Hydrotalcite-like compound derived copper-zinc-aluminum-zirconium catalyst as well as preparation method and application thereof

Abstract

The invention relates to the field of catalysts, in particular to a copper-zinc-aluminum-zirconium catalyst for preparing methanol through carbon dioxide hydrogenation as well as a preparation method and application of the copper-zinc-aluminum-zirconium catalyst. The catalyst is a Cu-ZnO-Al2O3-ZrO2 catalyst, the mass ratio of ZnO to Al2O3 is 3: 1, the mass fraction of CuO is 24%-60%, and the mass fraction of ZrO2 is 4%-12%. Cu in the copper-based catalyst is a main active component. The Cu-ZnO-Al2O3-ZrO2 catalyst provided by the invention is simple in preparation method, has high catalytic activity and methanol selectivity, is stable in performance, and is easy to realize industrial application.

Description

Technical Field

[0001] The present invention relates to the field of catalysts, and particularly to a copper-zinc-aluminum-zirconium catalyst for hydrogenating carbon dioxide to methanol, its preparation method and application. Background Art

[0002] With the acceleration of the global industrialization process, the consumption of fossil energy has led to a sharp increase in carbon dioxide (CO2) emissions, exacerbating the greenhouse effect and climate change. The high attention of the international community to the "carbon neutrality" goal has promoted the urgent need for CO2 resource utilization technologies. In this context, the research on catalytic conversion of CO2 into high-value chemicals (such as methanol) has become a hot topic. Methanol is not only an important chemical raw material and clean fuel, but also can be used as a hydrogen energy carrier, which is of great significance for achieving sustainable development.

[0003] However, CO2 molecules have high chemical stability, and the reaction of hydrogenating CO2 to methanol (CO2 + 3H2 → CH3OH + H2O) faces challenges both thermodynamically and kinetically, and requires an efficient catalyst to drive. Traditional copper-based catalysts (such as Cu / ZnO / Al2O3) have been industrialized because of their relatively low price and excellent catalytic performance, but there are bottlenecks such as easy sintering of active sites, low methanol selectivity, and high energy consumption caused by harsh reaction conditions. Therefore, extensive research has been carried out on different catalyst systems. Chinese Patent with Application No. 202411248776.5 discloses a Cu / ZnOZrO2 hydrophobic catalyst for hydrogenating carbon dioxide to methanol. This catalyst has good activity and hydrothermal tolerance. Under the conditions of 5 MPa, 250 °C, and 5000 h -1 conditions, the methanol selectivity can exceed 80%, the single-pass conversion rate of carbon dioxide can be more than 20%, and a good heat resistance retention rate can be maintained. However, the catalyst synthesis process has relatively high requirements for equipment. Chinese Patent with Application No. 202310042862.X discloses a method for synthesizing metal-organic framework materials by solvothermal method and then adsorbing Pt as a co-catalyst. This catalyst has the characteristics of high activity, high methanol selectivity, and long-term stable operation at high temperature and pressure. However, Pt is a noble metal, and its economic practicality is limited, which is not conducive to large-scale industrial production. Chinese Patent with Application No. 202110417516.6 discloses a solid-solution-like Zn-CdZrOx catalyst for hydrogenating carbon dioxide to methanol, but Cd metal has relatively high toxicity, which does not conform to the concept of green environmental protection.

[0004] Therefore, it is desirable to develop a catalyst with mild reaction conditions, low cost, green non-toxicity, and high carbon dioxide conversion rate, high methanol selectivity, and high stability.

