Catalyst for alcohol synthesis and method for producing alcohol using the same

Abstract

To provide a catalyst that enables conversion of carbon dioxide to alcohol.SOLUTION: In one aspect, the present invention provides a catalyst for alcohol synthesis comprising a) Fe; b) at least one selected from Zn and Cu; and c) at least two elements selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba, including K and at least one other element, or Cs and at least one other element. In another aspect, the present invention provides a catalyst for alcohol synthesis comprising a) Fe; b) at least one selected from Zn and Cu; c) at least one selected from K and Cs; and d) at least one selected from the group consisting of Ga, Y, Nb, Cd, Nd, Tb, Er, Yb, Ta, W, and Re.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a catalyst for alcohol synthesis and a method for producing alcohol using the same. [Background technology]

[0002] One of the countermeasures against global warming is the reduction of carbon dioxide emissions. Among the various emission reduction measures, there is considerable interest in the effective utilization of carbon dioxide by capturing and recycling it from the atmosphere. One such measure is the industrial conversion of carbon dioxide to alcohol, using carbon dioxide as a carbon source. Because the conversion of carbon dioxide to alcohol requires a high activation energy, efforts are being made to develop catalysts with higher conversion efficiency.

[0003] For example, Patent Document 1 discloses a method for hydrogenating carbon dioxide using a catalyst containing iron, copper, zinc, and potassium, and also discloses a catalyst containing, in addition to these metals, an element of Group VIII of the periodic table selected from cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum.

[0004] Patent Document 2 discloses a catalyst for alcohol synthesis that is characterized by containing Cu, Zn, Fe, and an alkaline earth metal.

[0005] Patent Document 3 discloses a CZA catalyst containing copper, zinc, one or more first elements selected from iron, nickel, or cobalt, aluminum, and oxygen. The catalyst optionally contains one or more second elements selected from Group V, VI, VII, VIII, IX, X, and XI metals (e.g., manganese, silver, niobium, zirconium, molybdenum, ruthenium, or palladium). The catalyst also optionally contains one or more Group IA metals. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 09-087217 [Patent Document 2] Japanese Patent Application Publication No. 2020-011228 [Patent Document 3] Special Publication No. 2023-531717 [Non-patent literature]

[0007] [Non-Patent Document 1] Gang Wang et al., “Accelerated discovery of multi-elemental reverse water-gas shift catalysts using extrapolative machine learning approach,” [online], Nature Communications, 14, No. 5861, 2023, [Retrieved January 29, 2024], Internet<URL:https: / / doi.org / 10.1038 / s41467-023-41341-3> Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention aims to provide a catalyst for converting carbon dioxide into alcohol, which is an alternative to the catalysts disclosed in the prior art. [Means for solving the problem]

[0009] The present inventors a) Fe and b) at least one of Zn and Cu; c) It has been found that a catalyst for alcohol synthesis comprising a catalytically active component containing at least two elements selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba, and including K and at least one other element, or Cs and at least one other element, can convert carbon dioxide into alcohol. a) Fe and b) at least one of Zn and Cu; c) at least one of K and Cs; d) The present inventors have found that a catalyst for alcohol synthesis comprising a catalytically active component containing at least one element selected from the group consisting of Ga, Y, Nb, Cd, Nd, Tb, Er, Yb, Ta, W, and Re can also convert carbon dioxide into alcohol, leading to the completion of the present invention. [Effects of the Invention]

[0010] The present invention provides a catalyst for converting carbon dioxide to alcohols that is an alternative to catalysts disclosed in the prior art. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of a catalytic reactor. [Figure 2] Figure 2 shows the relationship between the content (weight percent) of each transition metal element (Fe, Cu, Zn, Ga, Y, Nb, and Cd) in the supported catalyst and the ethanol reaction rate (mmol / g / h) derived from the machine learning model. [Figure 3] Figure 3 shows the relationship between the content (weight percent) of each transition metal element (Nd, Tb, Er, Yb, Ta, W, and Re) in the supported catalyst and the ethanol reaction rate (mmol / g / h) derived from the machine learning model. [Figure 4] Figure 4 shows the relationship between the content (weight percent) of each alkali metal element (Li, Na, K, Rb, and Cs) in the supported catalyst and the ethanol reaction rate (mmol / g / h) derived from the machine learning model. [Figure 5] FIG. 5 shows the relationship between the content (weight percent) of each alkaline earth metal element (Mg, Ca, Sr, and Ba) in the supported catalyst and the ethanol reaction rate (mmol / g / h) derived from the machine learning model. [Figure 6]FIG. 6 shows the relationship between the weight ratio of each transition element to Fe in the supported catalyst, derived by the machine learning model, and the ethanol reaction rate (mmol / g / h). [Figure 7] FIG. 7 shows the relationship between the weight ratio of each transition element to Fe in the supported catalyst derived by the machine learning model and the ethanol reaction rate (mmol / g / h). [Figure 8] FIG. 8 is a graph showing the relationship between the weight ratio of alkali metal elements to Fe in the supported catalyst derived by the machine learning model and the ethanol reaction rate (mmol / g / h). [Figure 9] FIG. 9 is a graph showing the relationship between the weight ratio of alkaline earth metal elements to Fe in the supported catalyst derived by the machine learning model and the ethanol reaction rate (mmol / g / h).

