Iron-manganese based catalyst, catalyst precursor and catalytic process

Abstract

The present invention provides a catalyst for the production of C5 + hydrocarbons, the catalyst comprising (i) an iron species; (ii) at least one transition metal selected from manganese and cobalt, or a salt, oxide or hydroxide thereof; and (iii) an alkali metal or a salt thereof. The invention also provides a process for converting carbon dioxide to C5 + hydrocarbons.

Description

[0001] This application is a divisional application of a patent application with application date April 1, 2020, application number 202080032524.2, and invention name “Iron-manganese-based catalysts, catalyst precursors and catalytic methods”. Technical Field

[0002] Described herein are hydrogenation catalysts, their precursors, and their use in methods suitable for converting carbon dioxide and / or carbon monoxide to hydrocarbons. In particular, the catalysts and methods described herein produce C 5+ Hydrocarbons, especially C 5+ Alpha olefins. Background Art

[0003] Olefins are widely used in the chemical industry as building blocks for the manufacture of a wide range of products and as a major component of fuels. α-Olefins have a double bond at the terminal, or α, position, which enhances reactivity at this position and makes them useful in the production of detergents, lubricants, plasticizers, pharmaceuticals, fine chemicals, and polymers.

[0004] The catalytic production of hydrocarbons from synthesis gas (syngas) is well known and is generally referred to as Fischer-Tropsch synthesis. However, Fischer-Tropsch synthesis tends to favor the formation of saturated alkanes.

[0005] Furthermore, the need to reduce greenhouse gas (GHG) emissions from the transport sector is well known. Thanks to improved fuel efficiency, hydrogen fuel cells, and electric vehicles, the UK reduced GHG emissions from road transport by 8.6% between 2002 and 2012. However, emissions from aviation, the second largest transport sector, increased by approximately 6%.

[0006] The production of fuels from CO2 or CO can address the aforementioned energy needs while meeting environmental standards. However, the most advanced CO2-to-fuel conversions primarily produce C1 products (synthesis gas, formic acid, methanol) and less commonly C2 to C4 products such as mixed alcohols and olefins. These processes can produce a mixture of long-chain hydrocarbons after methanol-to-olefins (MTO) or FT synthesis. However, obtaining fuels such as jet fuel directly via such routes is particularly challenging because they cannot produce the desired composition (i.e., containing C 5+ hydrocarbons) to meet stringent, well-established standards.

[0007] There is a need for new, high-performance catalysts and methods suitable for converting carbon dioxide and / or carbon monoxide to hydrocarbons. In particular, there is a need for inexpensive and abundant catalysts and methods using the catalysts that increase the conversion of carbon dioxide and / or carbon monoxide, and / or increase the conversion of valuable hydrocarbons such as C 5+ Hydrocarbons (including C 5+ (α) olefins) yield. Summary of the Invention

[0008] In a first aspect, the present invention is directed to a catalyst precursor comprising an iron species, an alkali metal or a salt thereof, and a complexing agent.

[0009] In a second aspect, the present invention relates to a method for preparing a catalyst precursor comprising:

[0010] (a) combining (i) an iron substance, (ii) an alkali metal or a salt thereof, (iii) a complexing agent, and (iv) a solvent;

[0011] (b) stirring the mixture of step (a) to provide a homogeneous mixture;

[0012] (c) heating the mixture of step (b) to partially remove the solvent, thereby providing a slurry or paste;

[0013] In a third aspect, the present invention relates to a catalyst precursor obtainable according to the process of the second aspect.

[0014] In a fourth aspect, the present invention relates to a catalyst obtainable by activating the catalyst precursor according to the first aspect.

[0015] In a fifth aspect, the present invention relates to a method for preparing a catalyst comprising:

[0016] (a) providing a catalyst precursor according to the first or third aspect of the present invention;

[0017] (b) optionally calcining the catalyst precursor; and

[0018] (c) activating the precursor.

[0019] In a sixth aspect, the present invention relates to a catalyst obtainable according to the process of the fifth aspect.

[0020] In a seventh aspect, the present invention relates to a process for the hydrogenation of carbon dioxide, the process comprising contacting a feedstock comprising hydrogen and carbon dioxide with a catalyst precursor according to the first aspect or a catalyst according to the fourth or sixth aspect at elevated temperature and pressure.

[0021] In an eighth aspect, the present invention relates to a process for the hydrogenation of carbon monoxide, the process comprising contacting a feedstock comprising hydrogen and carbon monoxide with a catalyst precursor according to the first aspect or a catalyst according to the fourth or sixth aspect at elevated temperature and pressure.

[0022] In a ninth aspect, the present invention relates to a process for producing olefins, the process comprising contacting a feedstock comprising hydrogen and carbon dioxide and / or carbon monoxide with a catalyst precursor according to the first aspect or a catalyst according to the fourth or sixth aspect at elevated temperature and pressure.

[0023] In a tenth aspect, the present invention relates to a process for producing a fuel, the process comprising contacting a feedstock comprising hydrogen and carbon dioxide and / or carbon monoxide with a catalyst precursor according to the first aspect or a catalyst according to the fourth or sixth aspect at elevated temperature and pressure.

[0024] In an eleventh aspect, the present invention relates to a heterogeneous mixture comprising the catalyst precursor according to the first aspect or the catalyst according to the fourth or sixth aspect and a gas containing hydrogen and carbon monoxide, and / or hydrogen and carbon dioxide.

[0025] Preferred, suitable and optional features of any particular aspect of the invention are also preferred, suitable and optional features of any other aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the equipment used to evaluate catalyst performance is shown.

[0027] Figure 2 The molar ratio of olefins:alkanes in the liquid products produced after CO2 hydrogenation via Fe-Mn-K (100:10:5) [Catalyst 3], Fe-Mn-K (100:10:8) [Catalyst 5], and Fe-Mn-K (100:20:5) [Catalyst 6] are shown.

[0028] Figures 3 to 7 Shown are the XRD spectra of various CO2 hydrogenation catalysts.

[0029] Figure 8 GC-MS spectra of the product curve after CO hydrogenation over a Fe-Co-Mn-Na (100:5:20:2) catalyst at 300°C are shown when the synthesis gas feedstock is 1:1 (H2:CO).

[0030] Figure 9 The CO2 hydrogenation performance of the Fe-Mn-K catalyst is shown as follows: (a) the conversion of CO2 and H2 with reaction time; (b) the selectivity of hydrocarbon products with reaction time.

[0031] Figure 10 Shown is the GC-MS spectrum of the fuel from CO2 hydrogenation over a Fe-Mn-K catalyst.

[0032] Figure 11Shown are the XRD spectra of the Fe—Mn—K catalyst precursor, the activated catalyst, and the used catalyst.

[0033] Figure 12 Shown are the XPS spectrum of the Fe-Mn-K catalyst precursor, 12a) the XPS measurement spectrum of the Fe-Mn-K catalyst; and 12b) the high-resolution XPS spectrum of Fe 2p.

[0034] Figure 13 Shown are SEM images of a) the Fe-Mn-K catalyst precursor and b) the used catalyst.

[0035] Figure 14 HRTEM images of Fe—Mn—K catalyst precursors ( 14a , 14b , 14c ) and used catalysts ( 14d , 14e , 14f ) are shown. DETAILED DESCRIPTION

[0036] definition

[0037] As used herein, the term "catalyst precursor" refers to a material for preparing a catalytically active substance. Typically, a precursor is prepared by calcining its components. Typically, a catalyst precursor needs to be converted into a catalytically active substance, for example, by oxidation, reduction and / or heat treatment, or a combination thereof. Suitably, via reduction activation. The catalyst precursor can be converted into a catalytically active substance (i.e., "activated") in situ (i.e., under reaction conditions), or the catalyst precursor can also be converted into a catalytically active substance before being added to the reaction.

[0038] As used herein, the term "liquid" refers to a material that is liquid at standard ambient temperature and pressure (SATP), ie, at a temperature of 298.15 K (25° C.) and at 100,000 Pa (1 bar, 14.5 psi, 0.9869 atm).

[0039] As used herein, the term "hydrocarbon" refers to an organic compound composed of carbon and hydrogen.

[0040] For the avoidance of doubt, hydrocarbons include straight-chain and branched, saturated and unsaturated aliphatic hydrocarbon compounds, including alkanes, alkenes and alkynes; and saturated and unsaturated cyclic aliphatic hydrocarbon compounds, including cycloalkanes, cycloalkenes and cycloalkynes; and hydrocarbon polymers, such as polyolefins.

[0041] Hydrocarbons also include aromatic hydrocarbons, ie hydrocarbons containing one or more aromatic rings. The aromatic rings may be monocyclic or polycyclic.

[0042] The term "hydrocarbon" (such compounds consisting solely of carbon and hydrogen) also includes, of course, aliphatic hydrocarbons substituted with one or more aromatic hydrocarbons and aromatic hydrocarbons substituted with one or more aliphatic hydrocarbons, and likewise linear or branched aliphatic hydrocarbons substituted with one or more cyclic aliphatic hydrocarbons and cyclic aliphatic hydrocarbons substituted with one or more linear or branched aliphatic hydrocarbons.

[0043] “C n-m Hydrocarbons" or "C n to C m A "Cn to Cm hydrocarbon" or "Cn to Cm hydrocarbon" (wherein n and m are integers) is a hydrocarbon as defined above having n to m carbon atoms. For example, C 5-16 Hydrocarbons are hydrocarbons as defined above having 5 to 16 carbon atoms, C 5+ Hydrocarbons are hydrocarbons as defined above having 5 or more carbon atoms, and so on.

[0044] As used herein, the term "alkane" refers to a linear or branched saturated hydrocarbon compound. Examples of alkanes include butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, and tetradecane. Alkanes such as dimethylbutane can be one or more of the possible isomers of the compound. Thus, dimethylbutane includes 2,3-dimethylbutane and 2,2-dimethylbutane. This also applies to all hydrocarbon compounds mentioned herein, including cycloalkanes, alkenes, and cycloalkenes.

[0045] As used herein, the term "cycloalkane" refers to a saturated cyclic aliphatic hydrocarbon compound. Examples of cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, methylcyclopentane, cycloheptane, methylcyclohexane, dimethylcyclopentane, and cyclooctane. Examples of C5-8 cycloalkanes include cyclopentane, cyclohexane, methylcyclopentane, cycloheptane, methylcyclohexane, dimethylcyclopentane, and cyclooctane. The terms "cycloalkane" and "cycloalkane" can be used interchangeably.

[0046] As used herein, the term "alkene" refers to a linear or branched hydrocarbon compound containing one or more carbon-carbon double bonds. Examples of alkene are butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, and tetradecene. Alkenes typically contain one or two double bonds. The terms "alkene" and "olefin" can be used interchangeably. One or more double bonds can be at any position in the hydrocarbon chain. Alkenes can be cis or trans olefins (or defined using E- and Z- nomenclature). Alkenes containing terminal double bonds can be referred to as "alkene-1-ene" (e.g., hex-1-ene), "terminal alkene" (or "terminal olefin"), or "alpha-alkene" (or "alpha-olefin"). As used herein, the term "alkene" also typically includes cycloolefins.

