Catalyst molded body for producing synthesis gas, method for producing catalyst molded body, and method for producing synthesis gas using

Abstract

A catalyst molded body for manufacturing synthesis gas includes a support molded body, metal active particles supported on the support molded body, and a metal oxide coating disposed on at least a portion of the metal active particles and the support molded body. The average particle size of the metal active particles is 5 nm to 30 nm.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0163926, filed with the Korean Intellectual Property Office on November 18, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a catalyst molding body for producing syngas, a method for producing the catalyst molding body, and a method for using the catalyst molding body to produce syngas. Background Technology

[0004] Gases including hydrogen and carbon monoxide are used in the automotive industry to supply hydrogen for fuel cells, in the steel industry for iron ore reduction, in the chemical industry for ammonia synthesis, methanol synthesis, Fischer-Tropsch synthesis, and the manufacture of other chemicals.

[0005] To produce such gases, catalysts made of nickel-based alumina or ruthenium-based alumina are used to produce syngas from hydrocarbons through a reforming process.

[0006] For example, in existing reforming processes, pellet-type catalysts can be loaded into the reactor. Pellets are typically manufactured through extrusion molding, and can be made into desired shapes, such as spherical, cylindrical, and porous particles.

[0007] In some cases, particulate catalysts may break into fragments due to various types of damage, such as damage caused by mechanical impact when loaded into the reactor, damage caused by thermal expansion and contraction during temperature rise to the reforming reaction temperature and during shutdown after the reaction, and damage caused by coking.

[0008] The small fragments generated by this phenomenon can fill the gaps between the particulate catalyst particles and accumulate at the bottom of the reactor, potentially causing flow resistance to the reformed gas and reducing catalyst activity. For these reasons, particle strength is considered when manufacturing particulate catalysts.

[0009] The performance and durability of catalysts used to produce syngas can be considered for industrial operations. In some cases, wet stirring can be used to provide metal nanoparticles supported on mesoporous supports, and the supports and metal nanoparticles can be coated with metal oxides.

[0010] In some cases, the strength of the molded body may decrease during loading and coating processes, and due to the small specific surface area of ​​the molded body, it may not be able to adequately load the metal nanoparticles, resulting in reduced catalyst performance. Summary of the Invention

[0011] This invention describes a catalyst profile for producing syngas that simultaneously ensures formability, crushing strength, and catalytic performance.

[0012] According to one aspect of the subject matter described in this invention, a catalyst profile for producing syngas includes a support profile, metal active particles supported on the support profile, and a metal oxide coating disposed on at least a portion of (i) the metal active particles and (ii) the support profile, wherein the average particle size of the metal active particles is from 5 nm to 30 nm.

[0013] Embodiments according to this aspect may include one or more of the following features. For example, the carrier molded body may include alumina and boehmite. In some examples, the metal active particles may include one or more of nickel (Ni), cobalt (Co), rhodium (Rh), ruthenium (Ru), iridium (Ir), palladium (Pd), platinum (Pt), gold (Au), and iron (Fe). In some examples, the metal oxide coating may include the metal components of the carrier molded body and the metal components of the metal active particles. In some examples, the metal oxide coating may include one or more of alumina (Al₂O₃), magnesium aluminate (MgAl₂O₄), calcium aluminate (CaAl₂O₃), and nickel aluminate (NiAl₂O₃). In some examples, the average thickness of the metal oxide coating may be from 2 nm to 10 nm.

[0014] In some embodiments, the metal composition of the active metal particles can be from 0.1% to 2% by weight relative to 100% by weight of the total catalyst molded body comprising the support molded body, the metal active particles, and the metal oxide coating. In some examples, the specific surface area of ​​the catalyst molded body can be 0.1 m². 2 / g to 30m 2 / g, with an average pore size ranging from 40nm to 200nm and a porosity ranging from 40% to 90%.

[0015] In some instances, the crushing strength of the catalyst molding body can be from 300 N to 3000 N. In some instances, the catalyst molding body may have one or more holes therein. In some embodiments, the catalyst molding body may be cylindrical with a diameter of 2 mm to 25 mm and a height of 1 mm to 30 mm.

[0016] According to another aspect, a method for manufacturing a catalyst molded body for producing syngas includes: forming a carrier molded body by molding carrier powder, depositing metal active particles on the carrier molded body using an atomic layer deposition process, and forming a metal oxide on at least a portion of (i) the carrier molded body and (ii) the metal active particles.

[0017] Embodiments according to this aspect may include one or more of the following features. For example, forming a carrier molded body may include applying a compressive strength of 1 kN to 20 kN to the carrier powder. After forming the carrier molded body, the carrier molded body may be heated to a temperature of 800°C to 1500°C.

