A supported metal oxide catalyst, its preparation method and use

Abstract

The application provides a supported metal oxide catalyst and a preparation method and application thereof, the catalyst comprising a carrier and an active component, wherein the carrier is alumina, the active component comprises one or more of copper oxide, zinc oxide, zirconium oxide and indium oxide, and the loading amount of the active component is 10wt%-40wt%. By optimizing the synthesis method, the active metal is in-situ grown on the pseudo-boehmite precursor, and through subsequent heat treatment, the active metal center is uniformly dispersed on the carrier, thereby forming a strong metal-carrier interaction. Based on this, by adjusting the synthesis and calcination conditions, the electronic structure of the metal oxide center can be optimized, thereby improving the intrinsic activity.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a multi-metal oxide catalyst, its preparation method, and its application. Background Technology

[0002] With the rapid development of the economy and society, the significance of CO2 resource utilization has gradually gained attention. Based on this, developing green and efficient carbon-reducing chemical processes can reduce carbon dioxide emissions in industrial production. However, for some reactions, carbon dioxide, as a product or byproduct, is unavoidable in its generation and emission. Therefore, carbon resource utilization is an indispensable link. As a cheap, readily available, and environmentally friendly renewable carbon resource, carbon dioxide resource utilization can not only reduce carbon dioxide emissions but also provide green production technology routes, which is of great significance to green and sustainable development.

[0003] CO2 exhibits high thermodynamic inertness, typically requiring the introduction of high-energy H2 to promote activation. The key to achieving efficient CO2 hydrogenation lies in catalyst design. Currently, commonly used catalyst systems include Cu-based catalysts, noble metal catalysts, In2O3-based catalysts, and other novel catalytic systems. Researchers often employ defect design, morphology control, and interface optimization to modulate catalysts, thereby improving CO2 conversion and methanol yield to some extent. However, existing catalyst systems still suffer from high cost and poor stability, making it difficult to meet industrialization requirements. Summary of the Invention

[0004] To address the aforementioned challenges, this invention designs and develops novel carbon dioxide catalytic conversion materials by improving preparation methods and carrier regulation.

[0005] The purpose of this invention is to provide a supported metal oxide catalyst, the catalyst comprising a support and an active component, wherein the support is alumina, and the active component comprises one or more of copper oxide, zinc oxide, zirconium oxide and indium oxide, and the loading of the active component is 10-40 wt%.

[0006] According to one embodiment of the present invention, the above-mentioned catalyst is prepared by in-situ growth of active components on pseudoboehmite.

[0007] Another object of the present invention is to provide a method for preparing the above-mentioned catalyst, comprising the following steps:

[0008] S1. Weigh an appropriate amount of boehmite and disperse it evenly in water to obtain mixture A;

[0009] S2. Add the metal salt to the above mixture A, disperse it evenly, and then add dilute acid to make it gel-soluble, to obtain mixture B; the metal salt is one or more of copper salt, zinc salt, zirconium salt, and indium salt;

[0010] S3. At temperature T1, slowly add the alkaline solution to the above mixture B, adjust the pH of the solution to 8-11, and react for a certain time at temperature T2.

[0011] S4. After the reaction is complete, the catalyst is centrifuged, washed, dried, calcined, and then slowly cooled to room temperature to obtain the supported metal oxide catalyst.

[0012] The centrifugation refers to the centrifugation separation of a fully reacted solid-liquid mixture to obtain a solid product.

[0013] In-situ growth of active metals on the alumina precursor boehmite can effectively improve its anti-sintering ability, catalyst stability, carbon dioxide conversion rate, and methanol selectivity. Compared with other alumina precursors such as aluminum isopropoxide and aluminum nitrate, the special properties of boehmite result in a significantly improved carbon dioxide conversion rate and methanol selectivity for the prepared catalyst.

[0014] According to one embodiment of the present invention, in step S1, the mass ratio of pseudoboehmite to water is 2:1 to 1:10.