[0047] As used herein, the term "cycloolefin" refers to a partially unsaturated cyclic hydrocarbon compound. Examples of cycloolefins include cyclobutene, cyclopentene, cyclohexene, cyclohexa-1,3-diene, methylcyclopentene, cycloheptene, methylcyclohexene, dimethylcyclopentene, and cyclooctene. Cycloolefins may contain one or two double bonds.

[0048] As used herein, the term "aromatic hydrocarbon" or "aromatic hydrocarbon compound" refers to a hydrocarbon compound containing one or more aromatic rings. The aromatic rings can be monocyclic or polycyclic. Typically, the aromatic compound contains a benzene ring. The aromatic compound can be, for example, a C6-14 aromatic compound, a C6-12 aromatic compound, or a C6-10 aromatic compound. Examples of C6-14 aromatic compounds are benzene, toluene, xylene, ethylbenzene, methylethylbenzene, diethylbenzene, naphthalene, methylnaphthalene, ethylnaphthalene, and anthracene.

[0049] As used herein, a "metallic substance" is any compound containing a metal. Thus, metallic substances include elemental metals, metal oxides, and other compounds containing metals, i.e., salts, alloys, hydroxides, carbides, borides, silicides, and hydrides of metals. When referring to a specific example of a metallic substance, the term includes all compounds containing that metal. For example, an iron substance includes, for example, elemental iron, iron oxides, iron salts, iron alloys, iron hydroxides, iron carbides, iron borides, iron silicides, and iron hydrides.

[0050] As used herein, the term "heterogeneous mixture" refers to a physical combination of at least two different substances, wherein the two different substances are not in the same phase. For example, one substance can be a solid and one substance can be a liquid or a gas.

[0051] Catalyst precursor

[0052] In one aspect, the present invention is directed to a catalyst precursor comprising at least one iron species, an alkali metal or a salt thereof, and a complexing agent.

[0053] In one embodiment, the present invention is directed to a catalyst precursor comprising iron or a salt thereof, an oxide thereof or a hydroxide thereof, an alkali metal or a salt thereof, and a complexing agent.

[0054] In one embodiment, complexing agent is suitable for making metal cation (particularly iron cation) complex.Therefore, suitable complexing agent comprises one or more functional groups selected from carboxylic acid, hydroxyl, amide group or amino group.Suitably, complexing agent comprises two or more functional groups selected from carboxylic acid, hydroxyl, amide group or amino group.Suitably, complexing agent is an organic compound.

[0055] In one embodiment, the complexing agent or organic compound is selected from hydroxycarboxylic acid, aminocarboxylic acid, polycarboxylic acid or its salt. Suitably, the complexing agent or organic compound is selected from hydroxycarboxylic acid and polycarboxylic acid, or its salt. Alternatively, the complexing agent or organic compound is selected from hydroxycarboxylic acid and aminocarboxylic acid, or its salt.

[0056] In one embodiment, the complexing agent or organic compound is a bidentate or multidentate hydroxycarboxylic acid or a salt thereof.

[0057] In one embodiment, the complexing agent or organic compound is selected from glycolic acid, lactic acid, hydracylic acid, hydroxybutyric acid, hydroxyvaleric acid, malic acid, mandelic acid, citric acid, sugar acid, tartronic acid, tartaric acid, oxalic acid, malonic acid, maleic acid, tannic acid, succinic acid, salicylic acid, glutaric acid, adipic acid, glycine, hippuric acid, EDTA (ethylenediaminetetraacetic acid), NTA (nitroilotiracetic acid), DTPA (diethylenetriaminepentaacetic acid), HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid), alanine, valine, leucine and isoleucine, and salts thereof.

[0058] In one embodiment, the complexing agent or organic compound is selected from glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, malic acid, mandelic acid, citric acid, sugar acid, tartronic acid, tartaric acid, oxalic acid, malonic acid, maleic acid, tannic acid, succinic acid, salicylic acid, glutaric acid, adipic acid, hippuric acid, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), and HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid), or a salt thereof.

[0059] In one embodiment, the complexing agent or organic compound is selected from hydroxybutyric acid, hydroxyvaleric acid, malic acid, mandelic acid, citric acid, sugar acid, tartronic acid, tartaric acid, oxalic acid, malonic acid, maleic acid, tannic acid, succinic acid, salicylic acid, glutaric acid, adipic acid, hippuric acid, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), and HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid), or a salt thereof.

[0060] In one embodiment, the complexing agent or organic compound is selected from hydroxybutyric acid, hydroxyvaleric acid, malic acid, mandelic acid, citric acid, sugar acid, tartronic acid, tartaric acid, oxalic acid, malonic acid, maleic acid, tannic acid, succinic acid, salicylic acid, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), and HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid), or a salt thereof.

[0061] In one embodiment, the complexing agent or organic compound is selected from citric acid, sugar acid, tartaric acid, oxalic acid, salicylic acid, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), and HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid), or a salt thereof.

[0062] In one embodiment, the complexing agent or organic compound is selected from citric acid, sugar acid, tartaric acid, oxalic acid, salicylic acid, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), and HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid), or a salt thereof.

[0063] In one embodiment, the complexing agent or organic compound is selected from citric acid, tartaric acid, oxalic acid, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), and HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid), or a salt thereof. Suitably, the complexing agent is citric acid.

[0064] In one embodiment, the molar ratio of complexing agent to metal is from about 0.4: 1 to about 4: 1. Suitably, the molar ratio of complexing agent to metal is from about 0.5: 1 to about 2:1.

[0065] In one embodiment, the molar ratio of complexing agent to metal is from about 0.8: 1 to about 4: 1. Suitably, the molar ratio of complexing agent to metal is from about 1: 1 to about 3:1.

[0066] In one embodiment, the molar ratio of complexing agent to metal is from about 0.5: 1 to about 5: 1. Suitably, the molar ratio of complexing agent to metal is from about 0.8: 1 to about 2:1.

[0067] In one embodiment, the molar ratio of complexing agent to iron is from about 0.5: 1 to about 5: 1. Suitably, the molar ratio of complexing agent to iron is from about 0.8: 1 to about 2:1.

[0068] In one embodiment, the iron species is selected from elemental iron, iron salts, iron oxides, iron alloys, iron hydroxides, iron carbides, iron borides, iron silicides, and iron hydrides. Suitably, the iron species is selected from elemental iron, iron salts, iron alloys, iron hydroxides, and iron silicides. More suitably, the iron species is selected from elemental iron, iron salts, and iron hydroxides.

[0069] In one embodiment, the iron species is an iron salt. In one embodiment, the iron salt is an iron nitrate, an iron sulfate, an iron halide (suitably an iron chloride), or an iron organic acid salt. Suitably, the iron salt is iron (III) nitrate or iron (II) nitrate.

[0070] In another embodiment, the iron species is iron powder. The skilled person will appreciate that iron powder is elemental iron in a commercially available form.

[0071] In another embodiment, the iron species is an iron oxide, suitably Fe3O4.

[0072] In one embodiment, the catalyst precursor comprises from about 5 wt% to about 90 wt% Fe. Suitably, the catalyst precursor comprises from about 10 wt% to about 90 wt% Fe. Suitably, from about 15 wt% to about 90 wt% Fe, more suitably from about 20 wt% to about 90 wt% Fe, more suitably from about 25 wt% to about 90 wt% Fe, more suitably from about 30 wt% to about 90 wt% Fe, more suitably from about 40 wt% to about 90 wt% Fe, more suitably from about 50 wt% to about 90 wt% Fe.

[0073] In one embodiment, the catalyst precursor comprises from about 5 wt% to about 80 wt% Fe. Suitably, the catalyst precursor comprises from about 10 wt% to about 80 wt% Fe. Suitably, from about 15 wt% to about 80 wt% Fe, more suitably from about 20 wt% to about 80 wt% Fe, more suitably from about 25 wt% to about 80 wt% Fe, more suitably from about 30 wt% to about 80 wt% Fe, more suitably from about 40 wt% to about 80 wt% Fe, more suitably from about 50 wt% to about 80 wt% Fe.

[0074] In another embodiment, the catalyst precursor comprises from about 10 wt% to about 90 wt% Fe. Suitably, the catalyst precursor comprises from about 10 wt% to about 80 wt% Fe. Suitably, from about 10 wt% to about 70 wt% Fe, more suitably from about 10 wt% to about 65 wt% Fe.

[0075] In another embodiment, the catalyst precursor comprises from about 10 wt% to about 80 wt% Fe. Suitably, the catalyst precursor comprises from about 10 wt% to about 70 wt% Fe. Suitably, from about 10 wt% to about 60 wt% Fe, more suitably from about 10 wt% to about 50 wt% Fe.

[0076] In one embodiment, the alkali metal is selected from potassium, sodium, lithium or cesium. Thus, the catalyst precursor may comprise potassium, sodium, lithium or cesium, or a salt thereof. Suitably, the alkali metal is present as a salt. Suitably, the alkali metal is an alkali metal carbonate, such as potassium carbonate, sodium carbonate, cesium carbonate, lithium carbonate.

[0077] In one embodiment, the catalyst precursor comprises from about 0.5 wt% to about 30 wt% alkali metal. Suitably, the catalyst precursor comprises from about 0.5 wt% to about 25 wt% alkali metal. Suitably, from about 0.5 wt% to about 20 wt% alkali metal, more suitably from about 0.5 wt% to about 15 wt% alkali metal, more suitably from about 0.5 wt% to about 10 wt% alkali metal, and even more suitably from about 0.5 wt% to about 5 wt% alkali metal.

[0078] In one embodiment, the catalyst precursor comprises from about 1 wt% to about 30 wt% alkali metal. Suitably, the catalyst precursor comprises from about 1 wt% to about 25 wt% alkali metal. Suitably, from about 1 wt% to about 20 wt% alkali metal, more suitably from about 1 wt% to about 15 wt% alkali metal, more suitably from about 1 wt% to about 10 wt% alkali metal, and more suitably from about 1 wt% to about 5 wt% alkali metal.

[0079] In one embodiment, the catalyst precursor may include additional metal species. Suitably, these additional metals will serve as promoters in the catalytically active material. In one embodiment, the additional metal species is a transition metal species. Suitably, the additional metal species is a transition metal, or a salt thereof, an oxide thereof, or a hydroxide thereof.

[0080] Suitably, the catalyst precursor further comprises cobalt, chromium, copper, iridium, manganese, molybdenum, palladium, platinum, rhenium, rhodium, ruthenium, strontium, tungsten, vanadium, zinc, or a salt, oxide or hydroxide thereof.

[0081] In another embodiment, the catalyst precursor further comprises cobalt, copper, manganese, zinc, or a salt, oxide or hydroxide thereof.

[0082] In one embodiment, the catalyst precursor comprises manganese oxide.

[0083] In one embodiment, the catalyst precursor comprises manganese nitrate.

[0084] In one embodiment, the catalyst precursor comprises from about 1 wt% to about 50 wt% of the additional metal species. Suitably, the catalyst precursor comprises from about 1 wt% to about 40 wt% of the additional metal species.

[0085] In another embodiment, the catalyst precursor comprises from about 5 wt% to about 30 wt% additional metal species, more suitably from about 5 wt% to about 20 wt% additional metal species, more suitably from about 5 wt% to about 15 wt% additional metal species, and even more suitably from about 5 wt% to about 15 wt% additional metal species.