[0018] In some instances, depositing active metal particles may include injecting an active metal particle precursor and heating it to a temperature of 100°C to 350°C.

[0019] In some instances, depositing active metal particles may include repeating (i) injecting the active metal particle precursor 100 to 1000 times, (ii) heating to a temperature of 100°C to 350°C, and (iii) purging.

[0020] In some cases, forming a metal oxide coating may involve injecting hydrogen and heating to a temperature of 600°C to 1000°C.

[0021] According to another aspect, a method for producing syngas includes injecting a reactant gas and an oxidant, contacting the reactant gas and oxide with the catalyst molding body described above, and reforming the reactant gas through an endothermic reaction to produce syngas.

[0022] Embodiments according to this aspect may include one or more of the following features. For example, the reaction gas may include one or more of C1 to C20 alkanes, C1 to C20 alkenes, C1 to C20 alkynes, ammonia (NH3), formaldehyde (HCO2H), and methanol (CH3OH).

[0023] In some instances, the oxidant may include one or more of carbon dioxide (CO2), water vapor (H2O), and oxygen (O2).

[0024] In some embodiments, the catalyst profile used to produce syngas can be made into various shapes and have structures that facilitate heat and mass transfer, thereby increasing the reaction surface area and preventing pressure drop.

[0025] In some embodiments, the catalyst molding body used to produce syngas has high breakage strength, thereby preventing flow resistance caused by breakage of the catalyst molding body.

[0026] In some implementations, catalyst activity can be improved even when using small amounts of active metal.

[0027] In some implementations, the same process can be used to reduce the active metal particles and form metal oxides before the reaction, thereby reducing process costs. Attached Figure Description

[0028] Figure 1 This is a schematic cross-sectional view of an example of a catalyst molding for producing syngas.

[0029] Figure 2 This is a schematic diagram illustrating an example of a catalyst molding for producing syngas.

[0030] Figure 3 This is a photograph of Example 1, analyzed using transmission electron microscopy (TEM).

[0031] Figure 4 This is a graph showing the particle size distribution of Ni in the catalyst molded body prepared in Example 1.

[0032] Figure 5 This is a photograph of Example 2, analyzed using transmission electron microscopy (TEM).

[0033] Figure 6 This is a graph showing the particle size distribution of Ni in the catalyst molded body prepared in Example 2.

[0034] Figure 7 This is a photograph of Comparative Example 1, analyzed using transmission electron microscopy (TEM).

[0035] Figure 8 This is a graph showing the particle size distribution of Ni in the catalyst molded body prepared in Comparative Example 1.

[0036] Figure 9 This is a photograph of the catalyst prototyping prepared in Example 1 after reduction, analyzed using transmission electron microscopy (TEM).

[0037] Figure 10 This is a graph showing the X-ray absorption fine structure (XAFS) analysis results of the catalyst molded body prepared in Example 1 after reduction.

[0038] Figure 11The images are of the catalyst prototyping prepared in Example 1 after reduction, analyzed by HAADF (High-angle-annular dark-field)-STEM.

[0039] Figure 12 and Figure 13 The image is an analysis of the catalyst prototyping prepared in Example 1 after reduction using fast Fourier transform (FFT).

[0040] Figure 14 This is a graph showing the results of catalyst activity tests performed on the catalyst molded articles prepared in Examples 1 and 2, and Comparative Examples 1 and 2. Detailed Implementation

[0041] Figure 1 This is a schematic cross-sectional view of an example of a catalyst molding 100 used for producing syngas.

[0042] In some implementations, such as Figure 1 As shown, the catalyst molded body 100 includes a carrier molded body 10 and metal active particles 20 loaded on the carrier molded body. A metal oxide coating 30 is disposed on at least a portion of the surfaces of the carrier molded body 10 and the metal active particles 20.

[0043] The structure of the catalyst molded body 100 will be described in detail.

[0044] In some embodiments, the support-shaped body comprises alumina (Al₂O₃) and boehmite (AlOOH). One aspect of the invention is to manufacture the shaped body by molding the support powder; when molding the support powder, cracking may occur if boehmite is not included. In some instances, the appropriate inclusion of boehmite can improve formability. The boehmite content can be from 10 parts by weight to 30 parts by weight relative to 100 parts by weight of alumina. Inadequate formability may be difficult to obtain if boehmite is not properly included. Including excessive boehmite may increase catalyst production costs. Alumina may be present in the form of α-alumina.

