Cu and Ga synergistically modified CdZrOx solid solution catalyst as well as preparation method and application thereof

Abstract

The invention discloses a Cu and Ga synergistically modified CdZrOx solid solution catalyst and a preparation method and application thereof.The preparation method comprises the steps that Cd (NO3) 2 hydrate, Zr (NO3) 4 hydrate, Ga (NO3) 3 hydrate and Cu (NO3) 2 hydrate are weighed and evenly mixed with water, then water bath is conducted, a precipitator is dropwise added into the mixture, then precipitates are taken out, centrifuged and washed, and the obtained precipitates are dried and calcined. The CdZrOx solid solution catalyst with abundant specific surface area and surface defect sites is obtained through synergistic modification of Cu and Ga, adsorption and activation of CO2 are promoted, and the generation rate and further hydrogenation performance of an intermediate are accelerated through synergistic modification of Cu and Ga. In addition, the catalyst is simple in preparation method, low in preparation cost and not easy to sinter and inactivate. The catalyst is applied to a CO2 hydrogenation reaction, and efficient conversion of CO2 can be achieved under low pressure.

Description

Technical Field

[0001] This invention pertains to catalysts, their preparation methods and applications, specifically Cu and Ga synergistic modification of CdZrOx solid solution catalysts, their preparation methods and applications. Background Technology

[0002] With the increasing population and continuous development of industrial and agricultural production, the concentration of carbon dioxide in the atmosphere has increased significantly, triggering global warming and leading to environmental problems such as extreme weather, drying in subtropical regions, glacial melting, and rising sea levels, bringing numerous disasters to the Earth, which is inextricably linked to human survival and development. High-value chemicals, such as methanol, which is produced by hydrogenating CO2, can not only alleviate a series of environmental problems caused by excessive CO2 emissions, but also utilize CO2 resources to reduce current dependence on chemical fuels. Therefore, using hydrogen sources such as "green hydrogen" to catalytically hydrogenate CO2 into methanol under certain temperature and pressure conditions is a highly promising carbon resource utilization route.

[0003] Cu-based catalysts, as a research hotspot and one of the mainstream industrial catalysts in the field of CO2 hydrogenation to methanol, possess advantages such as good CO2 and H2 adsorption and activation capabilities, and high activity under low-temperature conditions. However, numerous studies have shown that Cu-based catalysts suffer from poor thermal stability, easy sintering and deactivation of Cu nanoparticles at high temperatures, and low methanol selectivity. Solid solution catalysis can effectively avoid the problem of Cu aggregation caused by water during the catalytic process of copper-based catalysts. Furthermore, solid solution catalysts have advantages such as more lattice defects, abundant oxygen vacancies, and resistance to high-temperature sintering. However, the catalytic activity of solid solution catalysts at low pressures (2~3 MPa) still needs further improvement.

[0004] Therefore, how to improve the activity and stability of catalysts under low pressure and overcome the above-mentioned defects has become one of the focal issues of concern for researchers. Summary of the Invention

[0005] Purpose of the invention: To overcome the shortcomings of existing technologies, the purpose of this invention is to provide a simple, convenient, and low-cost method for synergistic modification of CdZrO by Cu and Ga. x Another objective of this invention is to provide a Cu and Ga synergistic modification of CdZrO with high methanol yield, high catalytic activity, and long service life. x Another object of the present invention is to provide a Cu and Ga synergistic modified CdZrO catalyst. x Application of solid solution catalysts in the catalytic hydrogenation of CO2 to methanol.

[0006] Technical solution: The present invention describes a Cu and Ga synergistic modification of CdZrO xThe preparation method of solid solution catalyst involves weighing Cd(NO3)2 hydrate, Zr(NO3)4 hydrate, Ga(NO3)3 hydrate, and Cu(NO3)2 hydrate, mixing them evenly with water, placing the mixture in a water bath, adding a precipitant dropwise, removing the precipitate, centrifuging and washing it, drying and calcining the resulting precipitate to obtain Cu and Ga synergistically modified CdZrO. x Solid solution catalyst.

