Electric field responsive CO2 hydrogenation to methanol catalyst, preparation method and application thereof

Abstract

The present application relates to a kind of electric field response type CO2 hydrogenation methanol catalyst and its preparation method and application, the electric field response type CO2 hydrogenation methanol catalyst includes positive phase Cu-In catalyst or reverse phase In-Cu catalyst;The electric field response type CO2 hydrogenation methanol catalyst, the existing state of Cu is CuO, the existing state of In is In2O3.The electric field response type CO2 hydrogenation methanol catalyst provided in the present application can realize the further reduction of Cu species under the action of electric field, so that it more exists in the form of Cu 0 It is advantageous to accelerate interface electron transfer and reactant molecule activation, so that CO2 hydrogenation methanol reaction still has high methanol selectivity and high methanol space-time yield under relatively mild reaction conditions.

Description

Technical Field

[0001] This invention belongs to the field of catalyst synthesis and application technology, and relates to a catalyst for CO2 hydrogenation to methanol, and more particularly to an electric field-responsive catalyst for CO2 hydrogenation to methanol, its preparation method and application. Background Technology

[0002] In the process of carbon dioxide resource utilization, developing efficient, stable, and highly selective catalyst systems is key to achieving high-value conversion and utilization of carbon dioxide. Among them, carbon dioxide hydrogenation to methanol is an important pathway for carbon dioxide resource utilization, and its catalysts are mainly copper-based materials. Although these catalysts have good hydrogenation activity, they suffer from problems such as single active sites, insufficient resistance to sintering, and poor selectivity.

[0003] In recent years, metal oxides, represented by indium oxide, have attracted widespread attention due to their high methanol selectivity. CN120771860A discloses a Pt-ZnO / In2O3 catalyst for the hydrogenation of carbon dioxide to methanol and its preparation method. Pt is loaded onto the surface of a ZnO / In2O3 catalyst via an impregnation method. The resulting Pt-ZnO / In2O3 catalyst does not exhibit sintering during use and has long-term stability. Furthermore, the modification and alteration of the In2O3-based catalyst with ZnO improves the conversion rate of carbon dioxide and the product selectivity.

[0004] However, indium oxide-based catalysts exhibit poor carbon dioxide activation ability, resulting in a low overall methanol space-time yield. While loading noble metals can improve their carbon dioxide activation ability, this significantly increases the catalyst preparation cost, limiting their industrial application. CN121372422A discloses a dual-active-site catalyst for carbon dioxide hydrogenation to methanol and its preparation method. It uses one of the following as a support: Al2O3, SiO2, molecular sieves, and carbon nanotubes, which possess large specific surface area and tunable surface properties. A highly dispersed In2O3 nanoarray is constructed on the support via chemical deposition, followed by the addition of Cu through ion exchange. 2+ Ions are precisely anchored to nearby molecular sieve acid sites, thereby forming enriched Cu. + -O-In active interface. This catalyst utilizes the confinement effect and acidity of the large surface area and abundant pores of the support material to generate a strong synergistic effect with the Cu-In components, as well as the interaction between Cu-In components, and exhibits good catalytic activity in the carbon dioxide hydrogenation to methanol reaction.

[0005] While the above methods have improved the catalytic activity of the catalyst to some extent, they still have problems such as low methanol selectivity and harsh reaction conditions, and the complex preparation process further increases the cost of catalyst preparation.

[0006] Therefore, how to develop a novel non-precious metal catalyst that can achieve high methanol selectivity and high methanol space-time yield in carbon dioxide hydrogenation under mild reaction conditions is an urgent problem to be solved in this field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide an electric field-responsive CO2 hydrogenation catalyst for methanol production, its preparation method, and its applications. The electric field-responsive CO2 hydrogenation catalyst provided by this invention can achieve further reduction of Cu species under the action of an electric field, allowing them to be converted into more Cu. 0 It exists in a form that exhibits excellent conductivity, which is beneficial for accelerating interfacial electron transfer and reactant molecule activation, enabling the CO2 hydrogenation to methanol reaction to still have high methanol selectivity and high methanol space-time yield under relatively mild reaction conditions.

[0008] To achieve this objective, the present invention employs the following technical solution:

[0009] In a first aspect, the present invention provides an electric field-responsive CO2 hydrogenation to methanol catalyst, wherein the electric field-responsive CO2 hydrogenation to methanol catalyst comprises a normal-phase Cu-In catalyst or a reverse-phase In-Cu catalyst; wherein in the electric field-responsive CO2 hydrogenation to methanol catalyst, Cu exists in the state of CuO and In exists in the state of In2O3.

