Iron- and zinc-based fischer-tropsch catalyst materials and processes for making and using same

Abstract

The present disclosure provides a Fischer-Tropsch catalyst material comprising at least 10 wt% iron, on an elemental basis exclusive of carbon; at least 3 wt% zinc, on an elemental basis exclusive of carbon; and at least 0.2 wt% alkali metal, on an elemental basis exclusive of carbon, wherein the atomic ratio of iron to zinc is in the range of 1 :2 to 20:1, and the Fischer-Tropsch catalyst material includes at least 10 wt% crystalline ZnFe2O4. Also provided are carbided versions of such catalyst materials, and methods for making and using the same.

Description

IRON- AND ZINC-BASED FISCHER-TROPSCH CATALYST MATERIALS AND PROCESSES FOR MAKING AND USING SAMECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority U.S. provisional application number 63 / 616,377, filed December 29, 2023 and European Patent application number 24166582.7, filed March 26, 2024, each of which is incorporated by reference herein in its entirety.BACKGROUND OF THE DISCLOSURE1 _ Field

[0002] The present disclosure relates generally to Fischer-Tropsch catalyst materials, processes of making the same, and Fischer-Tropsch processes using the Fischer-Tropsch catalyst materials described herein.2. _ Technical Background

[0003] The conversion of synthesis gas (i.e. , a mixture of carbon monoxide and hydrogen, also known as syngas) into hydrocarbons by the Fischer-Tropsch process has been known for decades, but has historically lagged in performance compared to other hydrocarbon synthesis techniques. The growing importance of alternative energy sources has resulted in renewed interest in the Fischer-Tropsch (FT) process as it allows a direct and environmentally-acceptable route to high-quality fuels and feedstock chemicals.

[0004] FT processes are known for producing linear hydrocarbons, as well as oxygenates, that can be useful in fuels and can also serve as valuable feedstock chemicals. The hydrocarbon fuel derived from FT processes is typically better able to meet increasingly stringent environmental regulations compared to conventional refinery-produced fuels, as FT-derived fuels typically have lower contents of sulfur, nitrogen, and aromatic compounds, which contribute to the emission of potent pollutants such as SO2, NOX, and particulates. Alcohols, olefins and other oxygenates obtained may also be used as reagents in other processes, such as in the synthesis of lubricants.

[0005] Currently, cobalt-based catalysts are the primary type of catalysts used in FT processes; they generally yield linear paraffins as primary products. Iron-based catalyst materials are also known, and can be lower in cost compared to cobalt-based catalyst materials. Iron-catalysed FT typically produces as part of the hydrocarbon product a significant amount of long-chain oxygenates and long-chain a-olefins, which in many cases are desirable products. However, in contrast to cobalt, iron-based catalysts generally exhibit high water gas shift (WGS) activity. The water gas shift reaction competes with the Fischer-Tropsch process by converting CO and H2O to CO2 and hydrogen, as shown below:CO + H2O co2+ H2This higher WGS activity leads to high CO2 yields and lower selectivity of the conversion of feedstock carbon monoxide.

[0006] As such, there is a need to provide improved iron-based Fischer-Tropsch catalyst materials and iron-based Fischer-Tropsch processes.SUMMARY

[0007] In one aspect, the present disclosure provides a Fischer-Tropsch catalyst material comprising: at least 10 wt% iron, on an elemental basis exclusive of carbon; at least 3 wt% zinc, on an elemental basis exclusive of carbon; and at least 0.2 wt% alkali metal, on an elemental basis exclusive of carbon, wherein the atomic ratio of iron to zinc is in the range of 1:2 to 20:1 , and the Fischer-Tropsch catalyst material includes at least 10 wt% crystalline ZnFe2C .

[0008] Another aspect of the present disclosure provides a process of making a Fischer- Tropsch catalyst material, the process comprising: providing one or more first liquids each comprising one or more iron-containing and / or one or more zinc-containing compounds dispersed in one or more first solvents; contacting the one or more first liquids with precipitating ions in the presence of alkali metal ions to provide an alkali-containing precipitate and supernatant; isolating the alkali-containing precipitate from the supernatant; optionally, washing the isolated precipitate with a washing liquid to reduce concentration of alkali metal thereof; and calcining the isolated precipitate to provide the Fischer-Tropsch catalyst material.

[0009] Another aspect of the present disclosure provides a process of making a Fischer- Tropsch catalyst material, the process comprising: providing one or more first liquids each comprising one or more iron-containing and / or one or more zinc-containing compounds dispersed in one or more first solvents; contacting the one or more first liquids with precipitating ions in the substantial absence of alkali metal ions to provide a substantially alkali-free precipitate and supernatant;isolating the alkali-free precipitate from the supernatant; adding alkali metal ions to the substantially alkali-free precipitate in order to provide an alkali-containing precipitate; and calcining the isolated precipitate to provide the Fischer-Tropsch catalyst material.

[0010] Another aspect of the present disclosure provides a Fischer-Tropsch catalyst material made by a process as described herein.

[0011] Another aspect of the present disclosure provides a carbided Fischer-Tropsch catalyst material, e.g., a catalyst material as described herein in a carbided form.

[0012] Another aspect of the present disclosure provides a carbided Fischer-Tropsch catalyst material comprising: at least 10 wt% iron, on an elemental basis exclusive of carbon; at least 3 wt% zinc, on an elemental basis exclusive of carbon; and at least 0.2 wt% alkali metal, on an elemental basis exclusive of carbon, wherein the atomic ratio of iron to zinc is in the range of 1:2 to 20:1 , and at least 50 atom% of the iron of the carbided Fischer-Tropsch catalyst material is in the form of iron carbide.Such materials can be made, e.g., by the carbiding of the ZnFe2O4-containing Fischer- Tropsch catalyst materials described herein.

[0013] Another aspect of the present disclosure provides a process for providing a carbided Fischer-Tropsch catalyst material as described herein, the process comprising: providing the Fischer-Tropsch catalyst material as described herein (e.g., made by a process as described herein); optionally, treating the Fischer-Tropsch catalyst material with a reducing gas stream comprising hydrogen for a time and at a temperature sufficient to provide at least 50 atom% of the iron of the Fischer-Tropsch catalyst material in metallic form; and then treating the Fischer-Tropsch catalyst material with a carbiding gas stream comprising carbon monoxide and / or carbon dioxide (e.g., carbon monoxide), at a temperature of at least 180 °C for a time sufficient to provide at least 50 atom% of the iron of the Fischer-Tropsch catalyst material in a carbided form (e.g., in the range of 5 to 20 hours).

[0014] Another aspect of the present disclosure provides a process for performing a Fischer-Tropsch process, the process comprising:providing a carbided Fischer Tropsch catalyst material as described herein and / or made by a process described herein; and contacting at a reaction temperature and at a pressure the carbided Fischer-Tropsch catalyst material with a feed stream comprising H2and CO2to provide a product stream comprising C5+ hydrocarbons.BRIEF DESCRIPTION OF FIGURES

[0015] The accompanying drawings are included to provide a further understanding of the processes of the disclosure, and are incorporated in and constitute a part of this specification. The drawings are not necessarily to scale, and sizes of various elements may be distorted for clarity. The drawings illustrate one or more embodiment(s) of the disclosure and together with the description serve to explain the principles and operation of the disclosure.

[0016] FIG. 1 is a schematic of a process for performing a Fischer-Tropsch process as described herein.

[0017] FIG. 2 is a schematic of a process for performing a Fischer-Tropsch process as described herein.

[0018] FIG. 3 is a schematic of a process for performing a Fischer-Tropsch process as described herein.

[0019] FIG. 4 is a schematic of a process for performing a Fischer-Tropsch process as described herein.

[0020] FIG. 5 is an X-ray diffraction (XRD) pattern of a catalyst material as described herein.

[0021] FIG. 6 is an XRD pattern of a catalyst material as described herein.

[0022] FIG. 7 is an XRD pattern of a catalyst material as described herein.

[0023] FIG. 8 is an XRD pattern of a catalyst material as described herein.

[0024] FIG. 9 is an XRD pattern of a catalyst material as described herein.DETAILED DESCRIPTION

[0025] The present disclosure is concerned with iron-based Fischer-Tropsch processes for converting CO2to hydrocarbons. Here, the iron-based catalyst is considered not only to convert CO to hydrocarbons via the Fischer-Tropsch reaction, but also to convert CO2to CO through a reverse water-gas shift to provide the CO for Fischer-Tropsch synthesis, thereby providing for a net conversion of CO2to hydrocarbons. One of the challenges associated with using CO2in the feed stream of Fischer-Tropsch processes is to activate the CO2atreasonable temperatures to form CO and simultaneously supply sufficient Fischer-Tropsch active catalyst sites that convert the formed CO further into C2+, and preferably into C5+ hydrocarbons. The present inventors note that high operating temperatures (i.e., >600 °C) are typically required in processes in which a reverse water-gas shift (rWGS) is performed in a separate reactor to convert carbon dioxide to carbon monoxide. But such high temperature limits chain growth during Fischer-Tropsch synthesis, leading to product distributions that are richer in light hydrocarbons as compared to the more desirable C5+ hydrocarbons.

[0026] The present inventors noted that the CO2 conversion in iron-based FT processes are limited by the water-gas shift equilibrium, i.e., in-situ formed CO and H2O can react back to a certain extent to CO2 and H2, limiting the CO2 conversion to a low level. This is particularly true as there is further H2O produced during the Fischer-Tropsch reaction, shown below:CO + 2 H2- [-CH2-] + H2OAccordingly, higher water gas shift (WGS) activity can lower the net CO2 conversion and lower selectivity of the conversion of feedstock carbon towards C5+ hydrocarbons, which are the generally-desired FT products. As such, the main challenge in iron-based FT processes is to obtain good CO2 conversion towards C5+ hydrocarbons while minimizing the effects of the forward water-gas reaction.

[0027] Here, the present inventors have determined that the reverse water-gas shift / water-gas shift activity of iron-based Fischer-Tropsch catalyst materials can be used to provide better C5+ conversion in Fischer-Tropsch processes. To do so, the present inventors have found that increasing the amount of alkali metal in the catalyst can increase both rWGS activity (i.e., CO2 conversion) and C5+ selectivity while decreasing C1-C4 selectivity to provide catalysts that have comparable or improved performance over other iron-based catalysts known in the art. Additionally, the present inventors have found that this selectivity for C5+ hydrocarbons with iron-based Fischer-Tropsch catalyst materials can be accomplished at relatively low FT reaction temperatures. Accordingly, the present disclosure provides ironbased Fischer-Tropsch catalysts with substantial rWGS activity, processes of making the same, and Fischer-Tropsch processes using the same with high carbon recovery in desirable C5+ products.Fischer-Tropsch Catalyst Materials

[0028] As described above, the present inventors have developed iron-based Fischer- Tropsch catalyst materials that can advantageously use CO2 as the carbon source when used in Fischer-Tropsch syntheses. Thus, in one aspect, the present disclosure provides aFischer-Tropsch catalyst material comprising at least 10 wt% iron, on an elemental basis exclusive of carbon; at least 3 wt% zinc, on an elemental basis exclusive of carbon; and at least 0.2 wt% alkali metal, on an elemental basis exclusive of carbon, wherein the atomic ratio of iron to zinc is in the range of 1:2 to 20:1, and wherein the Fischer-Tropsch catalyst material includes at least 10 wt% crystalline ZnFe2O4. These catalyst materials can be synthesized, stored and transported, e.g., as oxidic materials, as is common for catalyst materials. As the person of ordinary skill in the art will appreciate, during Fischer-Tropsch synthesis the active catalytic species is actually iron carbide - but regardless of form the ZnFe2C>4-containing catalyst materials described here can provide a desirable degree of water-gas shift activity together with a suite of other desirable properties when carbided (e.g., in situ in a Fischer Tropsch reactor, especially when carbided at high temperature) and used in Fischer-Tropsch synthesis.

[0029] Amounts of various atomic species as described herein are determined using inductively coupled plasma mass spectrometry (“ICP”). As the person of ordinary skill in the art will appreciate, ICP can detect most elements, but is blind to hydrogen, nitrogen and oxygen. Accordingly, amounts determined by ICP that are quantified “on an elemental basis” are determined with respect to amounts ICP-measurable elements, i.e., excluding hydrogen, oxygen and nitrogen. Carbon is detectable by ICP. But in order to maintain consonance between various amounts of materials in various catalyst states, amounts of various atomic species in catalyst materials can also quantified “on an elemental basis exclusive of carbon,” i.e., determined with respect to amounts of ICP-measurable elements, excluding hydrogen, oxygen, nitrogen and carbon. Quantifications are made without reference to the form in which the atomic species are present (e.g., oxide, metal, carbide, etc.). Measurements can be most conveniently performed on oxidic materials after initial synthesis and carbiding.

[0030] The Fischer-Tropsch catalyst materials described herein (e.g., whether ZnFe2O4- containing or in a carbided form) comprise iron, e.g., in an amount of at least 10 w% on an elemental basis exclusive of carbon. The iron may be present in the catalyst in a variety of forms; most commonly, iron is principally present as metal, metal carbide, metal oxide (such as a mixed metal oxide like a zinc ferrite (ZnFe2O4), or single metal oxides like Fe2O3, FeO and FesO4), metal halide, or a combination thereof. Iron can be provided in a variety of amounts. For example, in various embodiments as described herein, the Fischer-Tropsch catalyst material comprises at least 15 wt% iron, at least 20 wt% iron, or at least 25 wt% iron, on an elemental basis exclusive of carbon. In various embodiments as described herein, the Fischer-Tropsch catalyst material comprises at least 30 wt% iron, at least 35 wt% iron, or at least 40 wt% iron, on an elemental basis exclusive of carbon.

[0031] Along with iron, the Fischer-Tropsch catalyst materials described herein (e.g., whether ZnFe2O4-containing or in a carbided form) also include zinc in an amount of at least 3 wt%, on an elemental basis exclusive of carbon. The zinc may be present in the catalyst in a variety of forms; most commonly, zinc is principally present as metal, metal oxide (including a mixed metal oxide like zinc ferrite or a single metal oxide like ZnO), or a combination thereof. Zinc can likewise be provided in a variety of amounts. For example, in various embodiments as described herein, the Fischer-Tropsch catalyst material comprises at least 5 wt% zinc, at least 7 wt% zinc, or at least 10 wt% zinc, on an elemental basis exclusive of carbon. In various embodiments as described herein, the Fischer-Tropsch catalyst material comprises at least 12 wt% zinc, at least 15 wt% zinc, at least 17 wt% zinc, or at least 20 wt% zinc, on an elemental basis exclusive of carbon.

[0032] In addition to iron and zinc, the Fischer-Tropsch catalyst material described herein (e.g., whether ZnFe2O4-containing or in a carbided form) also comprise alkali metal in an amount of at least 0.2 wt%, on an elemental basis exclusive of carbon. The present inventors have found that use of alkali metal can provide increased water-gas shift activity, which, while typically undesirable in Fischer-Tropsch processes, can be useful when working with CO2as a feed of carbon to the process.

[0033] For example, in various embodiments, the Fischer-Tropsch catalyst includes at least 0.2 wt% alkali metal. The alkali metal may be present in the catalyst in a variety of forms; most commonly, alkali metal is principally present as metal, metal salt such as halide or carbonate, metal oxide, or a combination thereof. In various embodiments, the Fischer- Tropsch catalyst material includes at least 0.3 wt%, e.g., at least 0.4 wt% alkali metal, on an elemental basis exclusive of carbon. In various embodiments, the Fischer-Tropsch catalyst material comprises at least 0.5 wt%, e.g., at least 0.7 wt% alkali metal, on an elemental basis exclusive of carbon. For example, in various embodiments, the Fischer-Tropsch catalyst material comprises at least 1 wt%, e.g., at least 1.3 wt%, at least 1.5 wt%, or at least 1.7 wt% alkali metal, on an elemental basis exclusive of carbon. In various embodiments as described herein, the Fischer-Tropsch catalyst material comprises in the range of 0.2-5 wt% alkali metal, on an elemental basis exclusive of carbon. For example, in various embodiments, the Fischer-Tropsch catalyst material comprises in the range of 0.2-3 wt%, or 0.2-2 wt%, or 0.3-5 wt%, or 0.3-3 wt%, or 0.3-2 wt%, or 0.4-5 wt%, or 0.4-3 wt%, or 0.4-2 wt% alkali metal, on an elemental basis exclusive of carbon. In some embodiments as described herein, the Fischer-Tropsch catalyst material comprises in the range of 0.5-5 wt% alkali metal, e.g., 0.5-3 wt%, or 0.5-2 wt%, or 0.7-5 wt%, or 0.7-3 wt%, or 0.7-2 wt%, on an elemental basis exclusive of carbon. In various embodiments, the Fischer-Tropsch catalyst material comprises in the range of 1-5 wt% alkali metal, on an elemental basis exclusive ofcarbon. For example, in various embodiments, the Fischer-Tropsch catalyst material comprises 1-3 wt%, or 1-2 wt%, or 1.3-5 wt%, or 1.3-3 wt%, or 1.3-2 wt% alkali metal, on an elemental basis exclusive of carbon. In some embodiments described herein, the Fischer- Tropsch catalyst material comprises 1.5-5 wt% alkali metal, on an elemental basis exclusive of carbon. For example, in some embodiments the Fischer-Tropsch catalyst material comprises 1.5-3 wt%, or 1.5-2.5 wt%, or 1.5-5 wt%, or 1.5-3 wt%, or 1.5-2.5 wt% alkali metal, on an elemental basis exclusive of carbon.

[0034] The present inventor has found that, while some amount of alkali metal is desirable, too much can cause undesirable effects. Accordingly, in various embodiments of the disclosure, the catalyst material comprises 0.1-0.35 mol of alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon. For example, in various embodiments, the catalyst material comprises 0.1-0.32 mol of alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, e.g., 0.1-0.30 mol, or 0.1-0.28 mol, or 0.1-0.25 mol. In various embodiments, the catalyst material comprises 0.12-0.35 mol of alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, e.g., 0.12-0.32 mol, or 0.12-0.3 mol, or 0.12-0.28 mol, or 0.12-0.25 mol. In various embodiments, the catalyst material comprises 0.15-0.35 mol of alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, e.g., 0.15-0.32 mol, or 0.15-0.3 mol, or 0.15-0.28 mol, or 0.15-0.25 mol. In various embodiments, the catalyst material comprises 0.18-0.35 mol of alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, e.g., 0.18-0.32 mol, or 0.18-0.3 mol, or 0.18-0.28 mol, or 0.18-0.25 mol. In various embodiments, the catalyst material comprises 0.2-0.35 mol of alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, e.g., 0.2-0.32 mol, or 0.2-0.3 mol, or 0.2-0.28 mol, or 0.2-0.25 mol.

[0035] In some embodiments, the alkali metal present in the Fischer-Tropsch catalyst material is one or more of sodium, potassium, rubidium and cesium. In some embodiments as described herein, the alkali metal is one or more of sodium and potassium.

[0036] For example, in some embodiments as described herein, the alkali metal is sodium. In various embodiments, the Fischer-Tropsch catalyst material includes 1-6 wt% sodium, e.g., 1-5.5 wt%, or 1.5 wt%, or 1-4.5 wt%, or 1-4 wt%, or 1-3.5 wt%, or 1-3 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 1.5-6 wt% sodium, e.g., 1.5-5.5 wt%, or 1.5-5 wt%, or 1.5-4.5 wt%, or 1.5-4 wt%, or 1.5-3.5 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 2-6 wt% sodium, e.g., 2-5.5 wt%, or 2-5 wt%, or 2-4.5 wt%, or 2-4 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 2.5-6 wt% sodium, e.g., 2.5-5.5 wt%, or 2.5-5 wt%, or 2.5-4.5 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 3-6 wt% sodium,e.g., 3-5.5 wt%, or 3-5 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 3.5-6 wt% sodium, e.g., 3.5-5.5 wt%. In various such embodiments, the Fischer- Tropsch catalyst material includes no more than 0.5 wt% of any other alkali metal, e.g., no more than 0.2 wt%, or no more than 0.1 wt%.

