Reaction catalyst for preparing methanol through carbon dioxide hydrogenation

Abstract

The invention belongs to the technical field of chemical engineering, and relates to the technical field of heterogeneous catalytic reaction, in particular to a reaction catalyst for preparing methanol through carbon dioxide hydrogenation. The catalyst comprises a metal component, an auxiliary agent, a carrier and a rare earth element, the metal component comprises at least one of copper, gallium, alkali metal or alkaline earth metal and oxide of zirconium or titanium; wherein the addition amount of the auxiliary agent is 2-10%, the addition amount of the carrier is 5-20%, the addition amount of the rare earth element is 0.1-5%, and the balance is the metal component; in the metal components, the content of copper is 30-70%, the content of gallium is 1-10%, the content of alkali metal or alkaline earth metal is 0.1-3%, and the content of oxide of Zr or Ti is 1-10%. The application of the catalyst aims to convert greenhouse gas CO2 into valuable methanol, so that CO2 emission can be reduced, and a sustainable raw material source can be provided for the chemical industry.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical engineering, relates to the technical field of multiphase catalytic reaction, and specifically relates to a catalyst for the reaction of hydrogenating carbon dioxide to methanol. Background Art

[0002] Methanol, as one of the most basic chemical raw materials, has a wide range of uses and is also one of the most important products in C1 chemistry. Currently, the most commonly used catalyst for the catalytic hydrogenation of CO2 to methanol is a copper-based catalyst, which is usually prepared by the co-precipitation method. However, the catalyst prepared by the co-precipitation method generally has large particle size, poor dispersion, and a wide particle size distribution range. Therefore, the stability of this kind of catalyst is poor. The copper-based catalyst is extremely prone to particle agglomeration or sintering phenomena. Especially when the catalyst has low dispersion and uneven particle size, the agglomeration of active components is more likely to occur, resulting in a decrease in catalytic activity. Therefore, how to prepare a supported highly dispersed copper-based catalyst to inhibit the migration, agglomeration, ripening, and growth of copper particles to improve the stability of the catalyst is an important challenge.

[0003] Chinese Patent CN 104841429 A discloses a catalyst for the hydrogenation of CO2 to methanol. It prepares a copper-based catalyst by a multi-layer loading method and achieves high catalytic activity at a low loading rate. However, this method has relatively cumbersome preparation steps and uses a large amount of organic reagents during the preparation process, making it difficult to achieve large-scale production.

[0004] Chinese Patent CN 104549362 A discloses a highly dispersed copper-based catalyst, which has high catalytic activity and stability. However, precious metals are added during the preparation of this catalyst, so the production cost is too high.

[0005] Chinese Patent CN 107185543 A discloses a copper-based catalyst for the hydrogenation of CO2. This catalyst loads copper on a ZnO support with a specific morphology. Compared with the catalyst prepared by the co-precipitation method, the activity and methanol selectivity of the catalyst are significantly improved. However, the stability of this catalyst is relatively poor. Summary of the Invention

[0006] The purpose of the present invention is to overcome the problems that the stability of the catalyst for hydrogenating carbon dioxide to methanol in the prior art is relatively poor, and the existing solutions increase costs and have limited effects, etc., and to provide a catalyst for the reaction of hydrogenating carbon dioxide to methanol, as well as its preparation and application.

[0007] In order to achieve the above invention purpose, the specific technical solution of the present invention is as follows:

[0008] A catalyst for the reaction of hydrogenating carbon dioxide to methanol, wherein the catalyst composition comprises: a metal component, a promoter, a carrier and a rare earth element; wherein, the addition amount of the promoter is 2-10%, the carrier is 5-20%, the rare earth element is 0.1-5%, and the balance is the metal component, and the sum of the total mass percentages is 100%.

[0009] Further, the metal component includes at least one of copper, gallium, alkali metal and alkaline earth metal and at least one of transition metal oxides of zirconium (Zr) and titanium (Ti); that is, the metal component includes at least one of copper, gallium, and alkali metal, and zirconium (Zr) or titanium (Ti); or at least one of copper, gallium, and alkaline earth metal, and zirconium (Zr) or titanium (Ti).

[0010] Further, in the metal component, the content of copper (mass percentage) is 30-70%, the content of gallium is 1-10%, the content of alkali metal or alkaline earth metal is 0.1-3%, and the content of the oxide of Zr or Ti is 1-10%.