[0010] The electric field-responsive CO2 hydrogenation to methanol catalyst provided by this invention enables further reduction of Cu species under an applied electric field, regardless of whether it is a normal-phase Cu-In catalyst or a reverse-phase In-Cu catalyst, allowing Cu species to be more abundantly converted into Cu. 0 It exists in a form that exhibits excellent conductivity, which is beneficial for accelerating interfacial electron transfer and reactant molecule activation, enabling the CO2 hydrogenation to methanol reaction to still have high methanol selectivity and high methanol space-time yield under relatively mild reaction conditions.

[0011] Preferably, the normal-phase Cu-In catalyst is formed by supporting CuO on In2O3.

[0012] Preferably, in the normal phase Cu-In catalyst, the mass of CuO is 5wt% to 55wt% of the mass of In2O3, for example, it can be 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt% or 55wt%, etc., preferably 10wt% to 25wt%.

[0013] Preferably, the reversed In-Cu catalyst is formed by supporting In2O3 on CuO.

[0014] Preferably, in the reverse In-Cu catalyst, the mass of In2O3 is 10wt% to 30wt% of the mass of CuO, for example, it can be 10wt%, 15wt%, 20wt%, 25wt% or 30wt%, etc., preferably 15wt% to 20wt%.

[0015] In a second aspect, the present invention provides a method for preparing an electric field-responsive CO2 hydrogenation catalyst for methanol production as described in the first aspect, comprising the following steps:

[0016] The supporting metal oxide is added to the supporting metal salt solution and impregnated with equal volume to obtain the precursor; the precursor is calcined to obtain the electric field-responsive CO2 hydrogenation to methanol catalyst.

[0017] When the electric field-responsive CO2 hydrogenation to methanol catalyst is a normal-phase Cu-In catalyst, the supported metal oxide is In2O3, and the supported metal salt solution is a Cu salt solution.

[0018] When the electric field-responsive CO2 hydrogenation to methanol catalyst is a reverse-phase In-Cu catalyst, the supported metal oxide is CuO, and the supported metal salt solution is an In salt solution.

[0019] Preferably, the Cu salt in the Cu salt solution includes any one or a combination of at least two of copper nitrate, copper acetate, or copper acetylacetonate. Typical but non-limiting combinations include a combination of copper nitrate and copper acetate, a combination of copper acetate and copper acetylacetonate, a combination of copper nitrate and copper acetylacetonate, or a combination of copper nitrate, copper acetate, and copper acetylacetonate.

[0020] Preferably, the In salt in the In salt solution includes any one or a combination of at least two of indium nitrate, indium chloride, or indium formate. Typical but non-limiting combinations include combinations of indium nitrate and indium chloride, combinations of indium chloride and indium formate, combinations of indium nitrate and indium formate, and combinations of indium nitrate, indium chloride, and indium formate.

[0021] Preferably, the equal-volume impregnation is followed by drying to obtain the precursor.

[0022] Preferably, the drying is carried out in a forced-air drying oven.

[0023] Preferably, the drying temperature is 80℃~120℃, for example, it can be 80℃, 90℃, 100℃, 110℃ or 120℃.

[0024] Preferably, the drying time is 3h to 8h, for example, 3h, 4h, 5h, 6h, 7h or 8h.

[0025] Preferably, the calcination is carried out in a muffle furnace.

[0026] Preferably, the calcination is carried out in an air atmosphere.

[0027] Preferably, the calcination temperature is 350℃~550℃, for example, it can be 350℃, 400℃, 450℃, 500℃ or 550℃.

[0028] Preferably, the calcination time is 2h to 5h, for example, it can be 2h, 3h, 4h or 5h.

[0029] Preferably, the heating rate of the calcination is 4℃ / min to 12℃ / min, for example, it can be 4℃ / min, 5℃ / min, 8℃ / min, 10℃ / min or 12℃ / min, etc.

[0030] Preferably, after calcination, the catalyst is further subjected to tableting, crushing, and sieving to obtain the electric field-responsive CO2 hydrogenation to methanol catalyst.

[0031] Preferably, the pulverization and sieving process includes passing the material through a 40-mesh sieve, collecting the undersize material, and then passing it through a 20-mesh sieve to collect the oversize material, thereby obtaining a 20-40 mesh electric field-responsive CO2 hydrogenation to methanol catalyst.

[0032] Thirdly, the present invention provides an application of the electric field-responsive CO2 hydrogenation to methanol catalyst as described in the first aspect, wherein the electric field-responsive CO2 hydrogenation to methanol catalyst, after reduction and activation, is used to catalyze the electrothermal coupled CO2 hydrogenation to methanol reaction.

