system 701 can communicate with one or more remote computer systems via network 707. For example, computer system 701 can communicate with a user's remote computer system. Examples of remote computer systems include a personal computer (e.g., a portable PC), a slate or tablet PC (e.g., an Apple® iPad®, a Samsung® Galaxy Tab), a telephone, a smartphone (e.g., an Apple® iPhone®, an Android®-enabled device, a Blackberry®), or a personal digital assistant. A user can access computer system 701 via network 707.

[0540] The methods described in this disclosure may be performed by machine (e.g., computer processor) executable code stored in electronic storage locations of the computer system 701, such as memory 703 or electronic storage unit 704. The machine-executable or machine-readable code may be provided in the form of software. During use, the code may be executed by the processor 702. In some cases, the code may be retrieved from the storage unit 704 and stored in memory 703 for rapid access by the processor 702. In some situations, the electronic storage unit 704 may be omitted, and the machine-executable instructions are stored in memory 703.

[0541] The code may be pre-compiled and configured for use on a machine having a processor adapted to execute the code, or may be compiled on the fly. The code may be provided in a programming language that can be selected so that the code can be executed in pre-compiled or compiled form.

[0542] Aspects of the systems and methods provided herein, such as computer system 701, may be embodied in programming. Various aspects of the technology may be thought of as a "product" or "article of manufacture," typically in the form of machine (or processor) executable code and / or associated data carried on or embodied in a type of machine-readable medium. The machine-executable code may be stored on an electronic storage unit, such as memory (e.g., read-only memory, random-access memory, flash memory) or a hard disk. "Storage" type media may include any or all of the tangible memory of a computer, processor, etc., or their associated modules, such as various semiconductor memories, tape drives, disk drives, etc., which may provide non-transitory storage for software programming at any time. All or portions of the software may sometimes be communicated via the Internet or various other communications networks. Such communication may, for example, enable loading of the software from one computer or processor to another, such as from a management server or host computer to an application server computer platform. Thus, another type of medium that may carry software elements includes optical, electrical, and electromagnetic waves used across physical interfaces between local devices, via wired and optical landline networks, and over various air links. The physical elements that transmit such waves, e.g., wired or wireless links, optical links, etc., may also be considered software-bearing media. As used herein, unless limited to non-transitory, tangible "storage" media, the term, e.g., computer or machine "readable medium," refers to any medium that participates in providing instructions to a processor for execution.

[0543] Thus, machine-readable media, e.g., computer-executable code, may take many forms, including, but not limited to, tangible storage media, carrier wave media, or physical transmission media. Non-volatile storage media include, for example, optical or magnetic disks, any storage device, such as any computer, that may be used to implement, for example, the databases shown in the figures, etc. Volatile storage media include dynamic memory, such as the main memory of such a computer platform. Tangible transmission media include coaxial cables, copper wire, and fiber optics, including wiring that comprises a bus within a computer system. Carrier-wave transmission media may take the form of electric or electromagnetic signals, or acoustic or light waves, such as those generated during radio frequency (RF) and infrared (IR) communications. Thus, common forms of computer-readable media include, for example, a floppy disk, a flexible disk, a hard disk, magnetic tape, any other magnetic medium, a CD-ROM, a DVD or DVD-ROM, any other optical medium, punched card paper tape, any other physical storage medium with a pattern of holes, RAM, ROM, PROM and EPROM, FLASH-EPROM, any other memory chip or cartridge, a carrier wave transmitting data or instructions, a cable or link transmitting such a carrier wave, or any other medium from which a computer can read programming code and / or data. Many of these forms of computer-readable media may be involved in transmitting one or more sequences of one or more instructions to a processor for execution.

[0544] The computer system 701 may include or be in communication with an electronic display 708 that has a user interface (UI) 709 for providing. Examples of UIs include, but are not limited to, graphical user interfaces (GUIs) and web-based user interfaces.

[0545] The methods and systems of the present disclosure may be implemented by one or more algorithms, which may be implemented by software when executed by the central processing unit 702.

[0546] Catalyst manufacturing method In another aspect, the present disclosure provides catalysts for treating ammonia to produce hydrogen, and methods for manufacturing one or more catalysts. The methods may include subjecting the catalyst support to one or more physical or chemical processes to modify one or more pores of the catalyst support. In some cases, the one or more physical or chemical processes for modifying one or more pores of the catalyst support may include thermal treatment (i.e., controlled heating) of the catalyst support. In some cases, modifying the one or more pores may include adjusting one or more pore sizes, pore densities, and / or pore volumes of the catalyst support. In some cases, the methods may further include thermally or chemically treating the surface of the catalyst support material to modify one or more pores and / or one or more surface morphologies. In some cases, thermal treatment of the support material or chemical treatment of the support material may be carried out in an inert atmosphere (e.g., containing N or Ar), a non-reducing atmosphere (e.g., containing air, N, or O), a non-oxidizing atmosphere (e.g., containing N, Ar, CO, CO), or a reactive nitrogen-rich atmosphere (e.g., containing NH, H-N, or forming gas). In some embodiments, the catalyst support comprises a bead, pellet, powder, thin film, monolith, foam, reactor wall, heating element, wire, mesh, corrugated or textured sheet, or porous solid material form factor. In some cases, the catalyst is not a powder, e.g., a majority (e.g., 90% or more) of the catalyst may have a characteristic dimension or aspect (e.g., diameter or length) greater than 0.1 mm. In some embodiments, the catalyst is not a powder, e.g., a majority (e.g., 90% or more) of the catalyst may have a characteristic dimension or aspect greater than 1 mm.

[0547] In some embodiments, the method further includes (c) depositing a composite support material on a catalyst support, the composite support material including a morphology; and (c) depositing one or more active metals on at least one of the composite support material and the catalyst support, the one or more active metals including one or more nanoparticles configured to conform to the morphology of the composite support material, thereby modifying one or more active sites on the nanoparticles for ammonia treatment. In some cases, the composite support material may be deposited using chemical vapor deposition. In some embodiments, the composite support material may be deposited using a wet impregnation method. In some cases, the one or more active metals may be deposited using chemical vapor deposition. In some embodiments, the one or more active metals may be deposited using a wet impregnation method. The active metal may include one or more nanoparticles including one or more active sites to which one or more ammonia molecules can attach. The one or more ammonia molecules may be configured to bind to or attach to one or more active sites of the one or more active metal nanoparticles. The location, orientation, and / or density of the one or more active sites can be determined at least in part based on the morphology and / or surface chemistry or properties of the composite support material. In some embodiments, morphology can include grain structure, grain size, or grain shape.

[0548] In some cases, the catalyst support may include at least one of, for example, Al2O3, alumina, MgO, magnesia, CeO2, ceria, SiO2, silica, SiC, carborundum, Y2O3, yttria, TiO2, titania, ZrO2, or zirconia. x O y , Mg x O y , Ce x O y , Si x O y , Y x O y , Ti x O y , or Zr x O yIn some cases, the one or more active metals may include at least one of, for example, ruthenium (Ru), nickel (Ni), rhodium (Rh), iridium (Ir), cobalt (Co), molybdenum (Mo), iron (Fe), platinum (Pt), chromium (Cr), palladium (Pd), manganese (Mn), tungsten (W), vanadium (V), zinc (Zn), or copper (Cu). In some cases, the composite support may include a carbon-based material, a boron-based material, or a metal oxide. The carbon-based material may include, for example, activated carbon (AC), one or more carbon nanotubes (CNTs), one or more carbon nanofibers (CNFs), graphene oxide (GO), graphite, or reduced graphene oxide (rGO). The boron-based material may include, for example, hexagonal boron nitride (hBN), boron nitride nanotubes (BNNTs), hexagonal boron carbon nitride (hBCN), boron nitride carbon nanotubes (BCNNTs), boron nitride nanosheets (BNNSs), or boron nitride carbon nanosheets (BCNNS). The metal oxide may include, for example, TiO, titania, MgO, magnesia, magnesium aluminate (MgAlO), spinel, LaO, lanthana, CeO, ceria, YO, yttria, one or more CeO nanotubes, nanorods, or nanocubes, mesoporous silica (e.g., KIT-6), ZrO, zirconia, chromium oxide (CrO), or chromia. The metal oxide may include, for example, zinc aluminate (ZnAlO), gahnite, ferrous aluminate (FeAlO), hercynite, manganese aluminate (MnAlO), galaxite, magnesium ferrous aluminate ((MgFe)AlO), or pleonaste. The metal oxide may include, for example, lime, quicklime, calcium oxide (CaO), calcium hydroxide (Ca(OH)), slaked lime, calcium carbonate (CaCO), calcite, barium oxide (BaO), baria, barium carbonate (BaCO), strontium oxide (SrO), strontia, ferrous oxide (FeO), zinc oxide (ZnO), or manganese oxide (MnO). The metal oxide may include, for example, Ti x O y , Mg x Oy , La x O y , Ce x O y , Y x O y , Ce x O y , Zr x O y , Cr x O y , or Ca x O y In some cases, the composite support may include YSZ, hydrotalcite (MgAl-LDO), MOF (MIL-101, ZIF), alkali amide (NaNH, Ca(NH), Mg(NH), inorganic electride (CAl:e), halloysite nanotubes (HNT), ABO perovskite, ABO spinel, or MCM-41.

[0549] In some embodiments, the method may further include thermally activating the one or more active metals. Thermally activating the one or more active metals may induce the growth of one or more nanoparticles of the active metals. In some cases, the one or more nanoparticles may be configured to grow while conforming to the morphology of the composite support material. In some cases, the method may further include promoting the catalyst, the active metal nanoparticles, and / or the composite support material of the catalyst with one or more promoters. The one or more promoters may include, for example, sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba).

