Reduction catalysts, properties thereof, and methods of making and using the same

Abstract

A reduction catalyst comprising iron and zinc is disclosed having improved selectivity and activity. Methods of making and using the reduction catalyst for carbon dioxide hydrogenation are also disclosed.

Description

REDUCTION CATALYSTS, PROPERTIES THEREOF, AND METHODS OF MAKING AND USING THE SAMECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 546,900, filed November 1 , 2023, and U.S. Provisional Patent Application No. 63 / 567,700, filed March 20, 2024, the contents of each of which are incorporated herein by reference in their entirety.BACKGROUND OF THE INVENTION

[0002] As carbon dioxide concentrations in the atmosphere increase, it is advantageous from social welfare, human health, and energy security perspectives to develop technologies that remove carbon dioxide from the air. Carbon dioxide conversion technologies offer added benefit of producing commodity chemicals on-site, anywhere on the globe, with no cost or hazard risk of transportation when combined with air capture of carbon dioxide. This effort aligns with the growing global utilization of renewable electricity generation, such as solar photovoltaics and wind turbines, making it possible for the process to be powered completely by the renewable energy.

[0003] Of the available technologies to produce chemicals from carbon dioxide, hydrogenation of carbon dioxide or carbon monoxide using renewably-derived hydrogen gas from a water electrolyzer or equivalent system that produces carbon-neutral hydrogen gas, is capable of being powered completely by renewable (solar, wind, hydroelectric, etc.) electricity. A method such as this converts a carbon-based feedstock (carbon dioxide or carbon monoxide) and water into hydrocarbon chemicals using an external energy source; this is similar to the fundamental photosynthetic processes enabling life on our planet. For example, plants use photosynthesis to convert carbon dioxide, water, and solar energy into chemical energy by creating sugars and other complex hydrocarbons. This effectively stores the energy from the sun in the chemical bonds of a carbon-based compound. This process has been supporting the Earth's ecosystem and balancing carbon dioxide concentration in our atmosphere for billions of years.

[0003] To produce chemicals from carbonaceous feedstock, the Fischer-Tropsch (FT) process is one of the most widely used petrochemical process for fuel production today. Originally reported by Fischer and Tropsch in 1922 using alkaline iron catalysts, the FT process utilizes a mixture of CO and H2 at elevated temperature and pressure to produce paraffins and other hydrocarbons. Product distribution from the FT process is characterized by the polymerizationof CHXreaction intermediates on the surface of the FT catalyst. The CHXmonomers polymerize on the surface of the FT catalyst into CyHzintermediates of different carbon numbers, which under further hydrogenation or dehydrogenation to form paraffins, olefins, and other hydrocarbon compounds. In the FT process, the C-C coupling of active CHXand CyHzspecies on the surface of the FT catalyst is challenging to control, which leads to a statistical distribution of hydrocarbon products.

[0004] Catalysts for CO2 conversion, specifically, face a major challenge in that CO2 requires a substantial amount of energy to transform into other compounds. This makes stability and activity a key challenge for industrial catalysts for CO2 conversion. No known catalysts based on low-cost metals suitable for large-scale commercial deployment (e.g., not Pt-group metals such as Ru, Ir, and Rh) have yet been demonstrated as commercial catalysts for the hydrogenation of CO2 to paraffins or other hydrocarbons suitable for use as diesel or aviation fuel.

[0005] This is, in part, because prior reported compounds have not shown the stability that is required for scaling up the materials, since these catalysts decay into less active materials while on-stream in a reactor. It is also due to their low selectivity for the appropriate hydrocarbons, based on the distribution of carbon chain lengths that are produced under commercial reactor conditions. Because of the lack of stable and efficient catalysts for this process, no commercial chemical process was known that converts carbon dioxide into hydrocarbon products suitable for use in diesel or aviation fuel without a separate step in a chemical process that converts CO2 to CO or CH4 (as in the Sabatier process) first.SUMMARY OF THE INVENTION

[0006] A reduction catalyst is disclosed comprising: iron; zinc; one or more second elements selected from Group IA, IIA and X metals; and a binder. The reduction catalyst may have a selectivity for CO2 conversion to methane of less than about 15, or less than about 11. When the reduction catalyst is contacted with a continuous flow of fluid, the total concentration of iron, zinc, and one or more second elements in the effluent at a steady state may be less than about 50 ppm, or less than about 40 ppm. The reduction catalyst may maintain activity at over about 75% for about one year, over about two years, or about two years. The molar ratio of iron to zinc in the reduction catalyst may be about 1 : 1 to about 7: 1, or about 1 : 1 to about 4: 1. The binder may be selected from boehmite, silica-alumina hydrate, aluminate, silica, silicate, pseudoboehmite alumina, bentonite clay, montmorillinite clay, tungsten, zirconate, or any combination thereof, and optionally may be present in about 0.1% to about 60% by weight ofthe total catalyst. The binder may include a promoter element selected from Na, K, Cs, Li, Rb, or a combination thereof. The binder may be selected from Na- aluminate, K-aluminate, Na- silicate, K-silicate, Na - zirconate, K- zirconate, Na-tungsten, K-tungsten or a combination thereof. The binder may be present in about 0.1% to about 60% by weight of the total catalyst.

[0007] The one or more second elements in the reduction catalyst may be the Group IA or IIA metal selected from magnesium, calcium, potassium, sodium, cesium, or a combination thereof. The one or more second elements in the reduction catalyst may be selected from potassium, sodium, or a combination thereof. The one or more second elements in the reduction catalyst may be present in an amount of about 0.2% to about 10%, about 0.5% to about 5%, about 0.5% to about 3%, or about 1% to about 5% of the total weight of iron and zinc. The one or more second elements in the reduction catalyst may be the Group X metal selected from the group consisting of palladium, platinum, iridium, nickel, rhodium, and any combination thereof.

[0008] A method of CO2 hydrogenation comprising contacting a carbon source gas and a reduction gas with the reduction catalyst is disclosed, thereby producing a hydrocarbon product mixture comprising one or more paraffins and olefins.

[0009] Also disclosed are methods of making the reduction catalyst. One method of making the reduction catalyst comprises: providing a powder catalyst comprising iron, zinc and one or more second elements selected from Group IA, IIA and X metals; combining the powder catalyst, a binder and a lubricant to make a dry mixture; combining the dry mixture with a first solution comprising a peptizing agent, wherein the peptizing agent activates the binder thereby forming an extrudable dough; processing the extrudable dough in an extruder to afford formed catalyst, which may take the form of extrudates, pellets, tablets, or the like; and heating the formed catalyst to a drying temperature for a first period of time to afford a dried, formed catalyst, and / or heating to a calcining temperature for a second period of time to afford a calcined, formed catalyst.

[0010] Another method of making the reduction catalyst comprises: providing a powder catalyst made by any suitable method known in the art; combining the powder catalyst with a slurry comprising a peptizing agent and a binder to make an extrudable dough; processing the extrudable dough in an extruder to afford formed catalyst, which may take the form of extrudates, pellets, tablets, or the like; and heating the formed catalyst to a drying temperature for a first period of time to afford a dried catalyst, and / or heating to a calcining temperature for a second period of time to afford a calcined catalyst.DETAILED DESCRIPTION

[0011] The present disclosure provides catalysts made of iron and zinc for CO2 conversion to a hydrocarbon mixture. The catalysts of the disclosure may include a first element (Fe) as a metal promoting carbon-carbon bond formation. These catalysts may be used to inhibit the formation of gaseous byproducts during operation, e.g., CH4, to further enable effective recycle of unreacted gases during product gas recycle in a multi-pass gas to liquids reactor.

[0012] In certain embodiments, the present disclosure provides catalysts comprising iron oxide and zinc. The zinc aids in CO2 activation and conversion (e.g., by acting as a metal promoter). In further embodiments, the catalyst comprising iron oxide further comprises a support including alumina, a zeolite, or silica. In certain embodiments, the catalysts comprising iron oxide are useful for converting CO2 to a hydrocarbon mixture comprising olefins and paraffins.

[0013] In certain aspects, the present disclosure provides a chemical process to produce a hydrocarbon mixture from CCh and EE in a single reactor. The process differs from FT-based processes in that CCE is a feedstock rather than CO. Increasing concentrations of CO2 in the feedstock stream of typical cob alt-catalyzed FT processes causes the reactor to produce exclusively methane, as known to persons having ordinary skill in the art. The present invention, thus, represents a significant step forward in gas-to-liquids chemistry by using a catalyst and reaction conditions where little to no methane is produced with a feedstock stream comprised of CO2 and EE.

[0014] Transition metal catalysts, especially base metals, are particularly effective as reduction catalysts due to their high electron density, various oxidation states and rich spectrum of metalceramic materials, which provides enhanced carbon dioxide activations and flexible tuning of transformation pathways. In addition to the metal elements, the reduction catalyst may contain one or more additional materials, such as a binder, lubricant and / or supporting material, which can be added to optimize the forming catalyst process, metal dispersity and other chemical and physical properties.

[0015] The reduction catalyst disclosed herein may be a paraffin catalyst or an olefin catalyst. As used herein, the term “paraffin catalyst” refers to a catalyst used for the conversion of carbon sources and reduction gases to paraffins, predominantly, but which catalyst does not necessarily itself comprise paraffins. A paraffin catalyst may be selected when the desired product is paraffins. As used herein, the term “olefin catalyst” refers to a catalyst used for the conversion of carbon sources and reduction gases to olefins, predominantly, but which catalyst does not necessarily itself comprise olefins. An olefin catalyst may be selected when the desired product is olefins. The olefin catalyst may be used for the conversion of carbon sources andreduction gases to olefin predominantly, as well as paraffins and / or other hydrocarbons in a minority amount.

[0016] Reduction catalysts disclosed herein have improved selectivity for olefins and / or paraffins over methane and improved means for adjusting the olefin to paraffin ratio.