[0011] Further, the promoter is at least one of zinc (Zn), aluminum (Al), zirconium (Zr), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), tin (Sn) and their oxides; wherein the carrier is at least one of aluminum oxide (Al2O3), silicon dioxide, molecular sieve and porous material.

[0012] Further, the rare earth element is an element such as lanthanum, cerium, praseodymium, neodymium, yttrium, etc.

[0013] Further, the rare earth element is preferably cerium (Ce), and its content is preferably between 0.5wt% and 3wt% to optimize the catalytic performance.

[0014] A preparation method of a catalyst for the reaction of hydrogenating carbon dioxide to methanol, comprising the following steps:

[0015] a) Provide a soluble salt solution containing copper salt, gallium salt, and at least one selected from alkali metals and alkaline earth metals;

[0016] b) Mix the solution in step a) with a precursor of a promoter (such as a transition metal oxide of zirconium or titanium) to form a composite solution;

[0017] c) Add a compound containing a rare earth element to the composite solution in step b), and stir evenly to obtain a mixed solution;

[0018] d) Add a precursor substance of the promoter to the mixed solution in step c) according to a predetermined ratio, and stir and mix well;

[0019] e) Immerse the carrier material in the mixture solution of step d), add a precipitant to form a precipitate of metal ions for loading treatment, so that each component is evenly distributed on the carrier;

[0020] f) Dry and / or calcine the loaded carrier to fix the active components and form the final catalyst structure;

[0021] g) Reduce the product obtained in step f) to activate the metal components.

[0022] Preferably, the gallium salt in step a) is selected from gallium nitrate, gallium sulfate or gallium chloride.

[0023] Preferably, the precursor containing the promoter in step b) includes zinc salts, aluminum salts, etc.; the zinc salt is selected from zinc nitrate, zinc sulfate or zinc chloride; the aluminum salt is selected from aluminum nitrate, aluminum sulfate or aluminum chloride.

[0024] Preferably, the drying temperature in step f) ranges from 80°C to 200°C (specifically, it can be 80°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, etc.), the calcination temperature ranges from 300°C to 600°C (specifically, it can be 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, etc.), and the calcination time is 2 - 6 hours (specifically, it can be 2h, 3h, 4h, 5h, 6h, etc.); and the calcination atmosphere can be air, inert gas or reducing gas.

[0025] Preferably, the precipitant in step e) is selected from sodium carbonate, potassium carbonate, sodium hydroxide or potassium hydroxide.

[0026] Preferably, the reduction treatment in step g) is carried out in the presence of hydrogen or other reducing gases within the temperature range of 200°C to 400°C (specifically, it can be 200°C, 250°C, 300°C, 350°C, 400°C, etc.) to ensure the proper activation of the metal components.

[0027] Preferably, the time of the reduction treatment in step g) is 1 - 3 hours (specifically, it can be 1h, 1.5h, 2h, 2.5h, 3h, etc.).

[0028] The present invention also protects the application of the above - described catalyst (copper - based catalyst) or the catalyst (copper - based catalyst) prepared by the above method in the hydrogenation of carbon dioxide to methanol.

[0029] Preferably, a method for hydrogenating carbon dioxide to methanol using a copper - based catalyst includes the following steps:

[0030] (a) Load the copper - based catalyst into a reactor;

[0031] (b) Feed a mixed gas of carbon dioxide and hydrogen into the reactor;

[0032] (c) Conduct the reaction under the conditions of a reaction temperature of 200 - 300 °C and a reaction pressure of 1 - 10 MPa to produce methanol.

[0033] Preferably, in step (b), the molar ratio of the carbon dioxide to the hydrogen is 1:3 - 1:5.

[0034] Preferably, in step (c), the reaction time is 1 - 5 hours.

[0035] Compared with the prior art, the positive effects of the present invention are embodied in:

[0036] (1) Add gallium (Ga) to the copper-based catalyst. The introduction of gallium can adjust the electronic structure on the copper surface, thereby changing its selectivity for different reaction paths. For the hydrogenation of CO2 to produce methanol, the selectivity for the target product methanol can be enhanced by optimizing the copper-gallium interface, and the formation of by-products such as carbon monoxide (CO) or hydrocarbons can be reduced.