[0007] Furthermore, the molar ratio of Cd, Zr, Ga, and Cu is 1:4:0.26:0.011~0.58.

[0008] Furthermore, the water bath temperature is 65~75℃.

[0009] Furthermore, the precipitant is ammonium carbonate.

[0010] Furthermore, the rate of adding the precipitant is 1~10 mL / min.

[0011] Furthermore, the drying temperature is 70~150℃, and the drying time is 4~24 h.

[0012] Furthermore, the calcination temperature is 300~900℃, and the calcination time is 1~8 h.

[0013] Furthermore, Cd(NO3)2 hydrate is Cd(NO3)2·4H2O, Zr(NO3)4 hydrate is Zr(NO3)4·5H2O, Ga(NO3)3 hydrate is Ga(NO3)3, and Cu(NO3)2 hydrate is Cu(NO3)2·3H2O.

[0014] The Cu and Ga synergistic modification of CdZrO obtained by the above preparation method x Solid solution catalysts, including Cu, Ga and CdZrO x For solid solutions, x represents the number of moles of O atoms required to produce the corresponding molar amount of metal atoms at the given metal valence.

[0015] The Cu and Ga synergistic modification of CdZrO described in this invention x Application of solid solution catalysts in the catalytic hydrogenation of CO2 to methanol.

[0016] Furthermore, the molar ratio of hydrogen to carbon dioxide in the CO2 hydrogenation to methanol reaction is 3:1 to 9:1, the reaction pressure is 2 to 3 MPa, the reaction space velocity is 3000 to 48000 mL / g·h, and the reaction temperature is 220 to 340℃.

[0017] Preparation Principle: The improved catalyst performance is mainly attributed to the synergistic effect between Cu and Ga sites. This synergistic effect significantly increases the oxygen vacancy density of the Cu-Ga co-modified catalyst, thereby enhancing its adsorption and activation capacity for CO2 and promoting the formation of carbonate and bicarbonate species. Furthermore, the highly dispersed Cu and Ga play crucial roles in promoting H2 dissociation and activation, which further accelerates the conversion of carbon-containing intermediates to methanol via the formate pathway. Ultimately, this leads to an increase in methanol yield.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0019] 1. The obtained catalyst was applied to the CO2 hydrogenation to methanol reaction, achieving efficient CO2 conversion under relatively low pressure conditions and significantly improving the methanol yield. The highest yield of methanol was 373 mg·g under test conditions of 320℃, 3MPa, and 24000 mL / g·h. cat -1 h -1 The obtained catalyst exhibited high stability, with a methanol yield consistently maintained at 373 mg∙g under low-pressure conditions for 100 hours. cat -1 h -1 There were no significant fluctuations observed on either side.

[0020] 2. The catalyst preparation method is simple and low in cost. The co-precipitation method can synthesize solid solutions with single crystal form, large specific surface area and stable structure, which is suitable for large-scale industrial production.

[0021] 3. Due to the increased specific surface area of ​​the solid solution catalyst and the introduction of Ga, both promote the high dispersion of active metal Cu on the catalyst surface, thereby inhibiting Cu sintering deactivation and improving the service life of Cu-containing solid solution catalysts. Attached Figure Description

[0022] Figure 1 These are the XRD patterns of the solid solution catalysts prepared in Examples 1-4 and Comparative Examples 1-3 of this invention;

[0023] Figure 2 These are the CO2 conversion rate test results of the solid solution catalysts prepared in Examples 1-4 and Comparative Example 1 of this invention at different temperatures;

[0024] Figure 3 This is the long-term stability evaluation result of the solid solution catalyst prepared in Example 1 of this invention under a reaction pressure of 3 MPa;

[0025] Figure 4These are the BET test results of the solid solution catalysts prepared in Example 1 and Comparative Example 1 of this invention;

[0026] Figure 5 This is the carbon dioxide temperature programmed desorption curve (CO2-TPD) of the solid solution catalysts prepared in Example 1 and Comparative Example 1 of this invention.