[0033] It should be noted that, in this invention, the electrothermal coupled CO2 hydrogenation to methanol reaction of the electric field-responsive CO2 hydrogenation catalyst refers to the CO2 hydrogenation to methanol reaction carried out under the conditions of applying direct current, increasing temperature, and adding a reduced and activated electric field-responsive CO2 hydrogenation to methanol catalyst.

[0034] In the normal-phase Cu-In catalyst provided by the present invention, the content of Cu species as a support is low, and it is uniformly supported on the supported material (support) In2O3 in the form of CuO. After reduction and activation, CuO is reduced to elemental Cu and Cu2O.

[0035] In the reversed In-Cu catalyst provided by the present invention, the content of Cu species as the supported material (support) is relatively high. It is uniformly supported on In2O3 in the form of CuO. After reduction and activation, most of CuO is reduced to Cu2O and a small part is reduced to elemental Cu.

[0036] When a direct current is applied during the CO2 hydrogenation to methanol reaction, the electric field can further promote the reduction of Cu species, causing them to be converted into Cu. 0It exists in a form that exhibits excellent conductivity, which is beneficial for accelerating interfacial electron transfer and reactant molecule activation, enabling the CO2 hydrogenation to methanol reaction to still have high methanol selectivity and high methanol space-time yield under relatively mild reaction conditions.

[0037] Preferably, the reduction activation is carried out in a mixed atmosphere of hydrogen and nitrogen.

[0038] Preferably, in the mixed atmosphere of hydrogen and nitrogen, the volume fraction of hydrogen is 5 vol% to 20 vol%, for example, it can be 5 vol%, 10 vol%, 15 vol%, or 20 vol%.

[0039] Preferably, the reduction and activation temperature is 200℃~400℃, for example, it can be 200℃, 250℃, 300℃, 350℃ or 400℃.

[0040] Preferably, the reduction and activation time is 3h to 6h, for example, it can be 3h, 4h, 5h or 6h.

[0041] Preferably, the resistivity of the electric field-responsive CO2 hydrogenation to methanol catalyst after reduction and activation is 2Ω~15Ω, for example, it can be 2Ω, 5Ω, 8Ω, 10Ω, 12Ω or 15Ω.

[0042] Preferably, the power of the direct current in the electrothermal coupled CO2 hydrogenation to methanol reaction is 0.1W to 3W, for example, it can be 0.1W, 0.5W, 1W, 1.5W, 2W, 2.5W or 3W.

[0043] Preferably, the reaction temperature of the electrothermally coupled CO2 hydrogenation to methanol reaction is 180℃~240℃, for example, it can be 180℃, 190℃, 200℃, 210℃, 220℃, 230℃ or 240℃, etc.

[0044] Preferably, the reaction pressure of the electrothermally coupled CO2 hydrogenation to methanol reaction is 2MPa to 5MPa, for example, it can be 2MPa, 2.5MPa, 3MPa, 3.5MPa, 4MPa, 4.5MPa or 5MPa.

[0045] Preferably, the feed gas for the electrothermally coupled CO2 hydrogenation to methanol reaction is CO2 and H2.

[0046] Preferably, the molar ratio of CO2 to H2 in the raw gas is 1:(1~6), for example, it can be 1:1, 1:2, 1:3, 1:4, 1:5 or 1:6, etc.

[0047] Preferably, the reaction space velocity is 3000 mL / g / h to 9000 mL / g / h, for example, it can be 3000 mL / g / h, 4000 mL / g / h, 5000 mL / g / h, 6000 mL / g / h, 7000 mL / g / h, 8000 mL / g / h or 9000 mL / g / h.

[0048] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The electric field-responsive CO2 hydrogenation to methanol catalyst provided by this invention enables further reduction of Cu species under an applied electric field, regardless of whether it is a normal-phase Cu-In catalyst or a reverse-phase In-Cu catalyst, allowing Cu species to be more abundantly converted into Cu. 0 It exists in a form that exhibits excellent conductivity, which is beneficial for accelerating interfacial electron transfer and reactant molecule activation, enabling the CO2 hydrogenation to methanol reaction to still have high methanol selectivity and high methanol space-time yield under relatively mild reaction conditions. Detailed Implementation