[0017] By using a reduction catalyst disclosed herein with carbon conversion, a carbon source gas may be converted into a hydrocarbon mixture comprising olefins and paraffins. The hydrocarbon mixture may have an olefin to paraffin ratio (O / P) of greater than about 7. The olefin catalyst may afford a product stream having an olefin to paraffin ratio (O / P) of about 7 to about 9, about 8 to about 9, or about 8.

[0018] Methane is generally an undesirable byproduct of carbon dioxide conversion. Methane production is therefore a factor of the effectiveness of the catalyst, as methane production is undesirable. Accordingly, the lower the methane production (also referred to herein as methane selectivity, SCi, defined in Equation 1), the better the catalyst. Referring to Equation 1, Cmol.CEU represents mole fraction of methane in the product stream, Cmol.CChfeed represents mole fraction of CCh in the feed stream, and Cmol.CChproduct represents the mole fraction of CO2 in the product stream.Eq. 1: Selectivity for methane (SCi) = [Cmol.CEU / (Cmol.CChfeed - Cmol.CChproduct)]The reduction catalyst disclosed herein may have a methane selectivity (SCi) of less than about 15 carbon mole%, less than about 11 carbon mole%, or less than about 10 carbon mole%. The reduction catalyst may have a methane selectivity of about 2 to about 15, about 4 to about 15, about 5 to about 12, about 5 to about 11, about 6 to about 11, or about 8 to about 11 carbon mole%. The reduction catalysts described herein may have a selectivity for C2 to C4 hydrocarbons (SC2-C4) of greater than about 15, greater than about 20, greater than about 25, greater than about 30, greater than about 35, or greater than about 35 carbon mole%. The reduction catalysts described herein may have a SC2-C4 from about 15 to about 50, about 20 to about 45, or about 25 to about 45 carbon mole%. The reduction catalysts described herein may have a SC2-C4 of about 28, about 35, about 38, about 39, or about 45 carbon mole%. The selectivity for C2-4 is determined by adding (selectivity for C2) + (selectivity for C3) + (selectivity for C4), with each selectivity value calculated according to Equation 2. Referring to Equation 2: Cxrepresents a hydrocarbon having a carbon number of x; Cmol.Cx represents mole fraction of Cxin the product stream; Cmol.CChfeed represents mole fraction of CO2 in the feed stream; and Cmol.CChproduct represents the mole fraction of CO2 in the product stream.Eq. 2: Selectivity for hydrocarbon Cx(SCX) = [Cmol.Cx / (Cmol.CChfeedCmol . C'CTprodi id)]

[0019] The reduction catalysts disclosed herein may have a selectivity for C5+ hydrocarbons (SC5+, wherein C5+ refers to any hydrocarbons with a carbon number of 5 or higher) of greater than about 20, greater than about 22, greater than about 25, greater than about 28, greater than about 30, greater than about 32, or greater than about 34 carbon mole%. The reduction catalysts disclosed herein may have a selectivity for C5+ hydrocarbons (SC5+) from about 20 to about 45, about 22 to about 43, about 25 to about 43, about 28 to about 43, or about 30 to about 40 carbon mole%. The reduction catalysts disclosed herein may have a selectivity for C5+ hydrocarbons (SC5+) of about 29, about 31, about 33, about 34, about 35, or about 43 carbon mole%. The higher the selectivity for C5+ hydrocarbons, the better the catalyst performance for the processes of carbon dixode conversion disclosed herein.

[0020] Oxygenates are generally an undesirable byproduct of carbon dioxide conversion. The reduction catalyst disclosed herein may have an oxygenate selectivity (Soxy) of less than about 20, less than about 16, less than about 14, or less than about 15 carbon mole%. The reduction catalyst may have an oxygenate selectivity of about 2 to about 20, about 4 to about 18, or about 4 to about 16 carbon mole%.

[0021] Metal leaching can be a problem associated with the use of metal-containing catalysts. Metal leaching of the catalysts can cause a number of problems, including: i) Product contamination: metal ions from the catalyst can dissolve into liquids, which can contaminate the product stream, and may require significant downstream processing to remove the metals; ii) System corrosion: metal leaching can cause corrosion in the system; and iii) Catalyst deactivation: metal leaching can cause the loss of active species from the catalyst and loss of efficacy, in terms of activity and selectivity. The higher the rate of leaching, the faster the deactivation of the catalyst.

[0022] Reduction catalysts of the disclosure provide significant improvements in metal leaching over other catalysts, including unsupported metal catalysts. The formed reduction catalysts (that is, the catalyst including the binder) disclosed herein have a significant reduction in metal leaching over the powder form of the same catalyst (i.e., without the binder). Theamount of metal leaching when comparing the powder catalyst to a formed catalyst may be decreased by over about 50%, over about 70%, over about 80%, or over about 90%.

[0023] The amount of total metal leaching in the effluent may be measured once the reaction has reached a steady state by: i) separating the aqueous portion from the oil portion of the effluent; and ii) analyzing a sample of the aqueous portion by ICP-MS to obtain a concentration of metal leached in the aqueous sample. The method of measuring metal leaching may further include: iii) dissolving the oil portion in an acid, such as nitrohydrochloric acid; iv) analyzing a sample of the dissolved oil portion by ICP-MS to obtain a concentration of metal in the oil sample; and v) adding the concentration of metal in the oil sample and the concentration of metal in the aqueous sample to obtain the total metal leaching. After steady state has been reached the oil sample generally includes less than about 1 ppm of leached metal. Before steady state has been reached, the loose powder in the catalyst migrates into the effluent and dissolves in the oil portion of the effluent and may be tested if warranted. As the time on stream continues, the loose powder in the catalyst is eliminated and thus the concentration of metal in the oil portion of the effluent reduces to zero.

[0024] Steady state of the reaction may be reached after a time on stream that results in the concentration (ppm) of the second element being about 10 ppm or less, about 8 or less, or about 6 ppm or less. Steady state of the reaction may be reached after a time on stream that results in the concentration (ppm) of the second element being about 0 ppm to about 10 ppm, about 0 ppm to about 8 ppm, about 0 ppm to about 6 ppm, or greater than about 0 ppm to about 6 ppm. Steady state may be reached after about 100 hours to about 1000 hours, about 200 hours to about 800 hours, about 200 hours to about 600 hours time on stream. Steady state of the reaction may be determined by the concentration of the second element because the second element leaches more than the active metals and is in the lower amount in the catalyst than the active metals, a. When the reduction catalyst is contacted with a continuous flow of fluid, the total concentration of iron, zinc, and one or more second elements in the effluent at steady state may be less than about 50 ppm, less than about 40 ppm, less than about 20 ppm, or less than about 15 ppm. The total concentration of iron, zinc, and one or more second elements in the effluent at steady state may be less than about 50 ppm, less than about 40 ppm, less than about 20 ppm, less than about 15 ppm, less than about 10 ppm, or less than about 5 ppm. The total concentration of iron, zinc, and one or more second elements in the effluent tested at steady state may be about 0 ppm to about 50 ppm, greater than about 0 ppm to about 40 ppm, about 1 ppm to about 30 ppm, or about 1 ppm to about 20 ppm. The total concentration of iron, zinc,and one or more second elements may also be understood as the metal leaching in the reactor effluent stream tested after an amount of time on stream, or at steady state.

[0025] The total concentration of the one or more second elements in the effluent at steady state may be less than about 10 ppm, less than about 8 ppm, less than about 6 ppm, less than about 5 ppm, less than about 4 ppm, less than about 3 ppm, or less than about 2 ppm. The total concentration of the one or more second elements in the effluent tested at steady state may be about 0 ppm to about 10 ppm, about 0 ppm to about 8 ppm, about 0 ppm to about 6 ppm, or greater than about 0 ppm to about 6 ppm. When the second element is sodium, the total concentration of sodium, also understood as the concentration of sodium leached from the formed catalyst, in the effluent at steady state may be less than about 6 ppm, less than about 5 ppm, less than about 4 ppm, less than about 3 ppm, or less than about 2 ppm. The total concentration of sodium in the effluent tested at steady state may be about 0 ppm to about 6 ppm, or greater than about 0 ppm to about 6 ppm.

[0026] The total concentration of iron, zinc, and one or more second elements in the effluent tested after about 200 hrs to about 400 hrs of time on stream may be less than about 50 ppm, less than about 40 ppm, less than about 20 ppm, or less than about 15 ppm. The total concentration of iron, zinc, and one or more second elements in the effluent tested after about 400 hrs of time on stream may be less than about 50 ppm, less than about 40 ppm, less than about 20 ppm, less than about 15 ppm, less than about 10 ppm, or less than about 5 ppm. The total concentration of iron, zinc, and one or more second elements in the effluent tested after about 400 hrs of time on stream may be about 0 ppm to about 50 ppm, greater than about 0 ppm to about 40 ppm, about 1 ppm to about 30 ppm, or about 1 ppm to about 20 ppm. The total concentration of iron, zinc, and one or more second elements in the effluent tested after about 200 hrs of time on stream may be less than about 50 ppm, less than about 40 ppm, less than about 20 ppm, or less than about 15 ppm. The total concentration of iron, zinc, and one or more second elements in the effluent tested after about 200 hrs of time on stream may be about 0 ppm to about 50 ppm, about 1 ppm to about 40 ppm, about 1 ppm to about 20 ppm, or about 1 ppm to about 15 ppm. Metal leaching refers to the total amount (i.e., concentration) of iron, zinc and the second element selected from Group IA, IIA, and / or X metal ions present in the effluent tested after an amount of time on stream.

[0027] Because there may be less of the second element present in the catalyst than iron or zinc, reducing the leaching of the second element may be especially important in maintaining the life of the catalyst. The amount of leaching of the second element (e.g., Na, K) of the formed catalyst in the effluent tested after about 200 hrs to about 400 hrs of time on stream may be lessthan about 10 ppm, less than about 8 ppm, less than about 5 ppm, or less than about 2 ppm. The amount of leaching of the second element of the formed catalyst in the effluent tested after about 400 hrs of time on stream may be less than about 10 ppm, less than about 8 ppm, less than about 5 ppm, or less than about 2 ppm. The amount of leaching of the second element of the formed catalyst in the effluent tested after about 400 hrs of time on stream may be about 0 ppm to about 10 ppm, about 0 ppm to about 8 ppm, about 0 ppm to about 6 ppm, about 0.1 ppm to about 5 ppm, or about 1 ppm to about 4 ppm.