[0027] Figure 6 The above are XPS characterization results of the solid solution catalysts prepared in Example 1 and Comparative Example 1 of this invention. Detailed Implementation

[0028] Unless otherwise specified, all materials and reagents used in the following examples are commercially available. Experimental methods not specifically described in the examples are generally performed under standard conditions or as recommended by the manufacturer. CdZrO x In a solid solution, x represents the number of moles of O atoms required to represent the molar amount of metal atoms at the corresponding valence.

[0029] Example 1

[0030] A Cu and Ga synergistic modification of CdZrO x A method for preparing a solid solution catalyst includes the following steps:

[0031] Weigh Cd(NO3)2·4H2O and Zr(NO3)4·5H2O according to a Cd / (Cd+Zr) molar ratio of 1:5. Simultaneously, weigh the modifier Ga(NO3)3 according to a Ga / (Ga+Cd+Zr) molar ratio of 5:100, and weigh the modifier Cu(NO3)2·3H2O according to a Cu / (Cu+Ga+Cd+Zr) molar ratio of 2:100. That is, the molar ratio of Cd, Zr, Ga, and Cu is 1:4:0.26:0.11. After uniformly mixing the four nitrates with 350 ml of H2O, add 1 M ammonium carbonate precipitant dropwise to the well-mixed nitrate solution at a rate of 3 mL / min in a 70℃ water bath. After the precipitant is added, the resulting precipitate is aged (dried) at 70℃ for 2 hours. Then, the precipitate is removed, centrifuged and washed. The resulting precipitate is dried at 110℃ for 12 hours and then placed in a muffle furnace and calcined at 500℃ for 3 hours at a heating rate of 5℃ / min to obtain a solid solution catalyst.

[0032] Example 2

[0033] A Cu and Ga synergistic modification of CdZrO x A method for preparing a solid solution catalyst includes the following steps:

[0034] Weigh Cd(NO3)2·4H2O and Zr(NO3)4·5H2O according to a Cd / (Cd+Zr) molar ratio of 1:5. Simultaneously, weigh the modifier Ga(NO3)3 according to a Ga / (Ga+Cd+Zr) molar ratio of 5:100, and weigh the modifier Cu(NO3)2·3H2O according to a Cu / (Cu+Ga+Cd+Zr) molar ratio of 0.2:100. That is, the molar ratio of Cd, Zr, Ga, and Cu is 1:4:0.26:0.011. After uniformly mixing the four nitrates with 350 ml of H2O, add 1 M ammonium carbonate precipitant dropwise to the well-mixed nitrate solution at a rate of 3 mL / min in a 70℃ water bath. After the precipitant is added dropwise, the resulting precipitate is aged at 70℃ for 2 h. Then, the precipitate is removed, centrifuged and washed. The resulting precipitate is dried at 110℃ for 12 h and then placed in a muffle furnace and calcined at 500℃ for 3 h at a heating rate of 5 ℃ / min to obtain a solid solution catalyst.

[0035] Example 3

[0036] A Cu and Ga synergistic modification of CdZrO x A method for preparing a solid solution catalyst includes the following steps:

[0037] Weigh Cd(NO3)2·4H2O and Zr(NO3)4·5H2O according to a Cd / (Cd+Zr) molar ratio of 1:5. Simultaneously, weigh the modifier Ga(NO3)3 according to a Ga / (Ga+Cd+Zr) molar ratio of 5:100, and weigh the modifier Cu(NO3)2·3H2O according to a Cu / (Cu+Ga+Cd+Zr) molar ratio of 5:100. That is, the molar ratio of Cd, Zr, Ga, and Cu is 1:4:0.26:0.28. After uniformly mixing the four nitrates with 350 ml of H2O, add 1 M ammonium carbonate precipitant dropwise to the well-mixed nitrate solution at a dropping rate of 3 mL / min in a 70℃ water bath. After the precipitant is added dropwise, the resulting precipitate is aged at 70℃ for 2 h. Then, the precipitate is removed, centrifuged and washed. The resulting precipitate is dried at 110℃ for 12 h and then placed in a muffle furnace and calcined at 500℃ for 3 h at a heating rate of 5 ℃ / min to obtain a solid solution catalyst.