[0037] When operating under high temperature and high pressure conditions, the traditional copper-based catalyst may exhibit sintering phenomena, resulting in the loss of active sites. The presence of gallium can help stabilize the copper particles, prevent them from aggregating excessively, and thus maintain the long-term activity and stability of the catalyst.

[0038] Gallium changes the chemical properties of the copper surface, making CO2 more accessible and convertible into intermediates, which can then be further converted into methanol. This helps improve the adsorption capacity and activation efficiency of CO2, making the entire catalytic process more efficient.

[0039] The addition of an appropriate amount of gallium can affect the overall acid-base environment of the catalyst. An appropriate acid-base balance is crucial for the conversion of CO2 to methanol because it is related to how effectively the intermediate products are formed and desorbed. By adjusting this property, the entire catalytic process can be made more efficient.

[0040] The copper-based catalyst containing gallium exhibits better resistance to sulfur poisoning compared to the pure copper-based catalyst. This is very important for practical industrial applications because trace sulfur compound contamination is inevitably encountered in the actual operating environment.

[0041] The presence of gallium can also improve the thermal stability of the catalyst, enabling it to maintain good catalytic performance within a wider working temperature range, which is particularly important for long-term continuous operation in industrial applications.

[0042] Gallium as a doping element helps to evenly disperse metal nanoparticles, preventing them from agglomerating at high temperatures, thus maintaining a higher specific surface area and more active sites, which is crucial for enhancing the catalytic efficiency.

[0043] The addition of gallium causes changes in the electron density on the catalyst surface, and this change can affect the adsorption behavior of reactant molecules and the energy barrier of the reaction path, ultimately facilitating the improvement of catalytic activity and selectivity.

[0044] Metallic gallium, as an effective promoter, has shown great potential in improving copper-based catalysts for CO2 hydrogenation to methanol. However, the specific effects depend on factors such as the content and distribution of gallium and the interaction with other components, so optimization design needs to be carried out according to the actual situation.

[0045] (2) By selecting specific ratios of metal components (such as Cu and Ga), promoters, support materials, rare earth elements (especially cerium Ce), and alkali metals or alkaline earth metals, the selectivity and activity of the catalyst for the hydrogenation reaction of carbon dioxide can be effectively improved.

[0046] (3) Rare earth elements, especially cerium, contribute to optimizing the catalytic performance in this catalyst because rare earth elements can adjust the surface properties of this catalyst, enhance the interaction between the metal and the support, thereby improving the stability and activity of the catalyst.

[0047] (4) In the preparation method, we adopt the impregnation method combined with the precipitation loading technique, enabling each component to be evenly distributed on the support, simplifying the preparation process, and ensuring good dispersion and contact efficiency.

[0048] (5) Using common salts as precursor substances (such as nitrates, sulfates or chlorides), and selecting relatively low-cost precipitants (such as sodium carbonate, sodium hydroxide, etc.) reduces the production cost of the catalyst and increases the possibility of industrial production.

[0049] (6) The application of this catalyst aims to convert the greenhouse gas CO2 into a valuable chemical - methanol, which not only helps to reduce CO2 emissions but also provides a sustainable raw material source for the chemical industry.

[0050] (7) This catalyst is applied to the process of hydrogenating carbon dioxide to produce methanol, with a high carbon dioxide conversion rate and a high methanol selectivity. Specific implementation mode

[0051] All features disclosed in this specification, or all steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

[0052] Any feature disclosed in this specification (including claims and abstract), unless specifically stated, can be replaced by other equivalent or alternative features with similar purposes. That is, unless specifically stated, each feature is only an example in a series of equivalent or similar features.

[0053] The features and properties of the present invention will be further described in detail below in conjunction with embodiments.

[0054] In this application, unless otherwise specified, all percentages represent mass percentages. The relevant raw materials are all commercially available products; the process steps or devices not specified are all prior art.

[0055] Example 1

[0056] A catalyst for the reaction of hydrogenating carbon dioxide to methanol, calculated on a mass percentage of 100, contains 8% of a promoter, 15% of a carrier, and 2% of a rare earth element, with the balance being the metal component (where the copper content is 60%, the gallium content is 7%, the alkali metal sodium content is 1%, and the zirconium (Zr) content is 7%).