[0028] The amount of leaching of the second element of the formed catalyst in the effluent tested after about 200 hrs of time on stream may be less than about 10 ppm, less than about 8 ppm, less than about 5 ppm, or less than about 4 ppm. The amount of leaching of the second element of the formed catalyst in the effluent tested after about 200 hrs of time on stream may be about 1 ppm to about 10 ppm, about 1 ppm to about 8 ppm, about 1 ppm to about 5 ppm, or about 1 ppm to about 4 ppm.

[0029] The formed reduction catalyst referred to herein contains a binder and shape formed by any known means in the art, for example but not limited to, extrusion, press, powder pressed to pellets, tablets or other shaped forms. The formed catalyst (as extrudate or pellet) may have a crush strength greater than about 20 N / mm, greater than about 25 N / mm, greater than about 30 N / mm or greater than about 40 N / mm. The formed catalyst (as extrudate, pellet, or tablet) may have a crush strength of about 20 N / mm to about 100 N / mm, about 20 N / mm to about 80 N / mm, about 20 N / mm to about 65 N / mm, about 30 N / mm to about 65 N / mm, about 35 N / mm to about 60 N / mm, or about 40 N / mm to about 55 N / mm.

[0030] Due to the reduced metal leaching, the reduction catalyst disclosed herein have a longer life (i.e., before deactivation) than other catalysts. The reduction catalyst disclosed herein may maintain activity for over about one year, over about 18 months, over about 20 months, over about 36 months, or over about 48 months. The reduction catalyst disclosed herein may maintain activity for about one year to about 5 years, about two years to about 5 years, about 3 years to about 5 years, or about 4 years to about 5 years. The term “maintain activity” means that the activity of the catalyst in conversion of CO2 to hydrocarbons remains above about 75% of its initial activity.

[0031] The product stream may comprise C1-C40 hydrocarbons. The C1-C40 hydrocarbons of the product stream may comprise (i) paraffins (n-paraffms, iso-paraffins, cyclo-paraffins), olefins (n-olefins, iso-olefins), and (2) aromatics. The product stream may also comprise: (3) oxygenates (alcohols, ketones, esters, aldehydes and acids), and (4) water.

[0032] The feed stream may comprise a carbon source gas, e.g., CO2, and a reduction gas, e.g., H2, IN certain embodiments, the feed stream may further comprise one or more of the following: CO, CH4, C2H4,C2H6, C3H6, C3H8, C4H8, C4HIO.

[0033] The reduction catalyst may comprise iron and zinc, one or more second elements selected from Group IA, IIA, and X metals, and a binder. When the reduction catalyst includes a binder, it may also be referred to as a formed reduction catalyst. The reduction catalyst may comprise iron and zinc; optionally alumina; optionally a first element selected from copper, cobalt, manganese, chromium, or combinations thereof; optionally one or more second elements selected from Group IA, IIA, and X metals; and a binder

[0034] The reduction catalyst may comprise a first element selected from copper, cobalt, or combinations thereof. The first element may be copper. The first element may be cobalt. The first element may be a combination of copper, and / or cobalt. The reduction catalyst may be free of a first element selected from copper, cobalt, or combinations thereof.

[0035] The reduction catalyst may comprise the second element selected from one or more Group IA or IIA metals. The one or more Group IA or IIA metals may comprise magnesium, calcium, potassium, sodium, cesium, rubidium, or any combination thereof. The one or more Group I A or IIA metals may consist of magnesium, calcium, potassium, sodium, cesium, or rubidium. The one or more Group IA or IIA metals may comprise magnesium. The one or more Group IA or IIA metals may comprise calcium. The one or more Group IA or IIA metals may comprise potassium. The one or more Group I A or IIA metals may comprise sodium. The one or more Group I A or IIA metals may comprise cesium. The one or more Group I A or IIA metals may comprise rubidium. The one or more Group IA or IIA metals may consist of magnesium. The one or more Group IA or IIA metals may consist of calcium. The one or more Group I A or IIA metals may consist of potassium. The one or more Group I A or IIA metals may consist of sodium. The one or more Group IA or IIA metals may consist of cesium. The one or more Group IA or IIA metals may consist of rubidium.

[0036] The reduction catalyst may comprise the second element being a Group X metal. The Group X metal may be selected from palladium, platinum, iridium, nickel, and rhodium. The Group X metal may be platinum. The Group X metal may be palladium. The Group X metal may be nickel.

[0037] The reduction catalyst may also include one or more third elements selected from a Group V, VI, VII, VIII, IX, and XI metal (e.g., manganese, chromium, silver, niobium, zirconium, molybdenum, ruthenium). The reduction catalyst may include manganese. Thereduction catalyst may include silver. The reduction catalyst may be free of a third element selected from a Group V, VI, VII, VIII, IX, and XI metal

[0038] The reduction catalyst may comprise the Group IA, IIA, or X metal at about 0.1 wt% to about 60 wt% of the total weight of iron, zinc, and Group IA, IIA, or X metal. The reduction catalyst may comprise the Group IA, IIA, or X metal at about 0.1 wt% to about 20 wt%, about 0.1 wt% to about 10 wt%, about 0.1 wt% to about 5 wt%, about 0.1 wt% to about 2 wt%, about 0.4 wt% to about 1.5 wt%, or about 0.5 wt% to about 1.5 wt% of the total weight of iron, zinc, and Group IA, IIA, or X metal. The reduction catalyst may comprise a Group IA metal at about 0.1 wt% to about 60 wt% of the total weight of iron, zinc, and Group IA metal. The reduction catalyst may comprise the Group IA metal at about 0.1 wt% to about 20 wt%, about 0.1 wt% to about 10 wt%, about 0.1 wt% to about 5 wt%, about 0.1 wt% to about 2 wt%, about 0.4 wt% to about 1.5 wt%, or about 0.5 wt% to about 1.5 wt% of the total weight of iron, zinc, and Group I A metal.

[0039] The reduction catalyst may comprise Na, Mn, K, Cs, Li, Rb at a molar ratio from 0 to about 0.60 relative to iron. In certain embodiments, the reduction catalyst comprises: iron; K, Cs, Mg, Rh, Ca, or a combination thereof, at a molar ratio of from 0 to about 0.20 relative to iron; Na, Cu, Cr, Mn, or a combination thereof, at a molar ratio of from 0 to about 0.60 relative to iron; and / or Co, Ru, Ni, or a combination thereof, at a molar ratio of from 0 to about 0.50 relative to iron.

[0040] The iron may be in metal form, in the form of an iron oxide, or a combination thereof. In certain embodiments, the iron is in the iron oxide form. The iron oxide may be FeO, magnetite (FesCU), hematite (Fe20s), or a combination thereof. In some embodiments, the iron oxide is magnetite (FesCU). In other embodiments, the iron oxide is a combination of magnetite (FesCU) and hematite (Fe2O3). In other embodiments, the iron oxide is a combination of FeO, magnetite (FesO^ and hematite (Fe20s).

[0041] The reduction catalyst may comprise: iron; zinc; a first element selected from copper, cobalt, or combinations thereof; optionally one or more second elements selected from Group I A, IIA and X metals; and a binder.

[0042] The reduction catalyst may include: iron and zinc, with one or both of the iron and zinc being present in oxide or carbide forms. The iron oxide may be in the form of FeO, Fe20s (hematite), FesO4 (magnetite) or a combination thereof. The iron oxide may be substantially (e.g., over about 80%, or over about 90%) in the form of Fe20s. The iron oxide may be substantially (e.g., over about 80%, or over about 90%) in the form of FesO4.

[0043] The reduction catalyst may comprise zinc at a molar ratio of about 0.2 to about 3 relative to iron, or about 0.3 to about 3 relative to iron. In some embodiments, the reduction catalyst comprises zinc at a molar ratio of about 0.2 to about 1 relative to iron, or about 0.4 to about 1 relative to iron. In some embodiments, the reduction catalyst comprises zinc at a molar ratio of about 1.5 relative to iron. In other embodiments, the reduction catalyst comprises zinc at a molar ratio of about 1.0 relative to iron. In certain embodiments, the reduction catalyst comprises zinc at a molar ratio of about 0.75 relative to iron, about 0.6 relative to iron, about 0.5 relative to iron, about 0.4 relative to iron, about 0.3 relative to iron, or about 0.25 relative to iron. In some embodiments, the reduction catalyst comprises zinc at a molar ratio of about 0.5 relative to iron.

[0044] The reduction catalyst may comprise a molar ratio of iron to zinc of about 1 : 1 to about 7: 1, about 1 : 1 to about 6: 1; about 2:2 to about 6: 1, about 1 : 1 to about 4: 1, about 1 : 1 to about 3: 1, or about 2: l to about 3: l. The reduction catalyst may comprise a molar ratio of iron to zinc of about 1 : 1 to about 4.5: 1, about 1.5: 1 to about 3.5: 1, about 1.5: 1 to about 3: 1, or about 1.5: 1 to about 2.5: 1. The reduction catalyst may comprise a molar ratio of iron to zinc of about 2: 1.

[0045] In some embodiments, the reduction catalyst comprises: iron; zinc at a molar ratio of about 0.2 to about 6 relative to iron; and one or more Group IA and IIA metals. The one or more Group IA and IIA metals may be present at a molar ratio from 0 to about 0.60 relative to iron; and Zn at a molar ratio from 0 to about 0.50 relative to iron. In some embodiments, the reduction catalyst comprises: iron; zinc at a molar ratio of about 0.2 to about 6 relative to iron; and one or more Group IA, IIA, and X metals. The one or more Group IA, IIA, and X metals may be present at a molar ratio from 0 to about 0.60 relative to iron; and Zn at a molar ratio from 0.2 to about 3 relative to iron.