[0086] In one embodiment, the catalyst precursor comprises from about 1% to about 30% by weight of additional metallic species. Suitably, the catalyst precursor comprises from about 1% to about 25% by weight of additional metallic species. Suitably, from about 1% to about 20% by weight of additional metallic species, more suitably from about 1% to about 15% by weight of additional metallic species, more suitably from about 1% to about 10% by weight of additional metallic species, and more suitably from about 1% to about 5% by weight of additional metallic species.

[0087] In one embodiment, the catalyst precursor comprises iron or a salt, oxide or hydroxide thereof; at least one additional transition metal selected from Mn, Zn, Cu and Co, or a salt, oxide or hydroxide thereof; an alkali metal or a salt thereof; and a complexing agent.

[0088] In one embodiment, the catalyst precursor comprises iron or a salt, oxide or hydroxide thereof; at least one additional transition metal selected from Mn, Zn, Cu and Co, or a salt, oxide or hydroxide thereof; an alkali metal or a salt thereof; and an organic compound.

[0089] In another embodiment, the catalyst precursor comprises iron or a salt, oxide or hydroxide thereof; at least one additional transition metal or salt, oxide or hydroxide selected from Mn and Co; an alkali metal or a salt thereof; and a complexing agent.

[0090] In another embodiment, the catalyst precursor comprises iron or a salt, oxide or hydroxide thereof; at least one additional transition metal or salt, oxide or hydroxide selected from Mn and Co; an alkali metal or a salt thereof; and an organic compound.

[0091] In another embodiment, the catalyst precursor comprises iron or a salt, oxide or hydroxide thereof; an additional transition metal or salt, oxide or hydroxide selected from Mn and Co; an alkali metal or a salt thereof; and a complexing agent.

[0092] In another embodiment, the catalyst precursor comprises iron or a salt, oxide or hydroxide thereof; another transition metal or salt, oxide or hydroxide selected from Mn and Co; an alkali metal or a salt thereof; and an organic compound.

[0093] In another embodiment, the catalyst precursor comprises an iron salt, a manganese salt, an alkali metal or salt thereof, and a complexing agent.

[0094] In another embodiment, the catalyst precursor comprises an iron salt, a manganese salt, an alkali metal or a salt thereof, and an organic compound.

[0095] In another embodiment, the catalyst precursor comprises iron powder, a manganese salt, a cobalt salt, an alkali metal or its salt, and a complexing agent.

[0096] In another embodiment, the catalyst precursor comprises iron powder, a manganese salt, a cobalt salt, an alkali metal or its salt, and an organic compound. In another embodiment, the catalyst precursor comprises iron nitrate, manganese nitrate, an alkali metal or its salt, and a complexing agent.

[0097] In another embodiment, the catalyst precursor comprises iron nitrate, manganese nitrate, an alkali metal or a salt thereof, and an organic compound.

[0098] Suitably, the alkali metal is potassium. Thus, in one embodiment, the catalyst precursor comprises iron or a salt or oxide thereof; at least one additional transition metal selected from Mn, Zn, Cu and Co, or a salt or oxide thereof; potassium or a salt thereof; and a complexing agent.

[0099] In another embodiment, the catalyst precursor comprises iron or a salt, oxide or hydroxide thereof; at least one additional transition metal or salt, oxide or hydroxide selected from Mn and Co; potassium or a salt thereof; and a complexing agent.

[0100] In another embodiment, the catalyst precursor comprises iron or a salt, oxide or hydroxide thereof; at least one additional transition metal or salt, oxide or hydroxide selected from Mn and Co; potassium or a salt thereof; and an organic compound.

[0101] Suitably, the complexing agent or organic compound is as defined in one of the preceding embodiments. Suitably, the cobalt salt is cobalt nitrate. Suitably, the manganese salt is manganese nitrate.

[0102] In one embodiment, the catalyst precursor comprises iron (II or III) nitrate, manganese (II) nitrate, potassium carbonate, and citric acid. In another embodiment, the catalyst precursor consists essentially of iron (II or III) nitrate, manganese (II) nitrate, potassium carbonate, and citric acid.

[0103] In another embodiment, the catalyst precursor comprises iron powder, manganese (II) nitrate, cobalt nitrate, sodium carbonate, and citric acid. In another embodiment, the catalyst precursor consists essentially of iron powder, manganese (II) nitrate, cobalt nitrate, sodium carbonate, and citric acid.

[0104] In one embodiment, the catalyst precursor comprises (i) Fe or a salt thereof, (ii) Mn or a salt thereof, (iii) K or a salt thereof, and (iv) citric acid or a salt thereof.

[0105] In one embodiment, the catalyst precursor comprises (i) Fe or a salt thereof, (ii) Mn or a salt thereof, (iii) Co or a salt thereof, (iii) K or a salt thereof, and (iv) citric acid or a salt thereof.

[0106] Suitably, the molar ratio of Fe:Mn is from about 100:1 to about 4:1, more suitably from about 15:1 to about 5:1.

[0107] Suitably, the molar ratio of Fe:K is from about 100:1 to about 2:1; more suitably, the molar ratio of Fe:K is from about 20:1 to about 4:1, more suitably from about 10:1 to about 2:1.

[0108] Suitably, the molar ratio of (Fe+Mn+K):citric acid is from about 5:1 to 0.5:1, suitably from about 2:1 to about 1:1.

[0109] Suitably, the molar ratio of Fe:Co is from about 40:1 to about 10:1, more suitably from about 30:1 to about 10:1, more suitably about 20:1.

[0110] Method for preparing a catalyst precursor

[0111] In a second aspect, the present invention relates to a method for preparing a catalyst precursor comprising:

[0112] (a) combining (i) at least one iron substance, (ii) an alkali metal or a salt thereof, (iii) a complexing agent, and (iv) a solvent;

[0113] (b) stirring the mixture of step (a) to provide a homogeneous mixture;

[0114] (c) heating the mixture of step (b) to partially remove the solvent, thereby providing a slurry or paste.

[0115] In this aspect, the iron species, the alkali metal or salt thereof, and the complexing agent may be as defined in any one of the preceding embodiments.

[0116] In one embodiment, the solvent comprises water. Suitably, the solvent is water.

[0117] Step (a) may also comprise adding one or more further metal species, suitably further transition metal species. In one embodiment, in step (a) a further transition metal selected from Mn, Zn, Co and Cu, or a salt thereof, an oxide thereof or a hydroxide thereof is incorporated.

[0118] In step (b), the mixture may be agitated by any means known in the art, such as stirring, shaking, vortexing, and sonication.

[0119] In step (c) the mixture is suitably heated to a temperature of about 30°C to 120°C, more suitably about 30°C to about 80°C, more suitably about 50°C.

[0120] The method may further comprise a further step (d) wherein the slurry or paste of step (c) is calcined to provide a powder. Suitably, the calcination is carried out at a temperature of from about 300°C to about 500°C, more suitably about 350°C. Suitably, the calcination is carried out in air, suitably in static air. Typically, the calcination will result in combustion of the organic components of the precursor.

[0121] The method may further comprise a step (e) wherein the calcined powder is, for example, ground or milled to reduce the particle size.

[0122] In another aspect, the present invention relates to a method for preparing a catalyst precursor, the method comprising:

[0123] (a) combining (i) iron powder, (ii) an alkali metal or a salt thereof, and (iii) a complexing agent; and

[0124] (b) stirring the mixture of step (a) to provide a homogeneous mixture.

[0125] In one embodiment, step (a) may further comprise adding one or more additional metal species. In one embodiment, at least one additional transition metal selected from Mn, Zn, Co and Cu, or a salt, oxide or hydroxide thereof is incorporated into step (a). Suitably, Mn or a salt, oxide or hydroxide thereof and Co or a salt, oxide or hydroxide thereof are further incorporated into step (a).

[0126] In step (b), agitation may be performed by any means known in the art, such as stirring, shaking, milling and grinding.

[0127] In one embodiment, the method for preparing the catalyst precursor comprises:

[0128] (a) combining: (i) iron powder; (ii) potassium, sodium or lithium, or a salt thereof; (iii) citric acid; and (iv) at least one additional transition metal selected from Mn and Co, or a salt thereof, an oxide thereof or a hydroxide thereof; and

[0129] (b) stirring the mixture of step (a) to provide a homogeneous mixture.

[0130] Catalyst and method for preparing the same

[0131] In another aspect, the present invention relates to a catalyst obtainable by activating a catalyst precursor obtainable according to the process described herein, or a catalyst obtainable by activating a catalyst precursor as described herein.

[0132] Suitably, the catalyst is suitable for the hydrogenation of carbon dioxide and / or carbon monoxide.

[0133] In one embodiment, the catalyst comprises iron carbide, suitably Fe5C2.

[0134] In one embodiment, the catalyst comprises iron carbide; at least one additional transition metal selected from Mn, Zn, Cu, and Co, or a salt thereof, an oxide thereof, or a hydroxide thereof; and an alkali metal or a salt thereof.

[0135] In one embodiment, the catalyst comprises iron carbide; at least one additional transition metal or salt, oxide or hydroxide selected from Mn and Co; and an alkali metal or salt thereof.

[0136] In another embodiment, the catalyst precursor comprises iron carbide; manganese or its oxide; and an alkali metal.

[0137] In another embodiment, the catalyst comprises iron carbide; manganese or its oxide; cobalt or its oxide; and an alkali metal.

[0138] Suitably, the alkali metal is potassium.

[0139] In another embodiment, the catalyst comprises iron carbide; at least one additional transition metal or oxide thereof selected from Mn and Co; and potassium.

[0140] Suitably, the iron carbide is Fe5C2.

[0141] Suitably, the molar ratio of Fe:Mn is from about 100:1 to about 4:1, more suitably from about 15:1 to about 5:1.

[0142] Suitably, the molar ratio of Fe:K is from about 100:1 to about 2:1; more suitably, the molar ratio of Fe:K is from about 20:1 to about 4:1, more suitably from about 10:1 to about 2:1.

[0143] Suitably, the molar ratio of Fe:Co is from about 40:1 to about 10:1, more suitably from about 30:1 to about 10:1, more suitably about 20:1.

[0144] In another aspect, the present invention relates to a method for preparing a catalyst, the method comprising:

[0145] (a) providing a catalyst precursor as defined in any one of the above embodiments;

[0146] (b) optionally calcining the catalyst precursor; and

[0147] (c) activating the precursor.

[0148] In one embodiment, the catalyst is suitable for the hydrogenation of carbon dioxide and / or carbon monoxide.

[0149] Suitably, calcination is carried out at a temperature of about 100°C to about 500°C, or about 250°C to about 500°C, more suitably about 300°C to about 350°C. Suitably, calcination is carried out in air, suitably in static air. Typically, calcination will result in decomposition or partial combustion of the organic components of the precursor.

[0150] Step (b) may also comprise grinding or milling the calcined powder to reduce the particle size.

[0151] The calcined material of step (b) or the precursor of step (a) may be activated, for example, by reduction. Suitably, the material to be activated is exposed to a mixture of CO and hydrogen at a temperature of about 250°C to about 500°C, more suitably about 300°C to about 350°C.