[0012] Hereinafter, an embodiment of the present invention will be described. The present invention is not particularly limited to this embodiment, and can be carried out by making appropriate modifications to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Alcohol synthesis catalyst> The catalyst for alcohol synthesis according to this embodiment is a) Fe and b) at least one of Zn and Cu; c) A catalytically active component containing at least two elements selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba, and containing K and at least one other element, or Cs and at least one other element. It is a catalyst for alcohol synthesis.

[0014] The synthesis of alcohol, for example, ethanol, in this embodiment is represented by the following formula: 2CO2+6H2→ C2H5OH+3H2O

[0015] FIG. 1 is a schematic diagram of a system for using a reactor using the catalyst (Cat.) of this embodiment. The upper end of the reactor in the diagram is connected to gas supply sources of hydrogen (H2) and carbon dioxide (CO2) via T-shaped piping, mass flow controllers (MFCs), and gate valves. The reactor consists of a reaction vessel equipped with a catalyst. The lower end of the reactor in the diagram is connected to a gas chromatograph (GC) via a gate valve. In other embodiments, only a fractionator may be provided without a gas chromatograph (GC). The catalyst is placed as a solid catalyst inside the flow path connecting the upper and lower ends of the reaction vessel.

[0016] As shown in Figure 1, each gas is supplied to the reactor at a predetermined partial pressure ratio through an MFC and mixed in a T-pipe. The reactants, carbon dioxide and hydrogen, are sent in a mixed state into the reactor. The products, alcohol and water, are synthesized in the gas phase when the carbon dioxide and hydrogen in the gas phase come into contact with the surface of the catalyst. The products produced in the reactor are collected in the gas phase. In other embodiments not shown, the products may be collected in liquid form. The products are sent to a fractionation device. The products are separated from unreacted reactants by the fractionation device. The alcohol may be separated from water by the fractionation device.

[0017] The types and compositions of elements contained in the alcohol synthesis catalyst according to one aspect of the present embodiment are derived by a machine learning (ML) model and their derivatives. The machine learning model of the present embodiment uses, as predictive descriptors, elemental feature quantities, such as atomic radius, electronegativity, density, melting point, and ionization energy, multiplied by a predetermined elemental composition ratio. In this way, the machine learning model of the present embodiment designs a catalyst taking into account the electronic state. Compared to machine learning models that predict from elemental composition ratios alone, the machine learning model can predict the composition of a catalyst that is even more useful as a catalyst.

[0018] 2 and 3 are diagrams showing the relationship between the content (weight percent) of each metal element (Fe, Cu, Zn, Ga, Y, Nb, Cd, Nd, Tb, Er, Yb, Ta, W, and Re) in the supported catalyst, derived by the machine learning model, and the ethanol reaction rate (mmol / g / h). As shown in these figures, the ethanol synthesis rate when each metal element was incorporated into the alcohol synthesis catalyst of this embodiment was calculated using the machine learning model.

[0019] 4 and 5 are diagrams showing the relationship between the content (weight percent) of each alkali metal or alkaline earth metal element (Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba) in the supported catalyst and the ethanol reaction rate (mmol / g / h) derived by the machine learning model. As shown in these figures, the ethanol synthesis rate when each alkali metal or alkaline earth metal was incorporated into the alcohol synthesis catalyst of this embodiment was calculated by the machine learning model.

[0020] As shown in Figures 6 to 9, the relationship between the weight ratio of each element to Fe and the ethanol synthesis rate was calculated.

[0021] Next, the form of each element in the catalyst will be described. The catalyst for alcohol synthesis of this embodiment contains Fe. The form of Fe is not particularly limited. It may be in the form of any of reduced metal, oxide, sulfide, hydroxide, salt (e.g., carbonate, nitrate, acetate, sulfate, and salts formed with other acids), halide, complex, and other compounds containing Fe. From the viewpoint of catalyst activation, it is preferable that reduced metallic Fe is contained in the catalyst during the alcohol synthesis reaction. Fe may be divalent or trivalent. The content of Fe in the supported catalyst is 0% by weight or more and less than 50% by weight.