[0037] In some embodiments as described herein, the alkali metal is potassium. In various embodiments, the Fischer-Tropsch catalyst material includes 3-9 wt% potassium, e.g., 3-8.5 wt%, or 3-8 wt%, or 3-7.5 wt%, or 3-7 wt%, or 3-6.5 wt%, or 3-6 wt%, or 3-5.5 wt%, or 3-5 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes3.5-9 wt% potassium, e.g., 3.5-8.5 wt%, or 3.5-8 wt%, or 3.5-7.5 wt%, or 3.5-7 wt%, or 3.5- 6.5 wt%, or 3.5-6 wt%, or 3.5-5.5 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 4-9 wt% potassium, e.g., 4-8.5 wt%, or 4-8 wt%, or 4-7.5 wt%, or 4-7 wt%, or 4-6.5 wt%, or 4-6 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 4.5-9 wt% potassium, e.g., 4.5-8.5 wt%, or 4.5-8 wt%, or 4.5-7.5 wt%, or4.5-7 wt%, or 4.5-6.5 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 5-9 wt% potassium, e.g., 5-8.5 wt%, or 5-8 wt%, or 5-7.5 wt%, or 5-7 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 5.5-9 wt% potassium, e.g., 5.5-8.5 wt%, or 5.5-8 wt%, or 5.5-7.5 wt%. In various embodiments, the Fischer- Tropsch catalyst material includes 5.5-9 wt% potassium, e.g., 5.5-8.5 wt%, or 5.5-8 wt%, or5.5-7.5 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 6-9 wt% potassium, e.g., 6-8.5 wt%, or 6-8 wt%. In various embodiments, the Fischer-Tropsch catalyst material includes 6.5-9 wt% potassium, e.g., 7-9 wt%. In various such embodiments, the Fischer-Tropsch catalyst material includes no more than 0.5 wt% of any other alkali metal, e.g., no more than 0.2 wt%, or no more than 0.1 wt%.

[0038] As described above, the Fischer-Tropsch catalyst materials of the disclosure include both iron and zinc in an atomic ratio in the range of 1:2 to 20:1. For example, in various embodiments as described herein, the atomic ratio of iron to zinc is in the range of 1 : 1.5 to 20: 1 , or 1 : 1.2 to 20: 1 , or 1 : 1 to 20: 1. In various other embodiments as described herein, the atomic ratio of iron to zinc is in the range of 1 :2 to 10:1, or 1 :1.5 to 10:1 , or 1:1.2 to 10:1, or 1:1 to 10:1. In various embodiments as described herein, the atomic ratio of iron to zinc is in the range of 1 :2 to 7:1, or 1 :1.5 to 7:1, or 1 :1.2 to 7:1, or 1 :1 to 7:1. In various other embodiments as described herein, the atomic ratio of iron to zinc is in the range of 1 :2 to 5:1 , or 1:1.5 to 5:1 , or 1 :1.2 to 5:1, or 1 :1 to 5:1. In various embodiments as described herein, the atomic ratio of iron to zinc is in the range of 1 :2 to 3: 1 , or 1 : 1.5 to 3: 1 , or 1 : 1.2 to 3:1 , or 1:1 to 3:1.

[0039] As would be understood by the person of ordinary skill in the art, the iron and zinc may be present in the Fischer-Tropsch catalyst materials described herein in a variety offorms, much as a metal, metal halide, metal carbide, metal oxide (including mixed metal oxide), and combinations thereof. But as described above, in various aspects the Fischer- Tropsch catalyst material as described herein includes at least 10 wt% crystalline ZnFe2O4 (i.e. , zinc ferrite). The present inventors have noted that use of a catalyst material that has a significant amount of zinc ferrite can provide a variety of advantages in Fischer-Tropsch processes. Without intending to be bound by theory, the present inventors surmise that the zinc ferrite, when reduced and carbided, provides zinc oxide islands finely dispersed in iron carbide, which can allow for efficient promotion of reactivity at the carbide sites by zinc, and also improve stability of the carbide. In some embodiments as described herein, the Fischer-Tropsch catalyst material includes at least 20 wt% crystalline ZnFe2O4 or at least 30 wt%. In some embodiments as described herein, the Fischer-Tropsch catalyst material includes at least 40 wt% crystalline ZnFe2C>4 or at least 50 wt%. In some embodiments as described herein, the Fischer-Tropsch catalyst material includes at least 60 wt% crystalline ZnFe2C>4 or at least 70 wt%. In some embodiments as described herein, the Fischer- Tropsch catalyst material includes at least 80 wt% crystalline ZnFe2C>4 or at least 90 wt%.

[0040] In some embodiments as described herein, the crystalline ZnFe2C>4 has an average crystallite size in the range of 5-25 nm. In some embodiments as described herein, the crystalline ZnFe2C>4 has an average crystallite size in the range of 5-20 nm, or 5-15 nm, or 5-10 nm.

[0041] The amount of crystalline ZnFe2C>4 and the crystallite size may be measured by Powder XRD with Rietvald analysis. Accordingly, amounts of crystalline ZnFe2C>4 (and any other crystalline species quantified via XRD) are quantified as a weight percentage of total materials quantifiable by XRD (i.e., crystalline or otherwise ordered materials).

[0042] As would be understood by the person of skill in the art, at least some of the zinc present in various catalyst materials described herein is in the form of crystalline ZnFe2C>4. In some embodiments as described herein, at least 50 atom% of the zinc is in the form of crystalline ZnFe2C>4. For example, in various embodiments as described herein, at least 60 atom%, or at least 70 atom%, of the zinc is in the form of crystalline ZnFe2C>4. Similarly, in various catalyst materials as described herein, at least some of the iron present in various catalyst materials described herein is in the form of crystalline ZnFe2C>4. In some embodiments as described herein, at least 50 atom% of the iron is in the form of crystalline ZnFe2C>4. For example, in various embodiments as described herein, at least 60 atom%, or at least 70 atom%, of the iron is in the form of crystalline ZnFe2C>4. The person of ordinary skill in the art can, based on the present disclosure, select relative amounts of zinc and iron along with appropriate calcining conditions to provide a high degree of crystalline ZnFe2C>4.Amounts of zinc and iron in the form of crystalline ZnFe2C>4 are determined using XRD as described above, as a fraction of atoms in XRD-quantifiable species.

[0043] The Fischer-Tropsch catalyst materials described herein (e.g., whether ZnFe2O4- containing or in a carbided form) do not require copper. As described above, in some embodiments as described herein, the Fischer-Tropsch catalyst material includes less than 0.1 wt% copper, on an elemental basis exclusive of carbon. For example, in various embodiments as described herein, the Fischer-Tropsch catalyst material comprises no more than 0.05 wt% copper, no more than 0.01 wt% copper, no more than 0.005 wt% copper, or no more than 0.001 wt% copper, on an elemental basis exclusive of carbon. In some embodiments as described herein, the Fischer-Tropsch catalyst material is essentially free of copper.

[0044] However, the present inventors note that having some copper present can improve activity and selectivity for longer hydrocarbons during Fischer-Tropsch synthesis. The copper may be present in the Fischer-Tropsch catalyst material in a variety of forms; most commonly, copper is principally present as metal, metal halide, metal oxide, or a combination thereof. For example, in various embodiments as described herein, the Fischer-Tropsch catalyst material comprises at least 0.1 wt% copper, at least 0.5 wt% copper, at least 1 wt% copper, or at least 5 wt% copper, on an elemental basis exclusive of carbon. In some embodiments as described herein, the Fischer-Tropsch catalyst material comprises in the range of 0.1-20 wt% copper, on an elemental basis exclusive of carbon. For example, in various embodiments, the Fischer-Tropsch catalyst material comprises in the range of 0.1-15 wt%, or 0.1-10 wt%, or 0.5-20 wt%, or 0.5-15 wt%, or 0.5-10 wt% copper, on an elemental basis exclusive of carbon. In some embodiments described herein, the Fischer-Tropsch catalyst material comprises in the range of 1-20 wt% copper, on an elemental basis exclusive of carbon. For example, in various embodiments, the Fischer- Tropsch catalyst material comprises in the range of 1-15 wt%, or 1-10 wt%, or 5-20 wt%, or 5-15 wt%, or 5-10 wt% copper, on an elemental basis exclusive of carbon.

[0045] In some embodiments as described herein, the Fischer-Tropsch catalyst material is in substantially oxidic form (i.e. , a substantially non-metallic, non-carbided form). As described above, the oxidic form is the result of calcining, and can be especially convenient for storage and transport. As such, in various embodiments as described herein, the Fischer-Tropsch catalyst material is in a substantially non-metallic, non-carbide form. For example, in various embodiments as described herein, the iron, zinc, and alkali metal are substantially present as metal oxides (e.g., with a small amount of metal halide). Such materials can be the result of the precipitation, drying and calcining processes as described herein. The person of ordinary skill in the art will appreciate that oxidic catalyst materialssuch as these can be activated by carbiding to provide active catalyst materials for use in Fischer-Tropsch processes.

[0046] In some embodiments as described herein, the Fischer-Tropsch catalyst material (whether in oxidic, reduced, or carbided form, see below) is an unsupported catalyst material. As such, in some embodiments as described herein, at least 90 wt% of the Fischer-Tropsch catalyst material is made up of iron, zinc, alkali metal, and copper (if present), as determined by ICP on an elemental basis exclusive of carbon. For example, in various embodiments as described herein, at least 95 wt%, at least 98 wt%, at least 99 wt%, at least 99.5 wt%, or at least 99.8 wt% of the Fischer-Tropsch catalyst material is made up of iron, zinc, alkali metal, and copper (if present), on an elemental basis exclusive of carbon.

[0047] In some other embodiments as described herein, the Fischer-Tropsch catalyst material further comprises a support that supports the iron, zinc, alkali metal, and if present, copper. As such, in some embodiments as described herein, at least 90 wt% of the Fischer- Tropsch catalyst material is made up of iron, zinc, alkali metal, copper (if present), and the support, as determined by ICP. For example, in various embodiments as described herein, at least 95 wt%, at least 98 wt%, at least 99 wt%, at least 99.5 wt%, or at least 99.8 wt% of the Fischer-Tropsch catalyst material is made up of iron, zinc, alkali metal, copper, and the support. The support itself can be provided as discrete bodies of material, e.g., as porous particles, pellets or shaped extrudates, with iron, zinc, and alkali metal, and / or copper (if present), supported to provide the Fischer-Tropsch catalyst material. The support can also be provided as a binder that binds together particles containing iron and zinc. However, in other embodiments, the support can be provided as a monolithic material, e.g., an extrudate. In various embodiments, the support is formed from a refractory oxide. Of course, as would be understood by the person of ordinary skill in the art, other materials may be possible.

[0048] The person of ordinary skill in the art will appreciate that the Fischer-Tropsch catalyst materials of the disclosure can be provided in many forms, depending especially on the particular form of the reactor system in which they are to be used, e.g., in a fixed bed reactor, a fluid bed reactor, a bubble column reactor, a so-called CANS reactor.

[0049] Processes for Making Fischer-Tropsch Catalyst Materials

[0050] As described above, the present disclosure also provides processes for making a Fischer-Tropsch catalyst material (e.g., as described herein). Two particular precipitationbased processes for making catalyst materials are provided in detail in this disclosure: one that has alkali present during the co-precipitation, and one that uses post-precipitation impregnation of alkali metal. Analogous methods can be used to make copper-containing materials; the person of ordinary skill in the art will appreciate that the particular proceduresdescribed below can be performed substantially equivalently using copper-containing reagents to provide the corresponding copper-containing materials. In some situations, copper species can be precipitated as part of the precipitated material, or impregnated in a later step.

[0051] One process includes providing one or more first liquids each comprising one or more iron-containing and / or one or more zinc-containing compounds dissolved in one or more first solvents; contacting the one or more first liquids with precipitating ions in the presence of one or more alkali metal ions to provide an alkali-containing precipitate and a supernatant; isolating the alkali-containing precipitate from the supernatant; optionally, washing the isolated precipitate with a washing liquid to reduce concentration of alkali metal thereof; and calcining the isolated precipitate to provide the Fischer-Tropsch catalyst material. Here, the precipitation is performed in the presence of alkali metal ions. Without intending to be bound by theory, the present inventors surmise that while the alkali metal ions may not themselves substantially precipitate, the alkali metal-containing supernatant wets the precipitate sufficiently to provide significant alkali content to the precipitate. If necessary, this can be reduced to a desired level by the washing with the washing liquid.

[0052] As described above, the one or more first liquids include one or more iron- containing compounds and / or one or more zinc-containing compounds dissolved in one or more first solvents. As the person of ordinary skill in the art will appreciate, these metal species are conveniently provided in the same liquid. As such, in some embodiments as described herein, the process includes providing a first liquid comprising one or more iron- containing compounds and one or more zinc-containing compounds dissolved in a first solvent. However, other schemes are possible. For example, in other embodiments as described herein, the process includes providing more than one first liquids, wherein a first liquid comprises one or more iron-containing compounds and another first liquid comprises zinc-containing compounds; these can be combined with precipitating ions by simultaneous addition. In cases where multiple first liquids are used, the first solvents thereof are desirably miscible with one another.

[0053] The iron-containing and zinc-containing compounds are not particularly limited and the person of ordinary skill in the art would be able to choose appropriate compounds that are soluble in the first solvent(s). For example, in some embodiments of the disclosure as described herein, the iron-containing and zinc-containing compounds may be selected from metal salts (e.g., nitrates and acetates). The first solvent(s) are also not particularly limited and the person of ordinary skill in the art would be able to choose an appropriate solvent in which the iron-containing and zinc-containing materials are soluble. As the person of ordinary skill in the art will appreciate, a convenient choice for the solvent(s) of the firstliquid is water. Other aqueous systems can also be used; an aqueous solvent including a co-solvent such as ethanol may be desirable in some cases. And in some cases, substantially non-aqueous solvents can be used, e.g., one or more of ethanol, isopropanol and acetone, optionally together with ethylene glycol to improve dispersion. As would be understood by the person of skill in the art, the iron-containing and zinc-containing compounds may be provided in amounts in the one or more first liquids to provide the Fischer-Tropsch catalyst material with desired proportions of zinc and iron as described herein.

[0054] The person of ordinary skill in the art will provide the one or more first liquids at a desirable pH at which the iron and zinc compounds remain soluble. For example, in various embodiments, each of the one or more first liquids has a pH of no greater than 7.

[0055] The one or more first liquids are contacted with precipitating ions in the presence of one or more alkali metal ions to provide an alkali-containing precipitate. As the person of ordinary skill in the art will appreciate, this can be conveniently performed by addition of a solution of precipitating ions into a first liquid that includes both the zinc and iron compounds; addition of one or more first fluids into a solution of precipitating ions; or combination of one or more first liquids with a solution of precipitating ions in a separate vessel. The alkali ions can provided, e.g., as a salt of a non-precipitating ion; in the solution of precipitating ions, e.g., as a counterion to precipitation ions; or as part of a separate liquid.

[0056] The person of ordinary skill in the art can select desirable precipitating ions. In various embodiments, the precipitating ions are carbonate ions and / or hydroxide ions. The precipitating ions can be provided by use of an alkali metal-containing base to provide both precipitating ions and alkali metal ions, e.g., an alkali carbonate or an alkali hydroxide. In some embodiments, a combination with a non-metal containing base, e.g., ammonium carbonate or ammonium hydroxide, can be used to provide the alkali-containing precipitate with a desired level of alkali without the need for washing. As an alternative, a non-metal containing base can be used to provide substantially all the precipitating ions, with a separate alkali metal salt (e.g., as a nitrate or an acetate) providing the alkali metal.

[0057] As the person of ordinary skill in the art will appreciate, it can be desirable to perform the precipitation at a desirable alkaline pH. For example, in various embodiments, the contacting of the one or more first liquids with the precipitating ions is performed at precipitation pH in the range of 8-12, e.g., in the range of 8-11, or 8-10, or 8.5-12, or 8.5-11 , or 8.5-10, or 9-12, or 9-11, or 9-10. It can be desirable to maintain the pH of the precipitation within certain alkaline pH values. For example, in various embodiments, the process further comprises maintaining the pH of the contacting step at an alkaline pH, for example, in therange of 8-12, e.g., in the range of 8-11 , or 8-10, or 8.5-12, or 8.5-11, or 8.5-10, or 9-12, or 9-11, or 9-10. The pH of the contacting can be maintained, for example, by controlling a rate of addition of precipitating ions. The person of ordinary skill in the art can otherwise maintain desirable precipitation pH values by maintaining flow rates in the combination of liquids, and, if necessary, addition of additional acid or base components. The pH of the contacting step can be monitored to facilitate pH control.

[0058] In various embodiments as described herein, the contacting of the one or more first liquids with the precipitating ions is conducted at an elevated temperature. For example, in some embodiments as described herein, the contacting step is conducted at a temperature in the range of 60-100 °C, or 60-90 °C, or 60-80 °C, or 70-100 °C, or 70-90 °C, or 70-80 °C.

[0059] In some embodiments as described herein, the process further comprises aging the alkali metal-containing precipitate in contact with the supernatant. The aging process is not particularly limited. For example, in some embodiments as described herein, the aging is conducted at a temperature in the range of 60-100 °C, or 60-90 °C, or 60-80 °C, or 70-100 °C, or 70-90 °C, or 70-80 °C. In some embodiments as described herein, the aging is conducted for a time in the range of 1-5 hours, or 1-4 hours, or 1-2 hours.

[0060] The alkali-containing precipitate is then isolated from the supernatant. A variety of methods can be used in the isolation, including filtration, centrifugation, and settling and decanting.

[0061] In some embodiments, the amount of alkali metal present in the contacting step is sufficient to provide the isolated precipitate with a desired level of alkali metal. However, in other cases, washing the isolated precipitate with a washing liquid can be performed to reduce the alkali content thereof. The washing process is not particularly limited. In some embodiments as described herein, washing the isolated precipitate is repeated until a desired level of alkali metal is provided to the Fischer-Tropsch catalyst material. In some embodiments as described herein, the process includes repeating the washing step at least twice (e.g., at least three times or at least four times). The washing liquid is also not particularly limited and the person of ordinary skill in the art would be able to choose an appropriate liquid. For example, in some embodiments of the disclosure as described herein, the washing liquid is water. However, the present inventors note that the high surface tension of the residual water from the washing step can lead to pores collapsing during the subsequent drying step. As such, it can sometimes be advantageous to use a non-aqueous liquid, particularly in the final washing steps, to obtain catalyst materials with larger surface area and pore volume. For example, in some embodiments as describedherein, the washing liquid is a non-aqueous liquid (e.g., ethanol). In some embodiments, the washing liquid across all washing steps is one or more of water or a non-aqueous liquid, or a combination thereof.

[0062] The isolated precipitate, whether washed or not, can then be dried, for example, at an elevated temperature for a drying time. The person of ordinary skill in the art would be able to select appropriate drying apparatuses and conditions. For example, in some embodiments, the elevated temperature is in the range of 50-150 °C, e.g., in the range of 50-120 °C, or 50-100 °C, or 100-150 °C, or 100-120 °C. In some embodiments, the drying time is in the range of 1 to 48 hours, e.g., in the range of 10 to 36 hours, or 12 to 24 hours. For example, in particular embodiments, the drying time is about 24 hours. However, a separate drying operation is not necessary in all cases; in some embodiments, volatiles of the supernatant and / or washing liquids evaporate at a beginning stage of the calcining.

[0063] As noted above, the process further includes calcining the precipitate to provide the Fischer-Tropsch catalyst material. The calcining step will typically not only convert various metallic species to oxide forms, it will also form a substantial amount of ZnFe2C . In some embodiments of the present disclosure as described herein, calcining the precipitate is conducted for a calcining time and at a calcining temperature. For example, in some embodiments, the calcining time is in the range of 0.5 to 24 hours, or 0.5 to 15 hours, or 0.5 to 10 hours, or 0.5 to 5 hours. In some embodiments, the calcining temperature is in the range of 100-600 °C, e.g., in the range of 200-600 °C, or 300-600 °C, or 100-500 °C, or 200- 500 °C, or 300-500 °C. In some embodiments, the calcining temperature is in the range of 410-600 °C, e.g., in the range of 450-600 °C, or 500-600 °C, or 410-500 °C, or 425-500 °C, or 450-500 °C. The person of ordinary skill in the art can select calcining conditions to provide a desired high degree of ZnFe2C>4 as otherwise described herein.