[0005] To solve the above problems, the present invention has developed a Cu-ZnO-Al2O3-ZrO2 catalyst for the hydrogenation of carbon dioxide to methanol. Its strong metal-support interaction and CuZn alloy sites are conducive to achieving the goals of high selectivity of methanol, high conversion rate of carbon dioxide, and long-term stability of the catalyst. The catalyst preparation mainly adopts the co-precipitation method. Using Cu metal salt, Zn metal salt, Al metal salt, and Zr metal salt as precursors, Na2CO3 and NaOH as precipitants, and deionized water as a solvent for co-precipitation and deposition precipitation processes, and then high-temperature calcination. High-temperature reduction is carried out in a hydrogen atmosphere to construct nano-Cu particle sites on the catalyst surface. This Cu site serves as the active site for promoting the hydrogenation of carbon dioxide to methanol. ZrO2 overcomes the disadvantage of easy agglomeration of copper-based catalysts for the dispersion of Cu particles and the strong interaction between the metal and the support, greatly improving the selectivity and long-term stability of the hydrogenation of carbon dioxide to methanol. Summary of the Invention

[0006] The present invention provides a Cu-ZnO-Al2O3-ZrO2 catalyst for the hydrogenation of carbon dioxide to methanol, its preparation method and application. The catalyst has the characteristics of high activity, high methanol selectivity, and high stability. In addition, the Cu-ZnO-Al2O3-ZrO2 catalyst is prepared by the co-precipitation and deposition precipitation methods. Its preparation method is simple, highly reliable, low-cost, and easy to industrialize.

[0007] To achieve the objectives of the present invention, the specific technical solutions of the present invention are as follows: In the first aspect of the present invention, a Cu-ZnO-Al2O3-ZrO2 catalyst is provided, where the mass ratio of ZnO to Al2O3 is 3:1, the mass fraction of CuO is 24%-60%, and the mass fraction of ZrO2 is 4%-12%; Cu is the main active component in the copper-based catalyst.

[0008] In the second aspect of the present invention, a preparation method of the above-mentioned Cu-ZnO-Al2O3-ZrO2 catalyst is provided, which includes the following steps: 1) Co-precipitation: Weigh Zn salt, Al salt, and Zr salt respectively and dissolve them in deionized water. While stirring, gradually drip the precipitant through a peristaltic pump. All 75 mL of the salt solution is dripped within 30 minutes. After the precipitation process ends, continue to stir and age. After aging, stop stirring and cool to room temperature to obtain a mixture; 2) Deposition precipitation: Weigh Cu salt and dissolve it in a solvent. While stirring, gradually drip it into the mixture obtained in step 1) together with the precipitant dissolved in the same solvent. All 75 mL of the salt solution is dripped within 30 minutes. Continue to stir to obtain a mixture; 3) Separation: Separate the solid and liquid of the mixture obtained in step 2) to obtain a precipitate in a colloidal state; 4) Drying: Dry the precipitate obtained in step 3). 5) High-temperature roasting: Grind the dried precipitate in step 4) and then conduct high-temperature roasting to obtain solid powder. 6) Activation reduction: Reduce the solid powder obtained in step 5) in a reducing gas atmosphere to obtain the Cu-ZnO-Al2O3-ZrO2 catalyst.

[0009] Preferably, in step 1), the Zn salt, Al salt, and Zr salt are selected from one or more of nitrates, acetates, halides, and sulfates containing Zn, Al, and Zr elements; the precipitating agent is one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydroxide, or potassium hydroxide.

[0010] Preferably, in step 1), the stirring temperature is 35 - 45 °C and the stirring time is 4 - 12 h.

[0011] Preferably, in step 2), the Cu salt is selected from one or more of nitrates, acetates, halides, and sulfates containing Cu element; the precipitating agent is one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydroxide, or potassium hydroxide. The solvent is one of deionized water or absolute ethanol.

[0012] Preferably, in step 2), the stirring temperature is 35 - 45 °C and the stirring time is 6 - 9 h.

[0013] Preferably, in step 3), the solid-liquid separation is specifically carried out by suction filtration to obtain a light blue precipitate.

[0014] Preferably, in step 4), the drying temperature is 60 - 80 °C and the drying time is 4 - 12 h. Place it in an oven for drying.