[0022] The alcohol synthesis catalyst of this embodiment contains at least one of Zn and Cu. The form of Zn and Cu is not particularly limited. They may be in any form, such as reduced metal, oxide, sulfide, hydroxide, salt (e.g., carbonate, nitrate, acetate, sulfate, and salts of Zn, Cu, and other acids), halide, complex, or other compound containing Zn or Cu. From the viewpoint of activating the catalyst, it is preferable that reduced metallic Zn and Cu are contained during the alcohol synthesis reaction. Cu may be monovalent or divalent. The weight ratio of at least one of Zn and Cu to Fe is 0 to 8. The content of at least one of Zn and Cu in the supported catalyst is 0% by weight or more and less than 50% by weight.

[0023] The alcohol synthesis catalyst of this embodiment contains alkali metal and alkaline earth metal elements. These elements are at least two elements selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba. In one embodiment, either K or Cs is essential to the catalyst. The form of each element is not particularly limited. These elements may be in any form, such as reduced metal, oxide, sulfide, hydroxide, salt (e.g., carbonate, nitrate, acetate, sulfate, or salts of these elements with other acids), halide, complex, or other compound containing these elements. From the viewpoint of catalyst activation, it is preferable that the reduced metal state is contained during the alcohol synthesis reaction. When these elements have multiple oxidation states, each element may take any oxidation state. The weight ratio of each of the above elements to Fe is 0 to 3. The content of each of the above elements in the supported catalyst is 0 wt% or more and less than 30 wt%.

[0024] The alcohol synthesis catalyst of this embodiment may contain an element from Groups III to XIII of the periodic table. The element is at least one element selected from the group consisting of Ga, Y, Nb, Cd, Nd, Tb, Er, Yb, Ta, W, and Re. In one embodiment, the element is essentially contained in the catalyst. The form of each element is not particularly limited. These elements may be in any form, such as reduced metal, oxide, sulfide, hydroxide, salt (e.g., carbonate, nitrate, acetate, sulfate, or salts of these elements with other acids), halide, complex, or other compound containing these elements. From the viewpoint of catalyst activation, it is preferable that the reduced metal state is contained during the alcohol synthesis reaction. When these elements have multiple oxidation states, each element may take any oxidation state. The weight ratio of each of the above elements to Fe is 0 to 3. The content of each of the above elements in the supported catalyst is 0% by weight or more and less than 30% by weight.

[0025] Next, the reduction treatment will be described. The conversion to a reduced metal state is not particularly limited. For example, this can be achieved by subjecting a catalyst containing an oxidized metal to a reduction treatment before carrying out an alcohol synthesis reaction. Specifically, a method can be used in which the alcohol synthesis catalyst of this embodiment, which may contain metal oxides, metal salts, other metal element-containing compounds, and other catalytically active component-containing compounds, is subjected to a heat treatment under a pure hydrogen gas atmosphere or a mixed gas atmosphere of hydrogen and an inert gas. The heating temperature and reduction pressure for the reduction treatment are not particularly limited and can be appropriately adjusted based on known techniques. The heating time is not particularly limited, but is preferably 0.5 to 3 hours, and more preferably 1 to 2 hours. From the viewpoint of preventing reoxidation of the catalyst, such a reduction treatment of the catalyst is preferably carried out immediately before use in the alcohol synthesis reaction.

[0026] Next, the content of each element in the catalyst for alcohol synthesis of this embodiment will be described. The catalyst for alcohol synthesis of this embodiment is a supported catalyst further including a support (supported catalysts will be described later), and each catalytically active component is preferably contained in a predetermined content. Here, the catalytically active component refers to a component that can function as a catalyst, and in this embodiment, the above-mentioned metal elements are contained in the catalytically active component.

[0027] The content of any catalytically active component in the supported catalyst is expressed by the following formula based on the total weight of the catalytically active components. (Formula) [Content of any catalytically active component (wt%)] = [Weight of any catalytically active component] / ([Total weight of catalytically active components] + [Weight of support]) For example, the content of Fe that contributes to catalytic activity in a supported catalyst is expressed by the following formula based on the total weight of catalytically active components. (Formula) [Fe content (wt%)] = [Fe weight] / ([total weight of catalytically active components] + [weight of support])

[0028] A preferred content (wt %) of each catalytically active component is shown in Table 1. In addition, a preferred range of the weight ratio to Fe of each catalytically active component in the alcohol synthesis catalyst or supported catalyst of this embodiment is also shown in Table 1. Note that the numerical values ​​in the table mean "not less than" for the lower limit and "not more than" for the upper limit.