[0064] In alternative process for providing the Fischer-Tropsch catalyst materials of the disclosure, the precipitation is performed in the substantial absence of alkali metal and a small amount of alkali metal can be added to the Fischer-Tropsch catalyst material at a later stage. Accordingly, in another aspect of the disclosure, a process includes providing one or more first liquids each comprising one or more iron-containing and / or one or more zinc- containing compounds dissolved in one or more first solvents; contacting the one or more first liquids with precipitating ions in the substantial absence of alkali metal ions to provide a substantially alkali-free precipitate and a supernatant; isolating the substantially alkali-free precipitate from the supernatant; adding alkali metal ions to the substantially alkali-free precipitate in order to provide an alkali-containing precipitate; and calcining the isolated precipitate to provide the Fischer-Tropsch catalyst material. Here, the precipitation is performed in the substantial absence of alkali metal ions, and a desired level of alkali ionscan be added to the precipitated material in a separate step. This second process can otherwise be performed in a manner similar to that described above for the first process.

[0065] As described above, the one or more first liquids includes one or more iron- containing compounds and / or one or more zinc-containing compounds dissolved in one or more first solvents. As the person of ordinary skill in the art will appreciate, these metal species are conveniently provided in the same liquid. As such, in some embodiments as described herein, the process includes providing a first liquid comprising one or more iron- containing compounds and one or more zinc-containing compounds dissolved in a first solvent. However, other schemes are possible. For example, in other embodiments as described herein, the process includes providing more than one first liquids, wherein a first liquid comprises one or more iron-containing compounds and another first liquid comprises zinc-containing compounds; these can be combined with precipitating ions by simultaneous addition. In cases where multiple first liquids are used, the first solvents thereof are desirably miscible with one another.

[0066] The iron-containing and zinc-containing compounds are not particularly limited and the person of ordinary skill in the art would be able to choose appropriate compounds that are soluble in the first solvent(s). For example, in some embodiments of the disclosure as described herein, the iron-containing and zinc-containing compounds may be selected from metal salts (e.g., nitrates and acetates). The first solvent(s) are also not particularly limited and the person of ordinary skill in the art would be able to choose an appropriate solvent in which the iron-containing and zinc-containing materials are soluble. As the person of ordinary skill in the art will appreciate, a convenient choice for the first solvent(s) is water. Other aqueous systems can also be used; a co-solvent such as ethanol may be desirable in some cases. And in some cases, substantially non-aqueous solvents can be used, e.g., one or more of ethanol, isopropanol and acetone, optionally together with ethylene glycol to improve dispersion. As would be understood by the person of skill in the art, the iron- containing and zinc-containing compounds may be provided in amounts in the one or more first liquids to provide the Fischer-Tropsch catalyst material with desired proportions of zinc and iron as described herein.

[0067] The person of ordinary skill in the art will provide the one or more first liquids at a desirable pH at which the iron and zinc compounds remain soluble. For example, in various embodiments, each of the one or more first liquids has a pH of no greater than 7.

[0068] The person of ordinary skill in the art can select desirable precipitating ions. In various embodiments, the precipitating ions are carbonate ions and / or hydroxide ions. Theprecipitating ions can be provided by use of non-metal containing base, e.g., ammonium carbonate or ammonium hydroxide.

[0069] As the person of ordinary skill in the art will appreciate, it can be desirable to perform the precipitation at a desirable alkaline pH. For example, in various embodiments, the contacting of the one or more first liquids with the precipitating ions is performed at precipitation pH in the range of 8-12, e.g., in the range of 8-11, or 8-10, or 8.5-12, or 8.5-11 , or 8.5-10, or 9-12, or 9-11, or 9-10. It can be desirable to maintain the pH of the precipitation within certain alkaline pH values. For example, in various embodiments, the process further comprises maintaining the pH of the contacting step at an alkaline pH, for example, in the range of 8-12, e.g., in the range of 8-11 , or 8-10, or 8.5-12, or 8.5-11, or 8.5-10, or 9-12, or 9-11, or 9-10. The pH of the contacting can be maintained, for example, by controlling a rate of addition of precipitating ions. The person of ordinary skill in the art can otherwise maintain desirable precipitation pH values by maintaining flow rates in the combination of liquids, and, if necessary, addition of additional acid or base components. The pH of the contacting step can be monitored to facilitate pH control.

[0070] In various embodiments as described herein, the contacting of the one or more first liquids with the precipitating ions is conducted at an elevated temperature. For example, in some embodiments as described herein, the contacting step is conducted at a temperature in the range of 60-100 °C, or 60-90 °C, or 60-80 °C, or 70-100 °C, or 70-90 °C, or 70-80 °C.

[0071] In some embodiments as described herein, the process further comprises aging the precipitate in contact with the supernatant. The aging process is not particularly limited. For example, in some embodiments as described herein, the aging is conducted at a temperature in the range of 60-100 °C, or 60-90 °C, or 60-80 °C, or 70-100 °C, or 70-90 °C, or 70-80 °C. In some embodiments as described herein, the aging is conducted for a time in the range of 1-5 hours, or 1-4 hours or 1-2 hours.

[0072] The substantially alkali-free precipitate is then separated from the supernatant. A variety of methods can be used in the isolation, including filtration, centrifugation, and settling and decanting.

[0073] In various embodiments, the process further comprises washing the isolated precipitate with a washing liquid. Here, too, the washing liquid is also not particularly limited and the person of ordinary skill in the art would be able to choose an appropriate liquid. For example, in some embodiments of the disclosure as described herein, the washing liquid is water. However, the present inventors note that the high surface tension of the residual water from the washing step can lead to pores collapsing during the subsequent drying step.As such, it can sometimes be advantageous to use a non-aqueous liquid, particularly in the final washing steps, to obtain catalyst materials with larger surface area and pore volume. For example, in some embodiments as described herein, the washing liquid is a nonaqueous liquid (e.g., ethanol). In some embodiments, the washing liquid across all washing steps is one or more of water or a non-aqueous liquid, or a combination thereof.

[0074] The isolated precipitate, whether washed or not, can then be dried, for example, at an elevated temperature for a drying time. The person of ordinary skill in the art would be able to select appropriate drying apparatuses and conditions. For example, in some embodiments, the elevated temperature is in the range of 50-150 °C, e.g., in the range of 50-120 °C, or 50-100 °C, or 100-150 °C, or 100-120 °C. In some embodiments, the drying time is in the range of 1 to 48 hours, e.g., in the range of 10 to 36 hours, or 12 to 24 hours. For example, in particular embodiments, the drying time is about 24 hours. However, a separate drying operation is not necessary in all cases; in some embodiments, volatiles of the supernatant and / or washing liquids evaporate at a beginning stage of the calcining.

[0075] As noted above, the process further includes calcining the precipitate to provide the Fischer-Tropsch catalyst material. The calcining step will typically not only convert various metallic species to oxide forms, it will also form a substantial amount of ZnFe2C>4. In some embodiments of the present disclosure as described herein, calcining the precipitate is conducted for a calcining time and at a calcining temperature. For example, in some embodiments, the calcining time is in the range of 0.5 to 24 hours, or 0.5 to 15 hours, or 0.5 to 10 hours, or 0.5 to 5 hours. In some embodiments, the calcining temperature is in the range of 100-600 °C, e.g., in the range of 200-600 °C, or 300-600 °C, or 100-500 °C, or 200- 500 °C, or 300-500 °C. The person of ordinary skill in the art can select calcining conditions to provide a desired high degree of ZnFe2C>4 as otherwise described herein.

[0076] Addition of the alkali metal ions to the substantially alkali-free precipitate can be performed at any convenient time. For example, a small amount of an alkali metal ioncontaining liquid (e.g., an aqueous solution of alkali carbonate, alkali hydroxide, alkali acetate, or alkali nitrate) can be added to the isolated (and optionally washed) precipitate; the person of ordinary skill in the art will appreciate that techniques like incipient wetness impregnation can be used. The precipitate can then be calcined to provide the Fischer- Tropsch catalyst material. In another embodiment, the isolated precipitate can first be calcined, then alkali added and the material calcined again to provide the alkali in oxidic form.

[0077] The person of ordinary skill in the art can use similar techniques to provide materials that include copper. It is noted that in many cases, copper can precipitate together with the zinc and iron. But impregnation can also be used to provide copper.

[0078] In other aspects, the present disclosure provides a Fischer-Tropsch catalyst as described herein made by a process as described herein.

[0079] Carbided Fischer-Tropsch Catalyst Material

[0080] Another aspect of the present disclosure provides a carbided Fischer-Tropsch catalyst material. The active species in iron-based Fischer Tropsch synthesis are generally understood to be a carbide species. Thus, in some embodiments as described herein, the carbided Fischer-Tropsch catalyst material is the Fischer-Tropsch catalyst material as described herein in a carbided form. In the carbided form, at least some of the iron included in the Fischer-Tropsch catalyst material is in the form of iron carbide.

[0081] Accordingly, another aspect of the disclosure is a carbided Fischer-Tropsch catalyst material comprising: at least 10 wt% iron, on an elemental basis exclusive of carbon; at least 3 wt% zinc, on an elemental basis exclusive of carbon; and at least 0.2 wt% alkali metal, on an elemental basis exclusive of carbon, wherein the atomic ratio of iron to zinc is in the range of 1:2 to 20:1 , and at least 50 atom% of the iron of the carbided Fischer-Tropsch catalyst material is in the form of iron carbide.Such materials can be made, e.g., by the carbiding of the ZnFe2C>4-containing catalyst materials described herein.

[0082] It can be desirable to have a substantial fraction of the iron of the carbided Fischer-Tropsch catalyst material in carbide form, as it is carbide forms that are of highest catalytic activity. For example, in various embodiments of the carbided Fischer-Tropsch catalyst materials of the disclosure, at least 50 atom% of the iron is in a carbide form, e.g., at least 55 atom%, or at least 60 atom%. In various embodiments of the carbided Fischer- Tropsch catalyst materials of the disclosure, in the range of 50-95 atom% of the iron is in a carbide form, e.g., in the range of 50-90%, or 50-85%, or 50-80%. In various embodiments of the carbided Fischer-Tropsch catalyst materials of the disclosure, in the range of 55-95 atom% of the iron is in a carbide form, e.g., in the range of 55-90%, or 55-85%, or 55-80%. In various embodiments of the carbided Fischer-Tropsch catalyst materials of the disclosure, in the range of 60-95 atom% of the iron is in a carbide form, e.g., in the range of 60-90%, or 60-85%, or 60-80%. The amount of iron that is in the form of carbide is determined byMdssbauer spectroscopy, and as such is expressed as an atomic fraction of iron in the form of carbide of the total iron species visible to Mdssbauer spectroscopy.

[0083] The present inventors note that, while oxidic iron is not a highly active catalyst for Fischer-Tropsch synthesis, it can catalyze water-gas shift reactions. In cases where the feed to the FT synthesis includes a high proportion of CO2, the present inventors have determined that water-gas shift activity can be highly desirable to convert that CO2 to CO for use in the Fischer-Tropsch synthesis, thereby providing a single-reactor conversion of CO2 to hydrocarbons. Accordingly, the present inventors have determined that some oxidic iron in the carbided Fischer-Tropsch catalyst material can be beneficial. Accordingly, in various embodiments of the carbided Fischer-Tropsch catalyst materials of the disclosure, at least 5 atom% of the iron is in an oxide phase, e.g., at least 10 atom%, or at least 15 atom%, or at least 20 atom%. However, the present inventors also note that oxidic iron forms are generally not active catalysts for Fischer-Tropsch synthesis. Accordingly, in various embodiments, it can be desirable to limit the amount of oxidic iron in the carbided Fischer- Tropsch catalyst material. In various embodiments of the carbided Fischer-Tropsch catalyst materials of the disclosure, in the range of 5-50 atom% of the iron is in an oxide phase, e.g., 5-45 atom%, or 5-40 atom%. In various embodiments of the carbided Fischer-Tropsch catalyst materials of the disclosure, in the range of 10-50 atom% of the iron is in an oxide phase, e.g., 10-45 atom%, or 10-40 atom%. In various embodiments of the carbided Fischer-Tropsch catalyst materials of the disclosure, in the range of 15-50 atom% of the iron is in an oxide phase, e.g., 15-45 atom%, or 15-40 atom%. In various embodiments of the carbided Fischer-Tropsch catalyst materials of the disclosure, in the range of 20-50 atom% of the iron is in an oxide phase, e.g., 20-45 atom%, or 20-40 atom%. The amount of iron that is in the form of oxide is determined by Mdssbauer spectroscopy, and as such is expressed as an atomic fraction of iron in the form of oxide of the total iron species visible to Mdssbauer spectroscopy. The person of ordinary skill in the art can, based on the disclosure herein, select carbiding conditions to provide a desired degree of oxidic iron in the carbided Fischer-Tropsch catalyst materials of the disclosure.

[0084] The present inventors note that FesC has especially high water-gas shift activity. In various embodiments, at least 30 atom% of the oxidic iron of the carbided Fischer- Tropsch catalyst material is in the form of FesC . The present inventors note that this partially-reduced oxide has especially good activity as a reverse water-gas shift catalyst. In various embodiments, at least 40 atom% of the oxidic iron of the carbided Fischer-Tropsch catalyst material is in the form of FesC , e.g., at least 50 atom%. In various embodiments, at least 60 atom% of the oxidic iron of the carbided Fischer-Tropsch catalyst material is in the form of FesC , e.g., at least 70 atom%. The person of ordinary skill in the art can selectcarbiding conditions, particularly with respect to conditions under which the material is reduced, to provide a desired amount of Fe3C>4. The amount of oxidic iron present as of Fe3C>4 is determined using Mdssbauer spectroscopy.

[0085] Desirably, in the carbided Fischer-Tropsch catalyst materials of the disclosure the zinc remains largely in oxidic form. In various embodiments, at least 80 atom% of zinc present in the material is in oxidic form, e.g., at least 85 atom%, or at least 90%. The form of the zinc is measured by XRD, and as such is expressed as a fraction of zinc in oxidic form as compared to zinc in all forms detectable by XRD.

[0086] The amounts of iron and zinc, alkali metal, and if present, copper, and ratios of iron to zinc in the carbided materials can be substantially as described above.

[0087] In some embodiments as described herein, the carbided Fischer-Tropsch catalyst material is an unsupported catalyst material. As such, in some embodiments as described herein, at least 90 wt% of the Fischer-Tropsch catalyst material is made up of iron, zinc, alkali metal, and copper (if present), as determined by ICP on an elemental basis exclusive of carbon. For example, in various embodiments as described herein, at least 95 wt%, at least 98 wt%, at least 99 wt%, at least 99.5 wt%, or at least 99.8 wt% of the Fischer-Tropsch catalyst material is made up of iron, zinc, alkali metal, and copper (if present), on an elemental basis exclusive of carbon.

[0088] In some other embodiments as described herein, the Fischer-Tropsch catalyst material further comprises a support that supports the iron, zinc, alkali metal, and if present, copper. As such, in some embodiments as described herein, at least 90 wt% of the Fischer- Tropsch catalyst material is made up of iron, zinc, alkali metal, copper (if present), and the support, as determined by ICP on an elemental basis exclusive of carbon. For example, in various embodiments as described herein, at least 95 wt%, at least 98 wt%, at least 99 wt%, at least 99.5 wt%, or at least 99.8 wt% of the Fischer-Tropsch catalyst material is made up of iron, zinc, alkali metal, copper (if present), and the support, on an elemental basis exclusive of carbon. The support itself can be provided as discrete bodies of material, e.g., as porous particles, pellets or shaped extrudates, with iron, zinc, alkali metal, and / or copper (if present) to provide the Fischer-Tropsch catalyst material. The support can also be provided as a binder that binds together particles containing iron and zinc. However, in other embodiments, the support can be provided as a monolithic material, e.g., an extrudate. In various embodiments, the support is formed from a refractory oxide. Of course, as would be understood by the person of ordinary skill in the art, other materials may be possible.

[0089] The person of ordinary skill in the art will appreciate that the carbided Fischer- Tropsch catalyst materials of the disclosure can be provided in many forms, dependingespecially on the particular form of the reactor system in which they are to be used, e.g., in a fixed bed reactor, a fluid bed reactor, a bubble column reactor, a so-called CANS reactor.

[0090] Notably, the present inventors have determined that especially desirable carbided Fischer-Tropsch catalyst materials have a high degree of x-FesC2. The present inventors have noted that such materials can be made by carbiding at relatively high temperatures, as described herein. The present inventors have determined that, surprisingly, carbided Fischer-Tropsch catalyst materials having high amounts of crystalline x-Fe5C2 provide a significantly lower selectivity for oxygenated hydrocarbons and CO2 than that typically provided by iron-catalyzed Fischer-Tropsch processes. However, the Fischer-Tropsch catalyst materials described herein can still provide similar performance (i.e. , CO2 conversion and C5+ hydrocarbon selectivity) when carbided at a low temperature (e.g., 180 °C) but subjected to Fischer-Tropsch synthesis conditions at higher temperature. Without intending to be bound by theory, the present inventors believe that the increased temperature of the CO2 Fischer-Tropsch conditions (e.g., when at least about 300 °C), transforms iron carbide formed during low temperature carbiding (i.e., £-Fe3C and r|-Fe2C) into x-Fe5C2.

[0091] Accordingly, in various embodiments as described herein, the carbided Fischer- Tropsch catalyst material comprises x-Fe5C2. In various embodiments, at least 50 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of x-Fe5C2, e.g., at least 60 wt%, or at least 70 wt%. In various embodiments, at least 75 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of x-Fe5C2, e.g., at least 80 wt%. In various embodiments, at least 85 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of x-Fe5C2, e.g., at least 90 wt%. The state of the iron in the carbided catalyst is determined by Mbssbauer spectroscopy as described above.

[0092] In other embodiments, the carbided Fischer-Tropsch catalyst material comprises e-Fe3C and r|-Fe2C. The present inventors have found that such catalyst materials have relatively higher selectivity for oxygenated hydrocarbons, as well as relatively higher selectivity for CO2. In various embodiments, at least 50 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of £-Fe3C and r|-Fe2C, e.g., at least 60 wt%, or at least 70 wt%. In various embodiments, at least 75 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of £-Fe3C and r|-Fe2C, e.g., at least 80 wt%. In various embodiments, at least 85 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of £-Fe3C and r|-Fe2C, e.g., at least 90 wt%. The state of the iron in the carbided catalyst is determined by Mbssbauer spectroscopy as described above.

[0093] Processes for Carbiding

[0094] The carbided Fischer-Tropsch catalyst materials of the disclosure can be prepared by carbiding various catalyst materials described herein.

[0095] Accordingly, another aspect of the disclosure is a process for carbided Fischer- Tropsch catalyst material as described herein. The process comprises carbiding the Fischer-Tropsch catalyst material to provide the carbided Fischer-Tropsch catalyst material.

[0096] The carbiding can be performed in any convenient manner. Conventionally, iron- containing Fischer-Tropsch catalyst materials are prepared for use as active Fischer- Tropsch catalysts by treating them in situ with a reducing gas such as hydrogen, under conditions sufficient to convert a substantial amount of the iron oxides of the calcined Fischer-Tropsch catalyst material to metallic iron. Then, when exposed to Fischer-Tropsch reaction conditions, a substantial part of this iron is converted to carbide by carbon monoxide of the Fischer-Tropsch feed. It is thus not conventionally necessary to provide a separate carbiding treatment; rather, the carbiding is a natural result of Fischer-Tropsch reaction conditions. However, such Fischer-Tropsch processes tend to exhibit longer induction periods and a relatively higher degree of water-gas shift activity, especially at moderate Fischer-Tropsch reaction temperatures. This can result in a relatively lower conversion of carbon monoxide to desirable C5+ products. Without intending to be bound by theory, the present inventors believe that this could result from incomplete carbide formation, such that there is still partially reduced or in an oxidic form. The materials of the disclosure can be especially useful in such methods, since the higher concentrations of alkali metal and / or copper in the Fischer-Tropsch catalyst material can provide for relatively higher reverse water-gas shift activity, providing higher activity for CO2 to hydrocarbon conversion.

[0097] The Fischer-Tropsch catalyst materials of the disclosure can be advantageous in such in situ carbiding methods, i.e. , when carbiding is performed via exposure Fischer- Tropsch reaction conditions, when the Fischer-Tropsch reaction is performed at temperatures of at least 300 °C, e.g., at least 325 °C. or at least 350 °C. At such temperatures, the in situ carbiding can provide a high degree of carbide in the form of x- FesC2, e.g., to provide a carbided Fisher-Tropsch catalyst material of the disclosure for use in the Fischer-Tropsch synthesis.