[0550] In some aspects, the present disclosure provides a method for producing a catalyst. In some cases, the method includes heating a support to a target temperature. In some cases, the method includes depositing one or more promoter precursors on the support to produce the catalyst. In some cases, the catalyst is configured to decompose ammonia to produce hydrogen. In some cases, the catalyst is configured to decompose ammonia to produce hydrogen and nitrogen.

[0551] In some cases, the one or more active metal precursors include a Ru precursor, a Ni precursor, a Rh precursor, an Ir precursor, a Co precursor, a Fe precursor, a Pt precursor, a Cr precursor, a Mo precursor, a Pd precursor, or a Cu precursor. In some cases, the ruthenium precursor includes ruthenium iodide, ruthenium acetylacetonate, ruthenium chloride hydrate, ruthenium oxide hydrate, ruthenium chloride, bis(cyclopentadienyl)ruthenium, ruthenium nitrosyl nitrate, ruthenium iodide hydrate, triruthenium dodecacarbonyl, or any combination thereof.

[0552] In some cases, the catalyst comprises about 0.2% to about 20% by weight of ruthenium. In some cases, the catalyst comprises about 0.5% to about 5% by weight of ruthenium. In some cases, the catalyst comprises at least about 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20% by weight of ruthenium. In some cases, the catalyst comprises less than or equal to about 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 wt. % ruthenium.

[0553] In some cases, the treating further comprises (iii) treating the promoter or promoter precursor to produce or obtain a target molar ratio of dopant to support surface modifier in the support. In some cases, the promoter precursor comprises an alkali metal precursor. In some cases, the alkali metal of the alkali metal precursor comprises Li, Na, K, Rb, or Cs. In some cases, the catalyst is substantially free of alkali metals. In some cases, the catalyst is substantially free of promoters. In some cases, the catalyst is substantially free of rare earth metals. In some cases, the catalyst is substantially free of support surface modifiers.

[0554] In some cases, the promoter precursor comprises potassium or cesium as a soluble salt or complex, such as the metal: methylate, tetrafluoroborate, hydrogen fluoride, thiocyanate, disulfite, bisulfate, sulfide, methoxide, trifluoroacetate, dioxide, persulfate, formate, bicarbonate, sorbate, hydroxide, borohydride, dichloroacetate, iodate, chlorate, fluoride, chloride, nitrate, perchlorate, cyanate, or hexachloroiridate. In some cases, the promoter precursor is processed in an aqueous solution. In some cases, the promoter precursor is processed in an organic solution.

[0555] In some cases, the method includes drying the support in a vacuum. In some cases, the method includes heating the support to a first target temperature. In some cases, the method includes reducing one or more promoter precursors, support surface modifier, support, and / or mixed oxide on the support under hydrogen at a second target temperature. In some cases, the method includes drying the impregnated support in a vacuum before depositing one or more promoter or dopant precursors. In some cases, drying the impregnated support includes vacuum drying. In some cases, the vacuum includes a pressure less than 1 bar. In some cases, the vacuum may include a pressure less than about 1, 0.1, 0.01, 0.001, 0.0001, or 0.00001 bar. In some cases, the heating includes using an inert gas. In some cases, the heating includes using air. In some cases, the inert gas may include He, Ne, Ar, Kr, Xe, or N2.

[0556] In some cases, the promoter can be configured to modify the basicity of the composite oxide support. In some cases, the promoter can be configured to increase the electron density of the active metal to promote the elimination of recombined nitrogen and / or the cleavage of N-H bonds during the ammonia decomposition reaction.

[0557] In some cases, the catalyst may include a nanorod support. In some cases, nanorods include rods of material having a thickness or diameter of only a few nanometers. In some cases, the nanorod support may be produced using hydrothermal synthesis. In some cases, the process conditions of the hydrothermal synthesis may be adjusted to control the morphology of the support. For example, the morphology of the support may include nanorod diameter, nanorod length, polydispersity, aggregation, or any combination thereof. In some cases, the support may be produced using hydrothermal synthesis to co-precipitate an oxide with a promoter. In some cases, the support surface modifier and promoter may be co-precipitated. In some cases, co-impregnation of the promoter and oxide (e.g., KOH and Ce(NO3)3) may be performed under high pH reaction conditions.

[0558] In some cases, X-ray photoelectron spectroscopy (XPS) may be used to determine electron density by measuring the electron binding energy of the electronic state. In some cases, XPS may be used to analyze the electronic state by measuring the electron binding energy in the surface region. Note that a higher binding energy may indicate a greater difficulty in removing the electron. In some cases, a higher binding energy may indicate a more electropositive environment.

[0559] In some aspects, the present disclosure provides methods for producing a catalyst. In some cases, the methods include providing a support comprising alumina. In some cases, the methods include depositing a ruthenium-containing precursor and a phosphorus-containing precursor on the support. In some cases, the methods include treating the support by annealing the support under N2 at a first target temperature. In some cases, the methods include treating the support by reducing the support under H2 at a second target temperature to obtain the catalyst.

[0560] Selection of catalyst precursor In some cases, the ammonia decomposition reaction can be driven using a catalyst. The catalyst can include at least one active metal (e.g., Co, Mo, Fe, Ni, Zn, Cu, Ru) nanoparticle catalyst. The active metal nanoparticle catalyst can include one or more active metal nanoparticles. The active metal nanoparticle catalyst can be utilized to promote the ammonia decomposition reaction as described elsewhere herein and can be prepared by loading a given precursor onto a support (e.g., a support comprising alumina, zirconia, silica, silicon carbide, or carbon) or a modified support (e.g., a composite support, modified support, or doped support comprising alumina, zirconia, silica, silicon carbide, or carbon) and carrying out reduction at high temperature.

[0561] In some cases, the support comprises an amorphous, monoclinic, tetragonal, cubic, hexagonal, cubic, spinel, or perovskite phase. In some cases, the modified support comprises an amorphous, monoclinic, tetragonal, cubic, hexagonal, cubic, spinel, or perovskite phase. In some embodiments, a metal salt or metal salt hydrate, such as MNO, may first be deposited on the surface of an alumina support and then calcined at high temperature to produce an M-Al oxide support. As used herein, M may refer to any alkaline earth or spinel-forming metal. In some cases, the M-Al oxide may form an alumina support perovskite phase, MAlO / AlO. In some cases, the M-Al oxide may form an alumina support spinel phase, MAlO / AlO. In some cases, two or more metal salts or metal salt hydrates may be added to produce a mixed M-M-Al oxide support. An active metal (e.g., ruthenium) precursor can be deposited on the support, and the support and / or active metal precursor can be reduced at elevated temperatures (e.g., temperatures ranging from about 300°C to about 1300°C) to produce an improved nanoparticle catalyst. In some cases, a promoter can be added to the catalyst in the form of an electron donor (e.g., Cs or K), which can further improve ammonia conversion efficiency.

[0562] In some cases, the ruthenium nanoparticle catalysts of the present disclosure are, for example, Ru(NO)(NO), RuCl, and Ru(CO). 12 It can be synthesized using a variety of ruthenium precursors, including Ru(NO3)3, Ru(acac)3 (ruthenium acetylacetonate), Ru(NH3)6Cl3 (ruthenium hexaamine chloride), (CHD)Ru(CO)3 (cyclohexadiene ruthenium tricarbonyl), (BD)Ru(CO)3 (butadiene ruthenium tricarbonyl), or (DMBD)Ru(CO)3 (dimethylbutadiene ruthenium tricarbonyl).

[0563] Support precursor In some cases, the support comprises an amorphous, monoclinic, tetragonal, hexagonal, or perovskite phase. In some cases, the modified support comprises an amorphous, monoclinic, tetragonal, hexagonal, or perovskite phase. In some embodiments, a metal salt or metal salt hydrate, such as MNO, can first be deposited on the surface of the support and then calcined at high temperature to produce a mixed MX-oxide support (X can include, for example, Al, Zr, Si, or C). As used herein, M can refer to any type of metal. In some cases, the mixed MX-oxide can form an alumina-supported perovskite phase, MAlO / AlO. In some cases, the M-Al oxide may not form a perovskite phase. In some cases, the mixed MX-oxide comprises an amorphous, monoclinic, or tetragonal network structure of (Zr:X)O. In some cases, two or more metal salts or metal salt hydrates may be added to produce a mixed M1-M2-Al oxide support. Active metal (e.g., Ru, Co, Mo, Fe, Ni, Zn, Cu) precursors may be deposited onto this support, and the support and / or active metal precursors may be reduced (e.g., in an H2-containing atmosphere) at elevated temperatures (e.g., from about 300°C to about 1300°C, or from about 500°C to about 1300°C) to produce an improved nanoparticle catalyst. In some cases, a promoter may be added to the catalyst in the form of an electron donor (e.g., Cs or K), which can further improve ammonia conversion efficiency.

[0564] Catalyst support shape factor In some cases, the catalysts of the present disclosure may be synthesized using various alumina, zirconia, silicon, or carbon supports. The supports may be in the form of beads or cylindrical pellets, or a combination of both. In some cases, the supports may comprise any type of porous solid material. In other cases, the supports may comprise beads, pellets, powders, monoliths, foams, or any combination thereof. In some cases, smaller particle sizes may result in more active catalysts. In some cases, smaller particle sizes may result in increased pressure drop across the reformer. In some cases, the beads or pellets may have a diameter of at least about 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, or 9.5 millimeters (mm). In some cases, the beads or pellets may have a diameter of up to about 0.5, 1, 1.5, 2.0, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 mm. In some cases, the beads or pellets may have a diameter of up to about 50 mm. 2 / g~about 500m 2 In some cases, the beads or pellets may have a surface area per unit mass in the range of at least about 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, or 1150 m 2 In some cases, the beads or pellets may have a surface area per unit mass of at most about 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, or 1200 m 2The catalyst may have a surface area per unit mass of 1.5 mm / g. Examples of the effect of support shape factors on the hydrogen production performance of Ru-alumina catalysts are described herein. Over a temperature range of about 400°C to about 500°C, the catalyst based on 1.0 mm beads showed superior performance. At temperatures above about 500°C, the difference between the catalyst using 1.0 mm beads and the catalyst using 1.5 mm beads appears to be less significant. The catalyst based on 3.2 mm pellets shows lower performance than the other two catalysts over a temperature range of about 400°C to about 575°C. Referring to Figure 8, Ru-alumina catalysts can be prepared using the same composition according to the same method and materials (described herein). The catalyst was prepared using gamma-alumina ( [ka] -alumina). The catalyst may have a form factor of 1.0 mm beads, 801, 1.5 mm beads, 802, or 3.2 mm pellets, 803.