[0015] Preferably, in step 5), the roasting includes static roasting or roasting in a flowing atmosphere, and the roasting atmosphere is one or more of air, oxygen, and nitrogen; The roasting temperature is 200 - 250 °C, the roasting time is 3 - 5 h, and the heating rate is 2 - 10 °C / min.

[0016] Preferably, in step 5), the reducing atmosphere is hydrogen, or a mixture of hydrogen and nitrogen, or a mixture of hydrogen and argon. The flow rate of the reducing gas is 2 - 20 mL / min, the reducing temperature is 200 - 250 °C, the heating rate is 1 - 10 °C / min, the pressure is normal pressure, and the reducing time is 1 - 3 h.

[0017] The third aspect of the present invention provides an application of the Cu-ZnO-Al2O3-ZrO2 catalyst described in the first aspect of the present invention, and the catalyst is used for the reaction of hydrogenating carbon dioxide to methanol.

[0018] Preferably, the Cu-ZnO-Al2O3-ZrO2 catalyst is used for the gas-solid fixed-bed reaction of hydrogenating carbon dioxide to methanol, and the reaction conditions are as follows: the reaction pressure is 3-6 MPa, the reaction temperature is 200-260 °C, the reaction space velocity is 6000-24000 mL / (g / h), and the raw material gas is n(H2):n(CO2)=3:1.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention obtains a catalyst precursor by using the methods of co-precipitation, deposition-precipitation and high-temperature calcination, and then in-situ high-temperature reduction is used to construct the Cu sites on the catalyst surface, and successfully prepares a Cu-ZnO-Al2O3-ZrO2 catalyst in which Cu species exist in the form of nanoparticles. Compared with the traditional method of first preparing an oxide support and then impregnating and loading the active component copper source species and then calcining and reducing, in the method of the present invention, since CuO-ZnO-Al2O3-ZrO2 is first formed and then CuO therein is selectively reduced to Cu metal, the Cu metal particles have better dispersion and higher binding degree with the ZnO-Al2O3-ZrO2 support, so the catalytic performance is better and it is not easy to agglomerate or fall off.

[0020] 2. The Cu-ZnO-Al2O3-ZrO2 catalyst provided by the present invention jointly promotes the catalytic conversion of carbon dioxide to methanol through the synergistic effect between Cu and the ZnO-Al2O3-ZrO2 support. The strong interaction formed between the Cu particles and the ZnO-Al2O3-ZrO2 support effectively inhibits the agglomeration of Cu sites and has better catalytic performance than the traditional Cu-ZnO-Al2O3 catalyst.

[0021] 3. The Cu-ZnO-Al2O3-ZrO2 ternary catalyst of the present invention not only has high activity and high methanol selectivity, but also has high stability. The long-term stability evaluation results of the CZAZ 8Z42C catalyst of the present invention at a reaction temperature of 250 °C ( Figure 6 ) show that the carbon dioxide conversion rate remains at about 18-20% within 100 h of reaction time, and the methanol selectivity is stable at 42-46%. This indicates that the Cu-ZnO-ZrO2 ternary catalyst has excellent stability and good methanol selectivity.

[0022] 4. Compared with the catalysts containing precious metals, the Cu-ZnO-Al2O3-ZrO2 catalyst prepared by the present invention has higher economic value and market prospects and is suitable for industrial application.

[0023] 5. All the reagents used in the method of the present invention are only Cu salts, Zn salts, Al salts, Zr salts, sodium hydroxide, sodium carbonate, and deionized water, without any other organic reagents, and the raw materials are green and environmentally friendly.