[0015] According to one embodiment of the present invention, in step S2, the metal salt is selected from one or more of its corresponding nitrate, hydrochloride, sulfate, and acetylacetone salt.

[0016] According to one embodiment of the present invention, in step S2, the dilute acid is one or more of dilute hydrochloric acid, dilute sulfuric acid, dilute nitric acid, and dilute acetic acid.

[0017] By adding dilute acid to a mixed solution of boehmite and metal salt to make it gelatinous, the selectivity of the target product methanol and the catalyst's resistance to sintering can be improved.

[0018] According to one embodiment of the present invention, the concentration of the dilute acid is 0.1-2.0 mol / L, and the volume ratio of the dilute acid to the mixture A is 1:40-1:2.

[0019] According to one embodiment of the present invention, in step S3, the alkaline solution is one or more of sodium carbonate solution, potassium carbonate solution, ammonium carbonate solution, sodium hydroxide solution, potassium hydroxide solution, and ammonia water, and the concentration of the alkaline solution is 0.5-5.0 mol / L.

[0020] According to one embodiment of the present invention, in step S3, the temperature T1 is 10-70°C; the temperature T2 is 40-80°C, preferably 60°C; and the reaction time is 12-48 hours, preferably 24 hours.

[0021] According to one embodiment of the present invention, in step S3, the pH of the solution is preferably adjusted to 9-11.

[0022] According to one embodiment of the present invention, in step S4, the calcination temperature is 300-450°C, preferably 300-400°C; the heating rate from the drying temperature to the calcination temperature is 2-5°C per minute, and the time is 2-8 hours, preferably 2 hours.

[0023] According to one embodiment of the present invention, in step S4, the roasting atmosphere is air.

[0024] Another object of the present invention is to provide the application of the above-described catalyst or the catalyst prepared by the above-described preparation method in the hydrogenation of carbon dioxide to methanol.

[0025] Beneficial effects:

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] 1. This invention utilizes an optimized synthesis method to grow active metals in situ on a pseudoboehmite precursor. Subsequent heat treatment induces the active metal centers to be uniformly dispersed on the support, thereby forming a strong metal-support interaction. Based on this, the electronic structure of the metal oxide centers can be optimized by controlling the synthesis and calcination conditions, thus improving its intrinsic activity.

[0028] 2. The present invention grows active metals in situ on the pseudoboehmite precursor of alumina raw materials, which can effectively improve its anti-sintering ability, improve catalyst stability, improve carbon dioxide conversion rate and target product selectivity.

[0029] 3. The catalyst of this invention uses non-precious metal raw materials, which are inexpensive, do not require the addition of additional template agents, have a simple preparation process, good reproducibility, and are easy to scale up for production.

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0031] Figure 1 This is a transmission electron microscope (TEM) image of the supported metal oxide catalyst prepared in Example 1.

[0032] Figure 2 This is the X-ray diffraction (XRD) pattern of the supported metal oxide catalyst prepared in Example 1. Detailed Implementation

[0033] The technical solution of the present invention will be further described below with reference to specific embodiments. The scope of protection of the present invention is not limited to the following embodiments; these examples are provided for illustrative purposes only and do not limit the present invention in any way.

[0034] In the context of this specification, except where expressly stated, any matters or issues not mentioned herein are directly applicable to matters known in the art without modification. Furthermore, any embodiments described herein can be freely combined with one or more other embodiments described herein, and any resulting technical solutions or concepts shall be considered part of the original disclosure or original record of this invention, and should not be regarded as new content not disclosed or anticipated herein, unless those skilled in the art consider such combination to be clearly unreasonable.