[0565] Mixed Metal Oxide Composite Support In some cases, alumina supports can be modified at an early stage by incorporating Group 2 alkaline earth metals and / or spinel-forming metals (M) via high temperature treatment to produce an M-Al mixed metal alloy, mixed metal oxide, or mixed metal nitride layer adjacent to the support material, forming an M-Al mixed metal composite support that can function as an improved catalyst support. In some cases, alumina can be modified as alpha-alumina (α-alumina), gamma-alumina ( [ka] In some cases, the composite support may include at least one of an alkaline earth metal and / or spinel-forming metal oxide (MO) layer adjacent to the alumina. In some cases, the composite support may include an alkaline earth metal or spinel-forming metal aluminate (MAlO) spinel structure or layer adjacent to the alumina. In some cases, the composite support may include an alkaline earth metal and / or spinel-forming metal oxide (MO) layer adjacent to a MAlO spinel structure or layer adjacent to the alumina. In some cases, the composite support may include MO particles adjacent to a MAlO spinel structure or layer adjacent to the alumina. In some cases, the MO particles comprise MO nanoparticles. In some cases, the composite support may include discrete particles, regions, or zones of MO adjacent to a MAlO spinel structure or layer adjacent to the alumina. In some cases, separate regions or zones of MO adjacent to the MAlO spinel structure or layer can be produced by overloading an alumina support with MO or its precursor. In some cases, separate regions or zones of MO adjacent to the MAlO spinel structure or layer can be produced by leaching or etching a layer of MAlO using an aqueous acid or alkaline solution to remove Al. In some cases, separate regions or zones of MO adjacent to the MAlO spinel structure or layer can be produced by leaching or etching a layer of MAlO using an aqueous or alkaline solution and a resist layer, template, or framework to selectively remove Al. In some cases, separate regions or zones of MO adjacent to the MAlO spinel structure or layer can be produced by forming a layer of MO using a designed template or framework adjacent to the layer of MAlO. In some embodiments, the alkaline earth metal can be Mg, Ca, Sr, or Ba. In some embodiments, the spinel-forming metal can be at least one of Mg, Ca, Sr, Ba, Fe, Mn, or Zn.

[0566] In some embodiments, the concentration of alkaline earth metal and / or spinel-forming metal in the composite support is at least about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, In some embodiments, the concentration of alkaline earth metal and / or spinel-forming metal in the composite support may comprise about 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, or 89 mol %. , 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, or 90 mol% or less.

[0567] In some embodiments, the concentration of alkaline earth metal and / or spinel-forming metal in the composite support is at least about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 , 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, or 89% by weight. In some embodiments, the concentration of alkaline earth metal and / or spinel-forming metal in the composite support is about 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 ,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89, or 90% by weight or less.

[0568] Amounts of composite support metal species relative to each other In some embodiments, the composite carrier has a solubility of at least about 9.9:1, 9.8:1, 9.7:1, 9.6:1, 9.5:1, 9.4:1, 9.3:1, 9.2:1, 9.1:1, 9:1, 8.9:1, 8.8:1, 8.7:1, 8.6:1, 8.5:1, 8.4:1, 8.3:1, 8.2:1, 8.1:1, 8:1, 7.9:1, 7.8:1, 7.7:1, 7.6:1, 7.5:1, 7.4:1, 7.3:1 :1, 7.2:1, 7.1:1, 7:1, 6.9:1, 6.8:1, 6.7:1, 6.6:1, 6.5:1, 6.4:1, 6.3:1, 6.2:1, 6.1:1, 6:1, 5.9:1, 5.8:1, 5.7:1, 5.6:1, 5.5:1, 5.4:1, 5.3:1, 5.2:1, 5.1:1, 5:1, 4.9:1, 4.8:1, 4.7:1, 4.6:1, 4.5:1, 4.4:1, 4.3:1, 4.2 :1,4.1:1,4:1,3.9:1,3.8:1,3.7:1,3.6:1,3.5:1,3.4:1,3.3:1,3.2:1,3.1:1,3:1,2.9:1,2.8:1,2.7:1,2.6:1,2.5:1,2.4:1,2.3:1,2.2:1,2.1:1,2:1,1.9:1,1.8:1,1.7:1,1.6:1,1.5:1,1.4:1,1.3:1,1.2:1,1. The molar ratio of alkaline earth metal and / or spinel-forming metal to aluminum may be 1:1, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, or 1:9.

[0569] In some embodiments, the composite carrier is about 10:1, 9.9:1, 9.8:1, 9.7:1, 9.6:1, 9.5:1, 9.4:1, 9.3:1, 9.2:1, 9.1:1, 9:1, 8.9:1, 8.8:1, 8.7:1, 8.6:1, 8.5:1, 8.4:1, 8.3:1, 8.2:1, 8.1:1, 8:1, 7.9:1, 7.8:1, 7.7:1, 7.6:1, 7.5:1, 7.4:1, 7.3:1 :1,7.2:1,7.1:1,7:1,6.9:1,6.8:1,6.7:1,6.6:1,6.5:1,6.4:1,6.3:1,6.2:1,6.1:1,6:1,5.9:1,5.8:1,5.7:1,5.6:1,5.5:1,5.4:1,5.3:1,5.2:1,5.1:1,5:1,4.9:1,4.8:1,4.7:1,4.6:1,4.5:1,4.4:1,4.3:1,4. 2:1, 4.1:1, 4:1, 3.9:1, 3.8:1, 3.7:1, 3.6:1, 3.5:1, 3.4:1, 3.3:1, 3.2:1, 3.1:1, 3:1, 2.9:1, 2.8:1, 2.7:1, 2.6:1, 2.5:1, 2.4:1, 2.3:1, 2.2:1, 2.1:1, 2:1, 1.9:1, 1.8:1, 1.7:1, 1.6:1, 1.5:1, 1.4:1, 1.3:1, 1.2:1, 1 The molar ratio of alkaline earth metal and / or spinel-forming metal to aluminum may be 1:1, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, or 1:8.5 or less.

[0570] In some embodiments, the composite carrier is at least about 98:2, 97:3, 96:4, 95:5, 94:6, 93:7, 92:8, 91:9, 90:10, 89:11, 88:12, 87:13, 86:14, 85:15, 84:16, 83:17, 82:18, 81:19, 80:20, 79:21, 78:22, 77:23, 76:24, 75:25, 74:26,73:27,72:28,71:29,70:30,69:31,68:32,67:33,66:341,65:35,64:36,63:37,62:38,61:39,60:40,59:41,58:42,57:43,56:44,55:45,54:46,53:47,52:48,51:49,50:50,49:51,48: 52, 47:53, 46:54, 45:55, 44:56, 43:57, 42:58, 41:59, 40:60, 39:61, 38:62, 37:63, 36:64, 35:65, 34:66, 33:67, 32:68, 31:69, 30:70, 29:71, 28:72, 27:73, 26:74, 25:75, 24:76, 23:77, 22:78, 2 The mass ratio of alkaline earth metal and / or spinel-forming metal to aluminum may be 1:79, 20:80, 19:81, 18:82, 17:83, 16:84, 15:85, 14:86, 13:87, 12:88, 11:89, 10:90, 9:91, 8:92, 7:93, 6:94, 5:95, 4:96, 3:97, 2:98, or 1:99.

[0571] In some embodiments, the composite carrier is about 99:1, 98:2, 97:3, 96:4, 95:5, 94:6, 93:7, 92:8, 91:9, 90:10, 89:11, 88:12, 87:13, 86:14, 85:15, 84:16, 83:17, 82:18, 81:19, 80:20, 79:21, 78:22, 77:23, 76:24, 75:25 ,74:26,73:27,72:28,71:29,70:30,69:31,68:32,67:33,66:341,65:35,64:36,63:37,62:38,61:39,60:40,59:41,58:42,57:43,56:44,55:45,54:46,53:47,52:48,51:49,50:50,49:51,4 8:52, 47:53, 46:54, 45:55, 44:56, 43:57, 42:58, 41:59, 40:60, 39:61, 38:62, 37:63, 36:64, 35:65, 34:66, 33:67, 32:68, 31:69, 30:70, 29:71, 28:72, 27:73, 26:74, 25:75, 24:76, 23:77, 22:7 The mass ratio of alkaline earth metal and / or spinel-forming metal to aluminum may be less than or equal to 8, 21:79, 20:80, 19:81, 18:82, 17:83, 16:84, 15:85, 14:86, 13:87, 12:88, 11:89, 10:90, 9:91, 8:92, 7:93, 6:94, 5:95, 4:96, 3:97, or 2:98.