[0046] The reduction catalyst may comprise K, Na, Cs, Rh, Rb, Mn, Li, Pt, Pd, Ru, Cu, Mo, Ce, or a combination thereof at a molar ratio of about 0.01 to about 0.20, about 0.01 to about 0.10, about 0.01 to about 0.08, about 0.01 to about 0.05, or about 0.02 to about 0.4 relative to iron. In other embodiments, the reduction catalyst comprises Na or K at a molar ratio of about 0.01 to about 0.20, about 0.01 to about 0.10, about 0.01 to about 0.08, about 0.01 to about 0.05, or about 0.02 to about 0.4 relative to iron.

[0047] The reduction catalyst may comprise K, Na, Cs, Rh, Rb, Mn, Li, Pt, Pd, Ru, Cu, Mo, Ce, or a combination thereof in an amount of about 0.1 wt% to about 10 wt%, about 0.2% to about 10%, about 0.1% to about 2%, about 0.5% to about 5%, about 0.2% to about 1.5%, or about 0.5% to about 1.0% of the total weight of iron plus zinc. In certain embodiments, the reduction catalyst comprises Na or K in an amount of about 0.2% to about 10%, about 0.5% toabout 5%, about 0.5% to about 3%, about 0.5% to about 1%, or about 1% to about 5% of the total weight of iron plus zinc. In other embodiments the reduction catalyst may comprise Na in an amount of about 0.2% to about 10%, about 0.5% to about 5%, about 0.5% to about 3%, about 0.5% to about 1%, or about 1% to about 5%of the total weight of iron plus zinc.

[0048] The reduction catalyst may comprise iron, zinc and one or more Group IA or IIA metals, having a molar ratio of iron to zinc of about 1: 1 to about 4.5: 1, about 1.5: 1 to about 3.5: 1, about 1.5: 1 to about 3: 1, or about 1.5: 1 to about 2.5: 1; and the one or more Group IA or IIA metals present at about 0.5% to about 1.0% of the total weight of iron plus zinc.

[0049] The reduction catalyst may comprise iron, zinc, and the one or more Group IA, IIA or X metals being sodium, lithium, platinum, cesium, rubidium, manganese, or potassium, having a molar ratio of iron to zinc of about 1.5: 1 to about 2.5: 1; and the Na, Li, Rb, Mn, Cs, Pt, or K present at about 0.5% to about 1.0% of the total weight of iron plus zinc. The reduction catalyst may comprise iron, zinc, and the one or more Group IA or IIA metals being sodium or potassium, having a molar ratio of iron to zinc of about 1.5: 1 to about 2.5: 1; and the Na or K present at about 0.5% to about 1.0% of the total weight of iron plus zinc.

[0050] In certain aspects, the reduction catalysts further comprise a reduction catalyst support. The reduction catalyst support may be any suitable material that can serve as a catalyst support.

[0051] In some embodiments, the catalyst support comprises one or more materials selected from an oxide, nitride, fluoride, silicate, or carbide of an element selected from aluminum, silicon, titanium, zirconium, cerium, magnesium, yttrium, lanthanum, zinc, and tin. In further embodiments, the catalyst support comprises one or more materials selected from an oxide, nitride, fluoride, silicate, or carbide of an element selected from aluminum, silicon, titanium, zirconium, cerium, magnesium, yttrium, lanthanum, zinc, iron, and tin. In some preferred embodiments, the catalyst support comprises 7-alumina. In certain embodiments, the catalyst support is selected from carbon, silica, zeolite, alumina, zirconium oxide, titanium oxide, and silica carbide. In certain embodiments, the additional support is selected from carbon, silica, zeolite, alumina, iron oxide, zirconium oxide, titanium oxide, and silica carbide. In some embodiments, the catalyst support is an aluminum oxide that is formed in-situ as part of the catalyst. In some embodiments, the catalyst support is selected from, but not limited to, AI2O3, ZrCh, SnCh, SiCh, ZnO, and TiCh. In some embodiments, the catalyst support is selected from AI2O3, ZrCh, SnCL, SiCh, ZnO, and TiO2. In some embodiments, the catalyst support is selected from AI2O3, ZrO2, SnO2, SiO2, ZnO, Fe2O3, Fe3O4, FeO, and TiO2.

[0052] In some embodiments, the reduction catalyst support comprises one or more carbonbased materials. In some embodiments, the carbon-based material is selected from activated carbon, carbon nanotubes, graphene, and graphene oxide.

[0053] In some embodiments, the reduction catalyst support is selected from SiAlOx, SO4- ZrCE, zirconium tungstate, tungstated-titania, and anatases (SiCh-AhCh, SiCh-TiCh). In further embodiments, the reduction catalyst support is an aluminum-based material such as alumina (e.g., y-alumina), boehmite, crystalline boehmite, pseuodboehmites, gibbsites, and thermally shocked gibbsites.

[0054] In some embodiments, the reduction catalyst support is a zeolite such as Y-type zeolites, beta-zeolites, ZSM-type zeolites (e.g., ZSM-5, HZSM-5, ZSM-12, ZSM-22, ZSM-57), SAPO type zeolites (e.g., SAPO11, SAPO31, SAPO41), L zeolite (LTL), mordenite zeolites, MCM- 49, MCM-22, DA-114, microcrystalline USY zeolite, microcrystalline USY zeolite, and combinations thereof. In certain embodiments, the reduction catalyst support is MCM-49. In further embodiments, the zeolites comprise a modifier such as Zn, Ga, Fe, or other transition metals. In yet further embodiments, the modifier is present as zeolite supported metals or as isomorphous substitution in the zeolite framework.

[0055] In some embodiments, the reduction catalyst support is modified with molybdenum, chlorine, and / or sulfur.

[0056] In certain embodiments, the reduction catalyst support is a mesoporous material. In such embodiments, as will be appreciated by one of ordinary skill in the art, the physical characteristics of the mesoporous material, e.g., mesopore volume and surface area may be measured using standard gas absorption measurement techniques known in the art including, for example, the Barrett- Joy ner-Halenda (BJH) method for determining pore size distributions and pore volumes, and the Brunauer, Emmett and Teller (BET) method for obtaining the specific surface area (hereinafter “surface area”). In further embodiments, the reduction catalyst support has a mesopore volume from about 0.01 to about 3.0 cc / g.

[0057] In certain embodiments, the reduction catalyst support has surface area from about 10 m2 / g to about 1000 m2 / g. In certain embodiments, the reduction catalyst comprising the reduction catalyst support has a surface area from about 10 m2 / g to about 1000 m2 / g.

[0058] In certain embodiments, the reduction catalyst comprises the reduction catalyst support in a form of particles having an average size from about 10 nm to about 5 pm, about 20 nm to about 5 pm, about 50 nm to about 1 pm, about 100 nm to about 500 nm, or about 50 nm to about 300 nm.

[0059] In certain embodiments, the reduction catalyst comprises the reduction catalyst support in an amount from about 5 wt.% to about 80 wt.%, about 5 wt.% to about 70 wt.%, about 20 wt.% to about 70 wt.%, or about 30 wt.% to about 70 wt.% of the reduction catalyst.

[0060] In certain embodiments, the reduction catalyst support is a high surface area scaffold. In further embodiments, the reduction catalyst support comprises mesoporous silica. In yet further embodiments, the reduction catalyst support comprises carbon allotropes.

[0061] In certain embodiments, the reduction catalyst is a nanoparticle catalyst. In further embodiments, the particle sizes of the reduction catalyst on the surface of the scaffold are about 1 nm to about 5 nm, about 5 nm to about 100 nm, or about 100 to about 500 nm. In certain embodiments, the particles not subjected to agglomeration are 100-500 nm in particle size.

[0062] In certain embodiments, the reduction catalyst is pretreated with syngas. In yet further embodiments, the reduction catalyst is pretreated with hydrogen. In still further embodiments, the reduction catalyst is heated with inert gas (including but not limited to nitrogen gas, argon) before the production.

[0063] The reduction catalyst may include a binder. The binder may be any binder known for use in the art. The binder may be selected from the group consisting of: boehmite (e.g., PURAL® TH 100, PURAL® TH 80, PURAL® TH 200, PURAL® 200), silica-alumina hydrate (e.g., SIRAL® 1, SIRAL® 5, SIRAL® 10, SIRAL® 20, SIRAL® 40), aluminate (e.g., sodiumaluminate), silica (e.g., silicates, such as potassium-silicate and sodium-silicate, LUDOX®) pseudoboehmite alumina (e.g., VERSAL® V-250), bentonite clay, montmorillinite clay, tungsten, zirconate, or any combination thereof.

[0064] The binder may be present in an amount of about 0.1% to about 60% by weight, about 5% to about 40%, or about 10% to about 30% by weight of the total catalyst composition. In certain embodiments, the binder is present in about 0.1% to about 30%, about 0.1% to about 20%, about 1% to about 30%, about 1% to about 20%, about 5% to about 25%, about 5% to about 20%, about 10% to about 20%, about 5% to about 15%, or about 15% to about 25% by weight of the total catalyst composition.

[0065] The binder may contain a promoter element selected from Na, K, Cs, Li, Rb, or a combination thereof. It was found that a promoter in the binder improves catalyst performance, e.g., activity, selectivity and stability; by maintaining the promoter level constant on the active metal components. In particular, the benefits of doping the binder include:• improves methane selectivity;• the acidity improves hydrocarbon yield;creates meso-porosity to the formed catalyst which may improve product selectivity; and reduces metal leaching.

[0066] The binder may be heterogeneous, amorphous or micro-porous materials. In certain embodiments, the binder may be selected from the group consisting of: sodium-aluminate, potassium-silicate, sodium-silicate, and any combination thereof. The binder may be selected from Na- aluminate, K-aluminate, Na-silicate, K-silicate, Na - zirconate, K- zirconate, Na- tungsten, K-tungsten or a combination thereof.