[0035] Carbon dioxide hydrogenation activity test

[0036] The catalytic hydrogenation activity of carbon dioxide was tested using a fixed-bed microreactor. The feed gases were H2, CO2, and Ar in a volume ratio of 72:24:4, and the space velocity was 8000 mL·g. -1 ·min -1 The catalyst loading was 0.2 g, the silica sand content was 3.8 g, the reaction temperature was 200-300℃, and the sample analysis was performed using a chromatogram equipped with a flame ionization detector and a thermal conductivity detector.

[0037] Example 1:

[0038] Weigh 100 g of boehmite into 100 mL of water and disperse evenly. Add 15 g of copper nitrate to obtain a mixture. While stirring, add 10 mL of 0.5 mol / L dilute hydrochloric acid solution dropwise and continue stirring for 1 hour. Prepare a 1.0 mol / L sodium carbonate aqueous solution and slowly add it to the above mixture at a constant temperature of 40℃. Adjust the pH of the solution to 9.0. After reacting completely at 60℃ for 24 hours, centrifuge, wash, and dry. Calcinate in air at 300℃ for 2 hours at a heating rate of 2℃ per minute. After cooling to room temperature, the supported metal oxide catalyst is obtained. (Appendix) Figure 1 The image shows a TEM image of the supported metal oxide catalyst, revealing small particle size and good crystallinity. As shown in Appendix Table 1, in Example 1, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 11.0%, the methanol selectivity was 78.9%, the carbon monoxide selectivity was 19.5%, and the methane selectivity was 1.6%.

[0039] Example 2:

[0040] 100 g of boehmite was weighed and dispersed evenly in 100 mL of water. 15 g of indium nitrate was added to obtain a mixture. 5 mL of 0.5 mol / L dilute hydrochloric acid solution was added dropwise while stirring, and stirring continued for 1 hour. A 0.5 mol / L potassium carbonate aqueous solution was prepared and slowly added to the above mixture at a constant temperature of 40°C. The pH of the solution was adjusted to 10.0, and the mixture was reacted thoroughly at 70°C for 24 hours. After centrifugation, washing, and drying, the mixture was calcined at 300°C in air for 2 hours at a heating rate of 2°C per minute. After cooling to room temperature, the supported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Example 2, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 12.3%, the methanol selectivity was 72.3%, the carbon monoxide selectivity was 24.1%, and the methane selectivity was 3.6%.

[0041] Example 3:

[0042] 100 g of boehmite was weighed and dispersed evenly in 100 mL of water. 7.5 g of zinc nitrate and 7.5 g of zirconium nitrate were added to obtain a mixture. 5 mL of 0.5 mol / L dilute hydrochloric acid solution was added dropwise while stirring, and stirring was continued for 1 hour. A 0.5 mol / L sodium hydroxide aqueous solution was prepared and slowly added to the above mixture at a constant temperature of 40°C. The pH of the solution was adjusted to 9.0, and the mixture was reacted thoroughly at 60°C for 48 hours. After centrifugation, washing, and drying, the mixture was calcined at 300°C in air for 2 hours at a heating rate of 2°C per minute. After cooling to room temperature, the supported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Example 3, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 14.2%, the methanol selectivity was 78.0%, the carbon monoxide selectivity was 20.0%, and the methane selectivity was 2.0%.

[0043] Example 4:

[0044] 100 g of boehmite was weighed and dispersed evenly in 100 mL of water. 15 g of copper nitrate and 7.5 g of zinc nitrate were added to obtain a mixture. 10 mL of 0.5 mol / L dilute hydrochloric acid solution was added dropwise while stirring, and stirring continued for 1 hour. A 0.5 mol / L sodium carbonate aqueous solution was prepared and slowly added to the above mixture at a constant temperature of 40°C. The pH of the solution was adjusted to 9.0, and the mixture was reacted thoroughly at 60°C for 24 hours. After centrifugation, washing, and drying, the mixture was calcined at 350°C in air for 2 hours at a heating rate of 2°C per minute. After cooling to room temperature, the supported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Example 4, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 11.9%, the methanol selectivity was 82.3%, the carbon monoxide selectivity was 16.5%, and the methane selectivity was 1.2%.