[0051] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0052] The scope of this invention can be defined by lower and upper limits. The selected lower and upper limits define the boundaries of a specific range. The range defined in this way can be defined by the inclusion or exclusion of endpoints. Any endpoint can be independently selected for inclusion or exclusion, and all lower and upper limits can be arbitrarily combined to form new ranges. That is, any lower limit can be combined with any upper limit to form an effective range. For example, if the ranges of 60~120 and 80~110 are listed for specific parameters, it should be understood that the ranges of 60~110 and 80~120 also fall within the scope of this invention. In addition, if the minimum range values ​​1 and 2 are listed, and the maximum range values ​​3, 4 and 5 are also listed, then all ranges of 1~3, 1~4, 1~5, 2~3, 2~4 and 2~5 fall within the scope of this invention. In this invention, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0~5" means that all real numbers between 0 and 5 have been fully listed in this document, and "0~5" is only a shortened representation of this set of numerical combinations. When a parameter is expressed as an integer ≥2, it is equivalent to listing positive integers that meet the requirements, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. When a parameter is expressed as an integer selected from "2~10", it is equivalent to listing any integer among 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0053] Unless otherwise specified, the term "at least two combinations" in this invention refers to a quantity greater than or equal to 2. For example, "any one or at least two combinations" means that any one of the listed items can be selected, or a combination of at least two of the listed items formed in a manner that does not conflict and enables the implementation of this invention.

[0054] In this invention, unless otherwise specified, the feature or solution corresponding to "and / or" covers any one of two or more related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" represents a set consisting of A, B, and combinations of A and B. "Including A and / or B" can be understood, depending on the context of the statement, as including A, including B, or simultaneously including both A and B. In this invention, "optional" means that the corresponding feature, component, step, or solution is not essential, i.e., selected from either "present" or "absent" parallel solutions. If multiple "optional" limitations appear in a technical solution, unless otherwise specified and without technical conflict or mutual constraint, each "optional" limitation is independent and does not affect the others.

[0055] In this invention, technical features or solutions described using open-ended terms such as "comprising" or "including" do not exclude additional non-conflicting elements beyond the listed elements unless otherwise specified. They are considered to disclose both closed-ended features or solutions consisting solely of the listed elements and open-ended features or solutions that may include additional non-conflicting elements beyond the listed elements. For example, if A includes a1, a2, and a3, unless otherwise specified, this means that A may consist only of a1, a2, and a3, or it may include other non-conflicting elements based on a1, a2, and a3. This corresponds to the disclosure of technical solutions such as "A consists of a1, a2, and a3," "A is selected from a1, a2, and a3," and "A not only includes a1, a2, and a3, but may also include other non-conflicting elements."

[0056] All embodiments and optional embodiments of the present invention, unless otherwise specified and without technical conflict, can be combined to form new technical solutions, and such combinations fall within the scope of the present invention. The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment or implementation of the present invention. The appearance of this phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art can explicitly and implicitly understand that the embodiments described in this invention can be combined with other embodiments without technical conflict.

[0057] In this invention, the ordinal numbers “first,” “second,” “third,” and “fourth” used in expressions such as “first aspect,” “second aspect,” “third aspect,” and “fourth aspect” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. They serve only as a non-exhaustive enumeration and do not constitute a closed limitation on quantity.

[0058] In this invention, the order in which the steps are written in the methods described in each embodiment does not imply a strict execution order. The actual execution order of each step should be determined based on its function and possible internal logic. Unless otherwise specified, all steps of this invention can be executed in the order they are written, or in any order without technical conflict. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) executed sequentially, or it may include steps (b) and (a) executed sequentially. If the method also includes step (c), then step (c) can be added to the method in any order without conflict, including but not limited to the execution order of steps (a), (b), and (c), steps (a), (c), and (b), steps (c), (a), and (b), etc.

[0059] Example 1

[0060] This embodiment provides an electric field-responsive CO2 hydrogenation to methanol catalyst, which is a normal-phase Cu-In catalyst formed by CuO supported on In2O3, wherein the mass of CuO is 20 wt% of the mass of In2O3.

[0061] The method for preparing an electric field-responsive CO2 hydrogenation catalyst for methanol production provided in this embodiment includes the following steps:

[0062] (1) Add 3.04g Cu(NO3)2·3H2O to a beaker containing 2.8mL deionized water and stir to dissolve, to obtain a metal salt solution for loading. Add 5g In2O3 to the solution for impregnation of equal volume. After the impregnation, place the solution in a forced-air drying oven and dry at 110℃ for 5h.

[0063] (2) The product obtained in step (1) is placed in a muffle furnace and heated to 500°C for 4 hours at a heating rate of 10°C / min. After the heating is completed, the product is pressed into tablets and then crushed and sieved to obtain a field-responsive CO2 hydrogenation catalyst with a mesh size of 20-40 mesh.