[0045] The active metal particles 20 are components that have the activity of converting reactant gases into syngas and are loaded onto the carrier molded body 10. For example, the active metal particles may include one or more of nickel (Ni), cobalt (Co), rhodium (Rh), ruthenium (Ru), iridium (Ir), palladium (Pd), platinum (Pt), gold (Au), and iron (Fe). More specifically, they may include nickel (Ni).

[0046] In some embodiments, the average particle size of the metal active particles 20 can be from 5 nm to 30 nm. If the average particle size of the metal active particles 20 is too small, manufacturing reproducibility may decrease depending on manufacturing process conditions, etc. If the average particle size of the metal active particles 20 is too large, the metal may sinter during the reaction, thereby reducing catalyst activity. More specifically, the average particle size of the metal active particles 20 can be from 8 nm to 20 nm. The average particle size of the metal active particles 20 can be obtained from a magnified image of the cross-section of the catalyst profile taken using a transmission electron microscope or the like, and the particle size can refer to the equivalent circle diameter. The average particle size refers to the average value based on the number of metal active particles 20.

[0047] In some embodiments, the standard deviation of the particle size of the active metal particles 20 can be from 0.1 nm to 10 nm. A small standard deviation indicates that the active metal particles 20 are uniformly sized, which can be advantageous for catalyst activity. More specifically, the standard deviation of the particle size of the active metal particles 20 can be from 0.5 nm to 3 nm. The standard deviation of the particle size of the active metal particles 20 can be obtained from a magnified image of the cross-section of the catalyst profile taken using a transmission electron microscope or similar means; the particle size can refer to the equivalent circle diameter.

[0048] The metal oxide coating 30 is present on at least a portion of the surface of the metal active particles and the carrier molded body, thereby ensuring the durability of the metal active particles 20.

[0049] The metal oxide coating 30 may include the metal components of the carrier molded body 10 and the metal components of the metal active particles 20. For example, when the carrier molded body 10 includes alumina (Al2O3) and the metal active particles 20 include Ni, the metal oxide coating 30 may include nickel aluminate (NiAl2O4). In some embodiments, in the catalyst molded body 100, the metal active particles 20 are loaded onto the carrier molded body 10 using an atomic layer deposition process, and then the metal oxide coating 30 is formed on the surface of the carrier molded body 10 during a reduction process. In this process, some of the metal components of the metal active particles 20 and the carrier molded body 10 combine to form the metal oxide coating 30.

[0050] Specifically, the metal oxide coating 30 may include one or more of aluminum oxide (Al2O3), magnesium aluminate (MgAl2O4), calcium aluminate (CaAl2O4), and nickel aluminate (NiAl2O4). More specifically, the metal oxide coating 30 may include nickel aluminate (NiAl2O4).

[0051] The average thickness of the metal oxide coating 30 can be from 2 nm to 10 nm. If the metal oxide coating 30 is too thin, the active metal particles 20 may easily sinter; if the metal oxide coating 30 is too thick, mass transfer resistance may increase, thereby inhibiting catalyst activity. More specifically, the average thickness of the metal oxide coating 30 can be from 3 nm to 7 nm. The average thickness can be obtained from magnified images of the cross-section of the catalyst profile taken using a transmission electron microscope or similar method.

[0052] Relative to 100% by weight of the catalyst molded body 100, including the support molded body 10, the metal active particles 20, and the metal oxide coating 30, the metal component content of the metal active particles can be from 0.1% by weight to 2% by weight. For example, when the metal active particles 20 include Ni, the Ni in the catalyst molded body 100 can be from 0.1% by weight to 2% by weight. If the metal component content is too low, the amount of active metal used to convert the reactant gas may be insufficient, leading to an increase in unreacted substances. On the other hand, if the metal component content is too high, the specific surface area of ​​the metal active particles 20 may decrease, resulting in a decrease in reaction efficiency. More specifically, the metal component in the catalyst molded body 100 can be from 0.15% by weight to 1.5% by weight. The metal component can be measured using inductively coupled plasma (ICP).

[0053] The specific surface area of ​​the catalyst prototype 100 can be 0.1 m². 2 / g to 30m 2 / g, with an average pore size ranging from 40nm to 200nm and a porosity ranging from 40% to 90%.

[0054] If the specific surface area of ​​the catalyst molded body 100 is too small, the Ni particles may sinter during the reaction, leading to a decrease in performance. Conversely, if the specific surface area is too large, the catalyst molded body may not have adequate fracture strength and may be prone to breakage. More specifically, the specific surface area of ​​the catalyst molded body 100 can be 1 m². 2 / g to 15m 2 / g.