[0572] In some embodiments, the composite carrier has a solubility of at least about 9.5:1, 9:1, 8.5:1, 8:1, 7.5:1, 7:1, 6.5:1, 6:1, 5.5:1, 5:1, 4.5:1, 4:1, 3.5:1, 3:1, 2.5:1, 2:1, 1.5:1, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1: The molar ratio of alkaline earth metal and / or spinel-forming metal in the free oxide (i.e., MO) to alkaline earth metal and / or spinel-forming metal in the metal aluminate (i.e., MAl2O4) may be 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:10, 1:20:, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, or 1:100. In some embodiments, the composite carrier is about 10:1, 9.5:1, 9:1, 8.5:1, 8:1, 7.5:1, 7:1, 6.5:1, 6:1, 5.5:1, 5:1, 4.5:1, 4:1, 3.5:1, 3:1, 2.5:1, 2:1, 1.5:1, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16.5, 1:17, 1:18, 1:19, 1:10.5, 1:11.5, 1:12.5, 1:13, 1:14.5, 1:15, 1:16.5, 1:17.5, 1:18.5, 1:19 ... The alkaline earth metal and / or spinel-forming metal may comprise a molar ratio of alkaline earth metal and / or spinel-forming metal in the free metal oxide (i.e., MO) to alkaline earth metal and / or spinel-forming metal in the metal aluminate (i.e., MAl2O4) of 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:10, 1:20:, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, or 1:90 or less. In some embodiments, the alkaline earth metal and / or spinel-forming metal aluminate (i.e., MAl2O4) may comprise essentially all of the alkaline earth metal and / or spinel-forming metal, and any free alkaline earth metal and / or spinel-forming metal oxide (i.e., MO) may be at such low concentrations that it is undetectable.In some embodiments, the composite carrier has a solubility of at least about 9.5:1, 9:1, 8.5:1, 8:1, 7.5:1, 7:1, 6.5:1, 6:1, 5.5:1, 5:1, 4.5:1, 4:1, 3.5:1, 3:1, 2.5:1, 2:1, 1.5:1, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7 The mass ratio of alkaline earth metal and / or spinel-forming metal in the free metal oxide (i.e., MO) to alkaline earth metal and / or spinel-forming metal in the metal aluminate (i.e., MAl2O4) may be 1:7.5, 1:8, 1:8.5, 1:9, 1:10, 1:20:, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, or 1:100. In some embodiments, the composite carrier is about 10:1, 9.5:1, 9:1, 8.5:1, 8:1, 7.5:1, 7:1, 6.5:1, 6:1, 5.5:1, 5:1, 4.5:1, 4:1, 3.5:1, 3:1, 2.5:1, 2:1, 1.5:1, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16.5, 1:17, 1:18, 1:19, 1:10.5, 1:11.5, 1:12.5, 1:13, 1:14.5, 1:15, 1:16.5, 1:17.5, 1:18.5, 1:19 ... The mass ratio of alkaline earth metal and / or spinel-forming metal in the free metal oxide (i.e., MO) to alkaline earth metal and / or spinel-forming metal in the metal aluminate (i.e., MAl2O4) may be 1:7, 1:7.5, 1:8, 1:8.5, 1:9, 1:10, 1:20:, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, or 1:90 or less.

[0573] Figure 10 shows the effect of various concentrations of alkaline earth metals and / or spinel-forming metals on ammonia conversion efficiency for Ru catalysts prepared using mixed-metal (M-Al) oxide composite supports based on gamma-alumina support materials. The results again demonstrate that there may be a concentration range of alkaline earth metals and / or spinel-forming metals that is most effective in improving ammonia conversion efficiency. Interestingly, the inclusion of small amounts of metal (M) resulted in a significant increase in ammonia conversion efficiency between about 400 and about 550 °C. As the M concentration increased, there was no improvement in conversion efficiency until a threshold was reached. Above this threshold, conversion efficiency decreased to a level similar to that of lower M concentrations. Catalysts with molar concentrations of M between about 5 and about 30% were most effective below 550 °C.

[0574] With reference to Figure 10, catalysts can be prepared using alkaline earth metal and / or spinel-forming metal-Al mixed metal oxide composite supports using the same shape factors and materials described elsewhere herein. In these cases, the alkaline earth metal and / or spinel-forming metal (Ba) can be represented by M, as described herein. For comparison, catalysts were prepared using the same support material (gamma-alumina) and shape factors, but without M (line 1001). The catalysts contained the same concentrations of active metals, used the same shape factors, and were all subjected to the same high-temperature calcination and reduction treatments. The M-Al mixed metal oxide composite supports can include a range of molar concentrations of M from 5 to 30%: low (line 1002), medium (line 1003), medium-high (line 1004), and high (line 1005).

[0575] Mechanical strength of supports, modified supports, and catalysts To function efficiently and for extended periods, catalysts can be porous, exhibit excellent adsorption / desorption properties, and possess high mechanical strength. Mechanical deficiencies and physical disruption of structured catalysts can result in the formation of small fragments and particulates, filling the pores and gaps between the beads and pellets and creating blockages in fluid flow. This process can also increase the pressure drop across the reformer to unacceptable levels and cause extreme variations in heat transfer characteristics, significantly impairing catalyst and reformer performance. Therefore, several standard industry tests are available to evaluate the mechanical strength of solid catalyst materials and aid in catalyst development and achieving desired reaction processes. Each test is designed to allow comparisons between catalysts and supports with significantly different geometries (e.g., pellets, granules, tablets, spheres, rings, and extrudates) and very high hardness levels (where relatively small deformations often result in breakage or cracking).

[0576] ASTM D4179 (Single Pellet Crush Strength of Formed Catalysts and Catalyst Supports) is intended to evaluate the compression "side crush strength" (SCS) of single, regularly shaped pellets, such as spheres, short cylinders, or tablets. Radial and axial crush strengths can be measured, although it is understood that axial crush strength is higher than radial crush strength and less representative of catalyst behavior in a packed reformer. A force (0-220 N) is applied to the test pellet at a uniform rate until the test pellet crushes or disintegrates. The maximum crush strength occurring at the time of initial disintegration is recorded in N or lb-force.

[0577] ASTM D6175 (Radial Crush Strength of Extruded Catalyst and Catalyst Support Particles) involves measuring the radially compressed SCS of single extruded catalyst particles 1.6 to 3.2 mm in diameter, with a length to diameter ratio of ≥ 1:1, and an expected crush strength of 0 to 65 N / mm. Similar to ASTM D4179, force is applied to the pellet at a uniform rate until it fractures or disintegrates, and the force per millimeter of deformation (N / mm) is recorded.

[0578] ASTM D7084 (Determination of Bulk Crush Strength of Catalysts and Catalyst Supports) is preferred for industrial applications using catalyst materials made from irregular particles. This method can be used with catalyst particles with diameters of 0.8 to 4.8 mm, such as granules. The catalyst particles are loaded into a cylindrical sample holder and then crushed with a piston. Increasing pressure is applied to the bed of particles at a uniform rate, with the maximum pressure held for 30 seconds, after which the pressure is slowly released. The pressure required to force 1% of the fine particles through a sieve with a mesh size half the size of the particles is recorded. Typical pressure ranges are about 0.1 MPa to about 0.35 MPa (14.5 to 50.8 psi) for granules and 1 to 3.5 MPa (145 to 508 psi) for larger formed particles.

[0579] In some embodiments, the present disclosure describes a modified support comprising a support and a deposited layer adjacent to the layer, wherein the modified support has a molecular weight of at least about 2000, 2200, 2400, 2600, 2800, 3000, 3200, 3400, 3600, 3800, 4000, 4200, 4400, 4600, 4800, 5000, 5100, 5200, 5300, 5400, 5500, 5600, 5700, 5800, 5900, 6000, 6100, 6200, 6300, 6400, 6500, 6600, 6700, 6800, 6900, 7000, 7100, 7200, 7300, 7400, 7500, 7600, 7700, 7800, 7900, 8000, 8100, 8200, 8300, 8400, 8500, 8600, 8700, 8800, 8900, 9000, 9100, 9200, 9300, 9400, 9500, 9600, 9700, 9800, 9900, 1000, 10100, 10200, 10300, 10400, 10500, 10600, 10700, 10800, 10900, 1100, 1110, 1120 The peak stress in the ASTM D7084 crush test is shown as 00, 6900, 7000, 7100, 7200, 7300, 7400, 7500, 7600, 7700, 7800, 7900, 8000, 8100, 8200, 8300, 8400, 8500, 8600, 8700, 8800, 8900, 9000, 9100, 9200, 9300, 9400, 9500, 9600, 9700, 9800, 9900, 10000, 10100, 10200, 10300, 10400, 10500, 10600, 10700, 10800, or 10900 psi.

[0580] In some embodiments, the present disclosure describes a modified support comprising a support and a deposited layer adjacent to the support, wherein the modified support has a molecular weight of about 2200, 2400, 2600, 2800, 3000, 3200, 3400, 3600, 3800, 4000, 4200, 4400, 4600, 4800, 5000, 5100, 5200, 5300, 5400, 5500, 5600, 5700, 5800, 5900, 6000, 6100, 6200, 6300, 6400, 6500, 6600, 6700, 6800, 6900, 7000, 7100, 7200, 7300, 7400, 7500, 7600, 7700, 7800, 7900, 8000, 8100, 8200, 8300, 8400, 8500, 8600, 8700, 8800, 8900, 9000, 9100, 9200, 9300, 9400, 9500, 9600, 9700, 9800, 9900, 1000, 10100, 10200, 10300, 10400, 10500, 10600, 10700, 10800, 10900, 1100, 1110, 11200, 11300 The peak stress in the ASTM D7084 crush test is shown to be less than 000, 7100, 7200, 7300, 7400, 7500, 7600, 7700, 7800, 7900, 8000, 8100, 8200, 8300, 8400, 8500, 8600, 8700, 8800, 8900, 9000, 9100, 9200, 9300, 9400, 9500, 9600, 9700, 9800, 9900, 10000, 10100, 10200, 10300, 10400, 10500, 10600, 10700, 10800, 10900, or 11000 psi.