[0064] Example 2

[0065] This embodiment provides an electric field-responsive CO2 hydrogenation to methanol catalyst, which is the same as that in Example 1 except that the mass of CuO is 5 wt% of the mass of In2O3.

[0066] The electric field-responsive CO2 hydrogenation catalyst provided in this embodiment is the same as that in Example 1, except that the mass of Cu(NO3)2·3H2O in step (1) is adjusted to 0.75g.

[0067] Example 3

[0068] This embodiment provides an electric field-responsive CO2 hydrogenation catalyst for methanol production. Except that the mass of CuO is 10 wt% of the mass of In2O3, everything else is the same as in Example 1.

[0069] The electric field-responsive CO2 hydrogenation to methanol catalyst provided in this embodiment is the same as that in Example 1, except that the mass of Cu(NO3)2·3H2O in step (1) is adjusted to 1.52g.

[0070] Example 4

[0071] This embodiment provides an electric field-responsive CO2 hydrogenation catalyst for methanol production. Except that the mass of CuO is 30 wt% of the mass of In2O3, everything else is the same as in Example 1.

[0072] The electric field-responsive CO2 hydrogenation catalyst provided in this embodiment is the same as that in Example 1, except that the mass of Cu(NO3)2·3H2O in step (1) is adjusted to 4.56g.

[0073] Example 5

[0074] This embodiment provides an electric field-responsive CO2 hydrogenation catalyst for methanol production. Except that the mass of CuO is 40 wt% of the mass of In2O3, everything else is the same as in Example 1.

[0075] The electric field-responsive CO2 hydrogenation to methanol catalyst provided in this embodiment is the same as that in Example 1, except that the mass of Cu(NO3)2·3H2O in step (1) is adjusted to 6.08g.

[0076] Example 6

[0077] This embodiment provides an electric field-responsive CO2 hydrogenation to methanol catalyst, which is a reverse In-Cu catalyst, formed by In2O3 supported on CuO, with the mass of In2O3 being 20 wt% of the mass of CuO.

[0078] The method for preparing an electric field-responsive CO2 hydrogenation catalyst for methanol production provided in this embodiment includes the following steps:

[0079] (1) Add 2.16g In(NO3)3 to a beaker containing 2.8mL deionized water and stir to dissolve, to obtain a metal salt solution for loading. Add 5g CuO to the solution for impregnation in equal volume. After the impregnation, place the solution in a forced-air drying oven and dry at 110℃ for 5h.

[0080] (2) The product obtained in step (1) is placed in a muffle furnace and heated to 400°C for 5 hours at a heating rate of 5°C / min. After the heating is completed, the product is pressed into tablets and then crushed and sieved to obtain a field-responsive CO2 hydrogenation catalyst with a mesh size of 20-40 mesh.

[0081] Example 7

[0082] This embodiment provides an electric field-responsive CO2 hydrogenation catalyst for methanol production. Except that the mass of In2O3 is 10 wt% of the mass of CuO, everything else is the same as in Example 6.

[0083] The electric field-responsive CO2 hydrogenation catalyst provided in this embodiment is the same as that in Example 6, except that the mass of In(NO3)3 in step (1) is adjusted to 1.08g.

[0084] Example 8

[0085] This embodiment provides an electric field-responsive CO2 hydrogenation catalyst for methanol production. Except that the mass of In2O3 is 15 wt% of the total mass of CuO, everything else is the same as in Example 6.

[0086] The electric field-responsive CO2 hydrogenation to methanol catalyst provided in this embodiment is the same as that in Example 6, except that the mass of In(NO3)3 in step (1) is adjusted to 1.63g.

[0087] Example 9

[0088] This embodiment provides an electric field-responsive CO2 hydrogenation catalyst for methanol production. Except that the mass of In2O3 is 25 wt% of the total mass of CuO, everything else is the same as in Example 6.

[0089] The electric field-responsive CO2 hydrogenation to methanol catalyst provided in this embodiment is the same as that in Example 6, except that the mass of In(NO3)3 in step (1) is adjusted to 2.71g.

[0090] Example 10

[0091] This embodiment provides an electric field-responsive CO2 hydrogenation catalyst for methanol production. Except that the mass of In2O3 is 30 wt% of the total mass of CuO, everything else is the same as in Example 6.

[0092] The electric field-responsive CO2 hydrogenation to methanol catalyst provided in this embodiment is the same as that in Example 6, except that the mass of In(NO3)3 in step (1) is adjusted to 3.24g.