[0152] Process for the hydrogenation of CO2 or CO

[0153] In one aspect, the present invention relates to a process for the hydrogenation of carbon dioxide, the process comprising contacting a feed comprising hydrogen and carbon dioxide with a catalyst precursor or catalyst as defined herein at elevated temperature and pressure.

[0154] In another aspect, the present invention relates to a process for the hydrogenation of carbon monoxide, the process comprising contacting a feed comprising hydrogen and carbon monoxide with a catalyst precursor or catalyst as defined herein at elevated temperature and pressure.

[0155] In another aspect, the present invention relates to a process for the production of olefins, the process comprising contacting a feedstock comprising (i) hydrogen and (ii) carbon dioxide and / or carbon monoxide with a catalyst precursor or catalyst as defined herein at elevated temperature and pressure.

[0156] Suitably, the olefin is a C5+ olefin, or an alpha olefin, or a linear olefin. More suitably, the olefin is a C5+ alpha olefin. Suitably, the olefin is a linear alpha olefin. More suitably, the olefin is a C5+ linear alpha olefin.

[0157] Suitably, the olefin is C 5-16 More suitably, the olefin is C 5-16 More preferably, the olefin is C 5-16 Linear alpha olefins.

[0158] In another aspect, the present invention relates to a process for the production of hydrocarbons, the process comprising contacting a feedstock comprising (i) hydrogen and (ii) carbon dioxide and / or carbon monoxide with a catalyst precursor or catalyst as defined herein at elevated temperature and pressure.

[0159] Suitably, the hydrocarbon is a C5+ hydrocarbon, more suitably a C8 to C 18 Hydrocarbons, more preferably C8 to C 16 In one embodiment, the hydrocarbon is C8 to C 18 Alkanes, more preferably C8 to C 16 Alkanes. In one embodiment, the hydrocarbons are jet fuel range hydrocarbons.

[0160] In another aspect, the invention relates to a process for producing a fuel, the process comprising contacting a feedstock comprising (i) hydrogen and (ii) carbon dioxide and / or carbon monoxide with a catalyst precursor or catalyst as defined herein at elevated temperature and pressure.

[0161] Suitably, the fuel is selected from gasoline, diesel and aviation / jet fuel.

[0162] When performing carbon monoxide or carbon dioxide hydrogenation or olefin production, a catalyst or catalyst precursor is charged to the reaction zone. The catalyst is activated ex situ (e.g., by heating, or, if desired, by oxidation and subsequent reduction with synthesis gas or hydrogen). The catalyst precursor can be activated in situ, for example, under reaction conditions.

[0163] The catalyst can be used in a fixed bed, moving bed, ebullating bed, fluidized bed or slurry bed reactor. Suitably, the catalyst is used in a fixed bed reactor.

[0164] In one embodiment, when CO hydrogenation is desired, a feedstock comprising a mixture of hydrogen and carbon monoxide in a suitable H2:CO molar ratio is contacted with a catalyst bed and reacted under reaction conditions. Typically, the H2:CO molar ratio ranges from about 0.4:1 to about 6:1, suitably from about 0.5:1 to about 3:1, and more suitably from about 1:1 to about 2:1.

[0165] In another embodiment, when CO2 hydrogenation is desired, a feedstock comprising a mixture of hydrogen and carbon dioxide in a suitable H2:CO2 molar ratio is contacted with a catalyst bed and reacted under reaction conditions. Typically, the molar ratio of H2:CO2 ranges from about 0.4:1 to about 8:1, suitably from about 0.4:1 to about 6:1, suitably from about 0.5:1 to about 5:1, more suitably from about 1:1 to about 4:1. Suitably, the molar ratio of H2:CO2 ranges from about 0.5:1 to about 4:1, more suitably from about 1:1 to about 3:1.

[0166] The reaction temperature is elevated. As used herein, elevated temperature is a temperature that is elevated relative to standard ambient temperature, i.e., a temperature of 298.15 K (25° C.). In one embodiment, the feedstock is contacted with the catalyst precursor or catalyst at a temperature of about 180° C. to about 500° C., suitably about 250° C. to about 500° C., more suitably about 280° C. to about 350° C., or about 300° C. to about 350° C.

[0167] The reaction pressure is elevated. As used herein, elevated pressure is a pressure elevated relative to standard ambient pressure (i.e., a pressure of 100,000 Pa (1 bar, 14.5 psi, 0.9869 atm)). In one embodiment, the feedstock is contacted with the catalyst precursor or catalyst at a pressure of about 500 kPa to about 20 MPa, suitably about 500 kPa to about 10 MPa, suitably about 500 kPa to about 5 MPa, suitably about 500 kPa to about 2 MPa, suitably about 1 MPa.

[0168] The present invention will now be further described by the following numbered paragraphs:

[0169] 1. A catalyst precursor comprising an iron material (suitably iron or a salt thereof, an oxide thereof or a hydroxide thereof), an alkali metal or a salt thereof, and a complexing agent.

[0170] 2. The catalyst precursor according to paragraph 1, wherein the complexing agent comprises one or more functional groups selected from carboxylic acid, hydroxyl, amide, or amino groups.

[0171] 3. The catalyst precursor according to paragraph 1, wherein the complexing agent comprises one or more functional groups selected from carboxylic acid, hydroxyl, and amide groups.

[0172] 4. The catalyst precursor according to paragraph 1, wherein the complexing agent is selected from hydroxycarboxylic acids, aminocarboxylic acids, and polycarboxylic acids, or salts thereof.

[0173] 5. The catalyst precursor of paragraph 1, wherein the complexing agent is selected from glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, malic acid, mandelic acid, citric acid, sugar acid, tartronic acid, tartaric acid, oxalic acid, malonic acid, maleic acid, tannic acid, succinic acid, salicylic acid, glutaric acid, adipic acid, glycine, hippuric acid, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid), alanine, valine, leucine and isoleucine, and salts thereof.

[0174] 6. The catalyst precursor according to paragraph 1, wherein the complexing agent is selected from citric acid, tartaric acid, oxalic acid, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), and HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid), or a salt thereof.

[0175] 7. The catalyst precursor of any of the preceding paragraphs, wherein the complexing agent is citric acid and / or a salt thereof.

[0176] 8. The catalyst precursor of any of the preceding paragraphs, wherein the alkali metal is selected from potassium, sodium, lithium, and cesium.

[0177] 9. The catalyst precursor of any of the preceding paragraphs, wherein the alkali metal is selected from potassium, sodium, and cesium.

[0178] 10. The catalyst precursor of any of the preceding paragraphs, wherein the alkali metal is potassium.

[0179] 11. A catalyst precursor according to any preceding paragraph, wherein the iron species is an iron nitrate, suitably iron (II) nitrate or iron (III) nitrate.

[0180] 12. The catalyst precursor according to any one of paragraphs 1 to 10, wherein the iron species is selected from elemental iron, iron oxide, iron salt or iron hydroxide, suitably wherein the iron species is iron powder.

[0181] 13. The catalyst precursor of any of the preceding paragraphs comprising an additional metal species.

[0182] 14. The catalyst precursor of paragraph 13, wherein the additional metal species is present in an amount of about 1 wt% to about 20 wt%.

[0183] 15. The catalyst precursor according to any of the preceding paragraphs, further comprising one or more transition metals selected from the group consisting of Mn, Zn, Co and Cu, or a salt thereof, an oxide thereof or a hydroxide thereof.

[0184] 16. The catalyst precursor of paragraph 15, wherein the transition metal is selected from Mn and Co, or a salt thereof, an oxide thereof, or a hydroxide thereof.

[0185] 17. The catalyst precursor of any of the preceding paragraphs, comprising (i) Fe or a salt thereof, (ii) Mn or a salt thereof, (iii) K or a salt thereof, and (iv) citric acid or a salt thereof.

[0186] 18. The catalyst precursor of paragraph 17, further comprising (v) Co or a salt thereof.

[0187] 19. The catalyst precursor of any of paragraphs 1 to 11 and 13 to 17, comprising iron (III) nitrate, manganese (II) nitrate, potassium carbonate, and citric acid.

[0188] 20. The catalyst precursor of any of paragraphs 1 to 10 and 12 to 18, comprising iron powder, manganese (II) nitrate, cobalt nitrate, sodium carbonate, and citric acid.

[0189] 21. The catalyst precursor of any of the preceding paragraphs, wherein the molar ratio of Fe:alkali metal is from about 100:1 to about 4:1, suitably from about 20:1 to about 4:1, more suitably about 10:1.

[0190] 22. The catalyst precursor of any of the preceding paragraphs, wherein the molar ratio of the complexing agent to Fe is from about 1:1 to about 3:1.

[0191] 23. The catalyst precursor of any of paragraphs 15 to 20, wherein the molar ratio of Fe:Mn is from about 100:1 to about 4:1, suitably about 10:1.

[0192] 24. The catalyst precursor of any of paragraphs 15 to 20, wherein the molar ratio of (Fe+Mn+K):citric acid is from about 5:1 to about 0.5:1, suitably from about 2:1 to about 1:1.

[0193] 25. The catalyst precursor of any of paragraphs 15, 16, 18, and 20, wherein the molar ratio of Fe:Co is from about 40:1 to about 10:1, more suitably from about 30:1 to about 10:1, more suitably about 20:1.

[0194] 26. A method for preparing a catalyst precursor, comprising:

[0195] (a) combining (i) an iron material (suitably iron or a salt thereof, an oxide thereof or a hydroxide thereof), (ii) an alkali metal or a salt thereof, (iii) a complexing agent, and (iv) a solvent;

[0196] (b) stirring the mixture of step (a) to provide a homogeneous mixture;

[0197] (c) heating the mixture of step (b) to partially remove the solvent, thereby providing a slurry or paste.

[0198] 27. The method of paragraph 26, wherein step (a) further comprises incorporating one or more transition metals selected from the group consisting of Mn, Zn, Co, and Cu, or salts thereof, oxides thereof, or hydroxides thereof.

[0199] 28. The method of any of paragraphs 26 to 27, wherein step (a) comprises combining (i) Fe or a salt thereof, (ii) Mn or a salt thereof, (iii) K or a salt thereof, and (iv) citric acid or a salt thereof.

[0200] 29. The process of any one of paragraphs 26 to 28, wherein the iron species in step (a) is iron (III) nitrate.

[0201] 30. The process of any of paragraphs 26 to 29, wherein step (a) comprises combining iron (III) nitrate, manganese (II) nitrate, potassium carbonate, and citric acid.

[0202] 31. The process of any of paragraphs 26 to 30, wherein step (a) comprises combining iron (III) nitrate, manganese (II) nitrate, potassium carbonate, and citric acid with water.

[0203] 32. The process according to paragraph 28, wherein the weight ratio of (i) to (iv) to the solvent in step (a) is from about 3:1 to about 1:3, suitably about 2:1.

[0204] 33. The method of any of paragraphs 26 to 32, further comprising (d) calcining the paste or slurry of step (c) to provide a powder.

[0205] 34. The method of paragraph 33, wherein calcining is carried out at a temperature of about 100°C to about 500°C, suitably about 250°C to about 500°C, suitably about 300°C to about 350°C.

[0206] 35. The process of any of paragraphs 33 and 34, wherein calcination is carried out in air or an inert atmosphere, suitably in static air.