[0581] In some embodiments, the present disclosure describes a catalyst that includes a support, a layer deposited adjacent to the support, and a dopant deposited adjacent to the layer, wherein the catalyst has a dopant content of at least about 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400 ,3500,3600,3700,3800,3900,4000,4100,4200,4300,4400,4500,4600,4700,4800,4900,5000,5100,5200,5300,5400,5500,5600, or Peak stresses in ASTM D7084 crush tests of 7900 or 8000 psi are shown.

[0582] In some embodiments, the present disclosure describes a catalyst that includes a support, a layer deposited adjacent to the support, and a dopant deposited adjacent to the layer, wherein the catalyst has a surface roughness of about 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, 4000, 4100, 4200, 4300, 4400, 4500, 4600, 4700, 4800, 4900, 5000, 5100, 5200, 5300, 5400, 5500, 5600, 5700, 5800, 5900, 6000, 6100, 6200, 6300, 6400, 6500, 6600, 6700, 6800, 6900, 7000, 7100, 7200, 7300, 7400, 7500, 7600, 7700, 7800, 7900, 8000, 8100, 8200 The peak stress in the ASTM D7084 crush test is less than or equal to 00, 3800, 3900, 4000, 4100, 4200, 4300, 4400, 4500, 4600, 4700, 4800, 4900, 5000, 5100, 5200, 5300, 5400, 5500, 5600, 5700, 5800, 5900, 6000, 6100, 6200, 6300, 6400, 6500, 6600, 6700, 6800, 6900, 7000, 7100, 7200, 7300, 7400, 7500, 7600, 7700, 7800, or 7900, or 8000 psi.

[0583] Figure 11 shows the mechanical strength of various catalysts and support materials, reported as the peak stress achieved in the ASTM D7084 crush test. Surprisingly, incorporating alkaline earth metals and / or spinel-forming metals (e.g., MgO) into alumina to form a mixed-metal-Al oxide composite support can result in a significant (approximately 400%) increase in the mechanical strength of the alumina support material. Deposition and reduction of active metals (e.g., Ru) on the surface of the composite support unexpectedly significantly reduces the mechanical strength. However, even more surprisingly, if it is subjected to a high-temperature calcination step prior to the deposition and reduction of the active metal, much of the original support strength can be retained.

[0584] With reference to FIG. 11, various supports, doped supports, and catalysts can be subjected to mechanical strength testing according to the ASTM D7084 crush test procedure. Alpha-alumina (α-alumina), 1101, theta-alumina (θ-alumina), 1102, and gamma-alumina ( [ka] Commercially available alumina supports, including Ru on rare earth metal-doped theta-alumina, 1103, were obtained and tested without further treatment. Doped alumina supports included rare earth metal-doped theta-alumina, 1104, and rare earth metal-doped gamma-alumina, 1105. Competitor catalysts included Ru on rare earth metal-doped theta-alumina, 1106, Ru on rare earth metal-doped gamma-alumina, 1107, and Ru on rare earth metal and alkali metal promoter-doped theta-alumina, 1108.

[0585] Various catalysts have been prepared according to the materials, methods, and embodiments described herein by fabricating a gamma-alumina-based M-Al oxide composite support and subsequent Ru precursor deposition and reduction. In these cases, the alkaline earth metal and / or spinel-forming metal (Mg) used may be represented by M, as described herein. M:Al oxide composite supports were prepared with a 1:1 M:Al molar ratio and high-temperature calcination. 1109 Samples of this calcined M-Al oxide composite support were then subjected to active metal deposition and reduction. 1110

[0586] A range of gamma-alumina-based M-Al oxide composite supports were prepared using three different mass ratios of metals, each of which was divided into two samples. Each M-Al oxide composite support sample was then subjected to the same amount of active metal deposition and reduction as 1110, under the same temperature, atmosphere, and duration conditions. Another sample from each M-Al oxide composite support was calcined under the same temperature, atmosphere, and duration conditions as 1109, and then subjected to the same active metal deposition and reduction process as the other sample. This resulted in a total of six samples with active metals on the M-Al composite oxide support: 1111 (M:Al mass ratio 26:74, no calcination), 1112 (M:Al mass ratio 26:74, calcined), 1113 (M:Al mass ratio 30:70, no calcination), 1114 (M:Al mass ratio 30:70, calcined), 1115 (M:Al mass ratio 70:30, no calcination), and 1116 (M:Al mass ratio 70:30, calcined).

[0587] Dopant Application Many established techniques exist for applying metal oxides and their precursors onto the surface of supports to form composite, modified, or doped supports, including wet impregnation, template ion exchange, precipitation, sol-gel, citric acid process, deposition-precipitation, hydrothermal synthesis, chemical vapor deposition (CVD), physical vapor deposition (PVD), single atom catalysts, thermal shock high-entropy alloys, galvanic exchange, ferromagnetic induction heating, and nanoparticle transfer.

[0588] Examples of such dopant materials are rare earth metals, their oxides, and precursors. After the rare earth metal oxide or precursor is deposited on the surface of the metal oxide support, appropriate heat treatment conditions may be selected to form a mixed metal oxide layer on the surface of the doped support. The mixed metal oxide layer provides an improved surface for the deposition of the active metal oxide or precursor, and may achieve improved dispersion and nanoparticle properties for the active metal during further heat treatment.

[0589] Referring to Figure 12, Ru-alumina catalysts were prepared using the methods, materials, and support shape factors described herein. All contained the same wt% Ru based on the weight of the catalyst, but one of the catalysts was doped with a low concentration (less than 10 mol%) of rare earth metal. Test results showed that using a theta-alumina support 1202 can result in a catalyst with a higher ammonia conversion efficiency than using a gamma-alumina support 1201, but doping the theta-alumina support with a rare earth metal 1203 further increased the ammonia conversion efficiency.

[0590] Wet Impregnation Procedure Wet (or moist) impregnation can be a convenient technique, particularly for laboratory preparation, and procedures are described herein by way of example. Other techniques may also be used to prepare the catalysts of the present disclosure and should be considered to be included in the present disclosure.

[0591] Dopants can be applied to the support surface using separate solutions with a drying step between each application (sequential deposition or impregnation), or as a mixed solution of dopant metal precursors (co-impregnation or co-deposition). Mixed dopant and precursor solutions can be found to produce improved support properties for many final catalysts. When applying mixed dopant precursor solutions, it can be beneficial to ensure compatibility between them to avoid unintended precipitation. Alternatively, precipitation can be induced within the pore structure via gradual deposition of the dopant precursor followed by precipitation. A promoter / precipitant precursor may also be included at this stage (e.g., KOH, CsNO3, or CsOH). This can provide potential morphological control over the final surface overlayer and / or better inclusion of the precipitate (often a promoter, e.g., K or Cs) into the support pore structure.

[0592] To dope the support material, aqueous solutions of selected metal precursors (e.g., cobalt nitrate, ammonium molybdate, cobalt molybdate, magnesium chloride, magnesium nitrate hexahydrate Mg(NO)2.6H2O, cerium acetate, cerium nitrate hexahydrate Ce(NO)4.6H2O) can be prepared using water (e.g., deionized water, distilled water, or tap water). The mass of each dopant precursor can be selected to provide the desired metal loading on the support surface, and the volume of solvent water can be selected to approximately equal the mass of the support material before deposition.

[0593] The steps involved in this procedure may include (i) weighing the support material to determine its mass, (ii) understanding the chemical composition of the support and calculating the number of moles of support molecules (e.g., Al2O3, SiO2, or ZrO2) or major elements (e.g., Al, Si, Zr, or C), (iii) calculating the number of moles of dopant metal needed to achieve the desired loading (mol%) or molar ratio on the support, and (iv) preparing a solution of dopant precursor in an appropriate mass of water (approximately equal to the mass of the support material for incipient wetness). The number of moles of precursor (or metal ion) in the required volume of water (calculated from the required mass) establishes the molar concentration of the solution relative to precursor (or metal ion). If excess precursor solution is required, the mass of water and precursor is increased proportionally to the desired amount. In some cases, the volume of the impregnation solution may be at least about 5%, about 10%, about 15%, or about 20% greater than the pore volume of the support. In some cases, the volume of the impregnation solution may be no more than about 5%, about 10%, about 15%, or about 20% greater than the pore volume of the support.

[0594] Typically, metal loading on the support can be expressed as a molar ratio of dopant metal (e.g., Co, Mo, Mg, La, or Ce) to the support material or primary metal (e.g., Al2O3, C, SiC, SiO2, ZrO2, Al, Si, or Zr) in the support, and can range from about 0.1:1 to about 15:1, or from about 0.25:1 to about 15:1. The desired loading of each dopant metal on the support...

Claims

1. 1. A method for reforming ammonia, comprising: Ammonia-containing gas is contacted with the catalyst in a reactor at a temperature ranging from about 400° C. to about 700° C. to produce hydrogen (H ) with an ammonia conversion efficiency of at least about 70%. ２ ) and nitrogen (N ２ ), wherein the catalyst comprises: producing a catalyst comprising an electrically conductive support, the electrically conductive support having a resistivity greater than about 50 micro-ohm-centimeters (mohm-cm) and less than about 100 ohm-cm, the catalyst being in electrical communication with a pair of electrodes; applying a voltage across the pair of electrodes, thereby passing an electric current through the catalyst, to heat at least a portion of the catalyst from a first temperature to a second temperature in a period of less than about 60 minutes, wherein the second temperature is greater than about 200°C and less than about 700°C.

2. 10. The method of claim 1, wherein the ammonia produces hydrogen and nitrogen at an ammonia conversion efficiency of greater than about 90%.

3. The ammonia is greater than about 1000 milliliters and less than about 100,000 milliliters of NH 3 per milliliter of catalyst per hour. ３ 3. The process of claim 1 or 2, wherein the catalyst is contacted at a space velocity of

4. The method of any one of claims 1 to 3, wherein the catalyst is heated from the first temperature to the second temperature in less than about 30 minutes.