[0038] Example 4

[0039] A Cu and Ga synergistic modification of CdZrO x A method for preparing a solid solution catalyst includes the following steps:

[0040] Weigh Cd(NO3)2·4H2O and Zr(NO3)4·5H2O according to a Cd / (Cd+Zr) molar ratio of 1:5. Simultaneously, weigh the modifier Ga(NO3)3 according to a Ga / (Ga+Cd+Zr) molar ratio of 5:100, and weigh the modifier Cu(NO3)2·3H2O according to a Cu / (Cu+Ga+Cd+Zr) molar ratio of 10:100. That is, the molar ratio of Cd, Zr, Ga, and Cu is 1:4:0.26:0.58. After uniformly mixing the four nitrates with 350 ml of H2O, add 1 M ammonium carbonate precipitant dropwise to the well-mixed nitrate solution at a rate of 3 mL / min in a 70℃ water bath. After the precipitant is added dropwise, the resulting precipitate is aged at 70℃ for 2 h. Then, the precipitate is removed, centrifuged and washed. The resulting precipitate is dried at 110℃ for 12 h and then placed in a muffle furnace and calcined at 500℃ for 3 h at a heating rate of 5 ℃ / min to obtain a solid solution catalyst.

[0041] Example 5

[0042] A Cu and Ga synergistic modification of CdZrO x A method for preparing a solid solution catalyst includes the following steps:

[0043] Weigh Cd(NO3)2·4H2O and Zr(NO3)4·5H2O according to a Cd / (Cd+Zr) molar ratio of 1:5. Simultaneously, weigh the modifier Ga(NO3)3 according to a Ga / (Ga+Cd+Zr) molar ratio of 5:100, and weigh the modifier Cu(NO3)2·3H2O according to a Cu / (Cu+Ga+Cd+Zr) molar ratio of 2:100. That is, the molar ratio of Cd, Zr, Ga, and Cu is 1:4:0.26:0.11. After uniformly mixing the four nitrates with 350 ml of H2O, add 1 M ammonium carbonate precipitant dropwise to the well-mixed nitrate solution at a rate of 1 mL / min in a 65℃ water bath. After the precipitant is added dropwise, the resulting precipitate is aged at 70°C for 2 hours. Then, the precipitate is removed, centrifuged, and washed. The resulting precipitate is dried at 150°C for 24 hours and then placed in a muffle furnace and calcined at 300°C at a heating rate of 5°C / min for 8 hours to obtain the solid solution catalyst.

[0044] Example 6

[0045] A Cu and Ga synergistic modification of CdZrO x A method for preparing a solid solution catalyst includes the following steps:

[0046] Weigh Cd(NO3)2·4H2O and Zr(NO3)4·5H2O according to a Cd / (Cd+Zr) molar ratio of 1:5. Simultaneously, weigh the modifier Ga(NO3)3 according to a Ga / (Ga+Cd+Zr) molar ratio of 5:100, and weigh the modifier Cu(NO3)2·3H2O according to a Cu / (Cu+Ga+Cd+Zr) molar ratio of 2:100. That is, the molar ratio of Cd, Zr, Ga, and Cu is 1:4:0.26:0.11. After uniformly mixing the four nitrates with 350 ml of H2O, add 1 M ammonium carbonate precipitant dropwise to the well-mixed nitrate solution at a rate of 10 mL / min in a 75°C water bath. After the precipitant is added, the resulting precipitate is aged at 70°C for 2 hours. Then, the precipitate is removed, centrifuged, and washed. The resulting precipitate is dried at 150°C for 4 hours and then placed in a muffle furnace and calcined at 900°C for 1 hour at a heating rate of 5°C / min to obtain the solid solution catalyst.