[0045] Example 5:

[0046] 100 g of boehmite was weighed and dispersed evenly in 100 mL of water. 7.5 g of copper nitrate and 20.0 g of indium nitrate were added to obtain a mixture. 5 mL of 0.5 mol / L dilute hydrochloric acid solution was added dropwise while stirring, and stirring continued for 1 hour. A 0.5 mol / L potassium hydroxide aqueous solution was prepared and slowly added to the above mixture at a constant temperature of 50°C. The pH of the solution was adjusted to 11.0, and the mixture was reacted completely at 60°C for 24 hours. After centrifugation, washing, and drying, the mixture was calcined at 400°C in air for 2 hours at a heating rate of 2°C per minute. After cooling to room temperature, the supported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Example 5, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 16.7%, the methanol selectivity was 75.5%, the carbon monoxide selectivity was 23.6%, and the methane selectivity was 0.9%.

[0047] Example 6:

[0048] 100 g of boehmite was weighed and dispersed evenly in 100 mL of water. 7.5 g of indium nitrate and 7.5 g of zinc nitrate were added to obtain a mixture. 10 mL of 1.0 mol / L dilute hydrochloric acid solution was added dropwise while stirring, and stirring continued for 1 hour. A 1.0 mol / L sodium hydroxide aqueous solution was prepared and slowly added to the above mixture at a constant temperature of 40°C. The pH of the solution was adjusted to 9.0, and the mixture was reacted completely at 60°C for 24 hours. After centrifugation, washing, and drying, the mixture was calcined at 300°C in air for 2 hours at a heating rate of 2°C per minute. After cooling to room temperature, the supported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Example 6, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 17.4%, the methanol selectivity was 69.8%, the carbon monoxide selectivity was 29.7%, and the methane selectivity was 0.5%.

[0049] Example 7:

[0050] 100 g of boehmite was weighed and dispersed evenly in 100 mL of water. 5 g of indium nitrate, 5 g of copper nitrate, and 5 g of zinc nitrate were added to obtain a mixture. While stirring, 5 mL of 0.5 mol / L dilute hydrochloric acid solution was added dropwise to dissolve the boehmite. Stirring was continued for 1 hour. A 0.5 mol / L potassium carbonate aqueous solution was prepared and slowly added to the above mixture at a constant temperature of 50°C. The pH of the solution was adjusted to 10.0. After reacting fully at 70°C for 24 hours, the solution was centrifuged, washed, and dried. It was then calcined at 300°C in air for 2 hours at a heating rate of 2°C per minute. After cooling to room temperature, the supported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Example 7, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 16.9%, the methanol selectivity was 71.3%, the carbon monoxide selectivity was 19.2%, and the methane selectivity was 9.5%.

[0051] Example 8:

[0052] 100 g of boehmite was weighed and dispersed evenly in 100 mL of water. 5 g of copper nitrate, 5 g of zinc nitrate, and 5 g of zirconium nitrate were added to obtain a mixture. While stirring, 5 mL of 0.5 mol / L dilute hydrochloric acid solution was added dropwise to dissolve the boehmite. Stirring was continued for 1 hour. A 0.5 mol / L potassium carbonate aqueous solution was prepared and slowly added to the above mixture at a constant temperature of 40°C. The pH of the solution was adjusted to 10.0. After reacting fully at 70°C for 24 hours, the mixture was centrifuged, washed, and dried. It was then calcined at 300°C in air for 2 hours at a heating rate of 2°C per minute. After cooling to room temperature, the supported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Example 8, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 12.3%, the methanol selectivity was 76.1%, the carbon monoxide selectivity was 18.6%, and the methane selectivity was 5.3%.