[0207] 36. The method of any of paragraphs 33 to 35, further comprising (e) grinding the powder of step (d).

[0208] 37. A method for preparing a catalyst precursor, comprising:

[0209] (a) combining (i) iron powder, (ii) an alkali metal or a salt thereof, and (iii) a complexing agent; and

[0210] (b) stirring the mixture of step (a) to provide a homogeneous mixture.

[0211] 38. The method of paragraph 37, wherein step (a) further comprises adding one or more additional metal species.

[0212] 39. The process of any of paragraphs 37 and 38, wherein step (a) further comprises incorporating Mn or a salt thereof, an oxide thereof, or a hydroxide thereof and Co or a salt thereof, an oxide thereof, or a hydroxide thereof.

[0213] 40. The method of claim 37, comprising:

[0214] (a) combining: (i) iron powder; (ii) potassium, sodium or lithium, or a salt thereof; (iii) citric acid; and (iv) at least one additional transition metal selected from Mn and Co, or a salt thereof, an oxide thereof or a hydroxide thereof; and

[0215] (b) stirring the mixture of step (a) to provide a homogeneous mixture.

[0216] 41. The process of any one of paragraphs 27 to 36 and 38 to 40, wherein the molar ratio of Fe:Mn in step (a) is from about 100:1 to about 4:1, suitably about 10:1.

[0217] 42. The process of any one of paragraphs 26 to 41, wherein the molar ratio of Fe:alkali metal in step (a) is from about 100:1 to about 4:1, suitably from about 20:1 to about 4:1.

[0218] 43. The process of any of paragraphs 28, 30 to 32, wherein the molar ratio of Fe:K in step (a) is about 10:1.

[0219] 44. The process of paragraph 28, wherein the molar ratio of (Fe+Mn+K):citric acid in step (a) is from about 5:1 to 0.5:1, suitably from about 2:1 to about 1:1.

[0220] 45. The method of any of paragraphs 26 to 44, wherein the molar ratio of the complexing agent to Fe is from about 1:1 to about 3:1.

[0221] 46. ​​The process of any one of paragraphs 26 to 36, wherein step (c) comprises heating the mixture to about 30°C to 80°C, suitably about 50°C.

[0222] 47. The method of any of paragraphs 26 and 37, wherein the complexing agent is as described in any of paragraphs 2 to 7.

[0223] 48. The method of any of paragraphs 26 and 37, wherein the alkali metal is as described in any of paragraphs 8 to 10.

[0224] 49. The process of paragraph 40, wherein step (a) comprises combining iron powder, manganese (II) nitrate, cobalt nitrate, sodium carbonate, and citric acid.

[0225] 50. A catalyst obtainable by activating a catalyst precursor as defined in paragraphs 1 to 25, or obtainable by activating a catalyst precursor obtainable by a process according to any one of paragraphs 26 to 49.

[0226] 51. A method for preparing a catalyst, comprising:

[0227] (a) providing a catalyst precursor according to any one of paragraphs 1 to 25;

[0228] (b) optionally calcining the catalyst precursor; and

[0229] (c) activating the precursor.

[0230] 52. The method of paragraph 51, wherein calcining is carried out at a temperature of about 100°C to about 500°C, about 250°C to about 500°C, suitably about 300°C to about 350°C.

[0231] 53. The process of any of paragraphs 51 and 52, wherein calcination is carried out in air or an inert atmosphere, suitably in static air.

[0232] 54. A process according to any one of paragraphs 51 to 53, wherein step (c) comprises reducing the precursor, suitably by exposure to CO and hydrogen.

[0233] 55. The method of any of paragraphs 51 to 54, further comprising (d) grinding or granulating the product of step (c).

[0234] 56. A catalyst obtainable by the process according to any one of paragraphs 51 to 55.

[0235] 57. A method for producing C 5+A catalyst for hydrocarbons, comprising: (i) an iron substance; (ii) at least one transition metal selected from manganese and cobalt, or a salt thereof, an oxide thereof, or a hydroxide thereof; and (iii) an alkali metal or a salt thereof.

[0236] 58. The catalyst of paragraph 57, wherein the iron species comprises iron carbide.

[0237] 59. The catalyst of paragraph 57, wherein the alkali metal or salt thereof comprises potassium or a salt thereof.

[0238] 60. The catalyst of any of paragraphs 57 to 59, wherein the molar ratio of Fe:Mn is from 100:1 to 4:1.

[0239] 61. The catalyst of paragraph 60, wherein the molar ratio of Fe:Mn is from 15:1 to 5:1.

[0240] 62. The catalyst of any of paragraphs 57 to 59, wherein the molar ratio of Fe:alkali metal is from 100:1 to 2:1.

[0241] 63. The catalyst of paragraph 62, wherein the molar ratio of Fe:alkali metal is from 20:1 to 4:1.

[0242] 64. The catalyst of any of paragraphs 57 to 59, wherein the molar ratio of Fe:Co is from 40:1 to 10:1.

[0243] 65. The catalyst of paragraph 57, comprising 50% to 90% by weight iron.

[0244] 66. The catalyst of paragraph 58, wherein the iron carbide is Fe5C2.

[0245] 67. The catalyst according to paragraph 57, wherein the C 5+ Hydrocarbons are C8 to C 18 hydrocarbon.

[0246] 68. The catalyst according to paragraph 57, wherein the C 5+ Hydrocarbon is C 5+ Olefins.

[0247] 69. The catalyst according to paragraph 57, wherein the C 5+ Hydrocarbon is C 5+ α-olefins.

[0248] 70. Use of the catalyst according to any one of paragraphs 57 to 69 in the production of C 5+ Use of hydrocarbons, said use comprising contacting a feedstock comprising hydrogen and carbon dioxide with said catalyst.

[0249] 71. The use according to paragraph 70, comprising contacting the feedstock with the catalyst at a temperature of 180°C to 500°C and / or at a pressure of 0.5 MPa to 20 MPa.

[0250] 72. The use according to paragraphs 70 and 71, wherein the molar ratio of hydrogen to carbon dioxide in the feedstock is from 0.4:1 to 6:1.

[0251] 73. A process for the hydrogenation of carbon dioxide comprising contacting a feedstock comprising hydrogen and carbon dioxide with the catalyst precursor of paragraphs 1 to 25 or the catalyst of any of paragraphs 50 to 69 at elevated temperature and pressure.

[0252] 74. A method for converting carbon dioxide into C 5+ A process for producing hydrocarbons comprising contacting a feedstock comprising hydrogen and carbon dioxide with the catalyst of any of paragraphs 57 to 69 at a temperature of 180° C. to 500° C. and / or at a pressure of 0.5 MPa to 20 MPa.

[0253] 75. The method of paragraph 73, wherein the catalyst precursor is a catalyst precursor of paragraphs 11, 17, and 19.

[0254] 76. The process of any one of paragraphs 73 to 75, wherein the molar ratio of hydrogen to carbon dioxide in the feedstock is from 0.4:1 to 6:1, suitably from about 1:1 to about 3:1.

[0255] 77. A process for the hydrogenation of carbon monoxide comprising contacting a feedstock comprising hydrogen and carbon monoxide with the catalyst precursor of paragraphs 1 to 25 or the catalyst of any of paragraphs 50 to 69 at elevated temperature and pressure.

[0256] 78. The process of paragraph 77, wherein the catalyst precursor is a catalyst precursor of paragraphs 12, 15 to 18, and 20.

[0257] 79. The process of any of paragraphs 77 and 78, wherein the molar ratio of hydrogen to carbon monoxide in the feed is from 0.4:1 to 6:1, suitably from about 1:1 to about 2:1.

[0258] 80. A process for producing olefins comprising contacting a feedstock comprising hydrogen and carbon monoxide, or hydrogen and carbon dioxide, with the catalyst precursor of paragraphs 1 to 25 or the catalyst of any of paragraphs 50 to 69 at elevated temperature and pressure.

[0259] 81. The method of paragraph 80, wherein the molar ratio of H2:CO2 or H2:CO in the feedstock is from 0.4:1 to 6:1.

[0260] 82. The process according to any one of paragraphs 80 and 81, wherein the olefin is C 5+ Olefin, suitably C 5+ α-olefins.

[0261] 83. The method according to paragraph 82, wherein C 5+ Olefins are C 5-16 Olefins or C 5-16 α-olefins.

[0262] 84. The process of any of paragraphs 73 to 83, wherein the feedstock is contacted with the catalyst precursor or catalyst at a temperature of about 100°C to about 500°C, suitably about 250°C to about 500°C, suitably about 300°C to about 350°C.

[0263] 85. The process of any of paragraphs 73 to 84, wherein the feedstock is contacted with the catalyst precursor or catalyst at a pressure of about 500 KPa to about 2 MPa, suitably about 1 MPa.

[0264] 86. The process of any one of paragraphs 73 to 85, wherein the feedstock is allowed to react with the catalyst precursor or catalyst for about 100 hours. -1 to approximately 20,000 hours -1 , suitably about 1000 hours -1 About 5000 hours -1 Contact at GHSV (gas hourly space velocity).

[0265] 87. A heterogeneous mixture comprising the catalyst precursor of any of paragraphs 1 to 25 or the catalyst of any of paragraphs 50 to 69, and a gas comprising hydrogen and carbon monoxide, or hydrogen and carbon dioxide.

[0266] Example

[0267] 1.CO2 hydrogenation

[0268] All catalyst component materials were obtained from commercial sources as shown below and used without further modification.

[0269] The general method for preparing the catalyst utilizes an organic combustion method. Typically, an iron salt and an alkali metal salt are mixed with a complexing agent in the desired ratio and stirred in water to provide a uniform aqueous solution. The solution is heated at approximately 50°C for 1 to 2 hours to obtain a slurry. The slurry is then calcined in a furnace at approximately 350°C in static air for 4 hours to provide a catalyst precursor.

[0270] For example, preparing an Fe-Mn-K catalyst involves mixing citric acid monohydrate with iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate, wherein the molar ratio of citric acid to (Fe + Mn + K) is about 2, and the weight ratio of (Fe precursor, Mn precursor, and K precursor + citric acid) to water is about 2:1. The mixture is stirred to form a uniform aqueous solution and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. The paste is then fired at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0271] Carbon dioxide hydrogenation experiments were carried out in a fixed bed reactor ( Figure 1 ). Typically, 1.0 g of the catalyst precursor was mixed with 4.0 g of silicon carbide and loaded into the reactor. Prior to the reaction, the catalyst precursor was reduced in synthesis gas (H2:CO=2:1) ​​at atmospheric pressure with a GHSV (gas hourly space velocity) of 1000 mL / g / h at 320°C for 24 hours at a heating rate of 2°C / min to provide an activated catalyst.

[0272] After reduction, the temperature was lowered to about 50°C, and a mixture of H2 / CO2 (3:1) and N2 (as an internal standard) was used as the feed gas. The gas flow rate was set to 40 mL / min (GSVH = 2400 mL / g catalyst). N2 was added to the syngas feed as an inert gas for conversion calculation. Since the mass flow rate of N2 did not change before and after the reaction, the CO2 and H2 conversions, CO and C n H m Selectivity can be calculated as follows.