5. The method of any one of claims 1 to 4, wherein the first temperature is ambient temperature.

6. The method of any one of claims 1 to 5, wherein the first temperature is about 25°C.

7. The method of any one of claims 1 to 6, wherein the conductive support has a resistance greater than about 1 ohm.

8. 8. The method of any one of claims 1 to 7, wherein the current passes between the electrodes and through the catalyst at a distance greater than about 1 centimeter (cm) and less than about 10 meters.

9. 9. The method according to claim 1, wherein the combined resistance of the catalyst and the pair of electrodes is greater than about 0.1 ohms and less than about 100 ohms.

10. 10. The method of any one of claims 1 to 9, wherein the resistivity is the resistance of the catalyst multiplied by the cross-sectional area of ​​the catalyst divided by the distance the current passes between the electrodes and through the catalyst.

11. The method according to any one of claims 1 to 10, wherein the resistivity of the conductive support is a resistivity at a temperature greater than about 15°C and less than about 30°C.

12. 12. The method of any one of claims 1 to 11, wherein the current comprises a power per gram of catalyst greater than about 5 watts per gram (W / g) and less than about 500 W / g.

13. A method according to any preceding claim, wherein the period begins when the current begins to pass through the catalyst.

14. The method of any one of claims 1 to 13, wherein the catalyst is a monolith.

15. The method of any one of claims 1 to 13, wherein the catalyst comprises beads, pellets, or powder configured to form an electrical circuit between the electrodes.

16. The method of any one of claims 1 to 15, wherein the conductive support comprises a ceramic material.

17. The method of any one of claims 1 to 16, wherein the conductive support comprises silicon carbide (SiC), silicon (Si), or germanium (Ge).

18. The method of any one of claims 1 to 17, wherein the conductive support comprises a carbon-based material.

19. 20. The method of claim 18, wherein the carbon-based material comprises graphite or amorphous carbon.

20. The method of any one of claims 1 to 19, wherein the conductive support comprises NiCrAl, FeCrAl, NiFeCrAl, or NiCr.

21. The method of any one of claims 1 to 20, wherein the conductive support comprises a dopant comprising phosphorus (P), nitrogen (N), or boron (B).

22. The method of any one of claims 1 to 21, wherein the catalyst further comprises a layer adjacent to the conductive support.

23. The conductive support includes SiC, and the layer includes alumina (Al ２ O ３ 23. The method of claim 22, comprising:

24. The Al ２ O ３ 24. The method of claim 23, wherein comprises alpha-alumina, theta-alumina, or gamma-alumina.

25. The catalyst is Al ２ O ３ 25. The method of claim 23 or 24, further comprising an active metal adjacent to said layer comprising:

26. 26. The method of claim 25, wherein the active metal comprises Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu.

27. 27. The method of any one of claims 1 to 26, wherein a first electrode of the pair of electrodes is positioned proximate to a first side of the reactor and a second electrode of the pair of electrodes is positioned proximate to a second side of the reactor, the first side and the second side being positioned substantially opposite one another.

28. 28. The method of any one of claims 1 to 27, wherein the pair of electrodes are adjacent to each other and close to a side of the reactor.

29. 29. The method of any one of claims 1 to 28, further comprising reducing or ceasing application of a voltage between the electrodes based on the catalyst reaching the second temperature.

30. 30. The method of any one of claims 1 to 29, further comprising heating the reactor by combustion.

31. 31. The method of any one of claims 1 to 30, further comprising electrically heating the reactor in addition to heating the catalyst by passing the electric current through the catalyst.

32. The method of any one of claims 1 to 31, wherein the reactor further comprises a second catalyst.

33. 33. The method of claim 32, wherein the second catalyst is mixed with the catalyst.

34. 33. The method of claim 32, wherein the reactor comprises at least two zones, a first zone comprising the catalyst and a second zone comprising the second catalyst.

35. A method according to any preceding claim, wherein the voltage is provided by a battery.

36. The method of any one of claims 1 to 35, wherein the voltage is provided from a power grid.

37. the catalyst is heated to the second temperature, the second temperature being greater than about 600°C and less than about 700°C, for a period of less than 30 minutes; Said NH ３ with the catalyst to convert the H with an ammonia conversion efficiency of greater than about 95%. ２ and the N ２ The method of any one of claims 1 to 36, wherein

38. 1. A method for decomposing ammonia, comprising: contacting a gas comprising ammonia over a catalyst at a temperature in the range of about 400°C to about 700°C to produce a reformate stream comprising hydrogen and nitrogen with an ammonia conversion efficiency of at least about 70%, wherein the catalyst an electrically conductive support, the electrically conductive support comprising a resistivity greater than about 50 microohm-cm and less than about 100 ohm-cm; a layer adjacent to the conductive support, the layer comprising alumina, zirconia, iron oxide, magnesium oxide, manganese oxide, nickel oxide, silicon dioxide, titanium dioxide, vanadium dioxide, or zinc oxide; an active metal adjacent to the layer, the active metal comprising Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu.

39. 39. The method of claim 38, wherein the catalyst is in electrical communication with a pair of electrodes, and further comprising heating the catalyst by passing an electric current through the catalyst.

40. 1. A method for decomposing ammonia, comprising: contacting a gas comprising ammonia over a catalyst at a temperature in the range of about 400°C to about 700°C to produce a reformate stream comprising hydrogen and nitrogen with an ammonia conversion efficiency of at least about 70%, wherein the catalyst a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, or carbon nanotubes; a layer adjacent to the support, the layer comprising a support material doped with an oxide of at least one of an alkali metal, an alkaline earth metal, or a rare earth metal; and one or more active metal particles deposited adjacent to the layer, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu, wherein a concentration of the active metal particles is at least about 0.1 wt. % and no more than about 15 wt. %.

41. 1. A method for decomposing ammonia, comprising: contacting a gas comprising ammonia over a catalyst at a temperature in the range of about 400°C to about 700°C to produce a reformate stream comprising hydrogen and nitrogen with an ammonia conversion efficiency of at least about 70%, wherein the catalyst a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, or carbon nanotubes; a layer adjacent to the support, the layer comprising a support material doped with an oxide comprising at least one of an alkaline earth metal, Zn, Fe, or Mn; one or more active metal particles adjacent to the layer, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu; The method wherein the concentration of the one or more active metal particles ranges from about 0.1% to about 15% by weight.

42. 42. The method of any one of claims 38 to 41, wherein the ammonia is contacted over the catalyst at a temperature of from about 450°C to about 700°C and a space velocity of from about 1 to about 50 liters per gram of catalyst per hour.

43. 42. The method of any one of claims 38 to 41, wherein the ammonia is contacted over the catalyst at a temperature of from about 450°C to about 700°C and a gas hourly space velocity (GHSV) of from about 1 to about 50 liters per mL of catalyst per hour.

44. 44. The method of any one of claims 1 to 43, further comprising producing electricity by directing the hydrogen to at least one fuel cell, wherein the at least one fuel cell comprises a proton exchange membrane fuel cell (PEMFC), a solid oxide fuel cell (SOFC), a molten carbonate fuel cell (MCFC), an alkaline fuel cell (AFC), an alkaline membrane fuel cell (AMFC), or a phosphoric acid fuel cell (PAFC).

45. 45. The method of any one of claims 1 to 44, further comprising directing the hydrogen to one or more combustion engines or turbines.

46. 46. ​​The method of any one of claims 1 to 45, further comprising directing the hydrogen to one or more fuel cells, combustion engines, or turbines to produce electricity and / or motive power.

47. 47. The method of any one of claims 1 to 46, wherein contacting the catalyst with ammonia to produce the reformed stream is an autothermal reforming process such that at least a portion of the reformed stream provides heat for the autothermal reforming process.

48. 48. The method of claim 47, wherein said at least a portion of said reforming stream is (1) combusted to produce said heat or (2) converted by hydrogen-to-electricity conversion to produce said heat, thereby providing said heat for said autothermal reforming process.

49. 49. The method of any one of claims 1 to 48, further comprising removing undecomposed ammonia in the reformate stream using an ammonia filter.

50. 50. The method of claim 49, wherein the ammonia filter comprises an adsorber, a membrane separation module, or an ammonia scrubber.

51. A method according to any preceding claim, wherein a pressure swing adsorption (PSA) module is used to remove nitrogen from the reformate stream.

52. 52. The method of any one of claims 1 to 51, comprising: directing the ammonia to a first reformer containing the catalyst to produce the reformed stream; combusting the reformed stream in a fired heater to heat a second reformer; and directing additional ammonia to the second reformer to produce additional hydrogen for the reformed stream, wherein a first portion of the reformed stream is combusted to heat the second reformer.

53. 53. The method of claim 52, wherein the first reformer is heated using at least one of an electric heater or combustion of the reformate stream.

54. directing the ammonia at an ammonia flow rate to a reformer to produce the reformed stream; combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydroprocessing module; Based, at least in part, on the stimulus i. Varying the ammonia flow rate; ii. Varying the percentage of the reformate stream that is the first portion of the reformate stream; iii. Varying the percentage of the reformate stream that is the second portion of the reformate stream; or iv. performing one or more of the varying the oxygen flow rate.

55. directing the ammonia at an ammonia flow rate to a reformer to produce the reformed stream; combusting a first portion of the reformate stream with oxygen at an oxygen flow rate in a fired heater to heat the reformer; processing a second portion of the reformate stream in a hydroprocessing module; measuring the temperature in the reformer or the combustion heater; based, at least in part, on the measured temperature being outside a target temperature range for the reformer or the fired heater; i. Varying the ammonia flow rate; ii. Varying the oxygen flow rate; iii. Varying the percentage of the reformate stream that is the second portion of the reformate stream; iv. Varying the percentage of the reformate stream that is the first portion of the reformate stream; or v. varying the percentage of the reformate stream that is directed out of the fired heater.