[0067] When a promoter is added to the binder, performance (e.g., in terms of SCi and SC5+) of the catalyst improves significantly. When comparing performance of a catalyst having a binder without a promoter to the same catalyst and binder with a promoter, SCi may improve (that is, decrease) by about 20% to about 65%, about 30% to about 55%., about 30% to about 40%, or about 45% to about 55%. When comparing performance of a catalyst having a binder without a promoter to the same catalyst and binder with a promoter, SC5+ may improve (that is, increase) by about 25% to about 75%, 30% to about 50%, about 50% to about 75%, or about 55% to about 65%. For example, the foregoing comparisons may be between a non-doped silicate binder and a doped (with promoter) silicate binder, or between a non-doped alumina binder and a doped (with promoter) silicate binder.

[0068] A binder may be preferably selected that minimizes or does not form any strong metal support interactions with the active metal(s) because forming such interactions would inhibit the catalytic properties of the active metal. A preferred binder may bond the small active metal particles together and form a sizeable extrudate / pellets (l-5mm). These extrudates / pellets are suited for application in industrial reactors. They also have better handling properties and avoid pressure drops in large scale reactors.

[0069] The binder disclosed herein reduces metal leaching which improves the catalyst life span. With a powder, the surface area is very large and so by forming an extrudate with a binder, thermal shock in large scale reactors may be reduced.

[0070] In certain embodiments, when the reduction catalyst comprises iron oxide and zinc oxide, and a Group IA or IIA metal, and when the first carbon source gas and first reduction gas are fed into the reduction reactor, the iron oxide reacts to be in an active form selected from the group consisting of: FexOy, FexCy, and any combination thereof, where x is 1-3 and y is 0- 4. The active form acts to convert CO2 to hydrocarbons selected from the group consisting of: olefins, paraffins, oxygenates, and any combination thereof.Catalyst Compositions

[0071] In certain aspects, the present disclosure provides catalyst compositions, comprising one or more of the catalysts disclosed herein and an additional support. The additional support may be any suitable material that can serve as a catalyst support, as defined above

[0072] In some embodiments, the catalyst composition is in a form of particles having an average size from about 10 nm to about 5 pm. In some embodiments, the catalyst composition is in a form of particles having an average size from about 20 nm to about 5 pm. In some embodiments, the catalyst composition is in a form of particles having an average size from about 50 nm to about 1 pm. In some embodiments, the catalyst composition is in a form of particles having an average size from about 100 nm to about 500 nm. In some embodiments, the catalyst composition is in a form of particles having an average size from about 50 nm to about 300 nm.

[0073] In some embodiments, the catalyst composition comprises from about 5 wt. % to about 80 wt. % of the catalyst. In some embodiments, the catalyst composition comprises from about 5 wt. % to about 70 wt. % of the catalyst. In some embodiments, the catalyst composition comprises from about 20 wt. % to about 70 wt. % of the catalyst. In some embodiments, the catalyst composition comprises from about 30 wt. % to about 70 wt. % of the catalyst.

[0074] In some embodiments, the support is a high surface area scaffold. In some embodiments, the support comprises mesoporous silica. In some embodiments, the support comprises carbon allotropes.Methods of Preparation

[0075] The catalysts and catalyst compositions of the present disclosure may be prepared by any suitable method. In certain aspects, the present disclosure provides methods for preparing the catalysts or the catalyst compositions disclosed herein, comprising preparing the catalyst by coprecipitation, wet impregnation, or ball milling.

[0076] In some embodiments, a method of making a powder catalyst comprises the following steps:(a) providing a first solution comprising a source of zinc, iron, a base, and water;(b) heating the first solution at a first temperature for a first period of time, thereby producing the first reaction mixture;(c) heating the first reaction mixture at a second temperature for a second period of time to remove the water, thereby producing a solid precursor; and(d) heating the solid precursor to a third temperature for a third period of time to afford the catalyst.

[0077] In other embodiments, a method of making a powder catalyst comprises the following steps:(a) providing a second solution comprising a source of zinc, iron, and water;(b) providing a third solution comprising a base;(c) heating the third solution at a third temperature for a third period of time;(d) adding alumina to the third solution, thereby producing a second reaction mixture;(e) adding the second solution to the second reaction mixture at a fourth temperature for a fourth period of time, thereby producing a third reaction mixture;(f) heating the third reaction mixture at a fifth temperature for a fifth period of time, thereby producing a solid precursor;(g) isolating the solid precursor;(h) contacting the solid precursor with a solution comprising a Group IA metal, thereby producing a catalyst precursor; and(i) heating the catalyst precursor to a sixth temperature for a sixth period of time, thereby isolating the catalyst.

[0078] In some embodiments, the method comprises the following steps: providing a first solution comprising a source of zinc, and a source of aluminum. Combining the first solution with a basic precipitant, such as a carbonate, to increase the pH of the metal salt containing solution thereby precipitating solid particles. The solid particles are dried and calcined to form a solid catalyst.

[0079] In certain embodiments, the base comprises carbonate and a cation selected from potassium, sodium, ammonium, lithium, and cesium. In other embodiments, the base comprises bicarbonate and a cation selected from potassium, sodium, ammonium, lithium, and cesium.

[0080] In some embodiments, the method comprises the following steps: providing a first solution comprising a cobalt source and introducing it to a pre-made copper-zinc alumina material via incipient wetness or wet impregnation, followed by drying and calcining to form a solid catalyst.

[0081] In some embodiments, the method comprises the following steps: mixing a cobalt source and a support in a mill jar to provide a first mixture; ball milling the first mixture for between 2 hours to 2 weeks to thereby provide a first precipitate; filtering the first precipitate and heating to a first temperature to provide a ball milled cobalt source; mixing the ball milledcobalt source with a source of copper and zinc and a source of the alumina to provide a second mixture; and isolating a solid material from the second mixture.

[0082] In some embodiments, the method further comprises combining the solid material with a source of the one or more Group IA metals. In some embodiments, the method further comprises pressing the solid material into pellets. In some embodiments, the method further comprises pressing the solid material into pellets prior to introduction into a flow reactor.

[0083] A method of making a formed catalyst comprising: providing a powder catalyst made by any suitable method known in the art; combining the powder catalyst, a binder and a lubricant to make a dry mixture; combining the dry mixture with a first solution comprising a peptizing agent, wherein the peptizing agent activates the binder thereby forming an extrudable dough. The extrudable dough may be processed in an extruder to afford a formed catalyst, which may take the form of extrudates, pellets, tablets, or the like. The formed catalyst may be further processed by heating to a drying temperature for a first period of time to afford a dried, formed catalysts, and / or heating to a calcining temperature for a second period of time to afford a calcined, formed catalysts. The calcined, formed catalyst may be the formed catalyst, which may be selected from extrudates, pellets, tablets, or the like.

[0084] The first period of time for drying may be about 1 to about 3 hours, about 1.5 to about 2.5 hours, or about 2 hours. The drying temperature may be at about 80 °C to about 200 °C, about 100 °C to about 180 °C, or about 110 °C to about 130 °C. The second period of time for calcining may be about 2 to about 6 hours, about 3 to about 5 hours, about 3.5 to about 4.5 hours, or about 4 hours. The calcining temperature may be at about 280 °C to about 420 °C, about 300 °C to about 400 °C, or about 320 °C to about 370 °C.

[0085] Another method of making a formed catalyst comprises: providing a powder catalyst made by any suitable method known in the art; combining the powder catalyst with a slurry comprising a peptizing agent and a binder to make an extrudable dough. The extrudable dough may be processed as described above. The method may comprise combining the powder catalyst and a lubricant to make a dry mixture before combining with the slurry.

[0086] The lubricant may be any suitable lubricant known for use in the art. For example, the lubricant may be selected from magnesium stearate, stearic acid, calcium stearate, sodium stearyl fumarate, polyethylene glycols, silicone dioxide (also known as colloidal silicon dioxide), talc, beeswax, a hydrogenated vegetable oil (e.g., STEROTEX®, LUBRITAB®), and any combination thereof. The lubricant may be a hydrogenated vegetable oil.

[0087] The peptizing agent may be any suitable peptizing agent known for use in the art. For example, the peptizing agent may be selected from an acid, a Group IA hydroxide, a polymer,or a combination thereof. The peptizing agent may be an acid selected from the group consisting of inorganic and organic acids. The peptizing agent may be nitric acid, phosphoric acid, acetic acid, hydrochloric acid, formic acid, sulfuric acid, oxalic acid, and any combination thereof. The peptizing agent may be nitric acid.Methods of CO2 Conversion

[0088] The present disclosure provides various methods for conversion of carbon source gases to a hydrocarbon product mixture, which may comprise paraffins, olefins, and mixtures thereof. The disclosure includes exemplary process conditions (e.g., temperature, pressure, space velocities, etc.) which provide certain advantages in context of the systems and methods disclosed herein. However, any suitable conditions may be used, and the person of ordinary skill in the art will appreciate how to vary the conditions of any particular process described herein to obtain results and tune product distribution as needed for particular applications, as contemplated.

[0089] The present disclosure provides numerous catalysts that may be used to prepare paraffins, olefins, and mixtures thereof. The skilled artisan will recognize that any suitable catalyst or mixture of catalysts may be used in the methods and systems of the present disclosure to provide paraffins and olefins in the desirable ratios provided herein.

[0090] The present disclosure provides a method of carbon conversion comprising contacting a carbon source gas and a reduction gas with a reduction catalyst disclosed herein thereby providing a hydrocarbon product mixture comprising one or more paraffins and / or olefins. The step of contacting may occur at a reduction temperature and a reduction pressure.

[0091] In some embodiments, the reduction temperature is about 100° C to about 600° C., or about 275° C to about 350° C. In some embodiments, the reduction temperature is about 275° C. The reduction temperature may be at least 80°C, or at least 100°C, or at least 120°C. The reduction temperature may be 550 °C or less, or 600 °C or less, or 650 °C or less. The reduction temperature may be about 200 °C to about 500 °C, or about 300° C to about 350 °C.

[0092] In some embodiments, the reduction pressure is about 50 psi to about 4000 psi, about 50 to about 3000 psi, about 75 psi to about 225 psi, or about 900 to about 1100 psi. In some embodiments, the reduction pressure is about 75 psi, about 100 psi, about 125 psi, about 150 psi, about 175 psi, about 200 psi, about 225 psi, or about 1000 psi.