[0029] [Table 1]

[0030] The alcohol synthesis catalyst of this embodiment may further contain at least one element selected from the group consisting of Ru, Rh, Pd, Ir, Pt, and Au. Ru, Rh, Pd, Ir, Pt, and Au are known as PGM (Platinum Group Metals). The inclusion of these elements can improve the conversion efficiency to alcohol in the alcohol synthesis reaction. The form of the at least one element selected from the group consisting of Ru, Rh, Pd, Ir, Pt, and Au is not particularly limited, and may be in any of the following forms: reduced metal, oxide, sulfide, hydroxide, salt (e.g., carbonate, nitrate, acetate, sulfate, and salts of these elements with other acids), halide, complex, and other compounds containing these elements. It is preferable that the reduced metal state is present during the alcohol synthesis reaction. When these elements have multiple oxidation states, each element may take any oxidation state. The content of each of the above elements in the supported catalyst is 0% by weight or more and less than 2% by weight.

[0031] When the alcohol synthesis catalyst of this embodiment further contains at least one element selected from the group consisting of Ru, Rh, Pd, Ir, Pt, and Au, preferred contents (wt%) of each catalytically active component are shown in Table 2. Table 2 also shows preferred ranges for the weight ratio to Fe of each catalytically active component in the alcohol synthesis catalyst or supported catalyst of this embodiment. From an economical standpoint, it is preferable to limit the total PGM content to 2 wt% of the supported catalyst. The lower limit of the values ​​in the table means "at least" and the upper limit means "not more than."

[0032] [Table 2]

[0033] Further, as another embodiment of the catalyst for alcohol synthesis according to this embodiment, a) Fe and b) at least one of Zn and Cu; c) at least one of K and Cs; d) a catalytically active component containing at least one selected from the group consisting of Ga, Y, Nb, Cd, Nd, Tb, Er, Yb, Ta, W, and Re; It is a catalyst for alcohol synthesis. The form and content of each element contained in the catalyst for alcohol synthesis are as described above. The catalyst may further contain at least one element selected from the group consisting of Ru, Rh, Pd, Ir, Pt, and Au among PGMs, and the form and content of each of these elements in the catalyst are also as described above.

[0034] Next, the shape of the catalyst will be described. The shape of the catalyst for alcohol synthesis of this embodiment is not particularly limited. It may be any of spherical granules, irregular granules, cylindrical pellets, extruded shapes, and ring shapes. These sizes can be appropriately shaped taking into consideration plant constraints such as the type and size of the reactor, operating conditions, and economic efficiency. In the catalyst for alcohol synthesis of this embodiment, a uniform shape is preferred from the viewpoint of contact with the raw material.

[0035] <Supported catalyst> Next, supported catalysts will be described. A supported catalyst refers to a catalyst supported on a carrier. Supported refers to a state in which the catalyst is attached to a carrier. The catalyst for alcohol synthesis of this embodiment may be a supported catalyst further including a carrier from the viewpoint of improving reaction efficiency. A carrier is a substance that holds catalytically active components in a highly dispersed state on its surface. The carrier itself may be inactive, or may be active in part of the overall reaction. Examples of carriers include ZrO2, CeO2, Al2O3, TiO2, and Co3O4, and mixtures of these may also be used. The type of carrier used for the catalyst for alcohol synthesis of this embodiment is not particularly limited. For example, ZrO 2、 Chief Operating Officer 2、 Alternatively, a composite oxide of these is preferred. For example, ZrO 2、 A support containing CeO2, in which the CeO2 content is 25 to 50% in the support, can be used.

[0036] There are no particular limitations on the weight ratio of the carrier to the catalyst for alcohol synthesis of this embodiment, but the weight ratio of the carrier to the catalyst for alcohol synthesis of this embodiment is preferably 0.4 to 0.9, and more preferably 0.5 to 0.75.

[0037] The catalyst for alcohol synthesis of this embodiment may further contain a substance that does not adversely affect the reaction and that is used to uniformly disperse or support the essential components, such as alumina, silica, magnesia, titania, diatomaceous earth, and carbon.

[0038] <Method of manufacturing an alcohol synthesis catalyst> The method for preparing the catalyst for alcohol synthesis of this embodiment is not particularly limited, and may be an impregnation method, a precipitation method, a kneading method, a sol-gel method, an ion exchange method, a hydrothermal synthesis method, or any other chemical method.

