A high-stable single-atom catalyst, a synthesis method and application thereof in catalytic hydrogenation of carbon dioxide to methanol

Abstract

The application discloses a kind of high-stability single-atom catalyst and synthesis method and its application in carbon dioxide catalytic hydrogenation preparation methanol, acetylacetone metal salt A and acetylacetone metal salt B are ground, then are calcined twice, obtain high-stability single-atom catalyst;Acetylacetone salt A is acetylacetone platinum, acetylacetone palladium, acetylacetone rhodium or acetylacetone ruthenium;Acetylacetone metal salt B is acetylacetone manganese, acetylacetone iron, acetylacetone nickel, acetylacetone chromium, acetylacetone lanthanum, acetylacetone cerium, acetylacetone cobalt, acetylacetone copper, acetylacetone zinc, acetylacetone zirconium, acetylacetone indium, acetylacetone tin or acetylacetone molybdenum.The application is combined by adjusting the active interface of noble metal single atom and metal oxide carrier formed by machine grinding, so as to control the energy barrier of CO2 molecule adsorption activation to formate, and the active hydrogen of metal active site dissociation can continuously overflow to the surface of active center with lower energy barrier by the driving force of "lattice charge balance" of metal oxide carrier, so as to greatly improve the selectivity of product methanol.

Description

Technical Field

[0001] The present invention belongs to the technical field of air pollution control, and particularly relates to a highly stable single-atom catalyst and a synthesis method thereof, and application thereof in catalytic hydrogenation of carbon dioxide to produce methanol. Technical Background

[0002] With the increasing severity of global climate change and the energy crisis, converting excess CO2 in the atmosphere into usable carbon resources is a necessary path for humanity to achieve carbon neutrality and practice sustainable development. Among the numerous CO2 resource utilization technologies, thermodynamic CO2 hydrogenation technology has received extensive research and attention due to its advantages such as controllable conditions and ease of operation. Converting CO2 into high-energy-density fuels and high-value-added carbon products through hydrogenation reduction technology is one of the important ways to reduce CO2 concentration in the atmosphere, store intermittent renewable energy, and achieve carbon neutrality. Converting captured and pre-concentrated CO2 into high-value-added products such as methanol and dimethyl ether through a catalytic hydrogenation reduction process can not only effectively control the greenhouse effect caused by excessive CO2 emissions, but also help alleviate the energy crisis caused by the shortage of fossil energy.

[0003] The C=O bond of CO2 is activated by transferring electrons from the metal d-bonding orbital to the CO2 antibonding orbital to form CO2 δ- To achieve this, it is necessary to construct active centers with high charge density to improve the low-temperature activation efficiency of the molecule. Single-atom catalysts have been widely used in heterogeneous catalytic reactions because they have the highest metal atom utilization efficiency. The high atom utilization rate and unique electronic-geometric structure of single-atom catalysts enable them to exhibit excellent catalytic performance in a series of important reactions. However, common single-atom catalysts have poor stability and are easily agglomerated and deactivated in high-temperature and high-pressure reducing atmospheres. Therefore, they cannot be used in the catalytic hydrogenation of CO2 to methanol. In addition, the randomness of the coordination structure of traditional single-atom catalysts leads to uneven distribution of products after CO2 hydrogenation, and the selectivity of the high-value product methanol is low. Summary of the Invention

[0004] In order to overcome the technical problem of low methanol selectivity in the reaction of CO2 catalytic hydrogenation to methanol in the prior art, the purpose of the present invention is to provide a highly stable single-atom catalyst and a synthesis method and its application in the catalytic hydrogenation of carbon dioxide to methanol.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A method for synthesizing a highly stable single-atom catalyst comprises the following steps:

[0007] Acetylacetonate metal salt A and acetylacetonate metal salt B are mechanically ground and then calcined twice to obtain a highly stable single-atom catalyst;

[0008] Acetylacetonate A is platinum acetylacetonate, palladium acetylacetonate, rhodium acetylacetonate or ruthenium acetylacetonate;

[0009] The acetylacetonate metal salt B is manganese acetylacetonate, iron acetylacetonate, nickel acetylacetonate, chromium acetylacetonate, lanthanum acetylacetonate, cerium acetylacetonate, cobalt acetylacetonate, copper acetylacetonate, zinc acetylacetonate, zirconium acetylacetonate, indium acetylacetonate, tin acetylacetonate or molybdenum acetylacetonate.

[0010] Furthermore, the molar ratio of the acetylacetonate metal salt A to the acetylacetonate metal salt B is 1:10-50.

[0011] Furthermore, the ball milling speed is 2000-4000 rpm, and the ball milling time is 5-12 h.

[0012] Furthermore, the sample after mechanical ball milling is dried at a temperature of 60-80° C. for 6-12 h.

[0013] Furthermore, the primary calcination temperature is 300-400° C., and the calcination time is 3-4 hours.

[0014] Further, at 3-5℃·min -1 The heating rate is increased to 300-400℃.

[0015] Furthermore, the secondary calcination treatment temperature is 500-550° C., and the calcination time is 3-4 hours.

[0016] Further, at 1-2℃·min -1 The heating rate is increased to 500-550℃.