[0055] Specific surface area can be analyzed using the Brunauer-Emmett-Teller (BET) method. More specifically, the specific surface area can be measured by simultaneously measuring the amount of nitrogen during nitrogen adsorption and desorption.

[0056] If the average pore size of the catalyst molded body 100 is too small, the Ni particles may not be dispersed in the pores. Conversely, if the average pore size is too large, the dispersion of the Ni particles may be reduced, making them prone to sintering during the reaction. More specifically, the average pore size of the catalyst molded body 100 can be from 80 nm to 150 nm. The average pore size can be measured using a porosity analyzer.

[0057] If the porosity of the catalyst molded body 100 is too low, the dispersion of Ni particles may be reduced; conversely, if the porosity is too high, the catalyst molded body 100 may not have adequate breakage strength and may be prone to fracture. More specifically, the porosity of the catalyst molded body 100 can be between 60% and 85%. The porosity can be measured using a porosity analyzer (porosity meter).

[0058] The breakage strength of the catalyst molding 100 can range from 300 N to 3000 N. Due to the mechanical impact when loading the catalyst molding 100 into the reactor, thermal expansion and contraction during heating to the reforming reaction temperature (above 600°C), and shutdown and / or coking after the reaction, the catalyst molding 100 is easily broken into fragments. The small fragments generated by this phenomenon may fill the gaps between the catalyst moldings 100 and accumulate at the bottom of the reactor, potentially causing flow resistance to the reformed gas. If the breakage strength is too high, excessive energy may be consumed during the molding process, or the surface area on which the active metal can be loaded may be reduced, leading to inefficiency. More specifically, the breakage strength of the catalyst molding 100 can range from 400 N to 1000 N. The breakage strength can be measured by compressive strength using a universal testing machine.

[0059] Figure 2 This is a schematic diagram illustrating a catalyst molded body 100 used for producing syngas. The shape of the catalyst molded body 100 may be substantially the same as the shape of the carrier molded body 10 manufactured by molding carrier powder.

[0060] The shape of the catalyst molded body 100 is not particularly limited, but it can be, for example, a sphere, a cylinder, a dome-shaped cylinder, or a petal. Furthermore, the catalyst molded body 100 may have one or more pores inside, thereby facilitating pressure drop in the reactor. These pores, with a diameter of 1 mm or more, are intentionally formed during the molding process of the support molded body 10, and are distinct from pores.

[0061] More specifically, the catalyst molded body 100 may have a diameter (M) D The thickness ranges from 2mm to 25mm and the height (M) H It is a cylindrical shape ranging from 1mm to 30mm. Figure 2 A cylindrical catalyst molding body 100 with 10 (ten) pores 210 is shown. Specifically, the number of pores 210 can be from 3 to 10. Furthermore, the catalyst molding body 100 can have a diameter (M) D The thickness ranges from 3mm to 20mm and the height (M) H It is a cylindrical shape ranging from 3mm to 20mm.

[0062] A method for manufacturing a catalyst molded body 100 for producing syngas according to one aspect includes the following steps: manufacturing a carrier molded body 10 by molding a carrier powder; loading metal active particles 20 onto the carrier molded body 10 using an atomic layer deposition process; and forming a metal oxide coating on at least a portion of the surfaces of the carrier molded body and the metal active particles.

[0063] The carrier powder is shaped to manufacture the carrier molded body 10. For example, after mixing the binder with the carrier powder, the mixture is atomized and fed into a rotary continuous tableting machine to shape the mixture into a molded body of the desired shape. In this case, the pressure can be from 1 kN to 20 kN. For example, a compressive force of 1 kN to 20 kN can be applied to the mixture of carrier powder and binder. More specifically, a pressure of 2 kN to 5 kN can be used. The rotor speed can be from 5 RPM to 30 RPM. Since the shape of the carrier molded body 10 has been described relative to the catalyst molded body 100, redundant descriptions are omitted.

[0064] Regarding the carrier molded body 10, the type of carrier is described. Specifically, when the carrier comprises alumina and boehmite, the boehmite can be mixed with alumina using a dry impregnation method (incipient wetness impregnation) and compressed to manufacture the molded body. In this case, 2% to 5% by weight of binder can be added relative to the total carrier used for tableting.

[0065] After the step of manufacturing the support molded body 10, the support molded body 10 can be fired at a temperature of 800°C to 1500°C. If the firing temperature is too low, the strength of the catalyst molded body 100 may decrease. If the sintering temperature is too high, the strength cannot be further increased, and problems with catalyst activity may occur. More specifically, the support molded body can be fired at a temperature of 1000°C to 1300°C. In this case, the firing time can be in the range of 10 minutes to 300 minutes. More specifically, the firing time can be in the range of 60 minutes to 240 minutes. The heating rate can be in the range of 1°C / minute to 10°C / minute.