[0039] In the impregnation method, a catalyst raw material solution is impregnated into the pores of a degassed support, and the active components are fixed to the pore walls. The catalyst is then evaporated to dryness and calcined to support the active components on the support, thereby obtaining the catalyst for alcohol synthesis of this embodiment. When producing the catalyst for alcohol synthesis of this embodiment that further contains PGM, the catalyst supported on components other than PGM obtained by the impregnation method can be immersed in a solution containing a PGM salt, and the catalyst can be impregnated with the previous catalyst. For example, a precipitate containing various catalytically active components obtained by the precipitation method (including coprecipitation) described below can be immersed in a solution containing a PGM salt (e.g., nitrate, acetate, chloride, sulfate), and the PGM salt can be impregnated into the previous catalyst. The catalyst can then be evaporated to dryness and calcined to support the active components on the support, thereby obtaining the catalyst for alcohol synthesis of this embodiment that further contains PGM.

[0040] In the precipitation method, a precipitant (e.g., a basic aqueous solution of nitrate, acetate, chloride, sulfate, etc.) is added to a solution containing catalytically active components constituting the alcohol synthesis catalyst of this embodiment, such as Fe, Cu, or Zn, to form a precipitate. The precipitate is then calcined in an oxidizing gas atmosphere (e.g., in air), thereby obtaining the alcohol synthesis catalyst of this embodiment. Since the catalyst of this embodiment contains two or more catalytically active components, a coprecipitation method can be used in which these active components are precipitated simultaneously. Alternatively, a kneading method can be used in which precipitates containing each catalytically active component are obtained separately and then mechanically kneaded together.

[0041] In the ion exchange method, various zeolites, silica, silica alumina, ion exchange resins, oxidation-treated activated carbon, and the like can be used as a support having cation exchange capacity. The catalyst for alcohol synthesis of the present embodiment can be prepared by ion-exchanging the cations (metal ions, metal complex ions, and the like) of the catalyst component for alcohol synthesis of the present embodiment with the cations of the support.

[0042] If necessary, the method for preparing the catalyst for alcohol synthesis of this embodiment may further include filtering, washing with water, drying, and molding steps.

[0043] <Alcohol synthesis reaction hydrogenation method>

[0044] The apparatus used in the reaction of this embodiment is not particularly limited. For example, as shown in Figure 1, an apparatus including a gas supply source, a reaction vessel equipped with a catalyst, and a gas chromatography (GC) analyzer can be used.

[0045] The raw materials used in the reaction of this embodiment are carbon dioxide and hydrogen, or a mixed gas containing these and an inert gas. There are no particular limitations on the mixing ratio. From the viewpoints of reaction yield and ethanol synthesis selectivity, the CO2 / H2 molar ratio is preferably in the range of 0.1 to 10. The reaction temperature is preferably 100 to 600°C, more preferably 200 to 400°C. The reaction pressure is preferably 0.1 to 10 MPa, more preferably 0.5 to 5 MPa. The gas hourly space velocity (WHSV) is preferably 3000 mL / g·h to 24000 mL / g·h, more preferably 6000 mL / g·h to 18000 mL / g·h. The flow rate is preferably 10 mL / min to 80 mL / min, more preferably 20 mL / min to 60 mL / min.

[0046] The main reaction products are alcohols (methanol, ethanol, propanol, butanol, and other alcohols). By-products include paraffins, olefins, methane, carbon monoxide, and other carbon compounds. The products may be in either gaseous or liquid form. Liquid products, including ethanol, can be separated and recovered by distillation or other chemical separation methods. The amount of each reaction product can be calculated using GC (gas chromatography), GC / MS (gas chromatography / mass spectrometry), and other analytical methods.

[0047] Here, the yields of each reaction product, ethanol, paraffin, olefin, methane, and CO, are expressed by the following formulas: Yield (%) of each reaction product = Amount of each reaction product (mol) × Number of carbon atoms in each reaction product / Amount of carbon dioxide converted (mol) The yield of "C2+ alcohol" is expressed by the following formula: Yield (%) of "C2+ alcohol" = Sum (%) of yields of each alcohol excluding methanol

[0048] According to the reaction using the catalyst for alcohol synthesis of this embodiment, the yield of ethanol is 8.8% to 12.7%, and ethanol can be obtained with high selectivity and high yield. Furthermore, the yield of C2+ alcohols is 15.7% to 30.6%, and alcohols can be obtained with high selectivity and high yield. [Example]

[0049] The present invention will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples.

[0050] Example 1 First, a raw material solution was prepared by dissolving iron nitrate, zinc nitrate, potassium nitrate, strontium nitrate, niobium nitrate, cadmium nitrate, and ytterbium nitrate in ion-exchanged water so that the atomic ratios of each catalytically active component were as shown in Table 3, with the atomic ratio of each metal being Fe:Zn:K:Sr:Nb:Cd, Yb=19:5:3:1:3:3:3. Subsequently, a CeO2 (25%)-ZrO2 support was impregnated with the raw material solution.