[0098] However, the present inventors note that catalysts with a high degree of carbide in the form of x-FesC2 can be especially desirable for use in FT processes conducted at temperatures below 300 °C in order to provide higher C5+ selectivity, and so it can be especially desirable to carbide at high temperature in a separate operation as otherwise described herein.

[0099] Another aspect of the disclosure is a process for making a carbided Fischer- Tropsch catalyst material as described herein. The process comprises carbiding the Fischer-Tropsch catalyst material to provide the carbided Fischer-Tropsch catalyst material.

[0100] The carbiding can be performed in any convenient manner. For example, in various embodiments, the carbiding includes a reduction step, in which the Fischer-Tropsch catalyst material is treated with a reducing gas stream (e.g., containing hydrogen) for a time and at a temperature sufficient to provide at least 50 atom% of the catalyst in metallic form. Without intending to be bound by theory, the inventors understand this step to reduce oxidic iron species to metallic iron species, so that they can be more easily carbided in a subsequent treatment with a carbiding gas. Upon treatment with the reducing gas stream, a portion of the iron components present in the Fischer-Tropsch catalyst material as described herein react to metallic iron (Fe°). However, it was found that ZnO present in the Fischer- Tropsch catalyst material is not substantially reduced during the reducing treatment.

[0101] In various embodiments, the treatment with the reducing gas stream is performed in the substantial absence of carbon monoxide. For example, in various embodiments, the reducing gas stream comprises no more than 1 vol% carbon monoxide, e.g., no more than 0.5 vol%, or no more than 0.1 vol%, or no more than 0.05 vol%, or no more than 0.01 vol% carbon monoxide. In some embodiments as described herein, the reducing gas stream further comprises an inert gas. For example, in some embodiments, the inert gas is nitrogen. In some embodiments as described herein, the hydrogen and inert gas are present in the reducing gas stream in a ratio of at least 1 :1.

[0102] In various embodiments, treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted at a temperature in the range of 250-650 °C. For example, in various embodiments as described herein, treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted at a temperature in the range of 250-600 °C, or 250-550 °C, or 250-500 °C . In various embodiments as described herein, treating the Fischer-Tropsch catalyst material with the Fischer-Tropsch reducing gas stream is conducted at a temperature in the range of 300-650 °C, or 300-600 °C, or 300-550 °C, or 300-500 °C. In various embodiments as described herein, treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted at a temperature in the range of 350-650 °C, or 350-600 °C, or 350-550 °C, or 350-500 °C.

[0103] As described above, treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted for a time sufficient to provide at least 50 atom% of the iron of the Fischer-Tropsch catalyst material in metallic form. In various embodiments, treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted forat least 12 hours, e.g., at least 14 hours. For example, in various embodiments as described herein, treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted for a time in the range of 12 to 30 hours, e.g., in the range of 12 to 24 hours, or 14 to 30 hours, or 14 to 24 hours.

[0104] The person of ordinary skill in the art will be able to determine appropriate reducing conditions to provide a Fischer-Tropsch catalyst material with at least 50 atom% iron in reduced form. While the paragraphs above provide guidance for reducing gas streams, temperatures and times, the person of ordinary skill in the art will be able to, based on the present disclosure, provide suitable reduction conditions to provide a substantially reduced Fischer-Tropsch catalyst material. In various embodiments, the treatment with the reducing gas stream is performed to provide a Fischer-Tropsch catalyst material in which at least 60 atom% of the iron is in reduced form, e.g., at least 70 atom%. In various embodiments, the treatment with the reducing gas stream is performed to provide a Fischer- Tropsch catalyst material in which at least 80 atom% of the iron is in reduced form, e.g., at least 85 atom%. The proportion of iron in reduced form is measured by XRD.

[0105] Moreover, the present inventors note that in some cases a pre-reduction step may not be necessary, as there will often be hydrogen present during the carbiding, and that hydrogen can reduce iron to metallic iron, which can be subsequently converted to carbide. Accordingly, in some embodiments, the Fischer-Tropsch catalyst material is in oxidic form when treated with the carbiding gas stream; in such embodiments, the treatment with the carbiding gas stream is desirably performed in the presence of hydrogen.

[0106] The carbiding can include treating the Fischer-Tropsch catalyst material with a carbiding gas stream comprising carbon monoxide and / or carbon dioxide (e.g., carbon monoxide), at a temperature of at least 180 °C for a time sufficient to provide at least 50 atom% of the iron of the Fischer-Tropsch catalyst material in carbided form. This can be performed, e.g., after a treatment with a reducing gas as described above, or, in cases where hydrogen is present in the carbiding gas stream, on a Fischer-Tropsch catalyst material in substantially oxidic form.

[0107] The present inventors have determined that in particular carbiding can be performed in such a manner so as to tune the selectivity of the Fischer-Tropsch catalyst material as between oxygenated and olefinic hydrocarbon products. Thus, not only can the properties of the as-calcined catalyst material (e.g., relative amounts of metallic constituents and amount of ZnFe2C>4 crystalline phase) and the Fischer-Tropsch reaction parameters (e.g., temperature, GHSV, H2 / CO ratio) affect selectivity of the active catalyst, so too can the conditions under which the Fischer-Tropsch catalyst material is activated by carbiding. Thepresent inventors note that the Fischer-Tropsch catalyst materials described herein are robust and flexible with regard to the carbiding activation process, and thus a variety of carbiding conditions can be used to affect the product distribution in the product streams provided by the carbided Fischer-Tropsch catalyst material. Thus, while the compositions of the disclosure can be useful even when carbided under different conditions, in various embodiments, the Fischer-Tropsch catalyst materials of the disclosure are carbided as described herein.

[0108] In various embodiments, the Fischer-Tropsch catalyst material is treated with a carbon monoxide and / or carbon dioxide-containing gas (e.g., carbon monoxide-containing gas) to provide carbided material. In various embodiments, the carbiding gas stream comprises carbon monoxide. However, the present inventors note that in some cases carbon dioxide may be suitable for providing carbon for carbiding; without intending to be bound by theory the present inventors surmise that the high water-gas shift activity of iron (e.g., in oxide form) can cause carbon dioxide, in the presence of hydrogen, to be converted via the reverse water-gas shift reaction to carbon monoxide, which can be the active carbiding species.

[0109] Without intending to be bound by theory, the inventors surmise that reduced iron is converted to carbide, while oxidic zinc remains largely in oxide form. Oxidic iron, depending on carbiding reaction conditions, may remain as oxidic iron or may be reduced to metal by hydrogen in the carbiding gas stream then carbided; typically a combination of these will occur. Without being bound by theory, the present inventors hypothesize that the ZnO is positioned between carbide sites, holding them in place and preventing sintering that would decrease activity over time. Additionally, the basic character of zinc acts as promoter for higher chain growth probability when in the vicinity of iron carbide sites; the fine dispersion of the ZnO islands resulting from the use of zinc ferrite is especially beneficial in this regard.

[0110] The present inventors have determined that, despite the fact that carbon monoxide and / or carbon dioxide (e.g., carbon monoxide) is the species providing the carbon for the carbiding, it can be advantageous to use a significant amount of hydrogen in the carbiding gas stream. Thus, in various embodiments, the carbiding gas stream includes hydrogen in addition to carbon monoxide. For example, in some embodiments as described herein, the carbiding gas stream comprises hydrogen and carbon monoxide in a molar ratio of at least 1 :1. For example, in various embodiments, the carbiding gas stream comprises hydrogen and carbon monoxide and / or carbon dioxide in a molar ratio of hydrogen to carbon monoxide and carbon dioxide (e.g., hydrogen to carbon monoxide) of at least 2:1 , or at least 5:1 , or at least 10:1, or at least 15:1 , or at least 20:1 , or at least 25:1, or at least 30:1. Insome embodiments as described herein, the carbiding gas stream comprises hydrogen and carbon monoxide and / or carbon dioxide in a molar ratio of hydrogen to carbon monoxide and carbon dioxide (e.g., hydrogen to carbon monoxide) of 1 :1 to 100:1, e.g., in the range of 2:1 to 100:1, or 5:1 to 100:1, or 10:1 to 100:1, or 15:1 to 100:1, or 20:1 to 100:1, or 25:1 to 100:1, or 30:1 to 100:1. In some embodiments as described herein, the carbiding gas stream comprises hydrogen and carbon monoxide and / or carbon dioxide in a molar ratio of hydrogen to carbon monoxide and carbon dioxide (e.g., hydrogen to carbon monoxide) of 1:1 to 50:1, e.g., in the range of 2:1 to 50:1, or 5:1 to 50:1 , or 10:1 to 50:1, or 15:1 to 50:1 , or 20:1 to 50:1 , or 25:1 to 50:1, or 30:1 to 50:1. In various embodiments in which hydrogen is provided together with the carbon monoxide and / or carbon dioxide in the carbiding gas, it may not be necessary to perform a separate reduction step beforehand; hydrogen in the carbiding gas can reduce the oxidic iron to metallic iron, which can then be carbided by the carbon monoxide / carbon dioxide present.

[0111] As described above, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted at a temperature of at least 180 °C. For example, in various embodiments, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted at a temperature of at least 200 °C, e.g., at least 220 °C. For example, in various embodiments, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted at a temperature in the range of 180-450 °C (e.g., in the range of 180- 400 °C, or 180-350 °C, or 180-300 °C). In various embodiments, treating the Fischer- Tropsch catalyst material with a carbiding gas stream is conducted at a temperature in the range of 200-450 °C (e.g., in the range of 200-400 °C, or 200-350 °C, or 200-300 °C). In various embodiments, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted at a temperature in the range of 220-450 °C (e.g., in the range of 220- 400 °C, or 220-350 °C, or 220-300 °C). Without intending to be bound by theory, it is believed that carbiding at lower temperatures can provide carbided Fischer-Tropsch materials having a high proportion of carbide in the e-FesC and r|-Fe2C forms. However, carbiding at relatively low temperatures for longer times may provide catalysts with high amounts of x-FesC2. Such materials are believed to be useful catalyst materials, with lower selectivity to olefins and higher selectivity to oxygenated hydrocarbons. Moreover, these materials can have significant reverse water-gas shift activity, which can be desirable when using significant amounts of CO2 in the Fischer-Tropsch feed.

[0112] The present inventors have found that carbiding temperature has a significant effect on the activity of the carbided Fischer-Tropsch catalyst under FT reaction conditions. For example, the present inventors have found that carbiding at relatively high temperatures can provide a carbided Fischer-Tropsch catalyst material with high selectivity for C5+hydrocarbons, with an increased proportion of olefins. The present inventors have noted, unexpectedly, that high temperature carbiding can provide catalysts with high amounts of x- Fe5C2. The person of ordinary skill in the art can determine, based on the present disclosure, carbiding conditions suitable to provide a carbided Fischer-Tropsch catalyst material having a high degree of x-Fe5C2, for example, in proportions as described above.

[0113] Accordingly, in various embodiments, treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature in the range of at least 300 °C, e.g., at least 310 °C, or at least 325 °C, or at least 350 °C, or at least 375 °C, or at least 400 °C. For example, in various embodiments as described herein, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted at a temperature in the range of 300-650 °C, e.g., 300-600 °C, or 300-550 °C or 300-500 °C. For example, in various embodiments as described herein, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted at a temperature in the range of 310-650 °C, e.g., 310-600 °C, or 310-550 °C, or 310-500 °C. In various embodiments as described herein, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted at a temperature in the range of 325-650 °C, e.g., 325-600 °C, or 325-550 °C, or 325-500 °C. In various embodiments as described herein, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted at a temperature in the range of 350-650 °C, e.g., 350-600 °C, or 350-550 °C, or 350-500 °C. In various embodiments as described herein, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted at a temperature in the range of 375-650 °C, e.g., 375-600 °C, or 375-550 °C, or 375-500 °C. In some embodiments as described herein, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted at a temperature in the range of 400-650 °C, e.g., 400- 600 °C, or 400-550 °C, or 400-500 °C.

[0114] Moreover, even when a Fischer-Tropsch catalyst material is initially carbided under lower temperature conditions to form e-FesC and q-Fe2C, it can, under some high- temperature Fischer-Tropsch reaction conditions, convert to x-Fe5C2. This may require a significant induction period under Fischer-Tropsch reaction conditions. Moreover, in such high-temperature Fischer-Tropsch processes C5+ selectivity can suffer due to the formation of relatively more C1-C4 hydrocarbons; accordingly, it may often be desirable to perform a separate high-temperature carbiding and operate the Fischer-Tropsch synthesis itself at lower temperatures (e.g., below 300 °C).

[0115] As described above, treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted for a time sufficient to provide at least 50 atom% of the iron of the carbided Fischer-Tropsch catalyst material in carbided form. For example, in various embodiments, the treating of the Fischer-Tropsch catalyst material with a carbidinggas stream is conducted for a time of at least 3 hours, e.g., at least 5 hours. In various embodiments, the treating of the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted for a time in the range of 3-20 hours, e.g., 5-20 hours, or 3-15 hours, or 5-15 hours.

[0116] Fischer-Tropsch Processes

[0117] Another aspect of the present disclosure provides a process for performing a Fischer-Tropsch process using CO2 as a substantial feed material. The Fischer-Tropsch catalyst materials described herein can perform a reverse water-gas shift reaction to provide CO and H2O by reacting CO2 and H2 from a feed stream. The Fischer-Tropsch catalyst materials described herein can then react the generated CO with H2 from the feed stream to provide a product stream comprising C5+ hydrocarbons. Accordingly, in various embodiments described herein, the process includes providing a Fischer-Tropsch catalyst material as described herein, and contacting at a reaction temperature and pressure the Fischer-Tropsch catalyst with a feed stream comprising H2and CO2 to provide a product stream comprising C5+ hydrocarbons. An example of such a process is shown schematically in FIG. 1. In FIG. 1 , the process 100 includes contacting at a temperature and at a pressure a Fischer-Tropsch catalyst as described herein with a feed stream comprising H2and CO2 to provide a product stream comprising C5+ hydrocarbons. In the process 100 of FIG. 1 , the feed stream 121 , which is contacted with Fischer-Tropsch catalyst material 123, here, in a reaction zone (e.g., a reactor 120). This provides a product stream 122, which includes C5+ hydrocarbons.

[0118] H2and CO2 can be provided to the feed stream from a variety of sources. The person of ordinary skill in the art will appreciate that H2can be provided from a variety of sources, e.g., gasification, reforming, or H2O electrolysis. Moreover, as described in more detail below, H2can be recycled to the feed stream from the product stream. CO2 from a variety of sources, such as direct air capture or a CO2 emission source, may be utilized in a mixture with the streams as described herein. CO2 obtained from direct air capture may be collected or absorbed after release from an industrial process, or harvested directly from the atmosphere. Methods of CO2 capture are known to those of skill in the art. The CO2 emission source is not particularly limited and may derive from any industrial production known in the art.

[0119] As described above, H2and CO2 are substantial inputs to the claimed processes. Advantageously, the present inventors have recognized that each of these can come from renewable or otherwise environmentally responsible sources.

[0120] For example, H2can be provided from environmentally-responsible sources. In some embodiments, at least a part of the H2of the feed stream is from a renewable source. For example, in various embodiments, at least part (e.g., at least 25%, at least 50%, or at least 75%) of the H2of the feed stream can be so-called “green” hydrogen, e.g., produced from the electrolysis of water operated using renewable electricity (such as wind, solar, or hydro-electric power). In some embodiments, at least part (e.g., at least 25%, at least 50%, or at least 75%) of the H2of the feed stream may be from a so-called “blue” source, e.g., from a natural gas reforming process with carbon capture. Of course, other sources of H2can be used in part or in full. For example, in some embodiments, at least part (e.g., at least 25%, at least 50%, or at least 75%) of the H2of the feed stream is grey hydrogen, black hydrogen, brown hydrogen, pink hydrogen, turquoise hydrogen, yellow hydrogen, and / or white hydrogen.

[0121] The present inventors have noted that electrolysis of water can be a desirable way to provide hydrogen to the claimed processes. Accordingly, in some embodiments, the process includes providing at least a portion of H2to the feed stream by electrolysis of water. In some embodiments, the electrolysis of water is performed using at least partially electricity from a renewable source, e.g., to provide so-called “green hydrogen.” However, the present inventors have noted that electricity can be generated as part of the claimed process, e.g., using heat exchange from the first or second product stream, or by burning light hydrocarbons as described above. In some embodiments, the electrolysis of water is performed using at least partially electricity generated according to the processes as described herein. In some embodiments, at least a portion of O2generated in the electrolysis is provided to a partial oxidation reaction zone as described herein.

[0122] Similarly, CO2can also be provided from environmentally-responsible sources. In some embodiments, at least a part of the CO2of the feed stream is from a renewable source. For Example, in some embodiments, at least part (e.g., at least 25%, at least 50%, or at least 75%) of the CO2of the feed stream is from direct air capture. In some embodiments, at least part (e.g., at least 25%, at least 50%, or at least 75%) of the CO2of the feed stream is from a manufacturing plant such as a bioethanol plant (e.g., CO2produced fermentation), a steel plant, or a cement plant. Accordingly, the CO2to C5+ hydrocarbon FT processes of the disclosure as described herein can not only be carbon neutral, but in some cases, a net consumer of CO2. These benefits in particular make the one-step CO2to C5+ hydrocarbon FT processes highly attractive for decarbonizing transportation fuels, for both automotive and aviation sectors, since the carbon monoxide produced in the rWGS reaction is readily converted into liquid hydrocarbon fuels.

[0123] As described above, the feed stream contains both H2and CO2and the feed stream includes all feeds to the Fischer-Tropsch reaction zone, regardless of whether the feed stream is provided as a mixture of feeds or as feeds provided individually to a reaction zone. In various embodiments of the present disclosure as described herein, the feed stream has a H2:CO2ratio in the range of 0.5:1 to 6:1. In some embodiments, the feed stream has a H2:CO2ratio in the range of 1:1 to 3:1, or 1 :1 to 2.5:1. In some embodiments, the feed stream has a H2:CO2ratio of at least 1.4:1. For example, in some embodiments, the feed stream has a H2:CO2ratio in the range of 1.4:1 to 3:1, or 1.4:1 to 2.5:1. In some embodiments described herein, the feed stream has a H2:CO2ratio of at least 2.5:1, e.g., at least 3:1, or at least 4: 1 , or at least 5:1. For example, in various embodiments, the feed stream as a H2:CO2ratio in the range of 2.5:1 to 10:1 , or 3:1 to 10:1 , or 4:1 to 10:1, or 5:1 to 10:1, or 2.5:1 to 7:1, or 3:1 to 7:1 , or 4:1 to 7:1 , or 5:1 to 7:1. The person of ordinary skill in the art will provide a desired ratio of H2:CO2in the feed stream, based on the disclosure herein that provides a desirable conversion and selectivity in the Fischer-Tropsch process.

[0124] Carbon monoxide may also be provided as part of the feed stream. It can be desirable to maintain a relatively low amount of CO in the feed stream, however, to disfavor the forward reverse-gas shift process. Accordingly, in various embodiments, a molar ratio of CO:CO2is no more than 1 :1 , e.g., no more than 0.8:1 , or no more than 0.5:1. Carbon monoxide can, e.g., be recycled from the product stream.

[0125] Other gases may also be included in the feed stream. For example, it can be desirable to perform the Fischer-Tropsch process step in the presence of a significant amount of inerts (i.e., components that are not H2, CO, or CO2). For example, in various embodiments, the feed stream includes up to 80 mol% of one or more inerts, e.g., in the range of 3-80 mol%, or 5-80 mol%, or 10-80 mol%, or 15-80 mol%, or 30-80 mol% of one or more inerts. In various embodiments, the feed stream includes up to 70 mol% inerts, up to 60 mol% inerts, or up to 50 mol% inerts, e.g., 3-70 mol%, or 5-70 mol%, or 10-70 mol%, or 15-70 mol%, or 30-70 mol%, or 3-60 mol%, or 5-60 mol%, or 10-60 mol%, or 15-60 mol%, or 30-60 mol%, or 3-50 mol%, or 5-50 mol%, or 10-50 mol%, or 15-50 mol%, or 30-50 mol% inerts. In various embodiments, the feed stream includes up to 80% of one or more inerts selected from methane and nitrogen, e.g., up to 70 mol%, up to 60 mol%, or up to 50 mol%, or 15-70 mol%, or 30-70 mol%, or 15-60 mol%, or 30-60 mol%, or 15-50 mol%, or 30-50 mol%.