[0024] 6. The preparation method of the Cu-ZnO-Al2O3-ZrO2 catalyst provided by the present invention is simple and reliable, the preparation process is easy to operate, and it is suitable for large-scale production. Description of the Drawings

[0025] Figure 1 are the XRD patterns of the precursors of the Cu-ZnO-Al2O3-ZrO2 catalysts with different Cu contents or ZrO2 contents and the XRD patterns of the catalysts after hydrogen reduction; Figure 2 is the performance comparison diagram of the Cu-ZnO-Al2O3-ZrO2 catalysts with different Cu contents; Figure 3 is the performance comparison diagram of the Cu-ZnO-Al2O3-ZrO2 catalysts with different ZrO2 contents; Figure 4 is the space-time yield (STY) diagram of the Cu-ZnO-Al2O3-ZrO2 catalysts with different Cu contents or ZrO2 contents at different temperatures; Figure 5 is the performance comparison diagram of the CZAZ 8Z42C catalyst and the industrial CuZnAl catalyst of the comparative sample; Figure 6 is the long-term stability evaluation result of the CZAZ 8Z42C catalyst at a reaction temperature of 250°C. Detailed Embodiments

[0026] The present invention will be described below in conjunction with specific embodiments, but the embodiments of the present invention are not limited thereto. For the experimental methods without specific conditions noted in the embodiments, they are generally carried out according to conventional conditions and the conditions described in the manuals, or according to the conditions recommended by the manufacturers. For the general equipment, materials, reagents, etc., if not otherwise specified, they can all be obtained from commercial channels. The raw materials required in the following examples and comparative examples are all commercially available.

[0027] Examples 1-5 are the preparation of the Cu-ZnO-Al2O3-ZrO2 catalysts with different Cu contents: Example 1 (1)Weigh 5.5930 g of Zn(NO3)2·6H2O, 3.7534 g of Al(NO3)3·9H2O, and 0.8362 g of Zr(NO3)4·5H2O into a 250 mL beaker, add 75 mL of deionized water, and stir until dissolved. Weigh another 3.4 g of NaOH and 1.7 g of Na2CO3 into a 250 mL beaker, add 75 mL of deionized water, and stir to dissolve.

[0028] (2)Take a 1000 mL three-necked flask, add 200 ml of deionized water, and place the flask in a water bath at 40 °C. Dropwise add the alkali solution and metal salt solution from step (1) into the above three-necked flask, while stirring mechanically at a speed of 400 rpm. The total dropping time of the salt solution is 30 min, and during this period, control the pH value in the flask to be 8.0 ± 0.2. After dropping, continue to stir for 4 h under the condition of 40 °C water bath.

[0029] (3)Then weigh 2.1867 g of Cu(NO3)2·3H2O into a 250 mL beaker, add 75 mL of deionized water, and stir until dissolved. Dropwise add the alkali solution and Cu salt solution from step (1) into the three-necked flask in step (2) above, and the process is the same as the previous step. After dropping, continue to stir for 6 h under the condition of 40 °C water bath.

[0030] (4)Then filter the substances in the flask to obtain a gel-like solid. Wash it 3 times with deionized water, dry it in an oven at 60 °C for 12 h. Grind the obtained solid in an agate mortar until it becomes powdery.

[0031] (5)Weigh the above pale blue powder precursor and perform calcination in a muffle furnace. The calcination temperature is 250 °C, the calcination time is 4 h, and the heating rate is 5 °C / min. The catalyst obtained after calcination is denoted as CZAZ 8Z24C. Press the CZAZ 8Z24C catalyst (8 MPa, 5 min), crush it, and screen the 40 - 60 mesh catalyst for catalytic performance evaluation.

[0032] Weigh 0.1 g of the selected catalyst and load it into a reaction tube with an inner diameter of 8 mm. Reduce it at 250 °C for 3 h in a pure H2 atmosphere under atmospheric pressure, with a flow rate of 2.9 mL / min. Then introduce the feed gas with n(H2):n(CO2) = 3, and carry out catalytic performance evaluation under the conditions of 5 MPa, 200 - 250 °C, and GWSV = 20000 mL / (g·h -1 )

[0033] Example 2 The metal salts used for catalyst preparation were 4.6060 g of Zn(NO3)2·6H2O, 3.0910 g of Al(NO3)3·9H2O, 0.8362 g of Zr(NO3)4·5H2O, and 3.2800 g of Cu(NO3)2·3H2O was used in the deposition process. The precipitants used were 3.4 g of NaOH and 1.7 g of Na2CO3, and the resulting catalyst was denoted as CZAZ 8Z36C. Other preparation and evaluation steps were the same as those in Example 1.