[0047] Comparative Example 1

[0048] The preparation method of the solid solution catalyst specifically includes: weighing Cd(NO3)2·4H2O and Zr(NO3)4·5H2O according to a Cd / (Cd+Zr) molar ratio of 1:5; uniformly mixing the two nitrates with 350 ml of H2O; and then adding 1 M of ammonium carbonate precipitant dropwise to the uniformly mixed nitrate solution at a rate of 3 mL / min in a 70°C water bath. After the precipitant addition is complete, the resulting precipitate is aged at 70°C for 2 h, then the precipitate is removed, centrifuged, and washed. The resulting precipitate is dried at 110°C for 12 h, and then calcined in a muffle furnace at a heating rate of 5 °C / min to 500°C for 3 h to obtain the solid solution catalyst.

[0049] Comparative Example 2

[0050] The preparation method of the solid solution catalyst specifically includes: weighing Cd(NO3)2·4H2O and Zr(NO3)4·5H2O according to a Cd / (Cd+Zr) molar ratio of 1:5, and simultaneously weighing the modifier Ga(NO3)3 hydrate according to a Ga / (Ga+Cd+Zr) molar ratio of 5:100. After uniformly mixing the three nitrates with 350 ml of H2O, 1 M of ammonium carbonate precipitant is added dropwise to the uniformly mixed nitrate solution at a rate of 3 mL / min in a 70℃ water bath. After the precipitant addition is complete, the resulting precipitate is aged at 70℃ for 2 h, then the precipitate is removed, centrifuged, and washed. The resulting precipitate is dried at 110℃ for 12 h, and then calcined in a muffle furnace at a heating rate of 5℃ / min to 500℃ for 3 h to obtain the solid solution catalyst.

[0051] Comparative Example 3

[0052] The preparation method of the solid solution catalyst specifically includes: weighing Cd(NO3)2·4H2O and Zr(NO3)4·5H2O according to a Cd / (Cd+Zr) molar ratio of 1:5, and simultaneously weighing the modifier Cu(NO3)2 hydrate according to a Cu / (Cu+Cd+Zr) molar ratio of 2:100. After uniformly mixing the three nitrates with 350 ml of H2O, 1 M of ammonium carbonate precipitant is added dropwise to the uniformly mixed nitrate solution at a rate of 3 mL / min in a 70℃ water bath. After the precipitant addition is complete, the resulting precipitate is aged at 70℃ for 2 h, then the precipitate is removed, centrifuged, and washed. The resulting precipitate is dried at 110℃ for 12 h, and then calcined in a muffle furnace at a heating rate of 5℃ / min to 500℃ for 3 h to obtain the solid solution catalyst.

[0053] The solid solution catalysts obtained in Examples 1-4 and Comparative Examples 1-3 were applied to the carbon dioxide hydrogenation to methanol reaction. The specific activity evaluation methods are as follows:

[0054] 100 mg of catalyst was weighed and mixed with a certain amount of silicon carbide, then loaded into a tubular reactor with an inner diameter of 10 mm. Both the front and rear ends of the catalyst were septulated with quartz wool. In-situ reduction of the catalyst was employed. Before catalyst performance testing, the sample was reduced with pure hydrogen at atmospheric pressure and 300 °C for 2 h. After cooling to the target temperature, the reaction pressure was adjusted to 3 MPa, the reaction space velocity to 24000 mL / g·h, the hydrogen-to-carbon ratio to 3:1, and the reaction temperature to 220 °C–340 °C.