[0057] Furthermore, the promoter is zinc; the carrier is silica; the rare earth element is cerium.

[0058] The specific preparation method is as follows:

[0059] a) Weigh copper sulfate, gallium sulfate, and sodium sulfate in proportion and prepare a mixed solution by adding water.

[0060] b) Mix the solution in step a) with zirconium carbonate to form a composite solution.

[0061] c) Add a compound containing the rare earth element cerium (such as CeO2) to the composite solution in step b), stir evenly to obtain a mixed solution.

[0062] d) Add the precursor of the promoter (zinc powder) to the mixed solution in step c) according to a predetermined ratio, and stir well to mix.

[0063] e) Immerse the carrier material silica in the mixed solution in step d), add the precipitating agent sodium carbonate to form a precipitate for loading treatment, so that each component is evenly distributed on the carrier.

[0064] f) Dry and calcine the loaded carrier to fix the active components and form the final catalyst structure; obtain a (copper-based) catalyst.

[0065] The drying temperature range is 80 °C, the calcination temperature range is 450 °C, the calcination time is 4 hours, and the calcination atmosphere is air.

[0066] g) The product (catalyst) obtained in step f) is subjected to a reduction treatment (the reduction atmosphere is hydrogen, the reduction temperature is 350 °C, and the reduction time is 2 hours) to activate the metal components, obtaining the activated catalyst 1#.

[0067] Example 2:

[0068] A catalyst for the reaction of hydrogenating carbon dioxide to methanol, calculated on a mass percentage of 100, contains 5% of a promoter, 15% of a carrier, and 2.5% of a rare earth element, with the balance being metal components (where the copper content is 65%, the gallium content is 6.5%, the alkali metal sodium content is 1.5%, and the zirconium (Zr) content is 4.5%).

[0069] Furthermore, the promoter is chromium; the carrier is aluminum oxide; the rare earth element is cerium.

[0070] The specific preparation method is as follows:

[0071] a) Weigh copper sulfate, gallium sulfate, and sodium sulfate in proportion and prepare a mixed solution by adding water.

[0072] b) Mix the solution in step a) with zirconium carbonate to form a composite solution.

[0073] c) Add a compound containing the rare earth element cerium (such as CeO2) to the composite solution in step b), and stir evenly to obtain a mixed solution.

[0074] d) Add the precursor substance of the promoter chromium to the mixed solution in step c) according to a predetermined proportion, and stir well to mix.

[0075] e) Immerse the carrier material in the mixed solution in step d), add the precipitating agent sodium carbonate to form a precipitate for the metal ions to be loaded, so that each component is evenly distributed on the carrier.

[0076] f) The loaded carrier is subjected to drying and calcination treatments to fix the active components and form the final catalyst structure; obtaining the (copper-based) catalyst.

[0077] The drying temperature range is 100 °C, the calcination temperature range is 470 °C, the calcination time is 3.5 hours, and the calcination atmosphere is air.

[0078] g) The product (catalyst) obtained in step f) is subjected to a reduction treatment (the reduction atmosphere is hydrogen, the reduction temperature is 300 °C, and the reduction time is 3 hours) to activate the metal components, obtaining the activated catalyst 2#.

[0079] Example 3:

[0080] A catalyst for the reaction of hydrogenating carbon dioxide to methanol, calculated on a mass percentage of 100, contains 8% of a promoter, 15% of a carrier, and 2% of rare earth elements, with the balance being the metal components (where the copper content is 60%, the gallium content is 7%, the alkali metal potassium content is 1%, and the titanium (Ti) content is 7%).

[0081] Furthermore, the promoter is chromium; the carrier is silica; the rare earth element is cerium.

[0082] The specific preparation method is as follows:

[0083] a) Weigh copper sulfate, gallium sulfate, and potassium chloride in proportion and prepare a mixed solution by adding water.

[0084] b) Mix the solution in step a) with a titanium-containing substance (such as TiO2) to form a composite solution.

[0085] c) Add a compound containing the rare earth element cerium (such as CeO2) to the composite solution in step b), and stir evenly to obtain a mixed solution.

[0086] d) Add the precursor substance of the promoter chromium to the mixed solution in step c) according to a predetermined proportion, and stir well to mix.