56. 56. The method of any one of claims 38 to 55, wherein the active metal comprises Ru.

57. 57. The method of claim 56, wherein the concentration of Ru is greater than about 0.2 wt% and less than about 12 wt% based on the total weight of the catalyst including the support and the layer.

58. 1. A catalyst for ammonia decomposition, comprising: an electrically conductive support, the electrically conductive support comprising a resistivity greater than about 50 microohm-cm and less than about 100 ohm-cm; a layer adjacent to the conductive support, the layer comprising alumina, zirconia, iron oxide, magnesium oxide, manganese oxide, nickel oxide, silicon dioxide, titanium dioxide, vanadium dioxide, or zinc oxide; an active metal adjacent to the layer, the active metal comprising Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu.

59. 59. The catalyst of claim 58, wherein the catalyst is a monolith.

60. 60. The catalyst of claim 58 or 59, wherein the conductive support comprises SiC, the layer comprises the alumina, and the active metal comprises the Ru.

61. 61. The catalyst of any one of claims 58 to 60, wherein the alumina comprises alpha alumina, theta alumina, or gamma alumina.

62. 62. The catalyst of any one of claims 58-61, wherein the concentration of Ru comprises greater than about 0.5 wt% and less than about 3 wt% based on the total weight of the catalyst including the support and the layer.

63. 63. The catalyst of any one of claims 58 to 62, wherein the conductive support comprises a ceramic material.

64. 64. The catalyst of any one of claims 58 to 63, wherein the conductive support comprises silicon carbide (SiC), silicon (Si), or germanium (Ge).

65. 65. The catalyst of any one of claims 58 to 64, wherein the conductive support comprises a carbon-based material.

66. 66. The catalyst of claim 65, wherein the carbon-based material comprises graphite or amorphous carbon.

67. 67. The catalyst of any one of claims 58 to 66, wherein the conductive support comprises NiCrAl, FeCrAl, NiFeCrAl, or NiCr.

68. 68. The catalyst of any one of claims 58 to 67, wherein the conductive support comprises a dopant comprising phosphorus (P), nitrogen (N), or boron (B).

69. 1. A catalyst for ammonia decomposition, comprising: a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, and carbon nanotubes; and a layer adjacent to the support, the layer comprising a support material doped with at least one oxide of an alkali metal, an alkaline earth metal, or a rare earth metal; one or more active metal particles adjacent to the layer, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu; A catalyst wherein the concentration of said active metal particles is at least about 0.1 wt.% and not more than about 15 wt.%.

70. 70. The catalyst of claim 69, wherein the support comprises zirconium and oxygen.

71. 71. The catalyst of claim 69 or 70, wherein the layer comprises Ce.

72. 72. The catalyst of any one of claims 69 to 71, wherein the layer comprises a tetragonal network of zirconium, cerium, and oxygen.

73. The layer is made of Ce ３＋ ions and Ce ４＋ ions, and the Ce ３＋ The ion pair Ce ４＋ 73. The catalyst of any one of claims 69 to 72, wherein the ratio of ions is at least about 0.1:1 and not more than about 1:

1.

74. 70. The catalyst of claim 69, wherein the support comprises aluminum and oxygen.

75. 75. The catalyst of claim 74, wherein the layer comprises at least one of theta-alumina (θ-alumina) or gamma-alumina (γ-alumina).

76. 76. The catalyst of claim 74 or 75, wherein the layer comprises a perovskite phase.

77. 77. The catalyst of any one of claims 74 to 76, wherein the layer comprises La at a concentration of at least about 0.1 and up to about 50 mol%.

78. 78. The catalyst of any one of claims 74 to 77, wherein the layer comprises La and Ce, and the molar ratio of the La to the Ce is at least about 10:90 and not more than about 90:

10.

79. 79. The catalyst of any one of claims 69 to 78, wherein the layer comprises oxide nanoparticles of at least one of La, Ce, K, Cs, and Rb.

80. 80. The catalyst of any one of claims 69 to 79, wherein the layer comprises annealed nanoparticles of at least one of La, Ce, K, Cs, and Rb.

81. 81. The catalyst of any one of claims 69 to 80, wherein the support or at least one of the layers comprises one or more promoters.

82. 82. The catalyst of claim 81, wherein the one or more promoters comprise K, Cs, or Rb.

83. 83. The catalyst of claim 81 or 82, wherein the molar ratio of the one or more promoters to Ce in the support is at least about 1:2 and not more than about 10:

1.

84. Catalyst according to any one of claims 81 to 83, wherein the one or more promoters are co-impregnated with the Ce.

85. 1. A catalyst for ammonia decomposition, comprising: a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, and carbon nanotubes; and a layer adjacent to the support, the layer comprising a support material doped with an oxide comprising at least one of an alkaline earth metal, Zn, Fe, or Mn; and one or more active metal particles within, on, or adjacent to said layer, said one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, and Pd.

86. 86. The catalyst of claim 85, wherein the support comprises aluminum and oxygen.

87. 87. The catalyst of claim 85 or 86, wherein the support or at least one of the layers comprises at least one of alpha-alumina (α-alumina), theta-alumina (θ-alumina), or gamma-alumina (γ-alumina).

88. Catalyst according to any one of claims 85 to 87, wherein the layer comprises a spinel phase.

89. 89. The catalyst of any one of claims 85 to 88, wherein the concentration of the one or more active metal particles ranges from about 0.1 wt % to about 15 wt %, based on the weight of the catalyst.

90. 90. The catalyst of any one of claims 85 to 89, wherein the layer comprises at least one of Mg, Ca, Sr, Ba, Zn, Fe, or Mn, and wherein a concentration of the at least one of Mg, Ca, Sr, Ba, Zn, Fe, or Mn ranges from about 0.1 mol% to about 80 mol%.

91. 91. The catalyst of any one of claims 85-90, wherein the support and the layer comprise a modified support comprising an ASTM D7084 (Determination of Bulk Crush Strength of Catalysts and Catalyst Supports) crush strength of at least about 4000 psi (peak stress).

92. 92. The catalyst of any one of claims 85 to 91, wherein the layer comprises oxide nanoparticles comprising at least one of Mg, Ca, Sr, Ba, Zn, Fe, or Mn.

93. 93. The catalyst of any one of claims 85 to 92, wherein the layer comprises annealed nanoparticles comprising at least one of Mg, Ca, Sr, Ba, Zn, Fe, or Mn.

94. 94. The catalyst of any one of claims 85 to 93, wherein the catalyst comprises an ASTM D7084 crush strength of at least about 400 psi (peak stress).

95. 95. The catalyst of any one of claims 85 to 94, wherein the catalyst is substantially free of promoters.

96. 96. The catalyst of any one of claims 85 to 95, wherein the catalyst is substantially free of support surface modifiers.

97. 97. The catalyst of any one of claims 69 to 96, wherein the one or more active metal particles comprise ruthenium (Ru).

98. 98. The catalyst of any one of claims 69 to 97, wherein the concentration of Ru ranges from about 0.2 to about 12 wt%.

99. 99. The catalyst of any one of claims 69 to 98, wherein the one or more active metal particles comprise Ru nanoparticles.

100. 1. A method for producing a catalyst for ammonia decomposition, the catalyst comprising an electrically conductive support, the electrically conductive support comprising a resistivity greater than about 50 micro-ohm-cm and less than about 100 ohm-cm, the method comprising: a) dissolving the conductive support in a slurry containing (i) a binder and (ii) alumina (Al ２ O ３ depositing the alumina-containing layer adjacent to the conductive support by immersion in a slurry containing b) removing the conductive support and the catalyst containing layer from the slurry; c) drying the catalyst including the conductive support and the layer; d) heat treating the catalyst comprising the conductive support and the layer in a non-reducing atmosphere at a temperature greater than about 200°C and less than about 1400°C; e) immersing the catalyst comprising the conductive support and the layer in a solution comprising an active metal precursor to deposit the active metal precursor adjacent to the layer; f) heat treating the catalyst comprising the conductive support, the layer, and the active metal precursor in a non-oxidizing atmosphere at a temperature greater than about 200° C. and less than about 1300° C. to convert the active metal precursor to an active metal.

101. 101. The method of claim 100, wherein the slurry comprises a pH greater than about 0.1 and less than about 3.

102. 102. The method of claim 100 or 101, wherein the catalyst is a monolith.

103. 103. The method of any one of claims 100 to 102, wherein the binder is an alumina-derived sol-gel.

104. 104. The method of any one of claims 100 to 103, wherein the binder comprises boehmite, bayerite, or gibbsite.

105. The method of any one of claims 100 to 104, wherein the binder is a hydrocarbon-based binder.

106. 106. The method of claim 105, wherein the hydrocarbon-based binder comprises polyvinyl alcohol (PVA), polyethylene glycol (PEG), polyurethane (PUR), or polyethyleneimine (PEI).

107. 107. The method of any one of claims 100 to 106, wherein the conductive support is immersed in the slurry for a period of more than about 1 second and less than about 10 minutes.

108. 108. The method of claim 107, wherein the period begins based on the conductive support being completely immersed below the surface of the slurry.

109. 109. The method of any one of claims 100 to 108, wherein the drying comprises blowing air onto the catalyst including the conductive support and the layer.

110. 110. The method of any one of claims 100 to 109, wherein the drying comprises passing a flame or combustion product gases adjacent to or over the catalyst comprising the conductive support and the layer.

111. The non-reducing atmosphere is air, O ２ , N ２ , CO ２ , Ar, He, Kr, or Xe.

112. The non-oxidizing atmosphere is N ２ , H ２ , Ar, NH ３ , CO, CO ２ , He, Kr, or Xe.

113. 113. The method of any one of claims 100 to 112, wherein the alumina comprises alpha alumina, theta alumina, or gamma alumina.