[0066] Metal active particles 20 are loaded onto the carrier molded body 10 using an atomic layer deposition process. Since the type of metal active particles 20 has been described above, redundant descriptions are omitted.

[0067] The step of loading metal active particles 20 by atomic layer deposition may include injecting a metal active particle precursor and heating it to a temperature of 100°C to 350°C. The metal active particle precursor can be used without particular limitation, as long as it is a substance that decomposes when heated to 100°C to 350°C and allows the metal active particles to be loaded onto the surface of the carrier molded body 10.

[0068] Specifically, the metal active particle precursor may include one or more of the following: nickel 1-dimethylamino-2-methyl-2-butoxide, bis(ethylcyclopentadienyl)nickel, bis(cyclopentadienyl)nickel, allyl(cyclopentadienyl)nickel(II), bis(methylcyclopentadienyl)nickel(II), bis(N,N'-ditert-butylacetamidinate)nickel, and bis(alkyl-alkane-imidamidato)nickel. The metal active particle precursor can be decomposed (or loaded) within a short time, for example, less than 30 seconds.

[0069] Before injecting the metal active particle precursor, pretreatment can be performed in a vacuum atmosphere to remove moisture and internal air from the pores within the carrier molded body 10.

[0070] After injecting the metal active particle precursor, purging can be performed in an inert gas atmosphere. The purging time can be more than 30 seconds.

[0071] In this case, the step of loading the metal active particles may include repeatedly injecting the metal active particle precursor, heating to a temperature of 100°C to 350°C, and purging for 100 to 1000 times. By repeatedly injecting and purging the metal active particle precursor, the particle size of the metal active particles 20 can be controlled.

[0072] Next, a reduction process is performed before the synthesis gas is generated to form a metal oxide coating 30 on at least a portion of the surfaces of the carrier molded body 10 and the metal active particles 20. Since the metal oxide coating 30 has already been described above, redundant descriptions are omitted.

[0073] The steps for forming a metal oxide coating may include injecting hydrogen gas and heating to a temperature of 600°C to 1000°C. By appropriately controlling the temperature, further growth of active metal particles can be inhibited, and crushing strength can be improved.

[0074] In this case, the metal components of the carrier molded body 10 and the metal active particles 20 can be formed as metal oxides. For example, when the carrier molded body 10 includes alumina and the metal active particles 20 include Ni, the metal oxide coating 30 may include nickel aluminate (NiAl2O4).

[0075] A method for producing syngas, the method comprising injecting a reactant gas and an oxidant into contact with a catalyst molding body for producing syngas, and reforming the reactant gas through an endothermic reaction to produce syngas.

[0076] For example, a method for producing syngas is to convert methane and steam, which are feedstocks for existing steam reforming, into syngas by adding carbon dioxide, which is the main greenhouse gas, to methane and steam. For example, methane that combines steam and carbon dioxide can be reformed as shown in the following reaction scheme 1 to produce syngas comprising carbon monoxide and hydrogen.

[0077] [Reaction Scheme 1]

[0078]

[0079] The reactant gases may include C1 to C20 alkanes, C1 to C20 alkenes, C1 to C20 alkynes, ammonia (NH3), formaldehyde (HCO2H), methanol (CH3OH), or combinations thereof.

[0080] Oxidizing agents may include carbon dioxide (CO2), water vapor (H2O), oxygen (O2), or combinations thereof.

[0081] For example, the reactant gas may include methane and carbon dioxide and water as oxidants, in which case the syngas may include hydrogen and carbon monoxide. For example, water may be included in the reactant gas in the form of water vapor.

[0082] Syngas production methods involve adjusting the molar ratio of reactant gases to obtain the desired syngas composition.

[0083] The reactant gases may include methane and an oxidant (carbon dioxide and water) in a molar ratio of 1:1 to 1:3, for example, 1:1.2 to 1:2.

[0084] If the molar ratio of oxidant to methane is less than 1, the methane conversion rate will decrease and the carbon deposition will increase, which may lead to catalyst deactivation. If the molar ratio of oxidant to methane exceeds 3, the carbon dioxide conversion rate will decrease and the surface of the catalytically active material will be oxidized, which may reduce the amount of hydrogen produced. Considering the conversion rate of the reactant gases, the H2 / CO ratio in the product gases, and the amount of carbon deposition, a molar ratio of methane to oxidant of 1:1.2 to 1:2 is likely the optimal ratio.