[0093] Comparative Example 1

[0094] This comparative example provides a non-electric field responsive CO2 hydrogenation to methanol catalyst, which is a normal-phase Zn-In catalyst, formed by ZnO supported on In2O3, with the mass of ZnO being 20 wt% of the mass of In2O3.

[0095] The non-electric field-responsive CO2 hydrogenation catalyst provided in this comparative example is the same as that in Example 1, except that 3.04g Cu(NO3)2·3H2O in step (1) is replaced with 3.66g Zn(NO3)2·6H2O.

[0096] Application Examples 1 to 5

[0097] (1) Preparation of electric field responsive CO2 hydrogenation to methanol catalyst: Weigh 1.5g of the electric field responsive CO2 hydrogenation to methanol catalyst provided in Examples 1 to 5 and place them in the reaction tube of the fixed bed reactor. Insert the lower electrode rod and the upper electrode rod into the two ends of the reaction tube respectively, so that the two electrode rods are in contact with the electric field responsive CO2 hydrogenation to methanol catalyst but not in contact with each other.

[0098] (2) Reduction activation of the electric field responsive CO2 hydrogenation to methanol catalyst: 10 vol% H2 / 90 vol% N2 mixed gas was introduced into the reaction tube and reduced and activated at 300℃ for 4 h.

[0099] (3) Set the reaction conditions: set the DC power to 0.5W, the reaction temperature to 240℃, and the reaction pressure to 3MPa.

[0100] (4) Introducing raw material gas and carrying out CO2 hydrogenation to methanol reaction: After the reaction temperature stabilizes, introduce raw material gas and pressurize it to 3 MPa, and then carry out CO2 hydrogenation to methanol reaction. Among them, the molar ratio of CO2 and H2 in the raw material gas is controlled to be 1:3 and the reaction space velocity is 4000 mL / g / h by the flow meter.

[0101] (5) After the reaction is complete, stop applying DC power, stop heating, stop feeding raw gas, open the pressure relief valve and slowly depressurize to 0.1 MPa, and purge with N2 at a flow rate of 20 mL / min. After the temperature of the fixed bed reactor drops to room temperature, disassemble the fixed bed reactor.

[0102] Application Examples 6 to 10

[0103] (1) Preparation of electric field responsive CO2 hydrogenation to methanol catalyst: Weigh 1.5g of the electric field responsive CO2 hydrogenation to methanol catalyst provided in Examples 6 to 10 and place them in the reaction tube of the fixed bed reactor. Insert the lower electrode rod and the upper electrode rod into the two ends of the reaction tube respectively, so that the two electrode rods are in contact with the electric field responsive CO2 hydrogenation to methanol catalyst but not in contact with each other.

[0104] (2) Reduction activation of the electric field responsive CO2 hydrogenation to methanol catalyst: 10 vol% H2 / 90 vol% N2 mixed gas was introduced into the reaction tube and reduced and activated at 400℃ for 3 h.

[0105] (3) Set the reaction conditions: set the DC power to 2.0W, the reaction temperature to 200℃, and the reaction pressure to 4.6MPa.

[0106] (4) Introducing raw material gas and carrying out CO2 hydrogenation to methanol reaction: After the reaction temperature stabilizes, the raw material gas is introduced and pressurized to 4.6 MPa, and then the CO2 hydrogenation to methanol reaction is carried out. Among them, the molar ratio of CO2 and H2 in the raw material gas is controlled to be 1:3 and the reaction space velocity is 4000 mL / g / h by the flow meter.

[0107] (5) After the reaction is complete, stop applying DC power, stop heating, stop feeding raw gas, open the pressure relief valve and slowly depressurize to 0.1 MPa, and purge with N2 at a flow rate of 20 mL / min. After the temperature of the fixed bed reactor drops to room temperature, disassemble the fixed bed reactor.

[0108] Application Examples 11 to 13

[0109] In Application Examples 11 to 13, except that the DC power in step (3) is adjusted to 1.0W, 1.5W and 2.0W, everything else is the same as in Application Example 1.

[0110] Application Examples 14~16

[0111] In Application Examples 14 to 16, the only difference from Application Example 6 is that the DC power in step (3) is adjusted to 1.0W, 1.5W and 2.5W.

[0112] Comparative Application Example 1

[0113] In comparison with Application Example 1, except that in step (3), no DC power is applied, that is, the power of the DC power is adjusted to 0W, everything else is the same as in Application Example 1.

[0114] Comparative Application Example 2

[0115] In comparison with Application Example 2, except that in step (3), no DC power is applied, that is, the power of the DC power is adjusted to 0W, everything else is the same as in Application Example 6.