114. The active metal precursor is Ru(NO)(NO ３ ) ３ , Ru(NO ３ ) ３ , RuCl ３ , Ru ３ (CO) １２ , ruthenium(III) chloride hexaammoniumide Ru(NH ３ ) ６ Cl ３ , cyclohexadiene ruthenium tricarbonyl ((CHD)Ru(CO) ３ ), butadiene ruthenium tricarbonyl ((BD)Ru(CO) ３ ), or dimethylbutadiene ruthenium tricarbonyl ((DMBD)Ru(CO) ３ 114. The method of any one of claims 100 to 113, comprising:

115. 115. The method of any one of claims 100 to 114, wherein the active metal comprises ruthenium (Ru).

116. 116. The method of claim 115, wherein the concentration of Ru comprises greater than about 0.5 wt % and less than about 3 wt % based on the total weight of the catalyst including the conductive support and the layer.

117. 117. The method of any one of claims 100 to 116, wherein the slurry comprises solids including the binder and the alumina, and wherein the concentration of the solids comprises greater than about 20 wt% and less than about 60 wt%, based on the total weight of the slurry.

118. The method of any one of claims 100 to 117, wherein the conductive support comprises a ceramic material.

119. 119. The method of any one of claims 100 to 118, wherein the conductive support comprises silicon carbide (SiC), silicon (Si), or germanium (Ge).

120. 120. The method of any one of claims 100 to 119, wherein the conductive support comprises a carbon-based material.

121. 121. The method of claim 120, wherein the carbon-based material comprises graphite or amorphous carbon.

122. The method of any one of claims 100 to 121, wherein the conductive support comprises NiCrAl, FeCrAl, NiFeCrAl, or NiCr.

123. 123. The method of any one of claims 100 to 122, wherein the conductive support comprises a dopant comprising phosphorus (P), nitrogen (N), or boron (B).

124. 1. A method for producing a catalyst for ammonia decomposition, comprising: (a) providing a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, or carbon nanotubes, or precursors thereof; (b) depositing a layer adjacent to the support comprising at least one of an alkali metal oxide or precursor thereof, an alkaline earth metal oxide or precursor thereof, or a rare earth metal oxide or precursor thereof to form a doped support; (c) depositing a precursor of one or more active metal particles adjacent to the layer, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu; depositing, wherein the concentration of the active metal particles is at least about 0.1 wt. % and not more than about 15 wt. %; (d) maintaining the doped support at a temperature of at least about 200° C. and not more than about 1300° C. for a duration of at least about 0.1 hours and not more than about 168 hours in an atmosphere comprising hydrogen.

125. 125. The method of claim 124, wherein (b) further comprises maintaining the doped support at a temperature of at least about 20° C. and not more than about 150° C. in a vacuum or in an inert, oxygen-free, or non-oxidizing atmosphere below an absolute pressure of 5 bar for a duration of at least about 0.1 hours and not more than about 168 hours.

126. (b) is air, N ２ , CO ２ 126. The method of claim 124 or 125, further comprising maintaining the doped support at a temperature of at least about 300°C and not more than about 1300°C for a duration of at least about 0.1 hours and not more than about 168 hours in a non-reducing atmosphere comprising at least one of Ar, He, Kr, or Xe.

127. (b) is N ２ , H ２ , Ar, NH ３ , CO, CO ２ 127. The method of any one of claims 124-126, further comprising maintaining the doped support at a temperature of at least about 300°C and not more than about 1300°C for a duration of at least about 0.1 hours and not more than about 168 hours in an inert, oxygen-free, or non-oxidizing atmosphere comprising at least one of He, Kr, or Xe.

128. 128. The method of any one of claims 124 to 127, wherein the support comprises zirconium and oxygen.

129. 129. The method of claim 128, wherein the layer comprises Ce.

130. 130. The method of claim 128 or 129, wherein the layer comprises a tetragonal network of zirconium, cerium, and oxygen.

131. The layer is made of Ce ３＋ ions and Ce ４＋ ions, and the Ce ３＋ The ion pair Ce ４＋ 131. The method of any one of claims 128 to 130, wherein the ratio of ions is at least about 0.1:1 and not more than about 1:

1.

132. 128. The method of any one of claims 124 to 127, wherein the support comprises aluminum and oxygen.

133. 133. The method of claim 132, wherein the layer comprises at least one of theta-alumina (θ-alumina) or gamma-alumina (γ-alumina).

134. 134. The method of claim 132 or 133, wherein the layer comprises a perovskite phase.

135. 135. The method of any one of claims 132 to 134, wherein the layer comprises La at a concentration of at least about 0.1 and not more than about 50 mol%.

136. 136. The method of any one of claims 132 to 135, wherein the layer comprises La and Ce, and the molar ratio of the La to the Ce is at least about 10:90 and not more than about 90:

10.

137. 137. The method of any one of claims 124 to 136, wherein the layer comprises oxide nanoparticles of at least one of La, Ce, K, Cs, and Rb.

138. 138. The method of any one of claims 124 to 137, wherein the layer comprises annealed nanoparticles of at least one of La, Ce, K, Cs, and Rb.

139. 139. The method of any one of claims 124 to 138, wherein the carrier or at least one of the layers comprises one or more promoters.

140. 140. The method of claim 139, wherein the one or more promoters comprise K, Cs, or Rb.

141. 141. The method of claim 139 or 140, wherein the molar ratio of the one or more promoters to Ce in the carrier is at least about 1:2 and not more than about 10:

1.

142. 142. The method of any one of claims 139 to 141, wherein the one or more promoters are co-impregnated with the Ce.

143. 1. A method for producing a catalyst for ammonia decomposition, comprising: (a) providing a support comprising at least one of alumina, silica, carborundum, zeolite, ceria, zirconia, graphite oxide, carbon, graphene, carbon nanofibers, and carbon nanotubes, or precursors thereof; (b) depositing at least one of an alkaline earth metal oxide or precursor thereof, an iron oxide or precursor thereof, a manganese oxide or precursor thereof, or a zinc oxide or precursor thereof to form said layer in, on, or adjacent to said support such that said support comprises a doped support comprising said layer and said support; (c) depositing an oxide or precursor of one or more active metal particles adjacent to the doped support, the one or more active metal particles comprising at least one of Ru, Ni, Rh, Ir, Co, Fe, Pt, Cr, Mo, Pd, or Cu; depositing, wherein the concentration of the one or more active metal particles is in the range of about 0.1 to about 15 wt. %; (d) maintaining the doped support at a temperature of about 300 to about 1300° C. for a duration of about 0.1 to about 168 hours in an atmosphere comprising hydrogen.

144. 144. The method of claim 143, wherein (b) further comprises maintaining the doped support at a temperature of from about 20°C to about 150°C in a vacuum or in an inert or non-oxidizing atmosphere for a duration of from about 0.1 hours to about 168 hours, wherein the pressure of the non-oxidizing atmosphere ranges from about 0.1 bar absolute to about 5 bar absolute.

145. (b) is air, O ２ , N ２ , CO ２ 145. The method of claim 143 or 144, further comprising maintaining the doped support at a temperature of from about 300°C to about 1300°C in a non-reducing atmosphere comprising at least one member of the group of Ar, He, Kr, or Xe for a duration of at least about 0.1 hours to about 168 hours.

146. (b) is N ２ , CO ２ , CO, H ２ 146. The method of any one of claims 143-145, further comprising maintaining the doped carrier at a temperature of from about 300°C to about 1300°C in an inert, oxygen-free, or non-oxidizing atmosphere comprising at least one member of the group of Ar, He, Kr, or Xe for a duration of at least about 0.1 hours to about 168 hours.

147. 147. The method of any one of claims 143 to 146, wherein the support comprises aluminum and oxygen.

148. 148. The method of any one of claims 143 to 147, wherein the layer comprises at least one of alpha-alumina (α-alumina), theta-alumina (θ-alumina), or gamma-alumina (γ-alumina).

149. The method of any one of claims 143 to 148, wherein the layer comprises a spinel phase.

150. 150. The method of any one of claims 143 to 149, wherein the alkaline earth metal comprises at least one of Mg Ca, Sr, or Ba, and the concentration of the oxide of at least one of Mg, Ca, Sr, Ba, Zn, Fe, or Mn is in the range of about 0.1 to about 80 mol%.

151. 151. The method of any one of claims 143-150, wherein the carrier and the layer comprise a modified carrier comprising an ASTM D7084 crush strength of at least about 4000 psi (peak stress).

152. 152. The method of any one of claims 143 to 151, wherein the catalyst comprises an ASTM D7084 crush strength of at least about 400 psi (peak stress).

153. 153. The method of any one of claims 143 to 152, wherein the method does not include adding a promoter to the catalyst.

154. 154. The method of any one of claims 143 to 153, wherein the method does not include adding a support surface modifier to the catalyst.

155. 155. The method of any one of claims 124 to 154, wherein the active metal particles comprise ruthenium (Ru).

156. 156. The method of any one of claims 124 to 155, wherein the concentration of Ru is at least about 0.2 wt% and not more than about 12 wt%.

157. 157. The method of any one of claims 124 to 156, wherein the one or more active metal particles comprise nanoparticles of elemental Ru.

158. (c) the precursor of the one or more active metal particles is Ru(NO)(NO ３ ) ３ , Ru(NO ３ ) ３ , RuCl ３ , or Ru ３ (CO) １２ 158. The method of any one of claims 124 to 157, comprising at least one of:

159. (a) the support or a precursor thereof comprises beads or pellets; The beads or pellets are (i) at least about 0.1 mm and no more than about 10 mm in diameter, or (ii) at least about 50 mm. ２ / g and about 500m ２ 159. The method of any one of claims 124 to 158, comprising at least one of a surface area per unit mass of 1 / g or less.

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