[0126] To help increase reverse water-gas shift activity, it can be desirable to increase the amount of CO2present in the feed stream; as the water-gas shift is generally an equilibrium process, the presence of CO2helps to favor the conversion of CO2to CO. Invarious embodiments, the feed stream includes up to 80 mol% of CO2, e.g., up to 70 mol%, up to 60 mol%, or up to 50 mol%, or 15-70 mol%, or 30-70 mol%, or 15-60 mol%, or 30-60 mol%, or 15-50 mol%, or 30-50 mol%. Moreover, operating at relatively higher H2:CC>2 ratios as well as increasing temperature can help to increase conversion of CO2to CO via the reverse water-gas shift, although C5+ product selectivity may suffer at higher H2partial pressures.

[0127] Similarly, to increase reverse water-gas shift activity, it can be desirable to reduce the amount of water that is conducted to the Fischer-Tropsch process step. Accordingly, in various embodiments as otherwise described herein, the feed stream has a water content of no more than 10 mol%, e.g., or no more than 2 mol%, or no more than 0.5 mol%. Maintaining a low amount of water can have additional benefits, such as improving catalyst stability.

[0128] The Fischer-Tropsch catalyst materials as described herein are suitable for use in the Fischer-Tropsch processes described herein. The person of ordinary skill in the art will appreciate that the Fischer-Tropsch catalyst materials of the disclosure can be provided in many forms, depending especially on the particular form of the reactor system in which they are to be used, e.g., in a fixed bed or as a fluidized bed. The person of ordinary skill in the art will select an appropriate form of the Fischer-Tropsch catalyst material for the particular reactor system.

[0129] For example, in various embodiments, the Fischer-Tropsch catalyst material is first reduced by contact with a reducing gas. For example, hydrogen can be an especially suitable gas for activating the Fischer-Tropsch catalyst material, e.g., when the activation includes a reduction to metal(O) species. In various embodiments of the present disclosure as otherwise described herein, the feed stream and the reaction conditions in the Fischer- Tropsch reaction system can be adjusted to provide desired reduction conditions. In the process 200 shown schematically in FIG. 2, the feed stream 221 is adjusted appropriately and contacted with the Fischer-Tropsch catalyst 223 under appropriate reduction reaction conditions in reaction zone 220 to reduce it. The reduction can be performed, e.g., as described above.

[0130] In various embodiments, and as described above, the reduced Fischer-Tropsch catalyst material can be carbided by contact with CO. Here, too, the feed stream can be adjusted to provide a desired amount of CO, and reaction conditions in the reactor can be suitably modified to provide for carbidization of the Fischer-Tropsch catalyst material, as described above. In the process 200 shown schematically in FIG. 2, the feed stream 221 isadjusted appropriately and contacted with the Fischer-Tropsch catalyst material 223 in reaction zone 220 to carbide it. Carbiding can be performed, e.g., as described above.

[0131] However, separate carbiding processes are not necessary, as the Fischer- Tropsch catalyst material can be carbided under the Fischer-Tropsch reaction conditions, especially when treated first with a reducing gas as described above.

[0132] As described above, the process includes contacting at a temperature and at a pressure the Fischer-Tropsch catalyst with a feed stream. The person of ordinary skill in the art will select appropriate reaction conditions in conjunction with the particular feed and catalyst used to provide desired Fischer-Tropsch processes. In some embodiments of the disclosure as described herein, the temperature is in the range of 150-400 °C. For example, in various embodiments, the temperature is in the range of 150-350 °C, or 150-300 °C, or 150-250°C, or 150-200°C, or 200-400 °C, or 200-350 °C, or 200-300°C, or 200-250 °C, or 250-400 °C, or 250-350 °C, or 250-300 °C, or 300-400 °C. In some particular embodiments, the temperature is in the range of 200-350 °C. In other particular embodiments, the temperature is in the range of 300-400 °C; in such embodiments, the carbide form of the carbided Fischer-Tropsch catalyst material can be converted to the desirable x-Fe5C2 form, although C5+ selectivity may suffer somewhat due to increased C1-C4 hydrocarbon formation.

[0133] In some embodiments of the disclosure as described herein, the pressure is in the range of 10-50 barg. For example, in various embodiments, the pressure is in the range of 20-50 barg, or 25-50 barg, or 10-40 barg, or 20-40 barg, or 25-40 barg or 10-35 barg, or 20-35 barg, or 25-35 barg. In some embodiments of the disclosure as described herein, the pressure is in the range of 30-70 barg. For example, in various embodiments, the pressure is in the range of 30-60 barg, or 30-55 barg, or 30-50 barg, or 35-70 barg, or 35-60 barg, or 35-55 barg, or 35-50 barg, or 40-70 barg, or 40-60 barg, or 40-55 barg, or 40-50 barg. In some particular embodiments, the pressure is in the range of 20-50 barg.

[0134] The Fischer-Tropsch processes described herein can be performed at a variety of GHSV (gas hourly space velocity) values, as would be appreciated by the person of ordinary skill in the art. As such, the GHSV for performing the Fischer-Tropsch reaction is not particularly limited. For example, in some embodiments of the present disclosure, the process for performing the Fischer-Tropsch reaction is conducted at a GHSV in the range of 1 ,000 to 2,000,000 h’1. In various embodiments, the process for performing the reverse water-gas shift reaction is conducted at a GHSV in the range of 1 ,000 to 1 ,200,000 IT1, or 1 ,000 to 500,000 IT1, or 1 ,000 to 100,000 IT1, or 5,000 to 1 ,200,000 IT1, or 5,000 to 500,000 IT1, or 5,000 to 100,000 IT1, or 10,000 to 1 ,200,000 IT1, or 10, 000 to 500,000 IT1, or 10, 000 to 100,000 IT1. In various embodiments of the present disclosure, the process for performingthe Fischer-Tropsch reaction is conducted at a GHSV in the range of 1 ,000 to 50,000 IT1, or 2,000 to 50,000 h-1, or 5,000 to 50,000 IT1, or 10, 000 to 50,000, or 1 ,000 to 40,000 IT1, or 2,000 to 40,000 h-1, or 5,000 to 40,000 IT1, or 10, 000 to 40,000 IT1, or 1 ,000 to 30,000 IT1, or 2,000 to 30,000 h-1, or 5,000 to 30,000 IT1, or 10,000 to 30,000 IT1.

[0135] The Fischer-Tropsch process is typically used to make C5+ hydrocarbons, for example, unsubstituted C5+ hydrocarbons (e.g., alkanes and alkenes) and oxygenated C5+ hydrocarbons (e.g., C5+ alcohols, aldehydes, ketones, carboxylic acids). In various embodiments of the disclosure as described herein, contacting the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a C5+ selectivity (i.e. , for all C5+ species) of at least 30%, e.g., at least 50%, or at least 70%. For example, in some embodiments, the selectivity for C5+ alkanes is at least 40%, e.g., at least 60%, or at least 80%. In some embodiments, contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a C5+ selectivity of at least 60%, e.g., at least 70%, or at least 80%. In some embodiments, contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a C2-4 selectivity of no more than 30%, e.g., no more than 25%, or no more than 20%. In some embodiments, the contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a methane selectivity of no more than 20%, e.g., no more than 15%, or no more than 10%, or no more than 5%. In some embodiments, contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a C2-8 oxygenate selectivity of no more than 30%, e.g., no more than 25%, or no more than 20%. In some embodiments, contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a C2-8 oxygenate selectivity of no more than 15%, e.g., no more than 10%, or no more than 5%.

[0136] Additional components may be in present in the product stream. For example, in some embodiments, the product stream includes water, which is another product of the Fischer-Tropsch reaction. Also present can be one or more light hydrocarbons (i.e., C1-C4) as a side product. CO2 and / or H2can be present, e.g., unreacted from the feed stream. CO can be present, unreacted from the feed stream and / or produced by reverse water-gas shift and not further reacted. Other inerts as described herein can also be present. Such components of the product stream can be separated and / or recycled in various manners.

[0137] For example, in various embodiments, the process further comprises separating at least a portion of water from the product stream. This is shown schematically in FIG. 3. In the embodiment of FIG. 3, reaction zone 320 is a volume of the reactor 305 that includes the bed 324 containing the Fischer-Tropsch catalyst 323. The feed stream 321 is passed to the Fischer-Tropsch catalyst 323 to provide second product stream 322. Here, the processalso optionally includes separating at least a portion of water (e.g., at least 50%, at least 75%, or at least 90%) from the product stream 322 to provide water-containing stream 334.

[0138] Light hydrocarbons, while often not a desired portion of a Fischer-Tropsch product to be used as a fuel or a lubricant, can themselves be useful for a number of purposes. Accordingly, in various embodiments, the process further includes separating at least a portion of C1-C4 hydrocarbons from the second product stream to provide a light hydrocarbon stream. The light hydrocarbon stream can, for example, be recycled to the first feed stream or the second feed stream. For example, in the process 200 of FIG. 2, light hydrocarbons from product stream 222 can be provided as part of the recycle stream 236, which becomes part of the feed stream 221. In the process 300 of FIG. 3, light hydrocarbons can be provided as part of the recycle stream 336, which becomes part of the feed stream 321. In the process 400 of FIG. 4, light hydrocarbons are recycled via recycle stream 442 to first feed stream 421.

[0139] There are other uses for the light hydrocarbon stream. For example, in some embodiments, the process further comprises oxidizing at least a portion of the light hydrocarbon stream to provide a CO- and / or CO2-containing partial oxidation (pOX) stream, and including at least a portion of the pOX stream in feed stream. An example of such a process is shown schematically in FIG. 4, in which the process 400, the feed stream 421 , the product stream 422, the reaction zone 420, and the Fischer-Tropsch catalyst 423 can be as otherwise described herein. Here, the process includes oxidizing at least a portion of the light hydrocarbon stream 450, in a partial oxidation reaction zone 452 to provide a CO- and / or CO2 containing pOX stream, and including at least a portion of the pOX stream 454 stream in the feed stream 421.

[0140] Moreover, the light hydrocarbon stream can be burned to provide heat energy, which can be used to heat various process streams, or to generate electricity. Accordingly, in various embodiments, the process includes burning at least a portion of the light hydrocarbon stream to provide energy, e.g., heat energy or electrical energy. For example, in the process 400 of FIG. 4, a portion of light hydrocarbon stream 450 is burned in a power generation zone (here, in an electrical generator 470), to generate electricity stream 472. In various embodiments, the heat energy may be used to provide the needed heat duty for the Fischer-Tropsch process. For example, in the process 400 of FIG. 4, a portion of the light hydrocarbon stream 450 is burned in a power generation zone (here, in a heat generator 480), to generate heat stream 482. The heat stream 482 is conducted to a heat exchange zone 490 to heat the feed stream 421.

[0141] Heat can be exchanged from the product stream to provide heat to, for example, a feed stream or a steam generation zone. For example, in various embodiments, the process further comprises exchanging heat between at least a portion of the product stream and at least a portion of the feed stream, thereby cooling at least a portion of the product stream and heating at least a portion of the feed stream. In process 300 of FIG. 3, heat is exchanged between at least a portion of the product stream 322 and feed stream 321 in a second heat exchange zone 330, thereby cooling the product stream 322 and heating the feed stream 321. The person of ordinary skill in the art will appreciate that a wide variety of heat exchangers can be used for this purpose.

[0142] Of course, any excess heat in the product stream can be additionally or alternatively used for other purposes. For example, in various embodiments the process further comprises exchanging heat between at least a portion of the product stream and a steam generation zone, thereby cooling at least a portion of the product stream and providing heat to the steam generation zone. This is shown in FIG. 3. Here, after heat exchange with the feed stream 321, the product stream 322 is conducted to steam generation zone 332, to cool the product stream 322 and provide heat to the steam generation zone 332. Steam can be generated from the heat provided, and electricity can be generated from the steam (not shown here).

[0143] It can be desirable to recycle hydrogen from the product stream, for example, to the feed stream. For example, in various embodiments, the process includes recycling at least a portion of H2 of the product stream to the feed stream. For example, in the process of FIG. 2, at least a portion of H2of the product stream (e.g., at least 25%, at least 50%, or at least 75%) can be recycled to the feed stream 221 via recycle stream 236.

[0144] Similarly, it can be desirable to recycle CO2of the product stream, for example, to the feed stream. For example, in various embodiments, the process includes recycling at least a portion of CO2 of the product stream to the second feed stream. For example, in the process of FIG. 2, at least a portion of CO2 of the product stream (e.g., at least 25%, at least 50%, or at least 75%) can be recycled to the feed stream 221 via recycle stream 236.

[0145] In many cases, both CO2and H2of the second product stream will be recycled.

[0146] Moreover, when one or more inerts are used in the Fischer-Tropsch process step, it can be desirable to recycle these. For example, in various embodiments, the process includes recycling at least a portion of inerts of the product stream to the feed stream. For example, in the process of FIG. 2, at least a portion of inerts of the product stream (e.g., at least 25%, at least 50%, or at least 75%) can be recycled to the feed stream 221 via recycle stream 236. In various embodiments, the process includes recycling at leasta portion of inerts of the product stream to the feed stream. In various embodiments, a purge stream can be incorporated with the recycle stream to prevent uncontrolled accumulation of inerts in the recycle stream (not shown here).

[0147] As noted above, the Fischer-Tropsch process step provides a product stream that includes C5+ hydrocarbons (e.g., unsubstituted hydrocarbons like alkanes and alkenes, and / or oxygenated hydrocarbons such as alcohols). Accordingly, in various embodiments, one or more products are provided from at least a portion of C5+ hydrocarbons of the second product stream. The C5+ hydrocarbons can be used as the basis of a variety of fuels, e.g., gasoline, diesel, aviation fuel. Other products, like waxes and lubricants, can also be made. And alkenes and oxygenates can be used as feedstocks in a variety of other processes.

[0148] The person of ordinary skill in the art will use conventional post-processing techniques to convert the C5+ hydrocarbon-containing product to desirable products such as desirable fuels. For example, in various embodiments, the process further includes hydroprocessing at least a portion of C5+ hydrocarbons of the product stream. As the person of ordinary skill in the art will appreciate, hydroprocessing is a treatment of the hydrocarbon stream with hydrogen in the presence of a suitable catalyst. A wide variety of hydroprocessing techniques are known and the person of ordinary skill in the art will apply them here. For example, in the process 300 of FIG. 3, second product stream 322 is hydroprocessed in hydroprocessing reactor 350, to provide a hydroprocessed product stream 352.

[0149] The person of ordinary skill in the art will provide the materials and perform the processes described herein based on the general disclosure above, and with reference to the Examples below.EXAMPLES

[0150] The Examples that follow are illustrative of specific embodiments of the materials and process of the disclosure, and various uses thereof. They are set forth for explanatory purposes only, and are not to be taken as limiting the scope of the disclosure.

[0151] Example 1. Process for Preparing Alkali Metal-Containing Fe-Zn Catalyst Material Through Co-precipitation

[0152] For the preparation of mixed zinc iron systems, a co-precipitation was employed. In brief, Fe(NOs)3-9H2O and Zn(NO3)2’6H2O were both dissolved in DI water to obtain a clear solution A. Na2COs was dissolved in DI water to obtain Solution B. DI water was filled into a round bottom flask equipped with a mechanical stirrer, a heating mantle / temperature control system and a condenser. The temperature of the water in the round bottom flask wasincreased to 80 °C, and then the pH was adjusted to about 9 with Na2COs solution (i.e. , Solution B). Then, the solutions A and B were simultaneously added at roughly the same rate while monitoring the pH value of the slurry and adjusting it by adjusting the flowrate of solution B. After allowing the precipitate to age at 80 °C for 2 hours, the precipitate was filtered using Buchner Funnels and vacuum pumps.

[0153] The obtained precipitate has a high residual sodium content, which can be reduced via subsequent washing with DI water, and the use of washing is hence a means to vary the level of residual sodium in the precipitate.

[0154] The samples were taken at different levels of washings. Each sample was dried in a fume cupboard overnight followed by drying in a muffle furnace in air using the following conditions: 2°C / min to 110 °C for 12 hours. Following the drying, samples were calcined at 350 °C (at 2°C / min) and held at that temperature for 4 hours. From XRD analysis, it was determined that all samples comprise ZnFe2C>4 and ZnO with no zinc carbonate species observable by XRD.

[0155] From elemental analysis via ICP, it was determined that the initially obtained precipitate contained 12 wt% sodium (quantified as a fraction of the mass of the entire catalyst material, i.e., including oxygen), whereas after four washings it could be reduced to 2.2 wt% (Table 1 Error! Reference source not found.). The obtained sample had a BET surface area of 85 m2 / g and pore volume of 0.18 cc / g.

[0156] Each sample was analyzed by x-ray diffraction (XRD) and ICP. From XRD analysis, all samples comprise ZnFe2C>4 and ZnO with no observable zinc carbonate species. The obtained samples have a BET surface area of 85 m2 / g and a pore volume of 0.18 cc / g. The results elemental analysis via ICP are shown in Table 1. Materials were assumed to be in oxidic form; values here are reported as the mass of the given metal per se as a fraction of a mass of the entire mixed metal oxide material (i.e., including oxygen).

[0157] Table 1.

[0158] Example 2. Performance of Alkali Metal-Containing Fe-Zn Catalyst Materials Prepared Through Co-precipitation

[0159] The Fischer-Tropsch catalyst materials prepared in Example 1 were evaluated for their CO2 conversion and C5+ selectivity in Fischer-Tropsch synthesis. The Fischer-Tropsch reactions were carried out in a 16-fold parallel fixed bed reactor unit, wherein two blocks of 8 tubes, each having an inner diameter of 2.4 mm, are independently heated, and gas feed flows are egually split and distributed. The unit has hot knockout pots at 150 °C for collecting high boiling waxes and cold knockout pots at 10 °C to collect water and light organics. Around 250 mg of catalyst material corresponding to sample 2 was diluted with 500 mg SiC and placed in a reactor tube of the 16-fold parallel fixed bed reactor unit. The diluted catalyst material was activated using a high temperature carbiding protocol, wherein the catalyst material is first reduced under hydrogen atmosphere (50 vol% H2in N2, GSHV = 5000 IT1) at 400 °C for 16 hours, then carbided with a carbiding gas stream (4 vol% CO in H2, GSHV = 5000 IT1) at 400 °C for 6 hours. The catalyst material was then subjected to Fischer-Tropsch conditions as follows: GHSV = 4500 IT1; H2:CO2= 1.8:1; 30 bar. GHSV values herein are provided with respect to active species in the feed; inerts are not counted, but typically were 15-30 vol% in Fischer-Tropsch feeds. The reaction products were analyzed using gas chromatography. Table 2 describes the performance of the catalyst under various temperatures. The reported hydrocarbon selectivities do not include CO.

[0160] Table 2.

[0161] The Na-promoted ZnFe2O4 catalyst was compared to another Fe-based catalyst known in the art, an Fe-Mn-K catalyst prepared through organic combustion (Yao et al., “Transforming carbon dioxide into jet fuel using an organic combustion-synthesized Fe-Mn-K catalyst, NATURE COMMUNICATIONS, 11, 6395 (2020)). For this comparison, around 250 mg of each catalyst material was diluted in 500 mg SiC and placed into separate reactor tubes of a 16-fold parallel fixed bed reactor as described above. Both catalyst materials were activated prior to Fischer-Tropsch synthesis using the high temperature carbiding method described above, wherein the catalyst material is first reduced under hydrogen atmosphere (50 vol% H2in N2, GSHV = 5000 IT1) at 400 °C for 16 hours, then carbided witha carbiding gas stream (4 vol% CO in H2, GSHV = 5000 IT1) at 400 °C for 6 hours. In Table 3, the catalysts were each then subjected to Fischer-Tropsch conditions as follows: GHSV = 4500 IT1; H2:CO2= 1.8:1 ; 30 bar; 330 °C. The reactions were analyzed by gas chromatography, and the reported hydrocarbon selectivities do not include CO.

[0162] Table 3.