[0093] In some embodiments, the partial pressure of CO2 in the carbon source gas is from about 20 to about 1500 psi, about 200 to about 800 psi, about 200 to about 600 psi, about 200 to about 400 psi, or about 300 to about 400 psi.

[0094] The method may comprise: contacting a first reduction gas and a first carbon source gas with a reduction catalyst to afford: a light hydrocarbon product mixture comprising one or more C2-4 paraffins and / or olefins; a medium hydrocarbon product mixture comprising one or more C5-9 paraffins and / or olefins; and a target hydrocarbon product mixture comprising one or more C10-16 paraffins and / or olefins.

[0095] In certain embodiments, each of the light hydrocarbon product mixture, the medium product mixture, and / or the target hydrocarbon product mixture comprise olefins and paraffins. In further embodiments, the ratio of olefins to paraffins in each of the light hydrocarbon product mixture, the medium product mixture, and / or the target hydrocarbon product mixture is at least about 1 : 1, with the amount of olefins being about equal to or more than the amount of paraffins present therein. The ratio of olefins to paraffins in each of the light hydrocarbon product mixture, the medium product mixture, and / or the target hydrocarbon product mixture may be at least about 2: 1, at least about 3: 1, at least about 4: 1, at least about 5: 1, at least about 6:1, at least about 7: 1, at least about 8: 1, at least about 9:1, or at least about 10: 1. The ratio of olefins to paraffins in each of the light hydrocarbon product mixture, the medium product mixture, and / or the target hydrocarbon product mixture may be about 1 :1 to about 20: 1, about 5: 1 to about 20: 1, or about 5: 1 to about 15: 1.

[0096] In certain embodiments, contacting the first reduction gas and the carbon source gas with a reduction catalyst further affords a light hydrocarbon product mixture comprising one or more C2-4 paraffins and / or olefins. In some embodiments, the ratio of C2-4 olefins to C2-4 paraffins in the light hydrocarbon product mixture is at least about 5 : 1. In further embodiments, the ratio of C2-4 olefins to C2-4 paraffins in the light hydrocarbon product mixture is preferably at least about 8: 1. In certain embodiments, the ratio of C2-4 olefins to C2-4 paraffins in the light hydrocarbon product mixture is about 5: 1 to about 15: 1, or about 8: 1 to about 10: 1. In certain embodiments, the ratio of C2-4 olefins to C2-4 paraffins in the light hydrocarbon product mixture is about 5: 1, about 6: 1, about 7: 1, about 8: 1, about 9: 1, or about 10: 1.

[0097] In some embodiments, the medium hydrocarbon product mixture comprises one or more C5-9 paraffins and olefins. In certain embodiments, the ratio of C5-9 olefins to C5-9 paraffins in the medium hydrocarbon product mixture is at least about 3: 1, or at least about 5: 1. In certain embodiments, the ratio of C5-9 olefins to C5-9 paraffins in the medium hydrocarbon product mixture is about 3: 1 to about 12: 1. In certain embodiments, the ratio of C5-9 olefins to C5-9paraffins in the medium hydrocarbon product mixture is about 3: 1, about 4: 1, about 5: 1, about 6: 1, about 7: 1, or about 8: 1.

[0098] The reductant gas may be H2 or a hydrocarbon. In some embodiments, the reductant gas is H2. In some embodiments, the reductant gas is a hydrocarbon, such as CH4, ethane, propane, or butane. In certain embodiments, the hydrocarbon is CH4. In other such embodiments, the CT is a component of a gas mixture that also comprises other hydrocarbons, such as ethane, propane, or butane. For example, the gas mixture used to supply CH4 may be (or may be derived from) flare gas, waste gas, natural gas, or the like.

[0099] The carbon source gas may comprise CO2. The carbon source gas may comprise CO2 and CO. In certain embodiments, carbon source gas comprises less than 25% of CO, less than 20% of CO, less than 15% of CO, less than 10% of CO, less than 5% of CO, or less than 1% of CO. In some embodiments, the carbon source gas is substantially free of CO.

[0100] The ratio of reductant gas:CO2 in the feed mixture may be about 10:1 to about 1 : 10. In some embodiments, the ratio of reductant gas:CO2 in the feed mixture is about 5: 1 to about 0.5: 1. In some embodiments, the ratio of reductant gas:CO2 in the feed mixture is about 4: 1 to about 1 : 1. In some embodiments, the ratio of reductant gas:CO2 in the feed mixture is about 3: 1.

[0101] As used herein, the term “paraffins” refers to hydrocarbons which are preferably linear, but may include branched hydrocarbons. Certain paraffins have carbon numbers from 6-20, or from 9-16.

[0102] In some embodiments, the hydrocarbon product mixture is a liquid product mixture comprising paraffins, olefins, and other hydrocarbons. The liquid product mixture may comprise paraffins have carbon numbers from 6-20, or from 9-16. In some embodiments, the amount of paraffins is at least 50 wt. % of the total non-aqueous products. In some embodiments, the amount of paraffins is at least 10 wt. % of the total amount of liquid product mixture. In some embodiments, the amount of paraffins is at least 5 wt. % of the total amount of liquid product mixture. In some embodiments, the amount of paraffins is at least 2 wt. % of the total amount of liquid product mixture. In some embodiments, the molar ratio of paraffins to the total amount of carbon-containing products in the liquid product mixture is from about 1 :2 to about 1 : 10. In some embodiments, the amount of formic acid in the liquid product mixture is less than 1,000 ppm. In some embodiments, the amount of isopropanol in the liquid product mixture is less than 1,000 ppm.

[0103] An object of the present invention may be to use low GHSVs (gas hourly space velocity) to provide high gas product recyclability and avoid certain byproducts such as formaldehydeor methane. In some embodiments, the method does not produce Cl alkanes or aldehydes such as formaldehyde or methane. In some embodiments, the method produces less than about 0.5 wt % formaldehyde or methane. In some embodiments, the method produces less than about 0.05 wt % formaldehyde or methane. In some embodiments, the method produces less than about 50 ppm formaldehyde or methane. In some embodiments, the method produces less than 5 ppm formaldehyde or methane.

[0104] In some embodiments, the GHSV of reactant gases and recycle gases introduced to the reactor is from about 10 to about 20,000, about 10 to about 10,000, about 10 to about 5,000, or about 10 to about 2,000, about 10 to about 1,000, about 10 to about 500, or about 10 to about 100.

[0105] In some embodiments, the method comprises contacting the reduction catalyst with the feed mixture for at least 8,000 hours. In some embodiments, the method comprises contacting the catalyst with the feed mixture for at least 96 hours. In some embodiments, the method comprises contacting the catalyst with the feed mixture for at least 24 hours.

[0106] The method may comprise maintaining the activity of the reduction catalyst for over about one year, over about 18 months, over about 20 months, over about 36 months, or over about 48 months. The method may comprise maintaining the activity of the reduction catalyst for about one year to about 5 years, about two years to about 5 years, about 3 years to about 5 years, or about 4 years to about 5 years. The method may comprise maintaining the activity of the reduction catalyst for over about 8,000 hours time on stream. The method may comprise maintaining the activity of the reduction catalyst for about 8,000 to about 40,000, about 8,000 to about 30,000, about 8,000 to about 20,000, about 10,000 to about 40,000, about 15,000 to about 40,000, about 15,000 to about 30,000, or about 10,000 to about 30,000 hours time on stream (run hours). The method may comprise maintaining the activity of the reduction catalyst for over about 2 years and about 8,000 to about 40,000 time on stream (run hours).

[0107] In certain embodiments, methods of the disclosure further comprise one or more of the downstream processing steps disclosed in co-owned U.S. Application No. 18 / 934,440, filed November 1, 2024, entitled: SYSTEMS, METHODS, AND CATALYSTS FOR THE PRODUCTION OF SUSTAINABLE AVIATION FUEL, the entirety of which is incorporated by reference herein.

[0108] In some embodiments, the numbers used to describe and claim certain embodiments of the disclosure are modified in some instances by the term “about.” In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges andparameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. In certain embodiments, the term “about” means within 10% of a given value or range.Systems for CO2 Conversion

[0109] Provided herein are systems for the conversion of a carbon source gas and a reduction gas to hydrocarbons comprising a mixture of olefins and paraffins. Certain components of these systems are described as being “coupled” to one another. As will be appreciated, the term “coupled” as used herein describes components that are operationally linked to one another, but does not preclude the presence of intervening components between those said to be coupled to one another. Additionally, as will be appreciated, various system components are described as “having” certain features. For example, in certain embodiments the reduction reactor

[0025] is described as having a first reduction gas feed inlet

[0023] , a first carbon source inlet

[0023] , and a hydrocarbon product outlet

[0027] , Such descriptions do not preclude, and specifically contemplate, the presence of additional features, such as inlets, outlets, valves, control mechanisms, measurement devices, heating and / or cooling systems, etc. Additionally, in the systems of the present disclosure, certain components are described as having one or more outlets or inlets. Such outlets and inlets may represent separate structural elements, or may be combined into a single inlet or outlet as suitable. The person of ordinary skill in the art will recognize that, once the critical features and operating conditions of systems such as those described herein are understood, the detailed design and operation of such systems involved many choices, such as specific reagent flows, separation steps, etc. While the present disclosure provides a number of specific embodiments, any suitable combination of these design choices may be made.

[0110] Further, the various systems and methods of the present disclosure sometimes reference fractions with particular carbon numbers (e.g., CX-Y). AS will be understood, these carbon numbers refer to the carbon makeup of the majority of the fraction, but said fractions may include additional components with carbon numbers that are higher or lower than indicated. Separators which are capable of creating these fractions are well known in the art, and can be adjusted as needed to afford suitable product mixtures as disclosed herein, or as otherwisedesired by the operator. Certain components of said system are referred to by numbers in brackets (i.e.,

[0010] ).