[0053] Example 9:

[0054] 100 g of boehmite was weighed and dispersed evenly in 100 mL of water. 5 g of copper nitrate, 5 g of zinc nitrate, 5 g of indium nitrate, and 5 g of zirconium nitrate were added to obtain a mixture. While stirring, 5 mL of 0.5 mol / L dilute hydrochloric acid solution was added dropwise to dissolve the boehmite. Stirring was continued for 1 hour. A 0.5 mol / L potassium carbonate aqueous solution was prepared and slowly added to the above mixture at a constant temperature of 40°C. The pH of the solution was adjusted to 10.0. After reacting fully at 70°C for 24 hours, the solution was centrifuged, washed, and dried. It was then calcined at 300°C in air for 2 hours at a heating rate of 2°C per minute. After cooling to room temperature, the supported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Example 9, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 18.5%, the methanol selectivity was 85.5%, the carbon monoxide selectivity was 14.2%, and the methane selectivity was 0.3%.

[0055] Furthermore, comparative experiments confirmed that support optimization and in-situ loading play a crucial role in improving catalyst performance. The specific schemes are as follows:

[0056] Comparative Example 1:

[0057] 20 g of copper nitrate and 5 g of zinc nitrate were weighed and dispersed evenly in 100 mL of water to prepare a 0.5 mol / L sodium carbonate aqueous solution. This mixture was slowly added to the solution at a constant temperature of 40℃, and the pH was adjusted to 9.0. After reacting completely at 60℃ for 24 hours, the solution was centrifuged, washed, and dried. It was then calcined at 300℃ for 2 hours at a heating rate of 2℃ per minute. After cooling to room temperature, the unsupported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Comparative Example 1, at a reaction temperature of 280℃, the carbon dioxide conversion rate was 7.5%, the methanol selectivity was 46.9%, the carbon monoxide selectivity was 42.8%, and the methane selectivity was 10.3%.

[0058] Comparative Example 2:

[0059] Weigh 20 g of copper nitrate and 20 g of indium nitrate into 100 mL of water and disperse evenly. Prepare a 0.5 mol / L sodium carbonate aqueous solution and slowly add the above mixture at a constant temperature of 40℃. Adjust the pH of the solution to 9.0, and react fully at 60℃ for 24 hours. After centrifugation, washing, and drying, calcine at 400℃ for 2 hours with a heating rate of 2℃ per minute. After cooling to room temperature, the unsupported metal oxide catalyst is obtained. As shown in Appendix Table 1, in Comparative Example 2, at a reaction temperature of 280℃, the carbon dioxide conversion rate is 4.8%, the methanol selectivity is 51.7%, the carbon monoxide selectivity is 47.2%, and the methane selectivity is 1.1%.

[0060] Comparative Example 3:

[0061] Weigh 50 g of alumina into 100 mL of water and disperse it evenly. Add 15 g of copper nitrate and 7.5 g of zinc nitrate, and stir for 1 hour to obtain a mixture. Prepare a 0.5 mol / L sodium carbonate aqueous solution, and slowly add the above mixture at a constant temperature of 40℃. Adjust the pH of the solution to 9.0, and react fully at 60℃ for 24 hours. After centrifugation, washing, and drying, calcine at 350℃ in air for 2 hours at a heating rate of 2℃ per minute. After cooling to room temperature, the supported metal oxide catalyst is obtained. As shown in Appendix Table 1, in Comparative Example 3, at a reaction temperature of 280℃, the carbon dioxide conversion rate is 2.1%, the methanol selectivity is 64.5%, the carbon monoxide selectivity is 30.3%, and the methane selectivity is 5.2%.

[0062] Comparative Example 4:

[0063] Weigh 15 g of copper nitrate and 7.5 g of zinc nitrate, and stir for 1 hour to obtain a mixture. Prepare a 0.5 mol / L sodium carbonate aqueous solution, and slowly add the above mixture at a constant temperature of 40℃. Adjust the pH of the solution to 9.0, add 50 g of alumina, and react fully at 60℃ for 24 hours. After centrifugation, washing, and drying, calcine at 350℃ in air for 2 hours at a heating rate of 2℃ per minute. After cooling to room temperature, the supported metal oxide catalyst is obtained. As shown in Appendix Table 1, in Comparative Example 4, at a reaction temperature of 280℃, the carbon dioxide conversion rate is 4.2%, the methanol selectivity is 66.2%, the carbon monoxide selectivity is 31.3%, and the methane selectivity is 2.5%.