[0034] Example 3 The metal salts used for catalyst preparation were 4.1125 g of Zn(NO3)2·6H2O, 2.7598 g of Al(NO3)3·9H2O, 0.8362 g of Zr(NO3)4·5H2O, and 3.8267 g of Cu(NO3)2·3H2O was used in the deposition process. The precipitants used were 3.4 g of NaOH and 1.7 g of Na2CO3, and the resulting catalyst was denoted as CZAZ 8Z42C. Other preparation and evaluation steps were the same as those in Example 1.

[0035] Example 4 The metal salts used for catalyst preparation were 3.6190 g of Zn(NO3)2·6H2O, 2.4287 g of Al(NO3)3·9H2O, 0.8362 g of Zr(NO3)4·5H2O, and 4.3734 g of Cu(NO3)2·3H2O was used in the deposition process. The precipitants used were 3.4 g of NaOH and 1.7 g of Na2CO3, and the resulting catalyst was denoted as CZAZ 8Z48C. Other preparation and evaluation steps were the same as those in Example 1.

[0036] Example 5 The metal salts used for catalyst preparation were 2.6320 g of Zn(NO3)2·6H2O, 1.7663 g of Al(NO3)3·9H2O, 0.8362 g of Zr(NO3)4·5H2O, and 5.4668 g of Cu(NO3)2·3H2O was used in the deposition process. The precipitants used were 3.4 g of NaOH and 1.7 g of Na2CO3, and the resulting catalyst was denoted as CZAZ 8Z60C. Other preparation and evaluation steps were the same as those in Example 1.

[0037] Examples 6 - 9 were the preparation of Cu-ZnO-Al2O3-ZrO2 catalysts with different ZrO2 contents: Example 6 The metal salts used for catalyst preparation were 4.4415 g of Zn(NO3)2·6H2O, 2.9806 g of Al(NO3)3·9H2O, 0.4181 g of Zr(NO3)4·5H2O, and 3.8267 g of Cu(NO3)2·3H2O was used in the deposition process. The precipitants used were 3.4 g of NaOH and 1.7 g of Na2CO3, and the resulting catalyst was denoted as CZAZ 4Z42C. Other preparation and evaluation steps were the same as those in Example 1.

[0038] Example 7 The metal salts used for catalyst preparation were 4.2770 g of Zn(NO3)2·6H2O, 2.8702 g of Al(NO3)3·9H2O, 0.6272 g of Zr(NO3)4·5H2O, and 3.8267 g of Cu(NO3)2·3H2O was used in the deposition process. The precipitants used were 3.4 g of NaOH and 1.7 g of Na2CO3, and the resulting catalyst was denoted as CZAZ 6Z42C. Other preparation and evaluation steps were the same as those in Example 1.

[0039] Example 8 The metal salts used for catalyst preparation were 3.9480 g of Zn(NO3)2·6H2O, 2.6494 g of Al(NO3)3·9H2O, 1.0453 g of Zr(NO3)4·5H2O, and 3.8267 g of Cu(NO3)2·3H2O was used in the deposition process. The precipitants used were 3.4 g of NaOH and 1.7 g of Na2CO3, and the resulting catalyst was denoted as CZAZ 10Z42C. Other preparation and evaluation steps were the same as those in Example 1.