[0111] Systems for the production of a hydrocarbon product mixture comprising olefins and / or paraffins are disclosed herein. The systems may include: a first reduction gas feed; a first carbon source gas feed; and a reduction reactor comprising a reduction catalyst. The system may be any such system disclosed in U.S. Patent No. 12,018,221, or in co-owned U.S. Application No. 18 / 934,440, filed November 1, 2024, entitled: SYSTEMS, METHODS, AND CATALYSTS FOR THE PRODUCTION OF SUSTAINABLE AVIATION FUEL; or in coowned U.S. Application No. 18 / 934,474, filed November 1, 2024, entitled: SYSTEMS AND METHODS FOR THE PRODUCTION OF PARAFFINIC KEROSENE AND SUSTAINABLE AVIATION FUEL USING A REFORMING CATALYST, the entirety of each of which is incorporated by reference herein.

[0112] The reduction reactor may have a first reduction gas feed inlet, a first carbon source feed inlet, a target hydrocarbon outlet, and a medium hydrocarbon outlet. The first reduction gas feed inlet may be coupled to the first reduction gas feed. The first carbon source gas feed inlet may be coupled to the first carbon source gas feed. The reduction reactor may further comprise a light hydrocarbon outlet.

[0113] As used herein, the term “selectivity” and grammatical variants thereof refer to how selective a particular process or catalyst is for producing a particular product. The term refers to an exemplary selectivity value observed for a reaction performed with suitable reagents under conditions that have been selected, by a person of ordinary skill in the art, to maximize or minimize the production of a given product of interest. A value for selectivity may refer to the proportion of product(s) of interest compared to other products produced (which may not be of interest), or may refer to the proportion of other product(s) produced compared to product(s) of interest. Selectivity may be a function of the catalyst used in a process, and / or may be a function of process design or parameters (e.g., temperature, pressure, reagent concentration, GHSV, etc.), as would be understood by a person of ordinary skill in the art. Those of skill in the art are familiar with how to calculate selectivity for a given product. However, where an explicit calculation for selectivity is provided herein, that calculation method controls.

[0114] As used herein, the term “oligomerization,” and grammatical variants thereof, will be understood by those of skill in the art to refer to a process that may involve dimerization, trimerization, tetramerization, pentamerization, hexamerization, heptamerization, octamerization, nonamerization, decamerization, higher-order oligomerization, andcombinations thereof. The extent of oligomerization in a particular reaction will determine the composition of the product stream, and depends on aspects of the reactant stream, as well as the reaction conditions.EXAMPLES

[0115] The invention now being generally described, it will be more readily understood by reference to the following examples which are included merely for purposes of illustration of certain aspects and embodiments of the present invention, and are not intended to limit the invention.Example 1 : Preparation of Fe / Zn-Na reduction catalyst.

[0116] A solution of Fe and Zn metals was prepared using metal nitrates as the precursors. A base solution containing sodium carbonate at a 2.4 molar equivalent to the metal nitrates was prepared at 0.5 M concentration. To a 2 L round bottom flask, enough water was added to submerge the stirrer and it was heated to 343 K while continuously stirring. The metal and base solutions were transferred to the round bottom flask via peristaltic pump for parallel addition, with targeted flow rates so that the metal solution was completely added with half of the base solution over approximately 1 hour. The temperature was then increased to 353 k for 1 hour of aging. After an hour, the mixture was allowed to cool to room temperature before re-heating it to 343 K. The remaining base solution was added over the course of an hour, and the resulting slurry was aged for another hour at 353 K.

[0117] The precipitate was vacuum filtered using a 0.25 micro filter. The product was then washed 3 times and blended using approximately 300 mL water and filtered at each step to remove excess sodium to less than 0.1%. The resulting precipitate was dried at 393 K for 4 hours before grinding it to a fine powder and calcining for 6 hours at 623 K. The resulting catalyst was FeZn with 0.5%Na. The ratio of iron and zinc components can be adjusted as readily understood by one of skill in the art. For example, catalysts having the following ratio of Fe:Zn have been synthesized according to the processes above: 1 : 1, 2: 1, 3: 1, 4: 1, 6: 1 with 0.5% by weight Na.Example 2: Catalyst evaluation for CO2 hydrogenation.

[0118] Catalysts was made by the method of Example 1 and 9, FeZn, with the molar ratio of iron to zinc being about 6: 1, but with different metal promoters, i.e., Na, Rh or Cs. The catalystwas granulated to 40-60 mesh size and pretreated with H2 at 623K, 150 PSIG, GHSV 1200 for 5 hours. It was later conditioned with syngas (H2 / CO = 2), at GHSV 600 at 623 K. The catalyst was then tested for CO2 hydrogenation to produce a target hydrocarbon product mixture comprising C10-C16 paraffins and / or olefins. The CO2 conversion to C10-C16 paraffins and / or olefins for each of the different catalysts was measured in a fixed bed reactor under the conditions of 623 K, GHSV 1500, 450 PSIG using feed gas H2 = 72 mol %, CO2 = 24 mol % and N2 = 4 mol % as internal standard.Table 1 : Product Distribution by Catalyst FeZn with Group IA or IIA metal

[0119] Methane production is a factor of the effectiveness of the catalyst, as methane production is undesirable. Accordingly, the lower the methane production (SCi), the better the catalyst. O / P is the ratio of olefins to paraffins generated by the reaction between the feed and the catalyst. In this case, FeZnNa catalyst affords a product stream with less methane, higher olefin to paraffin ratio, and a greater amount of C5+ products than the FeZnRh and FeZnCs catalysts.

[0120] While this example was conducted with the FeZnNa catalyst having a molar ratio of about 6Fe: IZn, it was found through other experiments that adjusting the molar ratio of iron to zinc from 1 : 1 to about 7: 1 does not significantly affect the product distribution.

[0121] After selecting FeZn- 0.5%Na as the catalyst, the molar ratio of Fe:Zn was adjusted to 2.25: 1, and the partial pressure of the hydrogen feed was adjusted to determine the effect on methane production and O / P selectivity.Table 2: Product distribution with reduced H2 partial pressure

[0122] It was found that, by reducing the H2 / CO2 from 3 to 2, methane selectivity (SCi) lowered and O / P increased— improvements in both regards. In addition, the test demonstrated that there was no significant difference between the product selectivity for 6Fe: lZn and 2.25Fe: lZn.Example 3 : Catalyst evaluation of CO2 hydrogenation using Olefin and CF rich feed

[0123] Catalyst made by the method from Example 1, FeZnNa was granulated to 40-60 mesh size and pretreated with EE at 623K, 150 PSIG, GHSV 1200 for 5 hours. It was later conditioned with syngas (H2 / CO = 2), at GHSV 600 at 623 K. The catalyst was then tested for CO2 hydrogenation to produce a target hydrocarbon product mixture comprising C10-C16 paraffins and / or olefins. The CO2 conversion to C10-C16 paraffins and / or olefins measured in a fixed bed reactor under the conditions of 623 K, GHSV 1500, 450 PSIG using feed gas H2 = 47 mol %, CO2= 23.8 mol, CO = 3 mol %, CH4= 15 mol %, C2H4 = 2.2 mol %, C2H6=2.4 mol%, C3H6 = 2.3 mol%, CsH8= 0.3% and N2 = 4 mol % as internal standard will be evaluated. It is anticipated that the production of C5+ paraffins and / or olefins will increase and methane production will decrease.Table 3: Expected Product Distribution with Mixed Hydrocarbon FeedExample 4: Method of extrudate synthesis - Sodium Aluminate binder

[0124] 80g powder catalyst (FeZnNa) from Example 1, 20g sodium aluminate and 1g STEROTEX® were blended using a nutri-bullet to form a well-mixed dry powder. Nitric acid was added dropwise to 15.7951g de-ionized water to form solution A. Solution A was added dropwise to the powder at constant stirring rate. An additional 10.2g of de-ionized water was added to the slurry to achieve an extrudable dough. The prepared dough was extruded at 45Hz to 1.6 mm diameter extrudates. The first extrudates were discarded. Successful extrudates were collected separately. Extrudates were dried at 120°C for 2 hours and then calcined at 350°C for 4 hours to make a formed catalyst.Example 5: Method of extrudate synthesis- Sodium Silicate binder

[0125] 80g powder catalyst (FeZnNa) from Example 1, 20g sodium silicate and 1g STEROTEX® were blended using a nutri -bullet to form a well mixed dry powder. Nitric acid was added dropwise to 16.0213g de-ionized water to form solution A. Solution A was added dropwise to the powder at constant stirring rate. An additional 9.3138g of de-ionized water was added to the slurry to achieve an extrudable dough. The prepared dough was extruded at 45Hz to 1.6 mm diameter extrudates. The first extrudates were discarded. Successful extrudates were collected separately. Extrudates were dried at 120°C for 2 hours and calcined at 350°C for 4 hours to make a formed catalyst.Example 6: Detailed Method of extrudate synthesis- Potassium Silicate binder

[0126] 80g powder catalyst (FeZnNa) from Example 1, 20g potassium silicate and 1g STEROTEX® were blended using a nutri -bullet to form a well-mixed dry powder. Nitric acid was added dropwise to 30.3788g de-ionized water to form solution A. Solution A was added dropwise to the powder at constant stirring rate. An additional 10.2g of de-ionized water was added to the slurry to achieve an extrudable dough. The prepared dough was extruded at 45Hz to 1.6 mm diameter extrudates. The first extrudates were discarded. Successful extrudates were collected separately. Extrudates were dried at 120 °C for 2 hours and calcined at 350 °C for 4 hours to make a formed catalyst.Example 7: Catalyst evaluation of CO2 hydrogenation

[0127] Powder catalyst samples were prepared according to the procedures set forth in Example 1 having a final composition of molar ratio Fe:Zn = 2: 1 with 0.61 wt % Na. The powder catalyst was divided and finished according to the procedure in Example 2, except that different binders were incorporated to make the extrudates. Sample 2 was made with non-doped Alumina binder. Sample 3 was made with Na-doped Alumina binder. Sample 4 was made with K-doped Alumina binder. Sample 5 was made with non-doped Silica binder (LUDOX®). Sample 6 was made with non-doped Silica binder (Hi-Sil). Sample 7 was made with Na-doped Silica binder. Sample 8 was made with K-doped Silica binder.