[0163] Increasing the reaction temperatures from 275 °C 330 to °C improved both the conversion and selectivity towards C5+ hydrocarbons. The co-precipitated Na / ZnFe2O4 catalyst material performed similarly to Fe-Mn-K catalyst material with regards to CO2conversion, C5+ selectivity and C5+ yield. Advantageously, the co-precipitation preparation of the Na / ZnFe2O4 catalyst material does not come with the same industrial scale-up and safety concerns as the preparation of the Fe-Mn-K catalyst material, which requires sacrificing organic precursors to form a catalyst material that is low density, ash-like powder.

[0164] Example 3. Process for Preparing Alkali Metal-Containing Fe-Zn Catalyst Materials Through Incipient Wetness

[0165] The precipitating agent used in Example 1 , Na2COs, was replaced with ammonium hydroxide (NH4OH, 34% in water). In brief, the reaction was carried out as follows:

[0166] The metal salts (Fe(NO3) 9H2O, 40.4g; Zn(NO3)2'6H2O, 29.7g) were dissolved in 300 mL of deionized water and placed in a 1 liter 3 necked flask with a mechanical stirrer. NH4OH (34% in water) was placed in a pressure equalized dropping funnel. The reaction flask containing the metal nitrate solution was heated to 80 °C with stirring and once at temperature the ammonium hydroxide was added dropwise until the pH of the solution reached 8.3. After the solution reached a pH of 8.3 the solution is aged for 1 hour at 80 °C then cooled to room temperature. Upon cooling the mixture was filtered using a vacuum filtration system and then washed with 7 aliquots of deionized water (250 mL). The material was dried overnight in a fume hood, followed by drying in an oven at 110 °C for 12 hours.

[0167] Sodium was added to this material using incipient wetness impregnation using a sodium nitrate solution at a concentration to provide sample 3 with a sodium loading of 2.2 wt% of the total material (i.e., including oxygen), matching the level of sodium in sample 2. The level of water for an incipient wetness impregnation of the base materials was 1 mL. After impregnation, the materials were dried at room temperature followed by oven drying at 110 °C for 12 hours and calcination at 350 °C for 4 hours. The performance of catalyst materials corresponding to samples 2 and 3 were evaluated under Fischer-Tropsch reaction conditions. Around 250 mg of catalyst materials corresponding to sample 2 and 3 were each diluted with 500 mg SiC and placed into separate reactor tubes of the 16-fold parallel fixed bed reactor unit. The diluted catalyst materials were activated using a high temperature carbiding protocol, wherein the catalyst materials are first reduced under hydrogen atmosphere (50 vol% H2in N2, GSHV = 5000 IT1) at 400 °C for 16 hours, then carbided with a carbiding gas stream (4 vol% CO in H2, GSHV = 5000 I1) at 400 °C for 6 hours. The catalyst materials were then subjected to Fischer-Tropsch conditions as follows: GHSV = 4500 IT1; H2:CO2= 1.8:1; 30 bar; 330 °C. The reactions were analyzed using gas chromatography, and the performance of catalyst material samples 2 and 3 are shown in Table 4 below. Notably, performance was similar for catalysts made by the two different methods.

[0168] Table 4.

[0169] Example 4. Carbiding Robustness and Flexibility

[0170] To investigate the influence that the carbiding process has on the Fischer- Tropsch catalyst material performance, catalyst material corresponding to sample 2 and reference catalyst Fe-Mn-K were activated under both high temperature and low temperature carbiding procedures prior to Fischer-Tropsch synthesis. Around 250 mg of catalyst material corresponding to sample 2 and reference catalyst Fe-Mn-K was each diluted with 500 mg SiC and placed into separate reactor tubes of the 16-fold parallel fixed bed reactor unit. The diluted catalyst material were activated using a high temperaturecarbiding protocol, wherein the catalyst materials are first reduced under hydrogen atmosphere (50 vol% H2in N2, GSHV = 5000 IT1) at 400 °C for 16 hours, then carbided with a carbiding gas stream (4 vol% CO in H2, GSHV = 5000 I1) at 400 °C for 6 hours.

[0171] Another set of catalyst materials corresponding to sample 2 and reference catalyst Fe-Mn-K were activated under low temperature carbiding conditions in separate reactor tubes, wherein the catalyst materials are first reduced under hydrogen atmosphere (50 vol% H2in N2, GSHV = 5000 IT1) at 180 °C for 24 hours, then carbided with a carbiding gas stream (H2:CO ~2:1 , GSHV = 5000 IT1). All of carbided catalysts were then subjected to the following Fischer-Tropsch reaction conditions: GHSV = 4500 IT1; H2:CO2= 1.8:1; 30 bar; 330 °C. The reactions were analyzed using gas chromatography, and the results are shown below in Table 5. The reported hydrocarbon selectivities do not include CO.

[0172] Table 5.

[0173] The Fischer-Tropsch catalyst material activated under a low temperature carbiding step exhibited similar performance in terms of CO2conversion and C5+ selectivity to catalyst material activated under high temperature carbiding, when Fischer-Tropsch synthesis was performed at 330 °C. The similar performance of the Na / ZnFe2O4 catalyst across a variety of activating conditions highlights the robustness of the Fischer-Tropsch catalyst material. The present inventors have evaluated a variety of other activation methods for the Fischer-Tropsch catalyst material that all yielded similar performance during Fischer-Tropsch synthesis at high temperature. A list of these conditions are shown below in Table 6.

[0174] Table 6.

[0175] Example 5. Evidence of Iron Carbide in Spent Fischer-Tropsch Catalyst Material

[0176] Powder X-ray diffraction (XRD) patterns of spent Fischer-Tropsch catalyst material (i.e., sample BP MA8257) were obtained. Catalyst material BP MA8257, in which Zn:Fe 1 :1 , with 3 wt% Na (as calculated with respect to the entire material, including oxygen), was subjected to Fischer-Tropsch reaction conditions converting CO2 and H2to hydrocarbons over the course of 5 weeks. The powder XRD patterns were recorded ex situ with Co Kai,2 radiation from 20° to 90° (20) at a scan rate of 1.267min using a Panalytical X’Pert X-ray diffractometer. Powder XRD patterns were obtained for different sections of BP MA8257 in the reactor bed (i.e., top top, top, middle, and bottom). Panalytical software was used for Rietveld analysis to determine the phase composition and crystallite size. The XRD pattern of the “top top” section of the spent BP MA8257 catalyst material is shown in FIG. 5. The peaks in the XRD pattern can be assigned to a mixture of ZnO (46 wt%, 42 nm crystallite size), FesC2 (37 wt%, 64 nm crystallite size), and FeyCs (17 wt%, 53 nm crystallite size). SiC is also present in the sample, as it was used as a diluent in the catalyst bed.

[0177] The XRD pattern of the top section of the spent BP MA8257 catalyst material is shown in FIG. 6. The peaks in the XRD pattern can be assigned to a mixture of ZnO (30 wt%, 40 nm crystallite size), Fe5C2 (20 wt%, 48 nm crystallite size), Fe7C3 (13 wt%, 55 nmcrystallite size) and Fe3C>4 (37 wt%, 112 nm crystallite size). SiC is also present in the sample.

[0178] The XRD pattern of the middle section of the spent BP MA8257 catalyst material is shown below in FIG. 7. The peaks in the XRD pattern can be assigned to a mixture of Fe3O4 (89 wt%, 86 nm crystallite size), ZnO (7 wt%, 41 nm crystallite size), and Fe7C3(4 wt%, 55 nm crystallite size). SiC is also present in the sample.

[0179] The XRD pattern of the bottom section of the spent BP MA8257 catalyst material is shown below in FIG. 8. The peaks in the XRD pattern can be assigned to a mixture of Fe3O4 (92 wt%, 68 nm crystallite size) and ZnO (8 wt%, 44 nm crystallite size). SiC is also present in the sample. The phase composition data for each of the sections are summarized below in Table 7.

[0180] Table 7.

[0181] Table 7 highlights that, after a considerable time on stream, the iron in the beginning (i.e., top sections) of the reactor bed are generally in the carbide form, while iron towards the end (i.e., bottom sections) of the reactor bed are in an oxidic form. Without intending to be bound by theory, the present inventors believe that there is a higher concentration of water towards the end of the catalyst bed, as water is one of the products of Fischer-Tropsch synthesis. The increased concentration of water could contribute to the oxidation of the iron at the end of the reactor bed. FIG. 9 overlaps the XRD patterns of the “top top” and bottom sections of the catalyst bed, highlighting the difference in the carbide and oxide content of the iron catalyst between the two sections. Some of the matching peaks in the two spectra are due to the presence of SiC in both sections.

[0182] These data suggest that even the desirable x-FesC2 carbide form can be converted to oxide over time, and so occasional catalyst regeneration may be desirable in order to maintain high levels of carbide in the catalyst.