[0085] The oxidant may include carbon dioxide and water in a molar ratio of 0.2:1.5 to 1.2:0.2. When the molar ratio of water to carbon dioxide exceeds 1.5:0.2, unreacted residual water vapor may promote catalyst deactivation.

[0086] Note that in the case of combined reforming, the reactant gases may also include nitrogen, as well as methane, carbon dioxide, and water. The molar ratio of nitrogen to methane can be from 1:1 to 1:3. Nitrogen can be used as a diluent to reduce temperature fluctuations in the catalyst bed during the reaction.

[0087] The reactant gas can be supplied at a space velocity of 500 to 20,000 rpm, for example, 1,000 to 10,000 rpm. The supply rate of the reactant gas can be increased proportionally according to the size of the combined reforming reactor and the capacity of the catalyst.

[0088] The reaction temperature and pressure used for combined reforming can be appropriately adjusted according to the desired composition of the syngas. For example, the temperature conditions for combined reforming reactions can be 600°C to 1000°C, such as 650°C to 900°C, or 800°C to 950°C. If the reaction temperature is below 600°C, the conversion rate of carbon dioxide will be significantly reduced, and CO2 may be produced. If the reaction temperature exceeds 1000°C, the thermal energy consumption efficiency is low, which may lead to thermal deactivation of the catalyst.

[0089] Furthermore, the pressure conditions used for combined reforming reactions can be, for example, from 0.5 atm to 20 atm, or, for example, from 1 atm to 10 atm. If the reaction pressure exceeds 20 atm, the conversion rate of the reactant gases may decrease, and the H2 / CO ratio may change.

[0090] Depending on the method of using a catalyst to produce syngas, the conversion rate of methane and / or carbon dioxide relative to the reaction gas can be from 30 mol% to 99.9 mol%, and it can stably resist carbon deposition for up to 200 hours at 900 °C.

[0091] Specific embodiments of the present invention are given below. However, the embodiments described below are only for illustrating or describing the present invention in detail and should not be construed as limiting the scope of the present invention.

[0092] [Example: Preparation of Catalyst Molded Body]

[0093] 1) Preparation of carrier-shaped body

[0094] 8 g of commercial alumina (Al2O3, Sasol, HP14-150) and 2 g of boehmite (AlOOH) were mixed together in a solid state. 10 wt% deionized water was added relative to the boehmite solid content, and the mixture was stirred for 1 hour. After stirring, the mixture was dried in air at 100°C for 4 hours. Additionally, for tableting, 5 wt% binder (Al2O3 sol) was added relative to the solid content. After adding the binder, the mixture was dried at 100°C for 8 hours. After drying, the powder was atomized using a high-shear pulverizer. Before feeding the powder into the tableting equipment, deionized water was added to adjust the moisture content to 10 wt%. The moisture-adjusted powder was fed through a hopper into a rotary continuous tableting machine and tableted using a tableting pressure of 3 kN with the rotor speed set to 20 rpm to prepare the final carrier mold. Subsequently, the carrier was fired in air at 1200°C for 1 hour (heating rate of 5°C / min, Example 1) and 2 hours (heating rate of 2°C / min, Example 2) to prepare the carrier molded body.

[0095] 2) Loaded with active metal particles

[0096] The carrier-shaped body prepared in the above steps was cleaned to remove residual foreign matter and powdered alumina from the surface. Approximately 40 g of the prepared carrier-shaped body was placed in an ALD reactor and pretreated in a vacuum atmosphere at 150°C for 30 minutes to remove moisture and air from the pores. Then, while maintaining the heating temperature at 150°C, internal purging (Ar purging, 1 minute) was performed, and a 1-dimethylamino-2-methyl-2-butoxide nickel precursor heated to 95°C was injected and held for 15 seconds, followed by internal purging. The precursor injection and purging were repeated 100 times (Example 1) and 300 times (Example 2), respectively.

[0097] [Comparative Example 1]

[0098] 8 g of commercial alumina (Al₂O₃, Sasol, HP14-150) and 2 g of boehmite (AlOOH) were mixed together in a solid state. 10% by weight of deionized water was added relative to the boehmite solid content, and the mixture was stirred for 1 hour. After stirring, the mixture was dried in air at 100°C for 4 hours to prepare the carrier powder.

[0099] 10g of the prepared carrier powder and 2g of nickel nitrate were mixed together in a solid state. A small amount of deionized water was added to load the nickel nitrate. After stirring, the mixture was dried in air at 100°C for 10 hours.