[0116] Comparative Application Example 3

[0117] In Comparative Application Example 3, except that in step (1), the electric field-responsive CO2 hydrogenation to methanol catalyst provided in Example 1 was replaced with the non-electric field-responsive CO2 hydrogenation to methanol catalyst provided in Comparative Example 1, everything else was the same as in Application Example 1.

[0118] Comparative Application Example 4

[0119] In Comparative Application Example 4, except that in step (3), no DC power is applied, that is, the power of the DC power is adjusted to 0W, everything else is the same as in Comparative Application Example 3.

[0120] The reaction conditions and performance of the electrothermal coupled CO2 hydrogenation to methanol reaction after reduction activation of the electric field-responsive CO2 hydrogenation to methanol catalyst are shown in Table 1.

[0121]

[0122] As can be seen from Application Examples 1 to 5 in Table 1, in normal-phase Cu-In catalysts, when the mass of CuO is 5wt% to 55wt% of the mass of In₂O₃, the methanol selectivity and methanol space-time yield first increase and then decrease with increasing CuO loading. This is because: when the CuO loading is low, the applied electric field promotes Cu… 0 The formation of active species increases catalyst activity, leading to increased methanol selectivity and methanol space-time yield; however, excessively high CuO loading results in Cu... 0 Excessive generation of species leads to the aggregation of active sites, which cover defective active sites, weakens the carbon dioxide adsorption and activation capacity, reduces catalyst activity, and decreases methanol selectivity and methanol space-time yield.

[0123] As can be seen from Application Examples 6 to 10 in Table 1, in the reversed In-Cu catalyst, when the mass of In2O3 is 10wt% to 30wt% of the mass of CuO, the methanol selectivity and methanol space-time yield first increase and then decrease with the increase of In2O3 loading. This is because: when the In2O3 loading is low, it can provide adsorption sites for CO2 molecules, promote the activation of CO2 molecules, and increase the catalyst activity, thus increasing the methanol selectivity and methanol space-time yield; when the In2O3 loading is too high, it will cover Cu. 0 Active sites, and make Cu + Reduced to Cu 0 The species becomes more difficult to obtain, the hydrogen activation capacity decreases, which reduces catalyst activity, methanol selectivity and methanol space-time yield.

[0124] As can be seen from Application Examples 1 and 11-13 in Table 1, in the electrothermal coupled CO2 hydrogenation to methanol reaction, the methanol selectivity and methanol space-time yield gradually increase with the increase of DC power. This is because increasing the DC power is beneficial for promoting Cu... + Reduced to Cu 0 It promotes the formation of defect sites at the Cu-In interface, increasing the number of active sites on the catalyst; it also facilitates electron transfer at the Cu-In interface, improving the redox performance of the catalyst.

[0125] As can be seen from Application Examples 6 and 14-16 in Table 1, in the electrothermal coupled CO2 hydrogenation to methanol reaction, the methanol selectivity and methanol space-time yield gradually increase with the increase of DC power. This is because increasing the DC power is beneficial for promoting Cu + Reduced to Cu0 It promotes the formation of defect sites at the Cu-In interface, increasing the number of active sites on the catalyst; it also facilitates electron transfer at the Cu-In interface, improving the redox performance of the catalyst.

[0126] As can be seen from Application Example 1 and Comparative Application Example 1, as well as Application Example 6 and Comparative Application Example 2 in Table 1, in the electrothermal coupled CO2 hydrogenation to methanol reaction, when no direct current is applied, i.e., the power of the direct current is adjusted to 0W, the Cu species in the electric field-responsive CO2 hydrogenation to methanol catalyst cannot be further reduced, the conductivity is also poor, and it cannot further promote the readjustment and distribution of active sites, accelerate the interfacial electron transfer and promote the activation of CO2 molecules, resulting in a significant decrease in methanol selectivity and methanol space-time yield.

[0127] As can be seen from Application Example 1 and Comparative Application Examples 3-4 in Table 1, when the non-field-responsive CO2 hydrogenation to methanol catalyst is a normal-phase Zn-In catalyst, further reduction of ZnO cannot be achieved under the action of an electric field, and the catalyst has poor conductivity. Therefore, the applied electric field cannot promote interfacial electron transfer or regulate the distribution of active sites, resulting in a significant decrease in both methanol selectivity and methanol space-time yield. Furthermore, since the normal-phase Zn-In catalyst cannot achieve an electric field response, even applying a direct current cannot further improve methanol selectivity and methanol space-time yield compared to not applying a direct current.