[0183] Additional aspects of the disclosure are provided by the following enumerated embodiments, which may be combined in any number and in any combination that is not logically or technically inconsistent.Embodiment 1. A Fischer-Tropsch catalyst material comprising: at least 10 wt% iron, on an elemental basis exclusive of carbon; at least 3 wt% zinc, on an elemental basis exclusive of carbon; and at least 0.2 wt% alkali metal, on an elemental basis exclusive of carbon, wherein the atomic ratio of iron to zinc is in the range of 1:2 to 20:1, and the Fischer-Tropsch catalyst material includes at least 10 wt% crystalline ZnFe2C>4.Embodiment 2. The Fischer-Tropsch catalyst material according to embodiment 1, wherein the Fischer-Tropsch catalyst material comprises at least 15 wt%, iron, e.g., at least 20 wt% iron, or at least 25 wt% iron, on an elemental basis exclusive of carbon.Embodiment 3. The Fischer-Tropsch catalyst material according to embodiment 1, wherein the Fischer-Tropsch catalyst material comprises at least 30 wt%, iron, e.g., at least 35 wt% iron, or at least 40 wt% iron, on an elemental basis exclusive of carbon.Embodiment 4. The Fischer-Tropsch catalyst material according to any of embodiments 1-3, wherein the Fischer-Tropsch catalyst material comprises at least 5 wt% zinc, e.g., at least 7 wt% zinc, or at least 10 wt% zinc, on an elemental basis exclusive of carbon.Embodiment 5. The Fischer-Tropsch catalyst material according to any of embodiments 1-3, wherein the Fischer-Tropsch catalyst material comprises at least 12 wt% zinc, e.g., at least 15 wt% zinc, or at least 17 wt% zinc, or at least 20 wt% zinc, on an elemental basis exclusive of carbon.Embodiment 6. The Fischer-Tropsch catalyst material according to any of embodiments 1-5, comprising at least 0.2 wt% alkali metal, e.g., at least 0.3 wt%, or at least 0.4 wt%, on an elemental basis exclusive of carbon.Embodiment 7. The Fischer-Tropsch catalyst material according to any of embodiments 1-5, comprising at least 0.5 wt% alkali metal, e.g., at least 0.7 wt%, on an elemental basis exclusive of carbon.Embodiment 8. The Fischer-Tropsch catalyst material according to any of embodiments 1-5, wherein the Fischer-Tropsch catalyst material comprises at least 0.7 wt% alkali metal, e.g., at least 1 wt% alkali metal, or at least 1.3 wt% alkali metal, or at least 1.5 w% alkali metal, or at least 1.7 wt% alkali metal, on an elemental basis exclusive of carbon.Embodiment 9. The Fischer-Tropsch catalyst material according to any of embodiments 1-5, wherein the Fischer-Tropsch catalyst material comprises in the range of 0.2-5 wt% alkali metal, e.g., 0.2-3 wt%, or 0.2-2 wt%, or 0.3-5 wt%, or 0.3-3 wt%, or 0.3-2 wt%, or 0.4-5 wt%, or 0.4-3 wt%, or 0.4-2 wt%, on an elemental basis exclusive of carbon.Embodiment 10. The Fischer-Tropsch catalyst material according to any of embodiments 1-5, wherein the Fischer-Tropsch catalyst material comprises in the range of 0.5-5 wt% alkali metal, e.g., 0.5-3 wt%, or 0.5-2 wt%, or 0.7-5 wt%, or 0.7-3 wt%, or 0.7-2 wt%, on an elemental basis exclusive of carbon.Embodiment 11. The Fischer-Tropsch catalyst material according to any of embodiments 1-5, wherein the Fischer-Tropsch catalyst material comprises in the range of 1-5 wt% alkali metal, e.g., 1-3 wt%, or 1-2 wt%, or 1-2 wt%, or 1.3-5 wt%, or 1.3-3 wt%, or 1.3-2 wt%, on an elemental basis exclusive of carbon.Embodiment 12. The Fischer-Tropsch catalyst material according to any of embodiments 1-5, wherein the Fischer-Tropsch catalyst material comprises in the range of 1.5-5 wt% alkali metal, e.g., 1.5-3 wt%, or 1.5-2.5 wt%, or 1.5-5 wt%, or 1.5-3 wt%, or 1.5- 2.5 wt%, on an elemental basis exclusive of carbon.Embodiment 13. The Fischer-Tropsch catalyst material according to any of embodiments 1-12, wherein the Fischer-Tropsch catalyst material comprises 0.1-0.35 mol of alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, e.g., 0.1-0.32, or 0.1-0.30 mol, or 0.1-0.28 mol, or 0.1-0.25 mol.Embodiment 14. The Fischer-Tropsch catalyst material according to any of embodiments 1-12, wherein the Fischer-Tropsch catalyst material comprises 0.12-0.35 molof alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, e.g., 0.12-0.32 mol, or 0.12-0.3 mol, or 0.12-0.28 mol, or 0.12-0.25 mol.Embodiment 15. The Fischer-Tropsch catalyst material according to any of embodiments 1-12, wherein the Fischer-Tropsch catalyst material comprises 0.15-0.35 mol of alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, e.g., 0.15-0.32 mol, or 0.15-0.3 mol, or 0.15-0.28 mol, or 0.15-0.25 mol.Embodiment 16. The Fischer-Tropsch catalyst material according to any of embodiments 1-12, wherein the Fischer-Tropsch catalyst material comprises 0.18-0.35 mol of alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, e.g., 0.18-0.32 mol, or 0.18-0.3 mol, or 0.18-0.28 mol, or 0.18-0.25 mol.Embodiment 17. The Fischer-Tropsch catalyst material according to any of embodiments 1-12, wherein the Fischer-Tropsch catalyst material comprises 0.2-0.35 mol of alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, e.g., 0.2-0.32 mol, or 0.2-0.3 mol, or 0.2-0.28 mol, or 0.2-0.25 mol.Embodiment 18. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 1-6 wt% sodium, e.g., 1-5.5 wt%, or 1 .5 wt%, or 1-4.5 wt%, or 1-4 wt%, or 1-3.5 wt%, or 1-3 wt%.Embodiment 19. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 1.5-6 wt% sodium, e.g., 1.5-5.5 wt%, or 1.5-5 wt%, or 1.5-4.5 wt%, or 1.5-4 wt%, or 1.5-3.5 wt%.Embodiment 20. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 2-6 wt% sodium, e.g., 2-5.5 wt%, or 2-5 wt%, or 2-4.5 wt%, or 2-4 wt%.Embodiment 21 . The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 2.5-6 wt% sodium, e.g., 2.5-5.5 wt%, or 2.5-5 wt%, or 2.5-4.5 wt%.Embodiment 22. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 3-6 wt% sodium, e.g., 3-5.5 wt%, or 3-5 wt%.Embodiment 23. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 3.5-6 wt% sodium, e.g., 3.5-5.5 wt%.Embodiment 24. The Fischer-Tropsch catalyst material according to any of embodiments 18-23, wherein the Fischer-Tropsch catalyst material includes no more than 0.5 wt% of any other alkali metal, e.g., no more than 0.2 wt%, or no more than 0.1 wt%.Embodiment 25. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 3-9 wt% potassium, e.g., 3-8.5 wt%, or 3-8 wt%, or 3-7.5 wt%, or 3-7 wt%, or 3-6.5 wt%, or 3-6 wt%, or 3-5.5 wt%, or 3-5 wt%.Embodiment 26. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 3.5-9 wt% potassium, e.g., 3.5-8.5 wt%, or 3.5-8 wt%, or 3.5-7.5 wt%, or 3.5-7 wt%, or 3.5-6.5 wt%, or 3.5-6 wt%, or 3.5-5.5 wt%.Embodiment 27. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 4-9 wt% potassium, e.g., 4-8.5 wt%, or 4-8 wt%, or 4-7.5 wt%, or 4-7 wt%, or 4-6.5 wt%, or 4-6 wt%.Embodiment 28. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 4.5-9 wt% potassium, e.g., 4.5-8.5 wt%, or 4.5-8 wt%, or 4.5-7.5 wt%, or 4.5-7 wt%, or 4.5-6.5 wt%.Embodiment 29. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 5-9 wt% potassium, e.g., 5-8.5 wt%, or 5-8 wt%, or 5-7.5 wt%, or 5-7 wt%.Embodiment 30. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 5.5-9 wt% potassium, e.g., 5.5-8.5 wt%, or 5.5-8 wt%, or 5.5-7.5 wt%.Embodiment 31 . The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 5.5-9 wt% potassium, e.g., 5.5-8.5 wt%, or 5.5-8 wt%, or 5.5-7.5 wt%.Embodiment 32. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 6-9 wt% potassium, e.g., 6-8.5 wt%, or 6-8 wt%.Embodiment 33. The Fischer-Tropsch catalyst material according to any of embodiments 1-17, wherein the Fischer-Tropsch catalyst material includes 6.5-9 wt% potassium, e.g., 7-9 wt%.Embodiment 34. The Fischer-Tropsch catalyst material according to any of embodiments 25-33, wherein the Fischer-Tropsch catalyst material includes no more than 0.5 wt% of any other alkali metal, e.g., no more than 0.2 wt%, or no more than 0.1 wt%.Embodiment 35. The Fischer-Tropsch catalyst material according to any of embodiments 1-34, wherein the alkali metal is one or more of sodium, potassium, rubidium, and cesium.Embodiment 36. The Fischer-Tropsch catalyst material according to any of embodiments 1-34, wherein the alkali metal is one or more of sodium and potassium.Embodiment 37. The Fischer-Tropsch catalyst material according to any of embodiments 1-36, wherein the atomic ratio of iron to zinc is in the range of 1 :1.5 to 20:1 , e.g., 1 :1.2 to 20:1 , or 1 :1 to 20:1.Embodiment 38. The Fischer-Tropsch catalyst material according to any of embodiments 1-36, wherein the atomic ratio of iron to zinc is in the range of 1 :2 to 10:1 , e.g., 1 :1.5 to 10:1 , or 1 :1.2 to 10:1 , or 1 :1 to 10:1.Embodiment 39. The Fischer-Tropsch catalyst material according to any of embodiments 1-36, wherein the atomic ratio of iron to zinc is in the range of 1 :2 to 7:1 , e.g., 1 :1.5 to 7:1 , or 1 :1.2 to 7:1 , or 1 :1 to 7:1.Embodiment 40. The Fischer-Tropsch catalyst material according to any of embodiments 1-36, wherein the atomic ratio of iron to zinc is in the range of 1:2 to 5:1, e.g., 1:1.5 to 5:1, or 1:1.2 to 5:1 , or 1:1 to 5:1.Embodiment 41. The Fischer-Tropsch catalyst material according to any of embodiments 1-36, wherein the atomic ratio of iron to zinc is in the range of 1:2 to 3:1, e.g., 1:1.5 to 3:1, or 1:1.2 to 3:1, or 1:1 to 3:1.Embodiment 42. The Fischer-Tropsch catalyst material according to any of embodiments 1-41, wherein the Fischer-Tropsch catalyst material includes at least 20 wt% crystalline ZnFe2<D4, e.g., at least 30 wt%.Embodiment 43. The Fischer-Tropsch catalyst material according to any of embodiments 1-41, wherein the Fischer-Tropsch catalyst material includes at least 40 wt% crystalline ZnFe2<D4, e.g., at least 50 wt%.Embodiment 44. The Fischer-Tropsch catalyst material according to any of embodiments 1-41, wherein the Fischer-Tropsch catalyst material includes at least 60 wt% crystalline ZnFe2C>4, e.g., at least 70 wt%.Embodiment 45. The Fischer-Tropsch catalyst material according to any of embodiments 1-41, wherein the Fischer-Tropsch catalyst material includes at least 80 wt% crystalline ZnFe2C>4, e.g., at least 90 wt%.Embodiment 46. The Fischer-Tropsch catalyst material according to any of embodiments 1-41, wherein the crystalline ZnFe2C has an average crystallite size in the range of 5-25 nm, e.g., in the range of 5-20 nm, or 5-15 nm, or 5-10 nm.Embodiment 47. The Fischer-Tropsch catalyst material according to any of embodiments 1-46, wherein the Fischer-Tropsch catalyst material comprises less than 0.1 wt% copper, on an elemental basis exclusive of carbon.Embodiment 48. The Fischer-Tropsch catalyst material according to any of embodiments 1-46, wherein the Fischer-Tropsch catalyst material comprises no more than 0.05 wt% copper, e.g., no more than 0.01 wt% copper, or no more than 0.005 wt% copper, or no more than 0.001 wt% copper.Embodiment 49. The Fischer-Tropsch catalyst material according to any of embodiments 1-46, wherein the Fischer-Tropsch catalyst material is essentially free of copper.Embodiment 50. The Fischer-Tropsch catalyst material according to any of embodiments 1-46, wherein the Fischer-Tropsch catalyst material comprises at least 0.1 wt% copper, e.g., at least 0.5 wt%, or at least 1 wt%, or at least 5 wt%.Embodiment 51. The Fischer-Tropsch catalyst material according to any of embodiments 1-46, wherein the Fischer-Tropsch catalyst material comprises in the range of 0.1-20 wt% copper on an elemental basis exclusive of carbon, e.g., 0.1-15 wt%, or 0.1-10 wt%, or 0.5-20 wt%, or 0.5-15 wt%, or 0.5-10 wt%.Embodiment 52. The Fischer-Tropsch catalyst material according to any of embodiments 1-46, wherein the Fischer-Tropsch catalyst material comprises in the range of 1-20 wt% copper on an elemental basis exclusive of carbon, e.g., 1-15 wt%, or 1-10 wt%, or 5-20 wt%, or 5-15 wt%, or 5-10 wt%.Embodiment 53. The Fischer-Tropsch catalyst material according to any of embodiments 1-52, in substantially oxidic form.Embodiment 54. The Fischer-Tropsch catalyst material according to any of embodiments 1-53, wherein the Fischer-Tropsch catalyst material is an unsupported catalyst material.Embodiment 55. The Fischer-Tropsch catalyst material according to embodiment 54, wherein at least 90 wt% of the Fischer-Tropsch catalyst material is made up of iron, zinc, alkali metal, and copper, e.g., at least 95 wt%, or at least 98 wt%, or at least 99 wt%, or at least 99.5 wt%, or at least 99.8 wt%, on an elemental basis exclusive of carbon.Embodiment 56. The Fischer-Tropsch catalyst material according to any of embodiments 1-55, wherein the Fischer-Tropsch catalyst material is a supported catalyst material.Embodiment 57. The Fischer-Tropsch catalyst material according to embodiment 56, wherein the Fischer-Tropsch catalyst material further comprises a support that supports the iron, zinc, alkali metal, and, if present, copper.Embodiment 58. The Fischer-Tropsch catalyst material according to embodiment 56 or embodiment 57, wherein at least 90 wt% of the Fischer-Tropsch catalyst material is made up of iron, zinc, alkali metal, copper, and the refractory oxide, e.g., at least 95 wt%, or at least 98 wt%, or at least 99 wt%, or at least 99.5 wt%, or at least 99.8 wt%, on an elemental basis exclusive of carbon.Embodiment 59. The Fischer-Tropsch catalyst material according to embodiment 57 or embodiment 58, wherein the support is formed of a refractory oxide.Embodiment 60. A process for making a Fischer-Tropsch catalyst material according to any of embodiments 1-59, the process comprising: providing one or more first liquids each comprising one or more iron-containing and / or one or more zinc-containing compounds dispersed in one or more first solvents; contacting the one or more first liquids with precipitating ions in the presence of alkali metal ions to provide an alkali-containing precipitate and a supernatant; isolating the alkali-containing precipitate from the supernatant; optionally, washing the isolated precipitate with a washing liquid to reduce concentration of alkali metal thereof; and calcining the isolated precipitate to provide the Fisher-Tropsch catalyst material.Embodiment 61. The process of embodiment 60, wherein the iron-containing compounds and zinc-containing compounds are selected from water-soluble metal salts (e.g., nitrates and acetates).Embodiment 62. The process of embodiment 60 or embodiment 61 , wherein each of the one or more first solvents is an aqueous solvent, e.g., water.Embodiment 63. The process of any of embodiments 60-62, wherein each of the one or more first liquids has a pH of no greater than 7.Embodiment 64. The process of any of embodiments 60-63, wherein the precipitating ions are provided as an alkali metal base, e.g., a carbonate or a hydroxide.Embodiment 65. The process of any of embodiments 60-63, wherein the precipitating ions are provided as a non-metal containing base, e.g., ammonium carbonate or ammonium hydroxide.Embodiment 66. The process of embodiment 65, wherein the alkali metal ions are provided by an alkali metal salt.Embodiment 67. The process of any of embodiments 60-66, wherein the contacting of the one or more first liquids with the precipitating ions is performed at a precipitation pH that is alkaline.Embodiment 68. The process of embodiment 67, wherein the contacting of the one or more first liquids with the precipitating ions is performed at a precipitation pH in the range of8-12, e.g., in the range of 8-11 , or 8-10, or 8.5-12, or 8.5-11 , or 8.5-10, or 9-12, or 9-11 , or 9- 10.Embodiment 69. The process of embodiment 67, wherein the process further comprises maintaining the pH of the contacting step at an alkaline pH, for example, in the range of 8-12, e.g., in the range of 8-11 , or 8-10, or 8.5-12, or 8.5-11 , or 8.5-10, or 9-12, or9-11 , or 9-10.Embodiment 70. The process of any of embodiments 67-69, wherein the pH of the contacting step is maintained by controlling a rate of addition of precipitating ions.Embodiment 71 . The process of any of embodiments 60-70, wherein the process further comprising monitoring the pH of the contacting step.Embodiment 72. The process of any of embodiments 60-71 , wherein the contacting step is conducted at an elevated temperature (e.g., in the range of 60-100 °C, or 60-90 °C, or 60-80 °C, or 70-100 °C, or 70-90 °C, or 70-80 °C.).Embodiment 73. The process of any of embodiments 60-72, wherein the process further comprising aging the alkali-containing precipitate in contact with the supernatant (e.g., before isolation).Embodiment 74. The process of any of embodiments 60-73, wherein washing the isolated precipitate with an washing liquid to reduce concentration of alkali metal thereof is performed.Embodiment 75. The process of embodiment 74, wherein washing the precipitate is repeated until a desired level of alkali metal is provided to the Fischer-Tropsch catalyst material.Embodiment 76. The process of any of embodiments 60-75, wherein the process further comprises drying the isolated precipitate before calcining.Embodiment 77. The process of any of embodiments 60-76, wherein calcining is conducted for a time in the range of 0.5 to 24 hours (e.g., in the range of 0.5 to 15 hours, or 0.5 to 10 hours, or 0.5 to 5 hours).Embodiment 78. The process of embodiment 77, wherein calcining is conducted at a temperature is in the range of 100-600 °C, e.g., in the range of 200-600 °C, or 300-600 °C, or 100-500 °C, or 200-500 °C, or 300-500 °C, for example, in the range of 410-600 °C, e.g., in the range of 450-600 °C, or 500-600 °C, or 410-500 °C, or 425-500 °C, or 450-500 °C.Embodiment 79. A process of making a Fischer-Tropsch catalyst material according to any of embodiments 1-59, the method comprising: providing one or more first liquids each comprising one or more iron-containing and / or one or more zinc-containing compounds dispersed in one or more first solvents; contacting the one or more first liquids with precipitating ions in the substantial absence of alkali metal ions to provide a substantially alkali-free precipitate and supernatant; isolating the substantially alkali-free precipitate from the supernatant; adding alkali metal ions to the substantially alkali-free precipitate in order to provide an alkali-containing precipitate; and calcining the isolated precipitate to provide the Fischer-Tropsch catalyst material.Embodiment 80. The process of embodiment 79, wherein the iron-containing compounds and zinc-containing compounds are selected from water-soluble metal salts (e.g., nitrates and acetates).Embodiment 81. The process of embodiment 79 or embodiment 80, wherein each of the one or more first solvents is an aqueous solvent, e.g., water.Embodiment 82. The process of any of embodiments 79-81 , wherein the precipitating ions comprise carbonate and / or hydroxide ions.Embodiment 83. The process of any of embodiments 79-82, wherein the precipitating ions are provided as a non-metal containing base, e.g., ammonium carbonate or ammonium hydroxide.Embodiment 84. The process of any of embodiments 79-83, wherein the contacting of the one or more first liquids with the precipitating ions is performed at a precipitation pH that is alkaline.Embodiment 85. The process of embodiment 84, wherein the contacting of the one or more first liquids with the precipitating ions is performed at a precipitation pH in the range of8-12, e.g., in the range of 8-11 , or 8-10, or 8.5-12, or 8.5-11 , or 8.5-10, or 9-12, or 9-11 , or 9- 10.Embodiment 86. The process of embodiment 84, wherein the process further comprises maintaining the pH of the contacting step at an alkaline pH, for example, in the range of 8-12, e.g., in the range of 8-11 , or 8-10, or 8.5-12, or 8.5-11, or 8.5-10, or 9-12, or9-11, or 9-10.Embodiment 87. The process of any of embodiments 84-86, wherein the pH of the contacting step is maintained by controlling a rate of addition of precipitating ions.Embodiment 88. The method of any of embodiments 84-87, wherein the method further comprising monitoring the pH of the contacting step.Embodiment 89. The method of any of embodiments 79-88, wherein combining the one or more first liquids with the one or more second liquids is conducted at an elevated temperature (e.g., in the range of 60-100 °C, or 60-90 °C, or 60-80 °C, or 70-100 °C, or 70- 90 °C, or 70-80 °C.).Embodiment 90. The process of any of embodiments 79-89, wherein the process further comprises aging the substantially alkali-free precipitate in contact with the supernatant (e.g., before isolation).Embodiment 91. The process of any of embodiments 79-90, further comprising washing the isolated precipitate with a washing liquid.Embodiment 92. The process of any of embodiments 79-91 , wherein adding alkali metal ions to the substantially alkali-free precipitate in order to provide an alkali containing precipitate is performed before calcining the alkali-containing precipitate.Embodiment 93. The process of any of embodiments 79-92, wherein the process further comprises drying the isolated precipitate before the calcining.Embodiment 94. The process of any of embodiments 79-93, wherein calcining is conducted for a time in the range of 0.5 to 24 hours (e.g., in the range of 0.5 to 15 hours, or 0.5 to 10 hours, or 0.5 to 5 hours).Embodiment 95. The method of any of embodiments 79-94, wherein calcining is conducted at a temperature is in the range of 100-600 °C, e.g., in the range of 200-600 °C, or 300-600 °C, or 100-500 °C, or 200-500 °C, or 300-500 °C.Embodiment 96. A carbided Fischer-Tropsch catalyst material, that is the Fischer- Tropsch catalyst material of any of embodiments 1-59, or a Fischer-Tropsch catalyst material made by a process in any of claims 60-95, in carbided form.Embodiment 97. A carbided Fischer-Tropsch catalyst of Embodiment 96, wherein at least 50 atom% of the iron is in a carbide form.Embodiment 98. A carbided Fischer-Tropsch catalyst material comprising: at least 10 wt% iron, on an elemental basis exclusive of carbon; at least 3 wt% zinc, on an elemental basis exclusive of carbon; and at least 0.2 wt% alkali metal, on an elemental basis exclusive of carbon, wherein the atomic ratio of iron to zinc is in the range of 1:2 to 20:1 and at least 50 atom% of the iron of the carbided Fischer-Tropsch catalyst material is in the form of iron carbide.Embodiment 99. The carbided Fischer-Tropsch catalyst material of embodiment 97 or embodiment 98, wherein in the range of 50-95 atom% of the iron is in a carbide phase, e.g., in the range of 50-90%, or 50-85%, or 50-80%.Embodiment 100. The carbided Fischer-Tropsch catalyst material of embodiment 97 or embodiment 98, wherein at least 55 atom% of the iron is in a carbide phase, e.g., at least 60 atom%.Embodiment 101. The carbided Fischer-Tropsch catalyst material of embodiment 97 or embodiment 98, wherein in the range of 55-95 atom% of the iron is in a carbide phase, e.g., in the range of 55-90%, or 55-85%, or 55-80%.Embodiment 102. The carbided Fischer-Tropsch catalyst material of embodiment 97 or embodiment 98, wherein in the range of 60-95 atom% of the iron is in a carbide phase, e.g., in the range of 60-90%, or 60-85%, or 60-80%.Embodiment 103. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-102, wherein at least 5 atom% of the iron is in an oxide phase, e.g., at least 10 atom%, or at least 15 atom%, or at least 20 atom%.Embodiment 104. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-102, wherein in the range of 5-50 atom% of the iron is in an oxide phase, e.g., 5-45 atom%, or 5-40 atom%.Embodiment 105 The carbided Fischer-Tropsch catalyst material of any of embodiments 97-102, wherein in the range of 10-50 atom% of the iron is in an oxide phase, e.g., 10-45 atom%, or 10-40 atom%.Embodiment 106. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-102, wherein in the range of 15-50 atom% of the iron is in an oxide phase, e.g., 15-45 atom%, or 15-40 atom%.Embodiment 107 The carbided Fischer-Tropsch catalyst material of any of embodiments 97-102, wherein in the range of 20-50 atom% of the iron is in an oxide phase, e.g., 20-45 atom%, or 20-40 atom%.Embodiment 108. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-107, wherein at least 30 atom% of the oxidic iron of the carbided Fischer- Tropsch catalyst material is in the form of Fe3C>4.Embodiment 109. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-107, wherein at least 40 atom% of the oxidic iron of the carbided Fischer- Tropsch catalyst material is in the form of Fe3C>4, e.g., at least 50 atom%.Embodiment 110. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-107, wherein at least 60 atom% of the oxidic iron of the carbided Fischer- Tropsch catalyst material is in the form of Fe3C>4, e.g., at least 70 atom%.Embodiment 111. The carbided Fischer-T ropsch catalyst material of any of embodiments 97-110, wherein the amount of iron is as described in any of embodiments 2- 3.Embodiment 112. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-111 , wherein the amount of zinc is as described in any of embodiments 4- 5.Embodiment 113. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-112, wherein the alkali metal is as described in any of embodiments 6-36.Embodiment 114. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-113, wherein the atomic ratio of iron to zinc is as described in any of embodiments 37-39.Embodiment 115. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-114, wherein the crystalline ZnFe2C is as described in any of embodiments 42-46.Embodiment 116. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-115, wherein the amount of copper is as described in any of embodiments 47-52.Embodiment 117. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-116, wherein the carbided Fischer-Tropsch catalyst material is an unsupported catalyst material.Embodiment 118. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-117, wherein at least 90 wt% of the Fischer-Tropsch catalyst material is made up of iron, zinc, alkali metal, and if present, copper, e.g., at least 95 wt%, or at least 98 wt%, or at least 99 wt%, or at least 99.5 wt%, or at least 99.8 wt%, on an elemental basis exclusive of carbon.Embodiment 119. The carbided Fischer-Tropsch catalyst material of any of embodiments 97-116, wherein the carbided Fischer-Tropsch catalyst material is a supported catalyst material.Embodiment 120. The carbided Fischer-Tropsch catalyst material according to embodiment 119, wherein the Fischer-Tropsch catalyst material further comprises a support that supports the iron, zinc, alkali metal, and if present, copper.Embodiment 121. The carbided Fischer-Tropsch catalyst material of embodiment 119 or embodiment 120, wherein at least 90 wt% of the Fischer-Tropsch catalyst material is made up of iron, zinc, the support, alkali metal, and if present, copper, e.g., at least 95 wt%, or at least 98 wt%, or at least 99 wt%, or at least 99.5 wt%, or at least 99.8 wt%, on an elemental basis exclusive of carbon.Embodiment 122. The carbided Fischer-Tropsch catalyst material according to any of embodiments 119-121 , wherein the support is formed of a refractory oxide.Embodiment 123. The carbided Fischer-Tropsch catalyst material of any of embodiments 96-122, comprising x-FesC2.Embodiment 124. The carbided Fischer-Tropsch catalyst material of embodiment 123, wherein at least 50 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of x-Fe5C2, e.g., at least 60 wt%, or at least 70 wt%.Embodiment 125. The carbided Fischer-Tropsch catalyst material of embodiment 123, wherein at least 75 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of x-Fe5C2, e.g., at least 80 wt%.Embodiment 126. The carbided Fischer-Tropsch catalyst material of embodiment 123, wherein at least 85 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of x-Fe5C2, e.g., at least 90 wt%.Embodiment 127. The carbided Fischer-Tropsch catalyst material of any of embodiments 96-122, comprising £-Fe3C and r|-Fe2C.Embodiment 128. The carbided Fischer-Tropsch catalyst material of embodiment 127, wherein at least 50 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of £-Fe3C and q-Fe2C, e.g., at least 60 wt%, or at least 70 wt%.Embodiment 129. The carbided Fischer-Tropsch catalyst material of embodiment 128, wherein at least 75 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of £-Fe3C and r|-Fe2C , e.g., at least 80 wt%.Embodiment 130. The carbided Fischer-Tropsch catalyst material of embodiment 128, wherein at least 85 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of £-Fe3C and q-Fe2C, e.g., at least 90 wt%.Embodiment 131. A process for providing a carbided Fischer-Tropsch catalyst material of any of Embodiments 97-130, the process comprising carbiding a Fischer-Tropsch catalyst material of any of embodiments 1-59 or a Fischer-Tropsch catalyst material made by a process of any of claims 60-95 to provide the carbided Fischer-Tropsch catalyst material.Embodiment 132. A process for providing a carbided Fischer-Tropsch catalyst material of any of embodiments 97-130, the process comprising: optionally, treating the Fischer-Tropsch catalyst material with a reducing gas stream comprising hydrogen for a time and at a temperature sufficient to provide at least 50 atom% of the iron of the Fischer-Tropsch catalyst material in metallic form; then treating the Fischer-Tropsch catalyst material with a carbiding gas stream comprising carbon monoxide and / or carbon dioxide (e.g., carbon monoxide), at atemperature of at least 180 °C for a time sufficient to provide at least 50 atom% of the iron of the Fischer-Tropsch catalyst material in a carbided form (e.g., for at least 5 hours).Embodiment 133. The process of embodiment 132, wherein the treatment of theFischer-Tropsch catalyst material with the reducing gas stream is not performed.Embodiment 134. The process of embodiment 132, wherein the treatment of the Fischer-Tropsch catalyst with the reducing gas stream is performed.Embodiment 35. The process of embodiment 134, wherein the treating of the Fischer- Tropsch catalyst material with the reducing gas stream comprising hydrogen is performed in the substantial absence of carbon monoxide.Embodiment 136. The process of embodiment 134 or embodiment 135, wherein the reducing gas stream further comprises an inert gas (e.g., nitrogen).Embodiment 137. The process of embodiment 136, wherein the hydrogen and inert gas are present in the reducing gas stream in a ratio of at least 1:1.Embodiment 138. The process of any of embodiments 134-137, wherein treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted at a temperature in the range of 250-650 °C (e.g., in the range of 250-600 °C, or 250-550 °C, or 250-500 °C).Embodiment 139. The process of any of embodiments 134-137, wherein treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted at a temperature in the range of 300-650 °C (e.g., in the range of 300-600 °C, or 300-550 °C, or 300-500 °C).Embodiment 140. The process of any of embodiments 134-137, wherein treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted at a temperature in the range of 350-650 °C (e.g., in the range of 350-600 °C, or 350-550 °C, or 350-500 °C).Embodiment 141. The process of any of embodiments 134-140, wherein treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted for a time of at least 12 hours, e.g., at least 14 hours.Embodiment 142. The process of any of embodiments 134-140, wherein treating the Fischer-Tropsch catalyst material with the reducing gas stream is conducted for a time in the range of 12 to 30 hours (e.g., 12 to 24 hours, or 14 to 30 hours, or 14 to 24 hours).Embodiment 143. The process of any of embodiments 134-142, wherein the treatment with the reducing gas stream is performed to provide a catalyst material in which at least 60 atom% of the iron is in reduced form, e.g., at least 70 atom%.Embodiment 144. The process of any of embodiments 134-142, wherein the treatment with the reducing gas stream is performed to provide a catalyst material in which at least 80 atom% of the iron is in reduced form, e.g., at least 85 atom%.Embodiment 145. The process of any of embodiments 132-144, wherein the carbiding gas stream further comprises hydrogen.Embodiment 146. The process of embodiment 145, wherein the carbiding gas stream comprises hydrogen and carbon monoxide and / or carbon dioxide in a molar ratio of hydrogen to carbon monoxide and carbon dioxide (e.g., hydrogen to carbon monoxide) of at least 1:1 (e.g., at least 2:1, or at least 5:1, or at least 10:1 , or at least 15:1, or at least 20:1, or at least 25:1, or at least 30:1).Embodiment 147. The process of embodiment 145, wherein the carbiding gas stream comprises hydrogen and carbon monoxide and / or carbon dioxide in a molar ratio of hydrogen to carbon monoxide and carbon dioxide (e.g., hydrogen to carbon monoxide) of 1 :1 to 100:1, e.g., in the range of 2:1 to 100:1, or 5:1 to 100:1, or 10:1 to 100:1, or 15:1 to 100:1 , or 20:1 to 100:1 , or 25:1 to 100:1 , or 30:1 to 100:1.Embodiment 148. The process of embodiment 145, wherein the carbiding gas stream comprises hydrogen and carbon monoxide and / or carbon dioxide in a molar ratio of hydrogen to carbon monoxide and carbon dioxide (e.g., hydrogen to carbon monoxide) of 1 :1 to 50:1 , e.g., in the range of 2:1 to 50:1 , or 5:1 to 50:1 , or 10:1 to 50:1, or 15:1 to 50:1, or 20:1 to 50:1, or 25:1 to 50:1 , or 30:1 to 50:1.Embodiment 149. The process of any of embodiments 132-148, wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature of at least 200 °C, e.g., at least 220 °C.Embodiment 150. The process of any of embodiments 132-148, wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature in the range of 180-450 °C (e.g., in the range of 180-400 °C, or 180-350°C, or 180-300 °C).Embodiment 151. The process of any of embodiments 132-148, wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature in the range of 200-450 °C (e.g., in the range of 200-400 °C, or 200-350°C, or 200-300 °C).Embodiment 152. The process of any of embodiments 132-148, wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature in the range of 220-450 °C (e.g., in the range of 220-400 °C, or 220-350 °C, or 220-300 °C).Embodiment 153. The process of any of embodiments 132-148, wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature of at least 300 °C, e.g., at least 310 °C, or at least 325 °C, or at least 350 °C, or at least 375 °C, or at least 400 °C.Embodiment 154. The process of any of embodiments 132-148, wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature in the range of 300-650 °C, e.g., 300-600 °C, or 300-550 °C or 300-500 °C, for example, in the range of 310-650 °C, e.g., 310-600 °C, or 310-550 °C or 310-500 °C.Embodiment 155. The process of any of embodiments 132-148, wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature in the range of 325-650 °C, e.g., 325-600 °C, or 325-550 °C, or 325-500 °CEmbodiment 156. The process of any of embodiments 132-148, wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature in the range of 350-650 °C, e.g., 350-600 °C, or 350-550 °C or 350-500 °C.Embodiment 157. The process of any of embodiments 132-148, wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature in the range of 375-650 °C, e.g., 375-600 °C, or 375-550 °C, or 375-500 °C.Embodiment 158. The process of any of embodiments 132-148, wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature in the range of 400-650 °C, e.g., 400-600 °C, or 400-550 °C, or 400-500 °C.Embodiment 159. The process of any of embodiments 132-158, wherein treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted for a time of at least 3 hours, e.g., at least 5 hours.Embodiment 160. The process of any of embodiments 132-158, wherein treating the Fischer-Tropsch catalyst material with a carbiding gas stream is conducted for a time in the range of 3-20 hours, e.g., 5-20 hours, or 3-15 hours, or 5-15 hours.Embodiment 161. A process for performing a Fischer-Tropsch synthesis, the process comprising: a carbided Fischer Tropsch catalyst material of any of embodiments 97-130, or made by the process of any of embodiments 131-160; contacting at a reaction temperature and at a pressure the Fischer-Tropsch catalyst with a feed stream comprising H2 and CO2 to provide a product stream comprising C5+ hydrocarbons.Embodiment 162. The process of embodiment 161 , wherein the feed stream has a H2:CC>2 ratio in the range of 0.5:1 to 6:1.Embodiment 163. The process of embodiments 161 or embodiment 62, wherein the feed stream has a H2:CC>2 ratio in the range of 1:1 to 3:1, e.g., 1:1 to 2.5:1.Embodiment 164. The process of any of embodiments 161-163, wherein the feed stream has a H2:CC>2 ratio of at least 1.4:1 , e.g., in the range of 1.4:1 to 3:1, or 1.4:1 to 2.5:1.Embodiment 165. The process of any of embodiments 161-163, wherein the feed stream has a H2:CC>2 ratio of at least 2.5:1 , e.g., at least 3:1 , or at least 4:1, or at least 5:1, for example, in the range of 2.5:1 to 10:1, or 3:1 to 10:1, or 4:1 to 10:1 , or 5:1 to 10:1 , or 2.5:1 to 7:1 , or 3:1 to 7:1, or 4:1 to 7:1, or 5:1 to 7:1.Embodiment 166. The process of any of embodiments 161-165, wherein the feed stream includes up to 80% of one or more inerts, e.g., up to 70 mol%, up to 60 mol%, or up to 50 mol%, or 15-70 mol%, or 30-70 mol%, or 15-60 mol%, or 30-60 mol%, or 15-50 mol%, or 30- 50 mol%.Embodiment 167. The process of any of embodiments 161-165, wherein the feed stream includes up to 80% of one or more inerts selected from methane and nitrogen, e.g., up to 70 mol%, up to 60 mol%, or up to 50 mol%, or 15-70 mol%, or 30-70 mol%, or 15-60 mol%, or 30-60 mol%, or 15-50 mol%, or 30-50 mol%.Embodiment 168. The process of any of embodiments 161-167, wherein the feed stream includes up to 80 mol% of H2, e.g., up to 70 mol%, up to 60 mol%, or up to 50 mol%, or 15- 70 mol%, or 30-70 mol%, or 15-60 mol%, or 30-60 mol%, or 15-50 mol%, or 30-50 mol%.Embodiment 169. The process of any of embodiments 161-168, wherein the feed stream further comprises carbon monoxide, e.g., in a molar ratio of no more than 1 :1 CO:CC>2, for example, no more than 0.8:1 , or no more than 0.5:1.Embodiment 170. The process of any of embodiments 161-169, wherein the feed stream has a water content of no more than 10 mol%, e.g., or no more than 2 mol%, or no more than 0.5 mol%.Embodiment 171. The process of any of embodiments 161-170, wherein the reaction temperature is in the range of 150-400 °C (e.g., in the range of 150-350 °C, or 150-300 °C, or 150-250°C, or 150-200°C, or 200-400 °C, or 200-350 °C, or 200-300 °C, or 200-250 °C, or 250-400 °C, or 250-350 °C, or 250-300 °C, or 300-400 °C).Embodiment 172. The process of any of embodiments 161-170, wherein the reaction temperature is in the range of 200-350 °C.Embodiment 173. The process of any of embodiments 161-172, wherein the pressure is in the range of 10-50 barg (e.g., 20-50 barg, or 25-50 barg, or 10-40 barg, or 20-40 barg, or 25-40 barg or 10-35 barg, or 20-35 barg, or 25-35 barg).Embodiment 174. The process of any of embodiments 161-172, wherein the pressure is in the range of 30-70 barg (e.g., 30-60 barg, or 30-55 barg, or 30-50 barg, or 35-70 barg, or35-60 barg or 35-55 barg, or 35-50 barg, or 40-70 barg, or 40-60 barg, or 40-55 barg or 40- 50 barg).Embodiment 175. The process of any of embodiments 161-172, wherein the pressure is in the range of 20-50 barg.Embodiment 176. The process of any of embodiments 161-175, wherein the Fischer- Tropsch reaction is conducted at a GHSV in the range of 1 ,000 to 2,000,000 IT1(e.g., in the range of 1 ,000 to 1 ,200,000 IT1, or 1 ,000 to 500,000 IT1, or 1 ,000 to 100,000 IT1, or 5,000 to 1 ,200,000 IT1, or 5,000 to 500,000 IT1, or 5,000 to 100,000 IT1, or 10,000 to 1 ,200,000 IT1, or 10,000 to 500,000 IT1, or 10,000 to 100,000 IT1).Embodiment 177. The process of any of embodiments 161-176, wherein the contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a C5+ selectivity of at least 30%, e.g., at least 50%, or at least 70%.Embodiment 178. The process of any of embodiments 161-176, wherein the contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a C5+ selectivity of at least 40%, e.g., at least 60%, or at least 80%.Embodiment 179. The process of any of embodiments 161-176, wherein the contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a C2-4 selectivity of no more than 30%, e.g., no more than 25%, or no more than 20%.Embodiment 180. The process of any of embodiments 161-179, wherein the contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a methane selectivity of no more than 20%, e.g., no more than 15%, or no more than 10%, or no more than 5%.Embodiment 181. The process of any of embodiments 161-180, wherein the contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream is performed with a C2-8 oxygenate selectivity of no more than 30%, e.g., no more than 25%, or no more than 20%.Embodiment 182. The process of any of embodiments 161-180, wherein the contacting of the Fischer-Tropsch catalyst with the feed stream to provide the product stream isperformed with a C2-8 oxygenate selectivity of no more than 15%, e.g., no more than 10%, or no more than 5%.Embodiment 183. The process of any of embodiments 161-182, further comprising separating at least a portion of C1-C4 hydrocarbons from the product stream to provide a light hydrocarbon stream.Embodiment 184. The process of any of embodiments 161-183, further comprising burning at least a portion of the light hydrocarbon stream to provide energy, e.g., heat energy or electrical energy.Embodiment 185. The process of embodiment 184, wherein the heat energy is used to heat the feed stream.Embodiment 186. The process of embodiment 184, further comprising generating steam from the heat provided to the steam generation zone, and generating electricity from the steam.Embodiment 187. The process of embodiment 185 or embodiment 186, wherein steam is used to heat the feed stream.Embodiment 188. The process of any of embodiments 161-187, wherein the process further comprises exchanging heat between at least a portion of the product stream and at least a portion of the second stream, thereby cooling at least a portion of the product stream and heating at least a portion of the feed stream.Embodiment 189. The process of any of embodiments 161-188, further comprising recycling at least a portion of H2 of the product stream to the feed stream.Embodiment 190. The process of any of embodiments 161-189, further comprising recycling at least a portion of CO2 of the product stream to the feed stream.Embodiment 191. The process of any of embodiments 161-190, further comprising recycling at least a portion of inerts of the product stream to the feed stream.Embodiment 192. The process of any of embodiments 161-191 , wherein one or more products are provided from at least a portion of C5+ hydrocarbons of the product stream.Embodiment 193. The process of embodiment 192, wherein the one or more products include fuels (e.g., gasoline, diesel fuel, aviation fuel), lubricants and waxes.Embodiment 194. The process of any of embodiments 161-193, further comprising hydroprocessing at least a portion of C5+ hydrocarbons of the product stream.Embodiment 195. The process of any of embodiments 161-194, wherein at least part of the H2 of the feed stream is from a renewable source.Embodiment 196. The process of any of embodiment 161-195, wherein at least a portion of the hydrogen of the feed stream is green hydrogen.Embodiment 197. The process of any of embodiment 161-196, wherein at least a portion of the hydrogen of the feed stream is blue hydrogen.Embodiment 198. The process of any of embodiment 161-197, wherein at least a portion of the hydrogen of the first feed stream or the second feed stream is grey hydrogen, black hydrogen, brown hydrogen, pink hydrogen, turquoise hydrogen, yellow hydrogen, and / or white hydrogen.Embodiment 199. The process of any of embodiments 161-198, further comprising providing at least a portion of H2 to the first feed stream and / or the second feed stream by electrolysis of water.Embodiment 200. The process of embodiment 199, wherein the electrolysis of water is performed using at least partially electricity from a renewable source.Embodiment 201. The process of embodiment 199 or embodiment 200, wherein the electrolysis of water is performed using at least partially electricity generated from steam made by heat exchange from the first product stream and / or the second product stream, or by burning a light hydrocarbon stream (e.g., methane from biogas).Embodiment 202. The process of any of embodiments 161-201 , wherein at least a part of the CO2 of the feed stream is from a renewable resource.Embodiment 203. The process of any of embodiments 161-202, wherein at least part of the CO2 of the feed stream is from biogas.Embodiment 204. The process of any of embodiments 161-203, wherein at least part of the CO2 of the feed stream is from direct air capture.Embodiment 205. The process of any of embodiments 161-204, wherein at least part of the CO2 of the feed stream is from a CO2 emission source (e.g., from a manufacturing plant, e.g., a bioethanol plant, a steel plant, or a cement plant).