[0064] Comparative Example 5:

[0065] 100 g of aluminum nitrate was weighed and dispersed evenly in 100 mL of water. 5 g of copper nitrate, 5 g of zinc nitrate, and 5 g of zirconium nitrate were added to obtain a mixture. A 0.5 mol / L potassium carbonate aqueous solution was prepared, and the mixture was slowly added at a constant temperature of 40°C. The pH of the solution was adjusted to 10.0, and the reaction was carried out at 70°C for 24 hours. After centrifugation, washing, and drying, the catalyst was calcined at 300°C in air for 2 hours at a heating rate of 2°C per minute. After cooling to room temperature, the supported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Comparative Example 5, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 4.5%, the methanol selectivity was 67.0%, the carbon monoxide selectivity was 28.4%, and the methane selectivity was 4.6%.

[0066] Comparative Example 6:

[0067] 100 g of boehmite was weighed and dispersed evenly in 100 mL of water. 5 g of copper nitrate, 5 g of zinc nitrate, 5 g of indium nitrate, and 5 g of zirconium nitrate were added to obtain a mixture. A 0.5 mol / L potassium carbonate aqueous solution was prepared, and the above mixture was slowly added at a constant temperature of 40℃. The pH of the solution was adjusted to 10.0, and the mixture was reacted completely at 70℃ for 24 hours. After centrifugation, washing, and drying, the catalyst was calcined at 300℃ in air for 2 hours at a heating rate of 2℃ per minute. After cooling to room temperature, the supported metal oxide catalyst was obtained. As shown in Appendix Table 1, in Comparative Example 6, at a reaction temperature of 280℃, the carbon dioxide conversion rate was 3.9%, the methanol selectivity was 59.0%, the carbon monoxide selectivity was 37.6%, and the methane selectivity was 3.4%.

[0068] Comparative Example 7

[0069] Weigh 100 g of boehmite into 100 mL of water and disperse evenly. While stirring, add 10 mL of 0.5 mol / L dilute hydrochloric acid solution dropwise. After stirring for 30 minutes, add 15 g of copper nitrate and continue stirring for 1 hour. Prepare a 1.0 mol / L sodium carbonate aqueous solution and slowly add it to the above mixture at a constant temperature of 40℃. Adjust the pH of the solution to 9.0. After reacting completely at 60℃ for 24 hours, centrifuge, wash, and dry. Calcinate in air at 300℃ for 2 hours at a heating rate of 2℃ per minute. After cooling to room temperature, the supported metal oxide catalyst is obtained. Figure 1 The image shows a TEM image of the supported metal oxide catalyst, revealing small particle size and good crystallinity. As shown in Appendix Table 1, in Example 1, at a reaction temperature of 280°C, the carbon dioxide conversion rate was 11.0%, the methanol selectivity was 78.9%, the carbon monoxide selectivity was 19.5%, and the methane selectivity was 1.6%.

[0070] Table 1 shows the test results of the carbon dioxide catalytic reduction performance of the supported metal oxide catalysts.

[0071] Table 1

[0072]

[0073] As can be seen from the data in Table 1 of the examples and comparative examples, the catalyst prepared by the method of in-situ growth of active metal on boehmite precursor of the present invention has high conversion rate and methanol selectivity. Compared with other aluminum sources, boehmite as an aluminum source catalyst has higher activity. Furthermore, the addition of dilute acid can further improve the catalyst activity, resulting in higher conversion rate and methanol selectivity.