[0128] In summary, the electric field-responsive CO2 hydrogenation to methanol catalyst provided by this invention, under the action of an applied electric field, further reduces Cu species in both normal-phase Cu-In catalysts and reverse-phase In-Cu catalysts, allowing Cu species to be more abundantly converted into Cu. 0 The form exists and exhibits excellent conductivity, thereby promoting the activation of reactant molecules. In addition, the applied electric field accelerates the transfer of electrons at the interface and the formation of defect sites at the interface, promoting the activation of CO2 molecules. This allows the CO2 hydrogenation to methanol reaction to still have high methanol selectivity and high methanol space-time yield under mild reaction conditions.

[0129] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An electric field-responsive catalyst for CO2 hydrogenation to methanol, characterized in that, The electric field-responsive CO2 hydrogenation to methanol catalyst includes a normal-phase Cu-In catalyst or a reverse-phase In-Cu catalyst; In the electric field-responsive CO2 hydrogenation to methanol catalyst, Cu exists in the state of CuO and In exists in the state of In2O3.

2. The electric field-responsive CO2 hydrogenation to methanol catalyst according to claim 1, characterized in that, The normal-phase Cu-In catalyst is formed by supporting CuO on In2O3; Preferably, in the normal phase Cu-In catalyst, the mass of CuO is 5wt% to 55wt% of the mass of In2O3, and more preferably 10wt% to 25wt%.

3. The electric field-responsive CO2 hydrogenation to methanol catalyst according to claim 1, characterized in that, The reversed In-Cu catalyst is formed by supporting In2O3 on CuO; Preferably, in the reversed In-Cu catalyst, the mass of In2O3 is 10wt% to 30wt% of the mass of CuO, and more preferably 15wt% to 20wt%.

4. A method for preparing an electric field-responsive CO2 hydrogenation catalyst for methanol production as described in any one of claims 1 to 3, characterized in that, Includes the following steps: The metal oxide for loading is added to the metal salt solution for loading and impregnated with an equal volume to obtain the precursor; The precursor is then subjected to a reaction to obtain the electric field-responsive CO2 hydrogenation to methanol catalyst. When the electric field-responsive CO2 hydrogenation to methanol catalyst is a normal-phase Cu-In catalyst, the supported metal oxide is In2O3, and the supported metal salt solution is a Cu salt solution; When the electric field-responsive CO2 hydrogenation to methanol catalyst is a reverse-phase In-Cu catalyst, the supported metal oxide is CuO, and the supported metal salt solution is an In salt solution.

5. The preparation method according to claim 4, characterized in that, The Cu salt in the Cu salt solution includes any one or a combination of at least two of copper nitrate, copper acetate, or copper acetylacetonate. Preferably, the In salt in the In salt solution includes any one or a combination of at least two of indium nitrate, indium chloride, or indium formate.

6. The preparation method according to claim 4 or 5, characterized in that, The calcination is carried out in an air atmosphere; Preferably, the calcination temperature is 350℃~550℃; Preferably, the calcination time is 2h to 5h; Preferably, the heating rate of the calcination is 4℃ / min to 12℃ / min.

7. The application of an electric field-responsive CO2 hydrogenation catalyst as described in any one of claims 1 to 3, characterized in that, The electric field-responsive CO2 hydrogenation to methanol catalyst, after reduction and activation, is used to catalyze the electrothermal coupled CO2 hydrogenation to methanol reaction.

8. The application according to claim 7, characterized in that, The reduction activation is carried out in a mixed atmosphere of hydrogen and nitrogen; Preferably, in the mixed atmosphere of hydrogen and nitrogen, the volume fraction of hydrogen is 5 vol% to 20 vol%. Preferably, the reduction and activation temperature is 200℃~400℃; Preferably, the reduction and activation time is 3h to 6h; Preferably, the resistivity of the electric field-responsive CO2 hydrogenation to methanol catalyst after reduction and activation is 2Ω~15Ω.

9. The application according to claim 7 or 8, characterized in that, The power of the direct current in the electrothermally coupled CO2 hydrogenation to methanol reaction is 0.1W~3W; Preferably, the reaction temperature of the electrothermally coupled CO2 hydrogenation to methanol reaction is 180℃~240℃; Preferably, the reaction pressure of the electrothermally coupled CO2 hydrogenation to methanol reaction is 2 MPa to 5 MPa.

10. The application according to any one of claims 7 to 9, characterized in that, The feed gas for the electrothermally coupled CO2 hydrogenation to methanol reaction is CO2 and H2. Preferably, the molar ratio of CO2 to H2 in the raw gas is 1:(1~6); Preferably, the reaction space velocity is 3000 mL / g / h to 9000 mL / g / h.

Images