[0184] The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of various embodiments of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention, the description taken with the drawings and / or examples making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. Thus, before the disclosed processes and devices are described, it is to be understood that the aspects described herein are not limited to specific embodiments, apparatuses, or configurations, and as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and, unless specifically defined herein, is not intended to be limiting.

[0185] The terms “a,” “an,” “the” and similar referents used in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0186] All processes described herein can be performed in any suitable order of steps unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of theinvention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0187] Unless the context clearly requires otherwise, throughout the description and the claims, the words ‘comprise’, ‘comprising’, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”. Words using the singular or plural number also include the plural and singular number, respectively. Additionally, the words “herein,” “above,” and “below” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of the application.

[0188] As will be understood by one of ordinary skill in the art, each embodiment disclosed herein can comprise, consist essentially of or consist of its particular stated element, step, ingredient or component. As used herein, the transition term “comprise” or “comprises” means includes, but is not limited to, and allows for the inclusion of unspecified elements, steps, ingredients, or components, even in major amounts. The transitional phrase “consisting of’ excludes any element, step, ingredient or component not specified. The transition phrase “consisting essentially of” limits the scope of the embodiment to the specified elements, steps, ingredients or components and to those that do not materially affect the embodiment.

[0189] Unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0190] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0191] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and / or patentability. When any such inclusion or deletion occurs, the specification is deemed to contain the group asmodified thus fulfilling the written description of all Markush groups used in the appended claims.

[0192] Some embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

[0193] Furthermore, it is to be understood that the embodiments of the invention disclosed herein are illustrative of the principles of the present invention. Other modifications that may be employed are within the scope of the invention. Thus, by way of example, but not of limitation, alternative configurations of the present invention may be utilized in accordance with the teachings herein. Accordingly, the present invention is not limited to that precisely as shown and described.

Claims

We claim:Claim 1. A Fischer-Tropsch catalyst material comprising: at least 10 wt% iron, on an elemental basis exclusive of carbon; at least 3 wt% zinc, on an elemental basis exclusive of carbon; and in the range of 0.1-0.35 mol alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, wherein the atomic ratio of iron to zinc is in the range of 1:2 to 20:1, and the Fischer-Tropsch catalyst material includes at least 10 wt% crystalline ZnFe2<D4.Claim 2. The Fischer-Tropsch catalyst material according to Claim 1 , wherein the Fischer-Tropsch catalyst material comprises in the range of 0.1-0.25 mol alkali metal per 100 g catalyst material, on an elemental basis exclusive of carbon.Claim 3. The Fischer-Tropsch catalyst material according to Claim 1 , wherein the alkali metal is sodium and the Fischer-Tropsch catalyst material includes in the range of 1-6 wt% sodium, on an elemental basis exclusive of carbon.Claim 4. The Fischer-Tropsch catalyst material according to Claim 1 , wherein the alkali metal is potassium and the Fischer-Tropsch catalyst material includes in the range of 3-9 wt% potassium on an elemental basis exclusive of carbon.Claim 5. The Fischer-Tropsch catalyst material according to any of Claims 1-4, wherein the Fischer-Tropsch catalyst material includes at least 50 wt% crystalline ZnFe2C .Claim 6. The Fischer-Tropsch catalyst material according to any of Claims 1-5, wherein the Fischer-Tropsch catalyst material comprises less than 0.1 wt% copper, on an elemental basis exclusive of carbon.Claim 7. A process for making a Fischer-Tropsch catalyst material according to any of Claims 1-6, the process comprising: providing one or more first liquids each comprising one or more iron-containing and / or one or more zinc-containing compounds dispersed in one or more first solvents; contacting the one or more first liquids with precipitating ions in the presence of alkali metal ions to provide an alkali-containing precipitate and a supernatant;isolating the alkali-containing precipitate from the supernatant; optionally, washing the isolated precipitate with a washing liquid to reduce concentration of alkali metal thereof; and calcining the isolated precipitate to provide the Fisher-Tropsch catalyst material.Claim 8. A process of making a Fischer-Tropsch catalyst material according to any of Claims 1-6, the method comprising: providing one or more first liquids each comprising one or more iron-containing and / or one or more zinc-containing compounds dispersed in one or more first solvents; contacting the one or more first liquids with precipitating ions in the substantial absence of alkali metal ions to provide a substantially alkali-free precipitate and supernatant; isolating the substantially alkali-free precipitate from the supernatant; adding alkali metal ions to the substantially alkali-free precipitate in order to provide an alkali-containing precipitate; and calcining the isolated precipitate to provide the Fischer-Tropsch catalyst material.Claim 9. A carbided Fischer-Tropsch catalyst material, that is the Fischer-Tropsch catalyst material of any of Claims 1-6, the carbided Fischer-Tropsch catalyst material comprising: at least 10 wt% iron, on an elemental basis exclusive of carbon; at least 3 wt% zinc, on an elemental basis exclusive of carbon; and in the range of 0.1-0.35 mol alkali metal per 100 g of catalyst material, on an elemental basis exclusive of carbon, wherein the atomic ratio of iron to zinc is in the range of 1 :2 to 20:1 and at least 50 atom% of the iron of the carbided Fischer-Tropsch catalyst material is in the form of iron carbide.Claim 10. The Fischer-Tropsch catalyst material of Claim 9, wherein in the range of 10-50 atom% of the iron is in an oxide phase and / or wherein at least 30 atom% of the oxidic iron of the carbided Fischer-Tropsch catalyst material is in the form of FesC .Claim 11. The carbided Fischer-Tropsch catalyst material of Claim 9 or Claim 10, wherein at least 70 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of x-FesC2.Claim 12. The carbided Fischer-Tropsch catalyst material of Claim 9 or Claim 10, comprising e-Fe3C and r|-Fe2C, preferably wherein at least 70 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of e-Fe3C and r|-Fe2C.Claim 13. A process for providing a carbided Fischer-Tropsch catalyst material of any of Claims 9-12, the process comprising: optionally, treating the Fischer-Tropsch catalyst material with a reducing gas stream comprising hydrogen for a time and at a temperature sufficient to provide at least 50 atom% of the iron of the Fischer-Tropsch catalyst material in metallic form; then treating the Fischer-Tropsch catalyst material with a carbiding gas stream comprising carbon monoxide and / or carbon dioxide, at a temperature of at least 180 °C for a time sufficient to provide at least 50 atom% of the iron of the Fischer-Tropsch catalyst material in a carbided form.Claim 14. The process of claim 13, wherein the carbiding gas stream has a molar ratio of hydrogen to carbon monoxide in the range of 2:1 to 50:1 , and wherein treating the Fischer-Tropsch catalyst material with the carbiding gas stream is conducted at a temperature in the range of 300-650 °C, and wherein at least 70 atom% of the carbided iron of the carbided Fischer-Tropsch catalyst material is in the form of x-FesC2.Claim 15. A process for performing a Fischer-Tropsch synthesis, the process comprising: providing a carbided Fischer Tropsch catalyst material of any of Claims 9-12, or made by the process of Claim 13 or Claim 14; and contacting at a reaction temperature and at a pressure the Fischer-Tropsch catalyst with a feed stream comprising H2 and CO2 to provide a product stream comprising C5+ hydrocarbons.

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