[0040] Example 9 The metal salts used for catalyst preparation were 3.7835 g of Zn(NO3)2·6H2O, 2.5390 g of Al(NO3)3·9H2O, 1.2543 g of Zr(NO3)4·5H2O, and 3.8267 g of Cu(NO3)2·3H2O was used in the deposition process. The precipitants used were 3.4 g of NaOH and 1.7 g of Na2CO3, and the resulting catalyst was denoted as CZAZ 12Z42C. Other preparation and evaluation steps were the same as those in Example 1.

[0041] The crystal structures of all Cu-ZnO-Al2O3-ZrO2 catalysts after reduction were analyzed by X-ray diffraction (XRD), and the characterization results are shown in Figure 1After reduction, monoclinic CuO was reduced to cubic metallic Cu (2θ = 43.3° and 50.4°), and with the increase of Cu content or the decrease of ZrO2 content, the characteristic peaks of Cu were enhanced, indicating that the size of Cu particles was continuously increasing. It should be noted that the Cu characteristic diffraction peak at 2θ = 43.3° shifted to a lower angle, which indicated that during the reduction activation process of the catalyst, part of ZnO was reduced to Zn 0 , and interacted with Cu to form a CuZn alloy.

[0042] The catalysts obtained in Examples 1-9 were used for the reaction of hydrogenation of carbon dioxide to methanol, and their catalytic activities were compared. The test results are shown in Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 .

[0043] The catalytic performances of Cu-ZnO-Al2O3-ZrO2 catalysts with different Cu contents were compared. The test results are shown in Figure 2 and Figure 4 . Under the reaction conditions of 200 °C to 250 °C, the conversion rates and product selectivities of Cu-ZnO-Al2O3-ZrO2 catalysts with different Cu contents are shown in Figure 2 . With the increase of Cu content, the conversion rate showed a trend of first increasing and then decreasing, reaching the maximum when the precursor CuO content was 42 wt%; the selectivity was relatively stable. Since the change range of the conversion rate was greater than that of the selectivity, the overall trend of the space-time yield changing with the Cu content was similar to that of the conversion rate. With the increase of Cu content, the space-time yield also showed a volcano-shaped trend of first increasing and then decreasing. Therefore, the optimal value of the precursor CuO content was 42 wt%, and the CZAZ 8Z42C catalyst had the highest activity.

[0044] The catalytic performances of Cu-ZnO-Al2O3-ZrO2 catalysts with different ZrO2 contents were compared. The test results are shown in Figure 3 and Figure 4 . Under the reaction conditions of 200 °C to 250 °C, the conversion rates and product selectivities of Cu-ZnO-Al2O3-ZrO2 catalysts with a CuO content of 42% in the precursor but different ZrO2 contents are shown in Figure 2, as the ZrO2 content increases, the conversion rate first increases and then decreases, reaching the maximum when the ZrO2 content in the precursor is 8 wt%; the change range of the selectivity is very small, but the trend is the same as that of the conversion rate, first increasing and then decreasing. The overall trend of the space-time yield with the change of the ZrO2 content also shows a volcano-like trend of first increasing and then decreasing. Therefore, the optimal value of the ZrO2 content in the precursor is 8 wt%, and the CZAZ 8Z42C catalyst has the highest activity.

[0045] The present invention compares the catalytic performance of the CZAZ 8Z42C catalyst with that of the industrial CuZnAl catalyst, and the test results are shown in Figure 5 . The CZAZ 8Z42C catalyst achieves performance similar to that of the industrial catalyst under the condition of a relatively low Cu content.

[0046] The evaluation results of the long-term stability of the CZAZ 8Z42C catalyst at a reaction temperature of 250 °C ( Figure 6 ) show that the carbon dioxide conversion rate remains at about 17 - 20% within 100 h of the reaction time, and the methanol selectivity is stable at 42 - 46%. This indicates that the CZAZ8Z42C catalyst has excellent stability and good methanol selectivity.

[0047] In the present invention, the raw materials and equipment used, unless otherwise specified, are common raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are conventional methods in the art.