[0055] The analytical method for gas chromatography detection of the products is as follows: The gas pipeline was heated to 120°C with a heating belt. After the reaction system stabilized, the reaction products were analyzed online using a gas chromatograph equipped with a thermal conductivity detector (TCD) and a flame ionization detector (FID). Detection was performed continuously for 2 hours at each test reaction temperature, with an interval of 20°C between each test reaction temperature. The catalyst activity results are expressed as CO2 conversion rate and methanol yield, and the test results are shown in Table 1 below.

[0056] Table 1 Performance test results of the solid solution catalysts obtained in Examples 1-4 and the catalysts prepared in Comparative Examples 1-3

[0057]

[0058] Table 1 shows that the solid solution catalysts of Examples 1-3, which were modified by Cu and Ga synergistically, exhibited higher CO2 conversion rates and superior methanol yields compared to the unmodified Comparative Example 1 and the single-element modified Comparative Examples 2 and 3. This demonstrates the importance of Cu and Ga synergistically enhancing methanol synthesis performance. Among them, the solid solution catalyst prepared in Example 1 showed the best performance, significantly superior to Comparative Examples 1-3. Furthermore, it can be observed that when the content of the modifying element Ga is fixed, the CO2 conversion rate and methanol yield exhibit a volcano-shaped curve change with the amount of Cu incorporation, indicating that the appropriate Cu content and the synergy of Ga play an important role in improving the performance of the solid solution catalyst.

[0059] Depend on Figure 1 The XRD results showed that the catalysts prepared in Examples 1-4 and Comparative Examples 1-3 exhibited five distinct characteristic peaks at 2θ = 30.5°, 35.3°, 50.8°, 60.4°, and 63.2°, which were attributed to the tetragonal ZrO2 phase (t-ZrO2, PDF#50-1089). The diffraction peaks of the catalysts in Examples 1-4 and Comparative Examples 2-3 were similar to those of the unmodified Comparative Example 1 catalyst, indicating that all catalysts formed a solid solution.

[0060] Depend on Figure 2 It can be seen that the solid solution catalyst prepared in Example 1 has the best CO2 hydrogenation activity. As the temperature increases, the CO2 conversion rate gradually increases. However, due to thermodynamic limitations, the high temperature promotes the reverse water-gas reaction, resulting in a significant increase in the amount of CO byproduct generated, and consequently a significant decrease in methanol selectivity. The methanol yield is highest at 320℃. Therefore, the data in Table 1 are selected from the results at the optimal temperature of the examples and comparative examples.

[0061] Figure 3 The results of the stability test of Example 1 under the conditions of reaction temperature of 320℃, reaction pressure of 3 MPa, reaction space velocity of 24000 mL / g·h, and reaction hydrogen-to-carbon ratio of 3:1 for 100 h show that the solid solution catalyst for the hydrogenation of carbon dioxide to methanol prepared by this invention has strong stability. Under continuous testing for 100 h, the CO2 conversion rate and methanol yield of the catalyst remain basically unchanged.

[0062] Figure 4 The physical adsorption (BET) test data for Example 1 and Comparative Example 1 show that the adsorption-desorption curves of the catalysts are both type IV adsorption-desorption isotherms with an H2-type hysteresis loop, indicating the presence of a mesoporous structure. Furthermore, the BET test results show that the specific surface area of ​​Example 1 is 42.3 m². 2 / g is much larger than the specific surface area of ​​Comparative Example 1 (26.9 m²). 2The larger specific surface area ( / g) can more effectively promote the adsorption of CO2 in the CO2 hydrogenation to methanol reaction.

[0063] Figure 5 This is a graph showing the carbon dioxide temperature-programmed desorption curves for Example 1 and Comparative Example 1. From... Figure 5 The CO2-TPD results showed that the two desorption peaks at 111 / 117℃ and 419 / 392℃ corresponded to CO2 desorption from weakly basic and moderately basic sites, respectively. The desorption peak near 419 / 392℃ corresponds to O2 desorption from moderately basic sites. 2- Species-related, and these O 2- Speciation is caused by an increase in oxygen vacancies, and the desorption peak area of ​​the Cu-Ga synergistically modified solid solution catalyst is found to be larger. This result indicates that the Cu-Ga synergistically modified solid solution catalyst can increase both the oxygen vacancy concentration and the number and concentration of basic sites, thereby promoting CO2 adsorption. Generally, the stronger the CO2 adsorption capacity, the higher the reactivity. Therefore, Example 1 exhibits higher reactivity.