[0051] Next, water was removed by evaporation to dryness under vacuum conditions, and the mixture was dried overnight at 120°C under atmospheric pressure to obtain a solid. This solid was calcined in air at 500°C for 3 hours to obtain a catalyst powder. This catalyst powder was molded into pellets with a particle size of 0.5 to 0.8 mm by cold isostatic pressing (CIP) to prepare catalyst pellets containing the elements of the various active components of Example 1.

[0052] Examples 2 to 16 A raw material solution was prepared in the same manner as in Example 1 so that the atomic ratio of each metal was the numerical value of each catalytically active component in Examples 2 to 16 (listed in Table 3 or Table 4), and catalyst pellets were obtained by similarly undergoing drying, calcination, and molding processes using the CIP method.

[0053] (Comparative Examples 1 to 3) A raw material solution was prepared in the same manner as in Example 1 so that the atomic ratio of each metal was the numerical value of each catalytically active component in Comparative Examples 1 to 3 (listed in Table 4), and catalyst pellets were obtained by similarly undergoing drying, calcination, and molding processes using the CIP method.

[0054] (Reference Examples 1 and 2) A raw material solution was prepared in the same manner as in Example 1 so that the atomic ratio of each metal was the same as the value of each catalytically active component in Reference Example 1 or 2 (listed in Table 4), and catalyst pellets were obtained by similarly drying, calcining, and molding using the CIP method.

[0055] The resulting catalysts were packed into the reaction vessel shown in FIG. 1, and after reduction treatment under the following reaction conditions, alcohol synthesis was carried out. (Conditions for reduction treatment) Catalyst pellet particle size 0.5mm~0.8mm ·Catalyst loading amount 200mg Reaction vessel inner diameter 8mm Reducing gas (H2 99%), flow rate 40mL / min Reaction vessel temperature: 400℃ Reaction vessel pressure: 0.1 MPa Reaction time: 30 minutes (alcohol synthesis) Raw material gas (CO2 24.8%, H2 74.4%, Ar 0.8%) Flow rate 40mL / min Reaction vessel temperature: 360℃ Reaction vessel pressure: 4MPa The yields (%) of the produced ethanol, C2+ alcohols, paraffins, olefins, methane, and CO are shown in Tables 3 and 4. The numerical values ​​for each catalytically active component in Tables 3 and 4 represent the content (wt%) of each catalytically active component, and the content represents the weight of each catalytically active component relative to the total weight of the catalytically active components plus the weight of the support.

[0056] [Table 3]

[0057] [Table 4]

[0058] As shown in the above examples, the alcohol synthesis catalyst of this embodiment is useful as a catalyst capable of synthesizing alcohol, particularly ethanol, from CO and H with high selectivity and high yield. Furthermore, the alcohol production method of this embodiment using such an alcohol synthesis catalyst is useful as a method capable of efficiently producing alcohol from CO and H.

[0059] (Example of machine learning) An example of a machine learning model using elemental features is described in Non-Patent Document 1. Non-Patent Document 1 discloses that more than 100 types of catalysts for the reverse water-gas shift reaction that are superior to conventional catalysts have been identified. A suitable example of this is Pt(3) / Rb(1)-Ba(1)-Mo(0.6)-Nb(0.2) / TiO2.

[0060] In this example, a method for deriving a catalyst composition using such a machine learning model was also applied. The composition designed in this example was designed using a machine learning model. In the machine learning model, the product of elemental feature quantities, including atomic radius, electronegativity, density, melting point, and ionization energy, and a predetermined elemental composition ratio was used as a predictive descriptor. It was experimentally confirmed through follow-up that the catalyst composition obtained from the machine learning model using such elemental feature quantities had catalytic activity.