[0128] The effluent, or liquid product from the conversion reaction, was collected after steady state was reached. Steady state may be gauged by passage of time on stream (TOS), or it may be tested by collecting samples about every 24 hours and testing the concentration of metals in the sample to determine at which time steady state is reached. In a typical experiment the liquid products (hydrocarbons and aqueous phase) were collected every 24 h and analyzed for traceamounts of Fe, Zn and Na. In this example, after 200 hours TOS, the effluent was collected and divided into an aqueous product and an oil (hydrocarbons) product. The oil product was dissolved in Aqua regia acid and then analyzed using ICP-MS. Separately, a sample the aqueous product was injected into the instrument wherein the plasma ionizes the sample to provide a mass spectrometry readout. The MS data was analyzed for concentration of metals and the amount calculated for each of the samples was added to account for a total concentration. The total concentration of metals in both aqueous and oil phase was added and reported as total metal leaching in Table 4.Table 4: Examples of the effect of binder on the active metal catalyst performance

[0129] The results of the samples of formed catalyst having different binder compositions were compared. The performance of sample 2 having a non-doped binder was compared to the performance of the catalyst with the Na-aluminate binder in sample 3. Both the methane selectivity and the selectivity for C5+ hydrocarbons improved significantly with the doped binder. That is, between sample 2 and 3, SCi decreased by 37.5% and SC5+ increased by 61%.

[0130] The performance of samples 4 and 5 having a non-doped binder was compared to the performance of the catalysts with the Na- and K-silicate binder in samples 6 and 7. Both the methane selectivity and the selectivity for C5+ hydrocarbons improved significantly with the doped binders. That is, between non-doped sample 4, and doped samples 6 and 7, SCidecreased by 49%, and SC5+ increased by 36% and 38%, respectively. That is, between nondoped sample 5, and doped samples 6 and 7, SCi decreased by 53% and 52%, respectively and SC5+ increased by 70% and 72%, respectively.Example 8: Leaching Rates of Different Metals During Time on Stream

[0131] Powder catalyst from Example 1 having a final composition of molar ratio Fe:Zn = 2: 1 with 0.61 wt % Na, and a formed catalyst extrudate of Sample 3 were tested leaching rates after different times on stream. The metal leaching of the catalysts was analyzed using ICP-MS. The liquid products (hydrocarbons / oil and aqueous phase) were collected at the various time intervals, separated into the oil portion and the aqueous portion, and analyzed for trace amounts of Fe, Zn and Na. For the formed catalyst, the effluent was divided into the aqueous and the oil portion, and only the aqueous portion was analyzed for metal leaching because the reaction had reached steady state and the amount of metal in the oil portion would be less than 1 ppm. Table 5 shows metal leaching rates of the powder catalyst and Table 6 shows metal leaching rate of the formed catalyst. The introduction of the binder showed reduced metal leaching rates when comparing similar time on stream.Table 5: FeZn =2 mole ratio, 1% wt Na Powder catalystTable 6: FeZn =2 mole ratio, 1% wt Na with Na- Aluminate binder extrudate

[0132] While specific embodiments of the subject invention have been discussed, the above specification is illustrative and not restrictive. Many variations of the invention will become apparent to those skilled in the art upon review of this specification and the claims below. The full scope of the invention should be determined by reference to the claims, along with their full scope of equivalents, and the specification, along with such variations.

Claims

WHAT IS CLAIMED:

1. A reduction catalyst composition comprising: iron; zinc; one or more second elements selected from Group IA, IIA and X metals; and a binder selected from boehmite, silica-alumina hydrate, aluminate, silica, silicate, pseudoboehmite alumina, bentonite clay, montmorillinite clay, zirconate, tungsten, or any combination thereof.

2. The reduction catalyst composition of claim 1, wherein the binder comprises a promoter element selected from Na, K, Cs, Li, Rb, or a combination thereof.

3. The reduction catalyst composition of claim 1 or 2, wherein the reduction catalyst has a selectivity for carbon dioxide conversion to methane of less than about 15 carbon mole%.

4. The reduction catalyst composition of claim 1, wherein the selectivity for carbon dioxide conversion to methane is less than about 11 carbon mole%.

5. The reduction catalyst composition of any one of the preceding claims, wherein the reduction catalyst is a formed catalyst.

6. The reduction catalyst composition of any one of the preceding claims, wherein the reduction catalyst maintains activity at over about 75% for over about one year.

7. The reduction catalyst composition of claim 6, wherein the reduction catalyst maintains activity at over about 75% for about two years.

8. The reduction catalyst composition of any one of the preceding claims, wherein the molar ratio of iron to zinc is about 1 : 1 to about 7: 1.

9. The reduction catalyst composition of any one of the preceding claims, wherein the molar ratio of iron to zinc is about 1 : 1 to about 4: 1.

10. The reduction catalyst composition of any one of the preceding claims, wherein the binder is selected from Na-aluminate, K-aluminate, Na-silicate, K-silicate, Na-zirconate, K- zirconate, Na-tungsten, K-tungsten, , or a combination thereof.

11. The reduction catalyst composition of any one of claims 1-10, wherein the binder is in an amount of about 0.1% to about 60% by weight of the total catalyst.

12. The reduction catalyst composition of any one of claims 1-11, wherein the one or more second elements is the Group IA or IIA metal selected from magnesium, calcium, potassium, sodium, cesium, or a combination thereof.

13. The reduction catalyst composition of claim 12, comprising the Group IA metal selected from potassium, sodium, or a combination thereof.

14. The reduction catalyst composition of claim 12 or 13, wherein the one or more Group IA or IIA metals is present in an amount of about 0.2% to about 10% of the total weight of iron and zinc.

15. The reduction catalyst composition of any one of claims 1-11, wherein the one or more second elements is the Group X metal selected from the group consisting of palladium, platinum, iridium, nickel, rhodium, and any combination thereof.

16. The reduction catalyst composition of any one of the preceding claims, wherein when the catalyst is contacted with a continuous flow of fluid for about 100 hours to about 1000 hours, the total concentration of iron, zinc, and one or more second elements in the effluent is less than about 50 ppm.

17. The reduction catalyst composition of any one of claims 1-15, wherein when the catalyst is contacted with a continuous flow of fluid for about 100 hours to about 1000 hours, the total concentration of iron, zinc, and one or more second elements in the effluent is less than about 40 ppm.

18. The reduction catalyst composition of any one of claims 1-15, wherein when the catalyst is contacted with a continuous flow of fluid for about 100 hours to about 1000 hours, the total concentration of the one or more second elements in the effluent is less than about 10 ppm.

19. The reduction catalyst composition of any one of claims 1-15, wherein when the catalyst is contacted with a continuous flow of fluid for about 100 hours to about 1000 hours, the total concentration of the one or more second elements in the effluent is less than about 8 ppm.

20. A reduction catalyst composition comprising: iron; zinc; one or more second elements selected from Group IA, IIA and X metals; anda binder, wherein the reduction catalyst has a selectivity for carbon dioxide conversion to methane of less than about 15 carbon mole%; wherein when the catalyst is contacted with a continuous flow of fluid for about 100 hours to about 1000 hours, the total concentration of iron, zinc, and one or more second elements in the effluent is less than about 50 ppm; and wherein the reduction catalyst maintains activity at over about 75% for over about one year.

21. The reduction catalyst of any one of claims 1-20, wherein the reduction catalyst has a selectivity for C5+ hydrocarbons greater than about 28 carbon mole%.

22. A method of CO2 hydrogenation comprising contacting a carbon source gas and a reduction gas with the reduction catalyst composition of any one of claims 1-21; and producing a hydrocarbon product mixture comprising one or more paraffins and olefins.

23. The method of claim 22, wherein the hydrocarbon product mixture has an olefin to paraffin ratio (O / P) of greater than about 7.

24. A method of making the reduction catalyst composition of any one of claims 1-21, comprising: providing a powder catalyst comprising iron, zinc and one or more second elements selected from Group IA, IIA and X metals; combining the powder catalyst, a binder and a lubricant to make a dry mixture; combining the dry mixture with a first solution comprising a peptizing agent, wherein the peptizing agent activates the binder thereby forming an extrudable dough; processing the extrudable dough in an extruder to afford a formed catalyst; and heating the formed catalyst to a drying temperature for a first period of time to afford a dried extrudate, pellet, or tablet, and / or heating to a calcining temperature for a second period of time to afford a calcined extrudate, pellet, or tablet.

25. A method of making the reduction catalyst composition of any one of claims 1-21, comprising: providing a powder catalyst made by any suitable method known in the art; combining the powder catalyst with a slurry comprising a peptizing agent and a binder to make an extrudable dough; processing the extrudable dough in an extruder to afford a formed catalyst; andheating the formed catalyst to a drying temperature for a first period of time to afford a dried extrudate, pellet, or tablet, and / or heating to a calcining temperature for a second period of time to afford a calcined extrudate, pellet, or tablet.

26. The method of claim 25, further comprising combining the powder catalyst and a lubricant to make a dry mixture before combining with the slurry.

27. The method of any one of claims 24-26, wherein the first period of time for drying is about 1 to about 3 hours and the drying temperature is about 80 °C to about 200 °C28. The method of any one of claims 24-27, wherein the second period of time for calcining is about 2 to about 6 hours and the calcining temperature is about 280 °C to about 420 °C.

29. The method of any one of claims 24-28, wherein the lubricant is selected from magnesium stearate, stearic acid, calcium stearate, sodium stearyl fumarate, polyethylene glycols, silicone dioxide, talc, beeswax, a hydrogenated vegetable oil, and any combination thereof.

30. The method of claim 29, wherein the lubricant may be a hydrogenated vegetable oil.

31. The method of any one of claims 24-27, wherein peptizing agent is selected from an acid, a Group IA hydroxide, a polymer, or a combination thereof.

32. The method of claim 31, wherein the peptizing agent is an acid selected from the group consisting of inorganic and organic acids.

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