[0064] Figure 6 The XPS O 1s characterization results for Example 1 and Comparative Example 1 show that the asymmetric O 1s curves can be deconvolved into three peaks, corresponding to lattice oxygen O. I Oxygen vacancy O II and surface hydroxyl O III The results showed that the relative density of oxygen vacancies in Example 1 was higher than that in Comparative Example 1, and oxygen vacancies are crucial for CO2 activation and methanol formation.

[0065] In summary, the solid solution catalyst synergistically modified with Cu and Ga can significantly enhance the performance of CdZrO. x The solid solution catalyst exhibits good catalytic performance, but adding excess Cu reduces its activity in methanol synthesis. Among the prepared solid solution catalysts, Example 1 demonstrates the best methanol synthesis performance and exhibits excellent stability.

Claims

1. A Cu and Ga synergistic modification of CdZrO x A method for preparing a solid solution catalyst, characterized in that: Weigh out Cd(NO3)2 hydrate, Zr(NO3)4 hydrate, Ga(NO3)3 hydrate, and Cu(NO3)2 hydrate, mix them evenly with water, and place them in a water bath. Add a precipitant dropwise, then remove the precipitate, centrifuge and wash it. Dry and calcine the resulting precipitate to obtain Cu and Ga synergistically modified CdZrO. x Solid solution catalyst.

2. The Cu and Ga synergistic modification of CdZrO as described in claim 1 x A method for preparing a solid solution catalyst, characterized in that: The molar ratio of Cd, Zr, Ga, and Cu is 1:4:0.26:0.011~0.

58.

3. The Cu and Ga synergistic modification of CdZrO as described in claim 1 x A method for preparing a solid solution catalyst, characterized in that: The temperature of the water bath is 65~75℃.

4. The Cu and Ga synergistic modification of CdZrO according to claim 1 x A method for preparing a solid solution catalyst, characterized in that: The precipitant is ammonium carbonate.

5. A Cu and Ga synergistic modification of CdZrO according to claim 1 x A method for preparing a solid solution catalyst, characterized in that: The rate at which the precipitant is added is 1~10 mL / min.

6. A Cu and Ga synergistic modification of CdZrO according to claim 1 x A method for preparing a solid solution catalyst, characterized in that: The drying temperature is 70~150℃, and the drying time is 4~24 h.

7. A Cu and Ga synergistic modification of CdZrO according to claim 1 x A method for preparing a solid solution catalyst, characterized in that: The calcination temperature is 300~900℃, and the calcination time is 1~8 h.

8. A Cu and Ga synergistic modification of CdZrO according to any one of claims 1 to 7 x Cu and Ga synergistic modification of CdZrO obtained by the preparation method of solid solution catalyst x Solid solution catalyst, characterized in that: Including Cu, Ga and CdZrO x For solid solutions, x represents the number of moles of O atoms required to produce the corresponding molar amount of metal atoms at the given metal valence.

9. The Cu and Ga synergistic modification of CdZrO according to claim 8 x Application of solid solution catalysts in the catalytic hydrogenation of CO2 to methanol.

10. The Cu and Ga synergistic modification of CdZrO according to claim 9 x The application of solid solution catalysts in the catalytic hydrogenation of CO2 to methanol is characterized by: The molar ratio of hydrogen to carbon dioxide in the CO2 hydrogenation to methanol reaction is 3:1 to 9:1, the reaction pressure is 2 to 3 MPa, the reaction space velocity is 3000 to 48000 mL / g·h, and the reaction temperature is 220 to 340℃.

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