[0273] The reactor was heated at a heating rate of 2° C. / min until the reaction temperature (approximately 300° C. to 320° C.) The reaction pressure was controlled at 10 bar (1 MPa) by a back pressure regulator.

[0274] Gaseous products were analyzed on a Perkin Elmer Clarus GC, and collected liquid products were analyzed by GC-MS.

[0275] The conversion of CO2 and H2 and the product selectivity were calculated by the following equations:

[0276]

[0277] Table 1 provides examples of Fe-Mn-K catalysts prepared as described above with different Fe:Mn:K ratios using citric acid as a complexing agent. After the reaction was continued for 20 hours, the conversion of H2 and CO2 and the product selectivity for different catalysts are shown in Table 1.

[0278] Table 1

[0279]

[0280] Table 2 and Figure 2 The olefin:alkane molar ratio of the C2 to C4 hydrocarbons produced is provided.

[0281] Table 2

[0282]

[0283] Table 2 and Figure 2 The results show that the catalyst has a higher selectivity for olefins than for alkanes in the liquid products. The GC-MS spectrum of the liquid products shows that the products are concentrated in C6 to C 16 The main peak is attributed to linear α-olefins.

[0284] The XRD patterns of each catalyst were recorded on a Bruker D8 ECO X-ray diffractometer using graphite monochromatized Cu Ka radiation (λ=0.15418 nm, 2θ range from 20° to 80°, at a scan rate of 0.02° / s). Most of the peaks can be attributed to Fe3O4.

[0285] Based on the peak at 2θ = 35.9°, the crystallite size was calculated using the Debye-Scherrer formula:

[0286]

[0287] Where β is the full width at half maximum (FWHM) value of the XRD diffraction line, wavelength λ = 0.15418 nm, and θ is half of the diffraction angle 2θ. The catalyst showed a small crystallite size of about 10 nm (Table 3), which is consistent with the XRD spectrum ( Figure 3 ) is consistent with the broad peak in .

[0288] Table 3

[0289]

[0290] To investigate the effects of various promoters on CO2 hydrogenation, iron-based catalysts were prepared using potassium and various promoters. The catalysts were prepared using an organic combustion method similar to the one described above using citric acid as a complexing agent. The catalyst precursors for the catalysts investigated in Table 4 were prepared as follows:

[0291] Example 4: Citric acid monohydrate and iron (III) nitrate nonahydrate at a molar ratio of 2:1 were dissolved in water to form a uniform aqueous solution (the weight ratio of (iron (III) nitrate nonahydrate + citric acid monohydrate) to water was approximately 2:1), and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. The paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0292] Example 5: Citric acid monohydrate, iron (III) nitrate nonahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution, wherein the molar ratio of Fe:K was 100:10, the molar ratio of citric acid:(Fe+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + potassium carbonate + citric acid) / water was approximately 2:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0293] Example 6: Citric acid monohydrate, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of citric acid:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + citric acid) / water was approximately 2:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0294] Example 7: Citric acid monohydrate, iron (III) nitrate nonahydrate, zinc nitrate hexahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution, wherein the molar ratio of Fe:Zn:K was 100:10:10, the molar ratio of citric acid:(Fe+Zn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + zinc nitrate hexahydrate + potassium carbonate + citric acid) / water was approximately 2:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0295] Example 8: Citric acid monohydrate, iron (III) nitrate nonahydrate, copper (II) nitrate trihydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Cu:K was 100:10:10, the molar ratio of citric acid:(Fe+Cu+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + copper (II) nitrate trihydrate + potassium carbonate + citric acid) / water was approximately 2:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a catalyst powder.

[0296] The catalyst performance was evaluated in the CO2 hydrogenation as described above with a reaction time of 20 hours.

[0297] Table 4 shows the effect of including a transition metal (TM) promoter in the catalyst. The catalysts were prepared using citric acid as a complexing agent and had a molar ratio of K:Fe and TM:Fe of 1:10 where applicable. In Table 4, the hydrocarbon column headings have the following meanings: C 2-4 =: C2 to C4 olefins, C 2-4 0: C2 to C4 alkanes; C 5+ : Liquid product; C 5-16 =: C5 to C 16 Olefins.

[0298] Table 4

[0299]

[0300] Table 5 provides the olefin:alkane molar ratios of the C2 to C4 hydrocarbons produced.

[0301] Table 5

[0302]

[0303] The XRD patterns of each catalyst were recorded on a Bruker D8 ECO X-ray diffractometer using graphite monochromatized Cu Ka radiation (λ = 0.15418 nm, 2θ range from 10° to 90°, at a scan rate of 0.02° / s). Figure 4 ), the crystallite size was calculated using the Debye-Scherrer formula as described above. The catalysts showed different crystallite sizes (Table 6).

[0304] Table 6

[0305]

[0306] To study the effect of various alkali metals on CO2 hydrogenation, iron-based catalysts were prepared with a manganese promoter and alkali metals varying between Na, K, and Cs. The catalysts were prepared using an organic combustion method similar to that described above. The catalyst precursors for the catalysts studied in Table 7 were prepared as follows:

[0307] Example 9: Citric acid monohydrate, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and sodium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:Na was 100:10:10, the molar ratio of citric acid:(Fe+Mn+Na) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + sodium carbonate + citric acid) / water was approximately 2:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0308] Example 10: Citric acid monohydrate, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of citric acid:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + citric acid) / water was approximately 2:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a catalyst powder.

[0309] Example 11: Citric acid monohydrate, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and cesium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:Cs was 100:10:10, the molar ratio of citric acid:(Fe+Mn+Cs) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + cesium carbonate + citric acid) / water was approximately 2:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. The paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0310] The catalyst performance was evaluated in the CO2 hydrogenation as described above with a reaction time of 20 hours.

[0311] Table 7 shows the effect of including an alkali metal (AM) in the catalyst. The catalyst was prepared using citric acid as a complexing agent and had a molar ratio of AM:Fe and Mn:Fe of 1:10. In Table 7, the column headings for hydrocarbons have the following meanings: C 2-4=: C2 to C4 olefins, C 2-4 0: C2 to C4 alkanes; C 5+ : Liquid product; C 5-16 =: C5 to C 16 Olefins.

[0312] Table 7

[0313]

[0314] Table 8 provides the olefin:alkane molar ratios of the C2 to C4 hydrocarbons produced.

[0315] Table 8

[0316]

[0317] The XRD patterns of each catalyst were recorded on a Bruker D8 ECO X-ray diffractometer using graphite monochromatized Cu Ka radiation (λ = 0.15418 nm, 2θ range from 10° to 90°, at a scan rate of 0.02° / s). Figure 5 ), the crystallite size was calculated using the Debye-Scherrer formula based on the above. The catalysts showed different crystallite sizes (Table 9).

[0318] Table 9

[0319]

[0320] To investigate the effect of the complexing agent used in catalyst preparation on catalyst performance, a series of iron-based catalysts were prepared using various complexing agents. The catalysts contained potassium and manganese in a molar ratio of 1:10 relative to Fe. The catalysts were prepared using an organic combustion method similar to that described above. The catalyst precursors for the catalysts investigated in Table 10 were prepared as follows:

[0321] Example 12 (Reference): Iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution, wherein the molar ratio of Fe:Mn:K was 100:10:10 and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate) to water was approximately 2:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a dry mixture. The mixture was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0322] Example 13: Urea, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of urea:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + urea) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a urea-based slurry. The paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0323] Example 14: Tannic acid, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of tannic acid to (Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + tannic acid) to water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a tannic acid-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0324] Example 15: Ethylenediaminetetraacetic acid (EDTA), iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution, wherein the molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of EDTA:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + EDTA) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain an EDTA-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0325] Example 16: Citric acid, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of citric acid:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + citric acid) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a catalyst powder.

[0326] Example 17: Glycine, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of glycine:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + glycine) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a glycine-based slurry. The paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0327] Example 18: Oxalic acid, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of oxalic acid:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + oxalic acid) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain an oxalic acid-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0328] Example 19: Nitrilotriacetic acid (NTA), iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of NTA:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + NTA) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain an NTA-based slurry. The paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0329] Example 20: Diethylenetriaminepentaacetic acid (DTPA), iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of DTPA:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + DTPA) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a DTPA-based slurry. The paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0330] Example 21: Tartaric acid, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution, wherein the molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of tartaric acid:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + tartaric acid) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a tartaric acid-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0331] Example 22: Hydroxyethylethylenediaminetriacetic acid (HEDTA), iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution, wherein the molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of HEDTA:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + HEDTA) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain an HEDTA-based slurry. The paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0332] Example 23: Salicylic acid, iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of salicylic acid:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + salicylic acid) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a salicylic acid-based slurry. The paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0333] Example 24: Sugar (commercial granulated sugar), iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous solution. The molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of sugar:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + sugar) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a sugar-based slurry. This paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0334] Example 25: Flour (commercial white wheat flour (plain flour or self-raising flour)), iron (III) nitrate nonahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were dissolved in water to form a homogeneous aqueous slurry, wherein the molar ratio of Fe:Mn:K was 100:10:10, the molar ratio of flour:(Fe+Mn+K) was approximately 2, and the weight ratio of (iron (III) nitrate nonahydrate + manganese (II) nitrate tetrahydrate + potassium carbonate + flour) / water was approximately 1:1. The mixture was stirred and heated at 50°C for 1 to 2 hours to obtain a flour-based slurry. The slurry was calcined at 350°C (oven temperature) in static air for 4 hours to produce a powder.

[0335] The catalyst performance was evaluated in the CO2 hydrogenation as described above with a reaction time of 20 hours.

[0336] Table 10 shows the effect of the complexing agent used in the preparation of the catalyst on the performance. In Table 10, the column headings for hydrocarbons have the following meanings: C 2-4 =: C2 to C4 olefins, C 2-4 0: C2 to C4 alkanes; C 5+ : Liquid product; C 5-16 =: C5 to C 16 Olefins.

[0337] Table 10

[0338]

[0339] Table 11 provides the olefin:alkane molar ratios of the C2 to C4 hydrocarbons produced.

[0340] Table 11

[0341]

[0342] The XRD patterns of each catalyst were recorded on a Bruker D8 ECO X-ray diffractometer using graphite monochromatized Cu Ka radiation (λ = 0.15418 nm, 2θ range from 10° to 90°, at a scan rate of 0.02° / s). Figure 6 and 7 ), the crystallite size was calculated using the Debye-Scherrer formula based on the above. The catalysts showed different crystallite sizes (Table 12).

[0343] Table 12

[0344]

[0345] Catalysts based on iron prepared with complexing agents and the addition of Na, K and / or Cs have improved the selectivity of olefin production in the CO hydrogenation reaction. Further adding Mn, Zn and / or Cu promoters also shows a high selectivity for olefins relative to alkanes. Different organic compounds are used as complexing agents during the catalyst preparation. Catalysts prepared with citric acid, EDTA, oxalic acid, NTA, DTPA, tartaric acid, HEDTA show the highest selectivity for olefins. Catalysts can also be used for producing fuels (gasoline, diesel, aviation fuel / jet fuel) via CO and / or CO hydrogenation.