[0100] Then, an overlayer coating is applied using a metal oxide. 0.18 g of aluminum isopropoxide is added to 10 g of powder prepared according to the method described above, and the mixture is then stirred in a solid state for 30 minutes. In some embodiments, a melt-infiltration process is used to prepare the overlayer coating.

[0101] For tableting of the powdered catalyst, 5% by weight of a binder (Al2O3 sol) was added relative to the solids content. After adding the additive, the mixture was dried at 100°C for 8 hours. A shaped product was prepared and fired in the same manner as in the examples.

[0102] Nickel content analysis: To confirm the composition of the prepared catalyst profile, the contents of catalytically active metals and metal oxides were measured using inductively coupled plasma (ICP), and the results are shown in Table 1.

[0103] Shape analysis of the catalyst prototyping body: Transmission electron microscopy (TEM) was used to analyze the shape of the prepared catalyst prototyping body. The results are summarized in... Figures 3 to 8 And in Table 1. For example... Figures 3 to 8As shown, in Examples 1 and 2, the average particle size of the metal active particles was appropriately formed, and the size distribution of the metal active particles was also appropriately formed. In Comparative Example 1, coarse metal active particles were formed compared to Examples 1 and 2.

[0104] Analysis of metal oxide coatings: Figure 9 A photograph is shown illustrating the analysis of the catalyst prototyping prepared in Example 1 using transmission electron microscopy (TEM). Figure 9 As shown, a metal oxide coating is formed around the Ni particles. Figure 10 This is a graph showing the X-ray absorption fine structure (XAFS) analysis results of the catalyst prototyping prepared in Example 1 during the reduction process carried out in a hydrogen atmosphere and at a temperature of 900°C. NiO was reduced to Ni up to 570°C, and Ni-O-Al bonds appeared when the reducing atmosphere was maintained at 900°C for 1 hour. Figure 11 These are images obtained by HAADF (High Angle Ring Dark Field)-STEM analysis of the catalyst prototyping prepared in Example 1 after reduction. Figure 12 As shown, the active metal particles partially align with the Ni crystal plane orientation, as... Figure 13 As shown, the metal oxide coating matches the crystal plane orientation of NiAl2O4.

[0105] Pore ​​analysis of the catalyst prototyping: To analyze the pore structure of the catalyst, the BET (Brunauer-Emmett-Teller) specific surface area was analyzed. To remove moisture and surface adsorbed substances, the powdered catalyst was subjected to continuous heat treatment under vacuum: 1 hour at 90°C and 4 hours at 350°C. Then, nitrogen was adsorbed and desorbed at -196°C, and its content was measured to determine the specific surface area of ​​the powdered catalyst, as shown in Table 1. The average pore size and porosity were analyzed using a porosimeter, and the results are shown in Table 1.

[0106] Crushing strength measurement: To analyze the strength of the catalyst molding body, crushing strength was measured using a compression testing machine. The crushing strength was measured using a Unitech-M universal testing machine, and the results are shown in Table 1.

[0107] (Table 1)

[0108]

[0109] As shown in Table 1, in Examples 1 and 2, the average particle size of Ni particles was smaller and the Ni content was also lower.

[0110] Experimental example: Production of syngas from reforming feedstock

[0111] Syngas was prepared using the catalyst profiles prepared in Examples 1, 2, Comparative Example 1, and Comparative Example 2.

[0112] A combined reforming process was performed using methane as the reactant gas and carbon dioxide and water vapor as oxidants. The catalyst prototyping body was fixed 6 cm in a 1-inch reactor, and the temperature was raised to 900°C in a hydrogen atmosphere for 2 hours of reduction. Then, CH4, CO2, and H2O were injected at a space velocity (SV) of 9000 rpm in a CH4:CO2:H2O ratio of 1:0.5:1. The temperature was 900°C and the pressure was 1 bar.

[0113] Catalyst activity such as Figure 14 As shown.

[0114] like Figure 14 As shown, Examples 1 and 2, in which the particle size of the active metal particles was appropriately formed using an atomic layer deposition process, exhibited superior catalytic activity compared to Comparative Examples 1 and 2. In Example 1, although the Ni content was only 1 / 120 of Comparative Example 1, the CH4 conversion was 75.6% and the CO2 conversion was 34.5%. In Example 2, although the Ni content was about 1 / 40 of Comparative Example 1, the CH4 conversion was 72.4% and the CO2 conversion was 32.4%. Despite the lower Ni content in Example 1, the smaller Ni particle size resulted in superior performance. In Comparative Example 1, where a Ni-based powder catalyst with a metal oxide coating was extruded, the CH4 conversion was 67.5% and the CO2 conversion was 26.8%, exhibiting better performance than the commercial catalyst in Comparative Example 2. This indicates that the presence or absence of a metal oxide coating affects the sintering rate of Ni particles during the reaction.