Claims

1. A supported metal oxide catalyst, characterized in that, The catalyst comprises a support and an active component, wherein the support is alumina, and the active component comprises one or more of copper oxide, zinc oxide, zirconium oxide and indium oxide, wherein the loading of the active component is 10-40 wt%; the raw material precursor of the alumina support is boehmite. The method for preparing the catalyst includes the following steps: S1. Weigh an appropriate amount of boehmite and disperse it evenly in water to obtain mixture A; S2. Add the metal salt to the above mixture A, disperse it evenly, and then add dilute acid to make it gel-soluble, to obtain mixture B; the metal salt is one or more of copper salt, zinc salt, zirconium salt, and indium salt; S3. At temperature T1, slowly add the alkaline solution to the above mixture B, adjust the pH of the solution to 8-11, and react for a certain time at temperature T2. S4. After the reaction is complete, centrifuge, wash, dry, calcine, and cool to room temperature to obtain the supported metal oxide catalyst. In step S3, the temperature T1 is 10-70℃, the temperature T2 is 40-80℃, the alkaline solution is one or more of sodium carbonate solution, potassium carbonate solution, ammonium carbonate solution, sodium hydroxide solution, potassium hydroxide solution, and ammonia water, and the concentration of the alkaline solution is 0.5-5.0 mol / L.

2. The catalyst according to claim 1, characterized in that, The catalyst is prepared by in-situ growth of active components on a pseudoboehmite precursor of alumina raw materials.

3. The method for preparing the catalyst according to claim 1 or 2, characterized in that, Includes the following steps: S1. Weigh an appropriate amount of boehmite and disperse it evenly in water to obtain mixture A; S2. Add the metal salt to the above mixture A, disperse it evenly, and then add dilute acid to make it gel-soluble, to obtain mixture B; the metal salt is one or more of copper salt, zinc salt, zirconium salt, and indium salt; S3. At temperature T1, slowly add the alkaline solution to the above mixture B and adjust the pH of the solution to 8-11; react for a certain time at temperature T2. S4. After the reaction is complete, centrifuge, wash, dry, calcine, and cool to room temperature to obtain the supported metal oxide catalyst. In step S3, the temperature T1 is 10-70℃, the temperature T2 is 40-80℃, the alkaline solution is one or more of sodium carbonate solution, potassium carbonate solution, ammonium carbonate solution, sodium hydroxide solution, potassium hydroxide solution, and ammonia water, and the concentration of the alkaline solution is 0.5-5.0 mol / L.

4. The preparation method according to claim 3, characterized in that, In step S1, the mass ratio of the pseudoboehmite to water is 2:1 to 1:

10.

5. The preparation method according to claim 3, characterized in that, In step S2, the metal salt is selected from one or more of its corresponding nitrate, hydrochloride, sulfate, and acetylacetone salt.

6. The preparation method according to claim 3, characterized in that, In step S2, the dilute acid is one or more of dilute hydrochloric acid, dilute sulfuric acid, dilute nitric acid, and dilute acetic acid.

7. The preparation method according to claim 6, characterized in that, The concentration of the dilute acid is 0.1-2.0 mol / L, and the volume ratio of the dilute acid to the mixture A is 1:40-1:

2.

8. The preparation method according to claim 3, characterized in that, In step S3, the pH of the solution is adjusted to 9-11; and / or In step S3, the temperature T2 is 40-80℃, and the reaction time is 12-48 hours; and / or, In step S4, the calcination temperature is 300-450℃ and the calcination time is 2-8 hours.

9. The preparation method according to claim 8, characterized in that, In step S3, the temperature T2 is 60°C, and the reaction time is 24 hours; and / or, In step S4, the calcination temperature is 300-400℃ and the calcination time is 2 hours.

10. The application of the catalyst according to any one of claims 1-2 or the catalyst prepared by any one of claims 3-9 in the hydrogenation of carbon dioxide to methanol.

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