[0087] e) Immerse the carrier material in the mixed solution in step d), add the precipitating agent sodium carbonate to cause the metal ions to form a precipitate for loading treatment, so that each component is evenly distributed on the carrier.

[0088] f) Dry and calcine the loaded carrier to fix the active components and form the final catalyst structure; obtain a (copper-based) catalyst.

[0089] The drying temperature range is 80 °C, the calcination temperature range is 450 °C, the calcination time is 4 hours, and the calcination atmosphere is air.

[0090] g) Perform a reduction treatment on the product (catalyst) obtained in step f) (the reduction atmosphere is hydrogen, the reduction temperature is 350 °C, and the reduction time is 2 hours) to activate the metal components and obtain the activated catalyst 3#.

[0091] Example 4:

[0092] A catalyst for the reaction of hydrogenating carbon dioxide to methanol, calculated on a mass percentage of 100, contains 8% of a promoter, 15% of a carrier, and 2% of rare earth elements, with the balance being the metal components (where the copper content is 60%, the gallium content is 7%, the alkaline earth metal calcium content is 1%, and the zirconium (Zr) content is 7%).

[0093] Furthermore, the promoter is manganese; the carrier is molecular sieve; the rare earth element is cerium.

[0094] The specific preparation method is as follows:

[0095] a) Weigh copper sulfate, gallium sulfate and calcium chloride in proportion, and add water to prepare a mixed solution;

[0096] b) Mix the solution in step a) with zirconium carbonate to form a composite solution;

[0097] c) Add a compound containing rare earth element cerium (such as CeO2) to the composite solution in step b), and stir evenly to obtain a mixed solution;

[0098] d) Add the precursor substance of promoter manganese to the mixed solution in step c) according to a predetermined proportion, and stir and mix well;

[0099] e) Immerse the carrier material in the mixed solution in step d), add the precipitant sodium hydroxide to form a precipitate for the metal ions to be loaded, so that each component is evenly distributed on the carrier;

[0100] f) Dry and calcine the loaded carrier to fix the active components and form the final catalyst structure; obtain a (copper-based) catalyst;

[0101] The drying temperature range is 120 °C, the calcination temperature range is 470 °C, the calcination time is 4 hours, and the calcination atmosphere is air.

[0102] g) Carry out a reduction treatment on the product (catalyst) obtained in step f) (the reduction atmosphere is hydrogen, the reduction temperature is 250 °C, and the reduction time is 3 hours) to activate the metal components and obtain the activated catalyst 4#.

[0103] Comparative Example 1:

[0104] The preparation method of the catalyst is the same as that in Example 1, the only difference being that the metal component does not contain gallium, and the content of gallium is converted and added to the content of copper, and the other steps are the same.

[0105] Comparative Example 2:

[0106] The preparation method of the catalyst is the same as that in Example 1, the only difference being that the metal component does not contain zirconium (Zr), and the content of zirconium (Zr) is converted and added to the content of copper, and the other steps are the same.

[0107] In order to verify the application effects of the catalysts prepared in Examples 1-4 and Comparative Examples 1-2 in the hydrogenation of carbon dioxide to methanol, the following tests are carried out. The specific method steps are as follows:

[0108] (a) Load the copper-based catalyst into the reactor;

[0109] (b) Pass a mixed gas of carbon dioxide and hydrogen into the reactor; the molar ratio of carbon dioxide to hydrogen is 1:4 respectively;

[0110] (c) Methanol is produced at a reaction temperature of 280 °C, a reaction pressure of 3 MPa, and a reaction time of 3 hours. The space velocity of the raw material is 10,000 mL / (h·g).

[0111] For easy comparison, the catalysts prepared in Examples 1-4 and the results of the methanol synthesis reaction are listed in Table 1.

[0112] Table 1:

[0113] Reaction temperature Reaction pressure <![CDATA[CO2 conversion rate, %]]> Methanol selectivity, % Example 1 280℃ 3MPa 25.3 86.4 Example 2 280℃ 3MPa 26.1 85.5 Example 3 280℃ 3MPa 24.9 83.7 Example 4 280℃ 3MPa 25.8 85.1 Comparative example 1 280℃ 3MPa 6.3 59.6 Comparative example 2 280℃ 3MPa 12.4 62.8

[0114] The above-described embodiments merely represent specific implementation manners of the present application. Their descriptions are relatively specific and detailed, but should not be construed as limiting the protection scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the technical solution of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application.