[0346] 2.CO hydrogenation

[0347] All catalyst component materials were obtained from commercial sources as shown below and used without further modification.

[0348] Typically, the catalyst is prepared using iron powder as the iron source. Iron powder, cobalt nitrate, manganese nitrate, and an alkali metal salt (e.g., potassium carbonate, sodium carbonate, lithium carbonate, or cesium carbonate) are mixed together and ground until uniform. A complexing agent (citric acid) is added (suitably at a weight ratio of approximately 1:1 to iron) to the mixture, and the mixture is ground again until uniform. The resulting mixture is dried at 80°C for 24 hours. The dried mixture (not calcined) is ground into a powder to provide a catalyst precursor.

[0349] Prior to the reaction, the catalyst precursor was reduced in synthesis gas (H2:CO=2:1 or 1:1) at atmospheric pressure with a GHSV (gas hourly space velocity) of 1000 mL / g hour at 320°C for 32 hours with a heating rate of 5°C / min to provide an activated catalyst.

[0350] After reduction, the temperature was lowered to less than 50°C, and a mixture of H2 / CO (1:1) and N2 (as an internal standard) was used as the feed gas. The gas flow rate was set to 40 mL / min (GSVH = 2400 mL / g catalyst). N2 was added to the syngas feed as an inert gas for conversion calculation. Since the mass flow rate of N2 did not change before and after the reaction, the conversion rates of CO and H2, CO2 and C n H m Selectivity can be calculated as follows.

[0351] The reactor was heated at a heating rate of 2°C / min ( Figure 1 ) up to the reaction temperature (about 280° C. to 320° C.). The reaction pressure was controlled at 10 bar (1 MPa) by a back pressure regulator.

[0352] Gaseous products were analyzed on a Perkin Elmer Clarus GC, and collected liquid products were analyzed by GC-MS.

[0353] The conversion of CO and H2 and the product selectivity were calculated by the following equations:

[0354]

[0355] The effect of adding additional transition metal cobalt to the Fe-Mn-Na catalyst is studied in Table 13. After the reaction as described above, the reaction time, H2 and CO conversion, and product selectivity are shown in Table 13 for different catalysts.

[0356] Catalyst precursors for the catalysts studied in Table 13 were prepared as follows:

[0357] Examples 26 to 30: Iron powder, manganese (II) nitrate tetrahydrate, and sodium carbonate were mixed at a molar ratio of Fe:Mn:Na of 100:10:2. The mixture was ground until uniform. Citric acid was added to the mixture, and the mixture was ground again until uniform. The weight ratio of citric acid to iron powder was 4:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a powder.

[0358] Examples 31 to 35: Iron powder, cobalt (II) nitrate hexahydrate, manganese (II) nitrate tetrahydrate, and sodium carbonate were mixed at a molar ratio of Fe:Co:Mn:Na of 10:2:10:2. The mixture was ground until uniform. Citric acid was added to the mixture, and the mixture was ground again until uniform. The weight ratio of citric acid to iron powder was 4:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a powder.

[0359] Examples 36 to 44: Iron powder, cobalt (II) nitrate hexahydrate, manganese (II) nitrate tetrahydrate, and sodium carbonate were mixed at a molar ratio of Fe:Co:Mn:Na of 100:5:10:2. The mixture was ground until uniform. Citric acid was added to the mixture, and the mixture was ground again until uniform. The weight ratio of citric acid to iron powder was 4:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a powder.

[0360] Examples 45 to 50: Iron powder, cobalt (II) nitrate hexahydrate, manganese (II) nitrate tetrahydrate, and sodium carbonate were mixed at a molar ratio of Fe:Co:Mn:Na of 100:8:10:2. The mixture was ground until uniform. Citric acid was added to the mixture, and the mixture was ground again until uniform. The weight ratio of citric acid to iron powder was 4:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a powder.

[0361] Examples 51 to 55: Iron powder, cobalt (II) nitrate hexahydrate, manganese (II) nitrate tetrahydrate, and sodium carbonate were mixed at a molar ratio of Fe:Co:Mn:Na of 100:10:10:2. The mixture was ground until uniform. Citric acid was added to the mixture, and the mixture was ground again until uniform. The weight ratio of citric acid to iron powder was 4:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a powder.

[0362] Table 13

[0363]

[0364] Table 14 provides the olefin:alkane molar ratios of the C2 to C4 hydrocarbons produced.

[0365] Table 14

[0366]

[0367] Table 15 investigates the effects of various alkali metals on CO hydrogenation. Iron-based catalysts were prepared with manganese and cobalt promoters and alkali metals varying between Na, K, and Li. The catalysts were prepared using a method similar to that described above. The catalyst precursors for the catalysts investigated in Table 15 were prepared as follows:

[0368] Examples 56 to 65: Iron powder, cobalt (II) nitrate hexahydrate, manganese (II) nitrate tetrahydrate, and lithium carbonate were mixed at a molar ratio of Fe:Co:Mn:Li of 100:5:10:2. The mixture was ground until uniform. Citric acid was added to the mixture, and the mixture was ground again until uniform. The weight ratio of citric acid to iron powder was 1:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a powder.

[0369] Examples 66 to 70: Iron powder, cobalt (II) nitrate hexahydrate, manganese (II) nitrate tetrahydrate, and sodium carbonate were mixed at a molar ratio of Fe:Co:Mn:Na of 100:5:10:2. The mixture was ground into a uniform consistency. Citric acid was added to the mixture, and the mixture was ground into a uniform consistency again, wherein the weight ratio of citric acid to iron powder was 1:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a powder.

[0370] Examples 71 to 76: Iron powder, cobalt (II) nitrate hexahydrate, manganese (II) nitrate tetrahydrate, and potassium carbonate were mixed at a molar ratio of Fe:Co:Mn:K of 100:5:10:2. The mixture was ground into a uniform consistency. Citric acid was added to the mixture, and the mixture was ground into a uniform consistency again, wherein the weight ratio of citric acid to iron powder was 1:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a powder.

[0371] Table 15

[0372]

[0373] Table 16 provides the olefin:alkane molar ratios of the C2 to C4 hydrocarbons produced.

[0374] Table 16

[0375]

[0376] Table 17 investigates the effect of manganese loading on CO hydrogenation. Iron-based catalysts were prepared using manganese and cobalt promoters and sodium. The catalysts were prepared using methods similar to those described above. Specifically, the catalyst precursors for the catalysts of Table 17 were prepared as follows:

[0377] Examples 76 to 80: Iron powder, cobalt (II) nitrate hexahydrate, manganese (II) nitrate tetrahydrate, and sodium carbonate were mixed at a molar ratio of Fe:Co:Mn:Na of 100:5:10:2. The mixture was ground into a uniform consistency. Citric acid was added to the mixture, and the mixture was ground into a uniform consistency again, wherein the weight ratio of citric acid to iron powder was 1:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a powder.

[0378] Examples 81 to 88: Iron powder, cobalt (II) nitrate hexahydrate, manganese (II) nitrate tetrahydrate, and sodium carbonate were mixed at a molar ratio of Fe:Co:Mn:Na of 100:5:20:2. The mixture was ground until uniform. Citric acid was added to the mixture, and the mixture was ground again until uniform. The weight ratio of citric acid to iron powder was 1:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a catalyst powder.

[0379] Table 17

[0380]

[0381] Table 18 provides the olefin:alkane molar ratios of the C2 to C4 hydrocarbons produced.

[0382] Table 18

[0383]

[0384] Table 19 investigates the effect of feed composition on CO hydrogenation. Iron-based catalysts were prepared using manganese and cobalt promoters and sodium. The catalysts were prepared using a method similar to that described above. Reactions were performed using syngas with varying H2:CO ratios.

[0385] The catalyst precursors of the catalysts of Table 19 were prepared as follows:

[0386] Examples 89 to 110: Iron powder, cobalt (II) nitrate hexahydrate, manganese (II) nitrate tetrahydrate, and sodium carbonate were mixed at a molar ratio of Fe:Co:Mn:Na of 100:5:10:2. The mixture was ground into a uniform consistency. Citric acid was added to the mixture, and the mixture was ground into a uniform consistency again, wherein the weight ratio of citric acid to iron powder was 4:1. The resulting mixture was dried at 80°C for 24 hours. The dried mixture (uncalcined) was ground into a powder.

[0387] Table 19

[0388]

[0389] Table 20 provides the olefin:alkane molar ratios of the C2 to C4 hydrocarbons produced.

[0390] Table 20

[0391]

[0392] Tables 21 and 22 investigate the CO hydrogenation using a Fe-Co-Mn-Na catalyst (100:5:20:2) under various conditions. The GC-MS spectrum showing the product curve of Example 111 is shown in Figure 8 middle.

[0393] Table 21

[0394]

[0395] Table 22

[0396]

[0397] Iron powder is used as an iron source together with a complexing agent to prepare the catalyst. No calcination is required for the preparation, thus saving energy and reducing emissions. The prepared catalyst exhibits high CO conversion, low CH selectivity, high olefin selectivity, and stability. The addition of alkali metals and optional transition metals (e.g., Co, Mn) improves olefin selectivity in both gaseous and liquid products. When the H2:CO molar ratio in the feedstock is high, the catalyst can also be used to produce fuels (gasoline, diesel, aviation fuel / jet fuel).

[0398] Catalysts prepared for CO2 hydrogenation can also be used for CO hydrogenation and vice versa.

[0399] 3.CO2 hydrogenation to jet fuel

[0400] Jet fuel or aviation fuel is used in gas turbine engines to power aircraft. The main components of jet fuel are linear and branched alkanes and cycloalkanes with C8 to C 18 Typical carbon chain length distribution, preferably with C8 to C 16 The carbon chain length distribution.

[0401] The catalysts disclosed herein are used to produce jet fuel range hydrocarbons in the CO2 hydrogenation product.

[0402] Catalyst preparation

[0403] The catalyst was prepared by an organic combustion method. An Fe-Mn-K catalyst precursor was prepared by mixing citric acid monohydrate (99%, Sigma-Aldrich) with iron (III) nitrate nonahydrate (98%, Sigma-Aldrich), manganese (II) nitrate tetrahydrate (97%, Sigma-Aldrich) and potassium nitrate (99%, Sigma-Aldrich). The molar ratio of citric acid: (Fe + Mn + K) was 2, and the weight ratio of (Fe precursor, Mn precursor and K precursor + citric acid): water was 2:1. The mixture was stirred to form a uniform aqueous solution and heated at 50°C for 1 to 2 hours to obtain a citric acid-based slurry. The paste was calcined at 350°C (furnace temperature) in static air for 4 hours to produce a powder.

[0404] Catalysts with different transition metal (Mn, Cu, Zn) promoters were also prepared using the same method. The catalysts Fe-Cu-K and Fe-Zn-K were prepared using transition metal precursors of copper (II) nitrate trihydrate (99% to 104%, Sigma-Aldrich) and zinc nitrate hexahydrate (98%, Sigma-Aldrich), respectively.

[0405] Fe-Mn-Li, Fe-Mn-Na and Fe-Mn-Cs catalysts with different alkali metal promoters were prepared using lithium carbonate (99%, Sigma-Aldrich), sodium carbonate (99.6%, Acros Organics) and cesium carbonate (99%, Sigma-Aldrich) precursors, respectively.