[0061] The present invention includes the following embodiments. [1] a) Fe and b) at least one of Zn and Cu; c) A catalytically active component containing at least two elements selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba, and containing K and at least one other element, or Cs and at least one other element. Catalyst for alcohol synthesis. [2] The catalyst for alcohol synthesis is a supported catalyst further containing a carrier, and the catalyst contains, based on the total weight of the catalytically active component and the carrier, Contains 2 to 30 wt% Fe, containing 2 to 15% by weight of Zn and 2 to 25% by weight of Cu relative to the total weight of the catalytically active component and the carrier, With respect to the total weight of the catalytically active component and the carrier 0.5 to 10 wt. % Li, 0.5 to 2.5 wt.% Na, 0.5 to 5 wt.% K, 0.5 to 4 wt.% Rb, 0.5 to 5 wt% Cs, 0.5 to 3 wt.% Mg, 0.5 to 4 wt% Ca 0.5 to 4 wt.% Sr, and 0.5 to 4 wt.% Ba, Contains at least two elements from the group consisting of The above catalyst for alcohol synthesis. [3] In the above-mentioned catalyst for alcohol synthesis or the supported catalyst containing the above-mentioned catalyst for alcohol synthesis and a support, The weight ratio of Zn to Fe is 0.1 to 3.5, and the weight ratio of Cu to Fe is 0.1 to 4. The weight ratio to Fe is 0.04 to 0.35 Li, Na 0.03-0.5, K of 0.04 to 1.5, Rb of 0.04 to 1, Cs of 0.04 to 1.5, 0.01-0.3 Mg, 0.14-0.5 Ca 0.01 to 0.75 Sr, and Ba of 0.04 to 0.2, Contains at least two elements from the group consisting of The above catalyst for alcohol synthesis. [4] d) Further containing at least one element selected from the group consisting of Ga, Y, Nb, Cd, Nd, Tb, Er, Yb, Ta, W and Re The above catalyst for alcohol synthesis. [5] The catalyst for alcohol synthesis is a supported catalyst further containing a carrier, and the catalyst contains, based on the total weight of the catalytically active component and the carrier, 5-8 wt% Ga, 1 to 14 wt. % Y, 0.5 to 3 wt.% Nb, 1-23 wt% Cd, 1 to 6 wt.% Nd, 0.5 to 3 wt% Tb, 0.5 to 4 wt.% Er, 0.5 to 23 wt% Yb, 1 to 7 wt. % Ta, 1 to 4 wt. % W, and 0.5 to 5 wt% Re Further containing at least one element from the group consisting of The above catalyst for alcohol synthesis. [6] In the above-mentioned catalyst for alcohol synthesis or the supported catalyst containing the above-mentioned catalyst for alcohol synthesis and a support, The weight ratio to Fe is 0.1 to 0.75 Ga, Y of 0.1 to 2.4, 0.025~0.23 Nb, Cd of 0.1 to 2.75, Nd 0.065~0.32 0.05-0.16 Tb, Er of 0.05 to 0.12, 0.05 to 2.75 Yb, Ta of 0.15 to 0.27, W between 0.09 and 0.17, and Re of 0.025 to 0.5 Further comprising at least one element from the group consisting of The above catalyst for alcohol synthesis. [7] Further containing at least one element selected from the group consisting of Ru, Rh, Pd, Ir, Pt, and Au; The above catalyst for alcohol synthesis. [8] For synthesizing ethanol and other alcohols using carbon dioxide and hydrogen as raw materials, The above catalyst for alcohol synthesis. [9] A supported catalyst comprising the above catalyst for alcohol synthesis and a support.

[10] A method for producing alcohol, comprising synthesizing alcohol by bringing CO2 and H2 into contact with the above-mentioned catalyst for alcohol synthesis or the above-mentioned supported catalyst.

[11] a) Fe and b) at least one of Zn and Cu; c) at least one of K and Cs; d) a catalytically active component containing at least one selected from the group consisting of Ga, Y, Nb, Cd, Nd, Tb, Er, Yb, Ta, W, and Re; Catalyst for alcohol synthesis.

[12] The catalyst for alcohol synthesis in

[11] above is a supported catalyst further containing a carrier, and the catalyst active component and the carrier are Contains 2 to 30 wt% Fe, containing 2 to 15% by weight of Zn and 2 to 25% by weight of Cu relative to the total weight of the catalytically active component and the carrier, containing 0.5 to 5% by weight of either K or 0.5 to 5% by weight of Cs relative to the total weight of the catalytically active component and the carrier; With respect to the total weight of the catalytically active component and the carrier 5-8 wt% Ga, 1 to 14 wt. % Y, 0.5 to 3 wt.% Nb, 1-23 wt% Cd, 1 to 6 wt.% Nd, 0.5 to 3 wt% Tb, 0.5 to 4 wt.% Er, 0.5 to 23 wt% Yb, 1 to 7 wt. % Ta, 1 to 4 wt. % W, and 0.5 to 5 wt% Re Contains at least one element from the group consisting of The above catalyst for alcohol synthesis.