[0048] The above are only the preferred embodiments of the present invention, and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent transformations made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A hydrotalcite-derived copper-zinc-aluminum-zirconium catalyst, characterized in that: The catalyst is a Cu-ZnO-Al2O3-ZrO2 catalyst. Based on the entire catalyst, the mass ratio of ZnO to Al2O3 is 3:1; the mass fraction of CuO is 24%-60%, and the mass fraction of ZrO2 is 4%-12%.

2. The copper-zinc-aluminum-zirconium catalyst according to claim 1, characterized in that The catalyst precursor is a hydrotalcite-like structure, and the Cu is combined on a ZnO-Al2O3-ZrO2 carrier in the form of single-substance nanoparticles, and the particle size of the nanoparticles is 3-20nm.

3. The copper-zinc-aluminum-zirconium catalyst according to claim 1, characterized in that ZnO contains some Zn elemental Zn that forms an alloy with Cu, and this part of Zn accounts for 15%-25% of the total Zn molar amount.

4. A method for preparing the copper-zinc-aluminum-zirconium catalyst according to claim 1, characterized in that: It includes the following steps: Co-precipitation: Weigh Zn salt, Al salt, and Zr salt separately and dissolve them in a solvent. Add a precipitant dissolved in the same solvent dropwise while stirring. Continue stirring to obtain a mixture. Sedimentation precipitation: Weigh a Cu salt and dissolve it in a solvent, add it dropwise into the mixture obtained in step 1) together with a precipitant dissolved in the same solvent while stirring, and continue stirring to obtain a mixture; Separation: separating the mixture obtained in step 2) from solid and liquid to obtain a precipitate in a colloidal state; Drying: drying the precipitate obtained in step 3); High temperature calcination: grinding the precipitate dried in step 4) and then calcining it at high temperature to obtain a solid powder; Activation reduction: The solid powder obtained in step 5) is reduced in a reducing gas atmosphere to obtain the Cu-ZnO-Al2O3-ZrO2 catalyst.

5. The preparation method according to claim 4, characterized in that: In step 1) and step 2), the Cu salt, Zn salt, Al salt, and Zr salt are selected from one or more of nitrates, acetates, halides, and sulfates containing Cu, Zn, Al, and Zr elements; The solvent is one of deionized water or anhydrous ethanol; The precipitating agent is one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydroxide and potassium hydroxide.

6. The preparation method according to claim 4, characterized in that: In step 1), the stirring temperature is 35-45°C, the stirring time is 4-12h, and the pH value is 7.8-8.2; in step 2), the stirring temperature is 35-45°C, the stirring time is 6h, and the pH value is 7.8-8.2; in step 3), the drying temperature is 60-80°C, and the drying time is 4-12h.

7. The preparation method according to claim 4, characterized in that: In step 4), the calcination includes static calcination or flowing atmosphere calcination, and the calcination atmosphere is one or more of air, oxygen, and nitrogen; the calcination temperature is 200-250°C, the calcination time is 3-5h, and the heating rate is 2-10°C / min.

8. The preparation method according to claim 4, characterized in that: In step 5), the reducing atmosphere is hydrogen, or a mixture of hydrogen and nitrogen, or a mixture of hydrogen and argon, the flow rate of the reducing gas is 2-20 mL / min, the reducing temperature is 200-250°C, the heating rate is 1-10°C / min, the pressure is normal pressure, and the reducing time is 1-3h.

9. Use of the copper-zinc-aluminum-zirconium catalyst according to claim 1 for improving carbon dioxide conversion and methanol selectivity in a reaction and / or for improving catalyst stability.

10. The use according to claim 9, characterized in that ;The reaction pressure of carbon dioxide hydrogenation to produce methanol is 3-6MPa, the reaction temperature is 180-260℃, the reaction space velocity is 6000-24000 mL / (g / h), and the raw gas is n (H2): n (CO2) = 3:1.

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