[0115] Furthermore, for Example 1, long-term durability was evaluated by generating syngas as described above, but the reaction was carried out for 200 hours at a catalyst layer thickness of 3.4 cm and a space velocity of 9000 / h. This is summarized in Table 2 below.

[0116] (Table 2)

[0117]

[0118] As shown in Table 2, despite a long-term reaction of 200 hours under harsh conditions with a space velocity of 9000 / h, the conversion rate decreased by only about 6%. This example demonstrates the durability of the catalyst profile.

Claims

1. A catalyst profile for producing syngas, comprising: Carrier-shaped body; Multiple metal active particles are loaded on the carrier molded body, wherein the average particle size of the multiple metal active particles is 5 nm to 30 nm. as well as A metal oxide coating is disposed on (i) the plurality of metal active particles and (ii) at least a portion of the carrier molded body.

2. The catalyst molded body according to claim 1, wherein the carrier molded body comprises alumina and boehmite.

3. The catalyst molded body according to claim 1, wherein the plurality of metal active particles comprises one or more of nickel (Ni), cobalt (Co), rhodium (Rh), ruthenium (Ru), iridium (Ir), palladium (Pd), platinum (Pt), gold (Au) and iron (Fe).

4. The catalyst molded body according to claim 1, wherein the metal oxide coating comprises the metal component of the carrier molded body and the metal component of the plurality of metal active particles.

5. The catalyst molded body according to claim 1, wherein the metal oxide coating comprises one or more of aluminum oxide (Al2O3), magnesium aluminate (MgAl2O4), calcium aluminate (CaAl2O3), and nickel aluminate (NiAl2O3).

6. The catalyst molded body according to claim 1, wherein the average thickness of the metal oxide coating is 2 nm to 10 nm.

7. The catalyst molded body according to claim 1, wherein the metal composition of the plurality of metal active particles is from 0.1% to 2% by weight relative to 100% by weight of the total catalyst molded body.

8. The catalyst molded body according to claim 1, wherein the specific surface area of ​​the catalyst molded body is 0.1 m². 2 / g to 30m 2 / g, the porosity of the catalyst molding is 40% to 90%, and The average pore size of the catalyst molded body is 40 nm to 200 nm.

9. The catalyst molding body according to claim 1, wherein the crushing strength of the catalyst molding body is 300N to 3000N.

10. The catalyst molded body according to claim 1, wherein the catalyst molded body has one or more pores therein.

11. The catalyst molding body according to claim 1, wherein the catalyst molding body has a cylindrical shape with a diameter of 2 mm to 25 mm and a height of 1 mm to 30 mm.

12. A method for manufacturing a catalyst profile for producing syngas, comprising: A carrier molded body is formed by molding carrier powder; Metal active particles were deposited on the carrier molded body using atomic layer deposition (ALD) technology. as well as A metal oxide coating is formed on at least a portion of the carrier molded body (i) and the metal active particles (ii).

13. The method of claim 12, wherein forming the carrier molded body comprises applying a pressure of 1 kN to 20 kN to the carrier powder.

14. The method according to claim 12, further comprising: After the carrier molded body is formed, the carrier molded body is heated to a temperature of 800°C to 1500°C.

15. The method of claim 12, wherein depositing the metal active particles comprises injecting a metal active particle precursor and heating it to a temperature of 100°C to 350°C.

16. The method of claim 12, wherein depositing the metal active particles comprises repeating the following operations 100 to 1000 times: (i) injecting a metal active particle precursor, (ii) heating to a temperature of 100°C to 350°C, and (iii) purging.

17. The method of claim 12, wherein forming the metal oxide coating comprises injecting hydrogen and heating to a temperature of 600°C to 1000°C.

18. A method for producing syngas, comprising: Inject reactive gas and oxidant so that the reactive gas and oxidant come into contact with the catalyst molded body according to claim 1; as well as The reactant gas is reformed via an endothermic reaction to produce the syngas.

19. The method according to claim 18, wherein the reaction gas comprises one or more of C1 to C20 alkanes, C1 to C20 alkenes, C1 to C20 alkynes, ammonia (NH3), formaldehyde (HCO2H), and methanol (CH3OH).

20. The method of claim 18, wherein the oxidant comprises one or more of carbon dioxide (CO2), water vapor (H2O), and oxygen (O2).

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