[13] In the catalyst for alcohol synthesis according to the above

[11] or

[12] or a supported catalyst comprising the above catalyst for alcohol synthesis and a support, The weight ratio of Zn to Fe is 0.1 to 3.5, and the weight ratio of Cu to Fe is 0.1 to 4. The weight ratio of K to Fe is 0.04 to 1.5 and the weight ratio of Cs is 0.04 to 1.5, The weight ratio to Fe is 0.1 to 0.75 Ga, Y of 0.1 to 2.4, 0.025~0.23 Nb, Cd of 0.1 to 2.75, Nd 0.065~0.32 0.05-0.16 Tb, Er of 0.05 to 0.12, 0.05 to 2.75 Yb, Ta of 0.15 to 0.27, W between 0.09 and 0.17, and Re of 0.025 to 0.5 Contains at least one element from the group consisting of The above catalyst for alcohol synthesis.

[14] Further containing at least one element selected from the group consisting of Ru, Rh, Pd, Ir, Pt, and Au; The catalyst for alcohol synthesis according to

[11] to

[13] above.

[15] For synthesizing ethanol and other alcohols using carbon dioxide and hydrogen as raw materials, The catalyst for alcohol synthesis according to

[11] to

[14] above.

[16] A supported catalyst comprising the catalyst for alcohol synthesis according to any one of

[11] to

[15] above and a support.

[17] A method for producing alcohol, comprising synthesizing alcohol by bringing CO2 and H2 into contact with the catalyst for alcohol synthesis according to any one of

[11] to

[15] above or the supported catalyst according to

[16] above.

Claims

1. a) Fe, b) at least one of Zn and Cu; c) A catalytically active component containing at least two elements selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba, and containing K and at least one other element, or Cs and at least one other element. Catalyst for alcohol synthesis.

2. The catalyst for alcohol synthesis is a supported catalyst further containing a carrier, and the catalyst contains Contains 2 to 30 wt% Fe, containing 2 to 15% by weight of Zn and 2 to 25% by weight of Cu relative to the total weight of the catalytically active component and the carrier, With respect to the total weight of the catalytically active component and the carrier 0.5 to 10 wt. % Li, 0.5 to 2.5 wt. % Na, 0.5 to 5% by weight of K, 0.5 to 4 wt. % Rb, 0.5 to 5 wt. % Cs, 0.5 to 3 wt. % Mg, 0.5 to 4% by weight of Ca 0.5 to 4 wt. % Sr, and 0.5 to 4 wt. % Ba, Contains at least two elements from the group consisting of The catalyst for alcohol synthesis according to claim 1.

3. d) further comprising at least one element selected from the group consisting of Ga, Y, Nb, Cd, Nd, Tb, Er, Yb, Ta, W, and Re; The catalyst for alcohol synthesis according to claim 1.

4. The catalyst for alcohol synthesis is a supported catalyst further containing a carrier, and the catalyst contains 5 to 8 wt. % Ga, 1 to 14 wt. % Y, 0.5 to 3 wt.% Nb, 1 to 23 wt. % Cd, 1 to 6 wt. % Nd, 0.5 to 3 wt. % Tb, 0.5 to 4 wt. % Er, 0.5 to 23 wt. % Yb, 1 to 7 wt. % Ta, 1 to 4 wt. % W, and 0.5 to 5 wt% Re Further containing at least one element from the group consisting of The catalyst for alcohol synthesis according to claim 3.

5. Further containing at least one element selected from the group consisting of Ru, Rh, Pd, Ir, Pt, and Au; The catalyst for alcohol synthesis according to any one of claims 1 to 4.

6. a) Fe, b) at least one of Zn and Cu; c) at least one of K and Cs; d) A catalytically active component containing at least one selected from the group consisting of Ga, Y, Nb, Cd, Nd, Tb, Er, Yb, Ta, W, and Re. Catalyst for alcohol synthesis.

7. The catalyst for alcohol synthesis is a supported catalyst further containing a carrier, and the catalyst contains Contains 2 to 30 wt% Fe, containing 2 to 15% by weight of Zn and 2 to 25% by weight of Cu relative to the total weight of the catalytically active component and the carrier, With respect to the total weight of the catalytically active component and the carrier containing 0.5 to 5 wt% of K and 0.5 to 5 wt% of Cs, With respect to the total weight of the catalytically active component and the carrier 5 to 8 wt. % Ga, 1 to 14 wt. % Y, 0.5 to 3 wt.% Nb, 1 to 23 wt. % Cd, 1 to 6 wt. % Nd, 0.5 to 3 wt. % Tb, 0.5 to 4 wt. % Er, 0.5 to 23 wt. % Yb, 1 to 7 wt. % Ta, 1 to 4 wt. % W, and 0.5 to 5 wt% Re Contains at least one element from the group consisting of The catalyst for alcohol synthesis according to claim 6.

8. Further containing at least one element selected from the group consisting of Ru, Rh, Pd, Ir, Pt, and Au; The catalyst for alcohol synthesis according to claim 6 or 7.

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