[0406] In each case, the molar ratio of Fe:transition metal:alkali metal was 10:1:1.

[0407] Fe-Mn-K catalysts were also prepared using organic compounds other than citric acid. The organic compounds used were urea (Bio-Reagent, Sigma-Aldrich), tannic acid (ACS reagent, Sigma-Aldrich), ethylenediaminetetraacetic acid (EDTA, 99.5%, Fisher Scientific), oxalic acid (99.0%, Sigma-Aldrich), nitrilotriacetic acid (NTA (nitrilotriacetic acid), 99%, Sigma-Aldrich), diethylenetriaminepentaacetic acid (DTPA, 98%, Sigma-Aldrich), tartaric acid (99.5%, Sigma-Aldrich), N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA, 98%, Sigma-Aldrich), and salicylic acid (99.0%, Sigma-Aldrich). Unless otherwise stated, citric acid was used as the organic compound to prepare the catalyst.

[0408] Catalyst performance evaluation

[0409] As mentioned above, the CO2 hydrogenation experiments were carried out in a fixed-bed reactor. Before the reaction, the catalyst precursor was in situ reduced with synthesis gas (H2:CO=2:1) ​​at atmospheric pressure, with a GHSV (gas hourly space velocity) of 1000 mL g -1 Hour -1 , at 320 ° C for 24 hours. After the reactor temperature was cooled to below 50 ° C, a mixture of gas with a H2 / CO2 ratio of 3 and N2 (as an internal standard gas) was introduced into the reactor at a gas flow rate of 40 mL min -1 (GSVH=2400mL g -1 Hour -1 The reactor was heated at a heating rate of 2°C / min to the reaction temperature (300°C). The reaction pressure was fixed at 10 bar (1 MPa) by a back pressure regulator.

[0410] The effluent gaseous products were analyzed on an online gas chromatograph (Perkin Elmer Clarus 580GC) equipped with flame ionization detector (FID) and thermal conductivity detector (TCD) detectors, and the collected liquid products were analyzed by a gas chromatograph mass spectrometer (SHIMADZUGCMS-QP2010 SE).

[0411] CO2 and H2 conversions and product selectivities were calculated as described above.

[0412] Characterization methods

[0413] Powder X-ray diffraction (XRD) analysis of the catalysts was performed on a Bruker D8 Advance diffractometer using a Cu Kα (0.15418 nm) X-ray source (25 kV, 40 mA). Diffraction patterns were recorded over a 2θ angle range of 10° to 80° using a step size of 0.016°. Crystallite size was determined using the Scherrer equation.

[0414] Thermo Fisher Scientific Nexsa spectrometer is used to carry out X-ray photoelectron spectroscopy (XPS) of sample.Use micro-focusing monochromatic Al X-ray source (72W) to analyze sample on the area of ​​about 400mm.The data of full spectrum scan are recorded under the pass energy of 150eV, and the data of high resolution scan are recorded under the pass energy of 40eV, wherein step length is respectively 1eV and 0.1eV.The combination of low energy electron and argon ion is used to realize charge neutralization.The obtained spectrum is analyzed using Casa XPS peak fitting software, and the C1s signal of 284.8eV is used as reference correction sample charge.

[0415] The morphology of the catalysts was characterized by scanning electron microscopy (SEM) on a scanning electron microscope (SEM, JEOL 840F).

[0416] High-resolution transmission electron microscopy (HRTEM) images were obtained in a probe-calibrated JEOL ARM200F operating at 200 kV with a Gatan GIF Quantum 965ER spectrometer.

[0417] Catalytic performance of Fe-Mn-K (10:1:1) catalyst for CO2 hydrogenation.

[0418] In the case of the Fe-Mn-K (10:1:1) catalyst prepared with citric acid as described above, the conversion of CO2 and H2 in terms of product selectivity is shown in FIG. Figure 9 middle. Figure 9 The results show that the conversion of CO2 and H2 increases rapidly with the reaction time in the first 5 hours, reaching about 40%; from the start of the reaction until the reaction time of 20 hours, the methane selectivity decreases from 30% to 10%. In contrast, the liquid product (C 5+ ) remained stable at around 60% and showed a slight increase with reaction time.

[0419] The GC-MS spectrum of the collected liquid products from CO2 hydrogenation is shown in Figure 10 middle. Figure 10 The Fe-Mn-K catalyst was shown to have high selectivity for jet fuel range hydrocarbons in the liquid product, with the selectivity for total jet fuel range hydrocarbons reaching 47.8%.

[0420] Catalyst characterization

[0421] The powder X-ray diffraction (XRD) spectra of the above catalyst precursor, activated catalyst and used catalyst are shown in Figure 11 middle.

[0422] The surface elemental composition and oxidation state of the metals were analyzed by using XPS in the range of 0eV to 1350eV. Figure 12 a) Shows that the sample contains Fe, Mn, K and O. Figure 12 b shows the XPS spectrum of the Fe 2p region, which can be compared with the Fe 2p region with a binding energy gap of 13.7 eV. 3 / 2 and Fe 2p 1 / 2 The two spin-orbit doublets are attributed to Fe 3+ The shakeup satellite peaks of Fe3O4 are fitted and these peaks are consistent with those reported. 2+ :Fe 3+ The molar ratio is 1:2.34, which is very close to the stoichiometric Fe3O4.

[0423] Scanning electron microscopy (SEM) images of the catalyst and the used catalyst are shown in Figure 13 The catalyst precursor shows clearly packed regular particles ( Figure 13 (a)), the morphology of the catalyst changed significantly after use ( Figure 13 (b)), indicating changes in the catalyst surface before and after the reaction.

[0424] High-resolution transmission electron microscopy (HRTEM) of the catalyst precursor and the used catalyst is shown in Figure 14 middle. Figure 14 a shows the particle size of the catalyst precursor (about 15 nm), and the particle size does not change significantly after the reaction ( Figure 14 d). The lattice spacing of 0.25 nm and 0.3 nm corresponds to the (311) and (220) planes of Fe3O4 on the catalyst precursor, respectively. Figure 14 b and Figure 14 c). In addition to the Fe3O4 phase ( Figure 14 e), Fe5C2 phase was also observed on the used catalyst ( Figure 14 f).

[0425] Effect of transition metals on product curves

[0426] Catalysts Fe-Zn-K and Fe-Cu-K were prepared using the same method as the Fe-Mn-K catalyst. The catalytic performance of CO2 hydrogenation for different catalysts is shown in Table 23. The molar ratio of K and Mn (Zn or Cu) relative to Fe was 1:10, and data were obtained at a reaction time of 20 hours.

[0427] Table 23

[0428]

[0429] C 2-4 =: C2 to C4 olefins, C 2-4 0: C2 to C4 alkanes; C 5+ : Liquid product; C 8-16 : Jet fuel range hydrocarbons.

[0430] Effect of alkali metals on product curves

[0431] Different alkali metals were also used as promoters for CO2 hydrogenation catalysts, and the catalytic performance is listed in Table 24. The molar ratio of alkali metal and Mn relative to Fe was 1:10, and the data were obtained at a reaction time of 20 hours.

[0432] Table 24

[0433]

[0434] As can be seen from Table 24, Na, K and Cs exhibit both high activity for CO2 hydrogenation and high selectivity for the jet fuel range, and the Fe-Mn-K catalyst exhibits slightly better performance in terms of CO2 conversion and target product selectivity compared to the catalysts Fe-Mn-Na and Fe-Mn-Cs.

[0435] Effects of organic compounds on product curves

[0436] In the catalyst preparation, a series of Fe-Mn-K (molar ratio 10:1:1) catalysts were prepared from different organic compounds, and their catalytic performance in CO2 hydrogenation is shown in Table 25.

[0437] Table 25

[0438]

[0439] It is evident that all Fe-Mn-K catalysts prepared with organic compounds exhibited both higher CO conversion and higher selectivity to jet fuel range hydrocarbons compared to catalysts prepared without organic compounds, with catalysts prepared with EDTA, citric acid, oxalic acid, NTA, DTPA, tartaric acid, HEDTA, and salicylic acid exhibiting better catalytic performance.

[0440] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference in their entirety to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein (to the maximum extent permitted by law).

[0441] All headings and sub-headings are used herein for convenience only and should not be construed as limiting the invention in any way.

[0442] The use of any and all examples or exemplary language (e.g., "for example") provided herein is intended merely to better illustrate the invention and does not limit the scope of the invention unless otherwise specified. No language in this specification should be construed as indicating any non-illustrative element as essential to the practice of the invention.

[0443] The citation and incorporation of patent documents herein is done for convenience only and does not reflect any view of the validity, patentability, and / or enforceability of such patent documents.

[0444] This invention includes all modifications and equivalents of the subject matter recited in this appended paragraphs as permitted by applicable law.

Claims

1. A method for producing C 5+ A hydrocarbon catalyst, characterized in that The catalyst comprises (i) an iron substance; (ii) at least one transition metal selected from manganese and cobalt, or a salt, an oxide or a hydroxide thereof; and (iii) an alkali metal or a salt thereof.

2. The catalyst according to claim 1, characterized in that The iron species comprises iron carbide.

3. The catalyst according to claim 1, characterized in that The alkali metal or its salt includes potassium or its salt.

4. The catalyst according to any one of claims 1 to 3, characterized in that The molar ratio of Fe:Mn is 100:1 to 4:

1.

5. The catalyst according to claim 4, characterized in that The molar ratio of Fe:Mn is 15:1 to 5:

1.

6. The catalyst according to any one of claims 1 to 3, characterized in that The molar ratio of Fe:alkali metal is 100:1 to 2:

1.

7. The catalyst according to claim 6, characterized in that The molar ratio of Fe:alkali metal is 20:1 to 4:

1.

8. The catalyst according to any one of claims 1 to 3, characterized in that The molar ratio of Fe:Co is 40:1 to 10:

1.

9. The catalyst according to claim 1, characterized in that The catalyst comprises 50 to 90 wt% iron.

10. The catalyst according to claim 2, characterized in that The iron carbide is Fe5C2.

11. The catalyst according to claim 1, characterized in that The C 5+ Hydrocarbons are C8 to C 18 hydrocarbon.

12. The catalyst according to claim 1, characterized in that The C 5+ Hydrocarbon is C 5+ Olefins.

13. The catalyst according to claim 1, characterized in that The C 5+ Hydrocarbon is C 5+ α-olefins.

14. Use of the catalyst according to any one of claims 1 to 13 in the production of C 5+ Use of hydrocarbons, characterized in that The use comprises contacting a feedstock comprising hydrogen and carbon dioxide with the catalyst.

15. The use according to claim 14, characterized in that The use comprises contacting the feedstock with the catalyst at a temperature of 180° C. to 500° C. and / or at a pressure of 0.5 MPa to 20 MPa.

16. The use according to claim 14 or 15, characterized in that The molar ratio of hydrogen to carbon dioxide in the raw material is 0.4:1 to 6:

1.

17. A method for converting carbon dioxide into C 5+ A method for producing hydrocarbons, characterized in that include: A feedstock comprising hydrogen and carbon dioxide is contacted with the catalyst according to any one of claims 1 to 13 at a temperature of 180 to 500° C. and / or at a pressure of 0.5 to 20 MPa.

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