[0115] This background art section is provided to generally present the context of the present invention. The work of the currently named inventors, to the extent described in this background art section, and aspects described in this section that were not prior art at the time of filing this application are neither expressly nor impliedly admitted to be prior art of the present invention.

Claims

1. A catalyst for the reaction of hydrogenating carbon dioxide to methanol, characterized in that: The catalyst comprises a metal component, a promoter, a support and a rare earth element; the metal component includes at least one of copper, gallium, an alkali metal or an alkaline earth metal, and an oxide of zirconium or titanium; wherein, the addition amount of the promoter is 2-10%, the support is 5-20%, the rare earth element is 0.1-5%, and the balance is the metal component, and the sum of the total mass percentages is 100%.

2. The carbon dioxide hydrogenation to methanol reaction catalyst according to claim 1, wherein: Among the metal components, the content of copper is 30-70%, the content of gallium is 1-10%, the content of the alkali metal or the alkaline earth metal is 0.1-3%, and the content of the oxide of zirconium or titanium is 1-10%.

3. The carbon dioxide hydrogenation to methanol reaction catalyst according to claim 1, characterized in that: The promoter is at least one of zinc, aluminum, zirconium, titanium, chromium, manganese, iron, cobalt, nickel, tin and their oxides; the support is at least one of aluminum oxide, silicon dioxide, molecular sieve and porous material.

4. The carbon dioxide hydrogenation to methanol reaction catalyst according to claim 1, wherein: The rare earth element is cerium; the addition amount of the rare earth element is 0.5wt%-3wt%.

5. The preparation method of the catalyst for the reaction of hydrogenating carbon dioxide to methanol according to any one of claims 1 to 4, characterized in that It includes the following steps: a) Prepare a soluble salt solution containing a copper salt, a gallium salt and at least one of an alkali metal and an alkaline earth metal; b) Mix the solution in step a) with a transition metal oxide precursor containing zirconium or titanium to form a composite solution; c) Add a compound containing a rare earth element to the composite solution in step b), and stir evenly to obtain a mixed solution; d) Add a precursor substance of the promoter to the mixed solution in step c) according to a predetermined ratio, and stir and mix well; e) Immerse the support in the mixed solution in step d), add a precipitant to form a precipitate of metal ions for loading treatment, so that each component is evenly distributed on the support; f) Perform drying and / or calcination treatment on the support loaded in step e) to fix the active components and form the final catalyst structure; g) Perform reduction treatment on the product obtained in step f) to activate the metal component.

6. The preparation method according to claim 5, wherein The gallium salt in step a) is selected from gallium nitrate, gallium sulfate or gallium chloride; the precursor substance of the promoter in step d) is a zinc salt or an aluminum salt; the zinc salt is selected from zinc nitrate, zinc sulfate or zinc chloride; the aluminum salt is selected from aluminum nitrate, aluminum sulfate or aluminum chloride.

7. The preparation method according to claim 5, characterized in that, The precipitant in step e) is selected from sodium carbonate, potassium carbonate, sodium hydroxide or potassium hydroxide; the drying temperature range in step f) is 80°C-200°C, the calcination temperature range is 300°C-600°C, the calcination time is 2-6 hours, and the calcination atmosphere is air, an inert gas or a reducing gas.

8. The preparation method according to claim 5, characterized in that, The reduction treatment in step g) is carried out in the presence of hydrogen in the temperature range of 200°C-400°C, and the reduction time is 1-3 hours.

9. The application of the catalyst according to any one of claims 1 to 4 or the catalyst prepared by the method according to any one of claims 6-8 in the hydrogenation of carbon dioxide to methanol.

10. The application according to claim 9, wherein, The catalyst is a copper-based catalyst, and the method includes the following steps: (a) Load the copper-based catalyst into a reactor; (b) Introduce a mixed gas of carbon dioxide and hydrogen into the reactor; the molar ratio of carbon dioxide to hydrogen is 1:3-1:5; (c) React under the conditions of a reaction temperature of 200-300°C and a reaction pressure of 1-10 MPa to produce methanol; the reaction time is 1-5 hours.