[0017] A highly stable single-atom catalyst, wherein noble metal active sites in the catalyst are atomically dispersed on the surface of a metal oxide support.

[0018] Application of a highly stable single-atom catalyst in the heterogeneous catalytic hydrogenation of CO2 to methanol.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention is based on optimizing the coordination structure between noble metal atoms and oxide supports and enhancing their strong interaction. First, noble metal precursors and transition metal precursors are ball-milled and mixed by a solvent-free mechanochemical synthesis method. In this step, mechanical ball milling is used to generate a strong coordination force between different metal precursors, thereby enhancing the strong interaction ability between noble metal atoms and the support. Subsequently, during low-temperature rapid calcination, the stable and rapid dissociation of organic ligands in the metal salt precursor is promoted. Subsequently, through solvent thermal washing, the noble metal ions with weak binding force with the metal oxide support are removed from the catalyst surface, so that the remaining noble metal atom active centers have a strong interaction with the support. Finally, through high-temperature slow baking, these noble metal atoms are firmly anchored on the surface of the metal oxide support, thereby preparing a highly stable single-atom catalyst.

[0021] In the present invention, the bonding mode of the active interface formed by the noble metal single atom and the metal oxide support is adjusted by optimizing the mechanical ball milling time, thereby regulating the energy barrier for the adsorption and activation of CO2 molecules into formate. At the same time, the "lattice charge balance" driving force of the metal oxide support enables the active hydrogen (H*) dissociated from the metal active site to continuously overflow to the surface of the active center with a lower energy barrier, thereby suppressing the generation of CO and CH4 products during the heterogeneous catalytic hydrogenation of CO2 and greatly improving the selectivity of the product methanol. The catalyst prepared by the present invention has a high performance under the conditions of 280°C, 3Mpa, and a space velocity of 12,000h -1 Under the conditions of a gas ratio of 70% H2:25% CO2:5% N2, a CO2 conversion efficiency exceeding 8% and a selectivity for the product methanol exceeding 80% were achieved, with stable operation for over 200 hours. The present invention features a simple process, environmental friendliness, large production volumes, good scalability, and adjustable precious metal loading. It is expected to address the technical bottlenecks of poor stability and sintering of traditional precious metal-based catalysts in CO2 catalytic hydrogenation reactions, promoting theoretical innovation and technological progress in the fields of CO2 resource utilization and renewable energy development. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 These are spherical aberration electron microscope (STEM) images of the highly stable Pd1-ZnO single-atom catalyst in the present invention, where (a) is before the catalytic reaction and (b) is after the catalytic reaction.

[0023] Figure 2 These are spherical aberration electron microscope (STEM) images of the highly stable Pd1-In2O3 single-atom catalyst in the present invention, where (a) is before the catalytic reaction and (b) is after the catalytic reaction.

[0024] Figure 3 These are spherical aberration electron microscope (STEM) images of the highly stable Rh1-ZnO single-atom catalyst in the present invention, where (a) is before the catalytic reaction and (b) is after the catalytic reaction.

[0025] Figure 4 The ball difference electron microscope STEM image and EDS-mapping image of the high-stable Rh1-In2O3 single-atom catalyst in the application, wherein (a) is the ball difference electron microscope STEM image, and (b) is the EDS-mapping image.

[0026] Figure 5 The activity test results of the high-stable single-atom catalysts of Examples 1-4 in the application. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the application, the application will be described more fully below with reference to the accompanying drawings. The preferred embodiments of the application are shown in the drawings. However, the application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the application can be more thoroughly and completely understood.

[0028] The application designs and develops a high-stable single-atom catalytic material system with simple preparation method and high universality, so as to improve the catalytic stability and product selectivity of the single-atom catalyst for CO2 hydrogenation. The application provides a scientific basis and theoretical basis for the design of CO2 hydrogenation high-performance materials and the selection of product selectivity control methods, and has important application prospects in the field of CO2 emission reduction control and high-value conversion.

[0029] In the application, a high-stable single-atom catalyst is synthesized by a solvent-free mechanical chemical synthesis method. In this step, different metal precursors are mixed by mechanical ball milling to generate strong coordination forces between the metal precursors, thereby improving the strong interaction ability between the noble metal atoms and the carrier. Then, in the low-temperature rapid calcination process, the stable and rapid dissociation of the organic ligand in the metal salt precursor is promoted. Subsequently, through solvent thermal washing, the noble metal ions with weak binding force between the catalyst surface and the metal oxide carrier are removed, so that the remaining noble metal active centers have strong interaction with the carrier. Finally, through high-temperature slow calcination, the noble metal atoms are firmly anchored on the surface of the metal oxide carrier, thereby preparing a high-stable single-atom catalyst.

[0030] In addition, by optimizing the mechanical ball milling time, the binding mode of the active interface formed by the noble metal single atom and the metal oxide carrier is adjusted, so as to control the energy barrier of the adsorption and activation of CO2 molecules to form formate. At the same time, the "lattice charge balance" driving force of the metal oxide carrier enables the active hydrogen (H*) dissociated from the metal active site to continuously overflow to the surface of the active center with a low energy barrier, thereby inhibiting the generation of CO and CH4 products in the process of heterogeneous catalytic hydrogenation of CO2, and greatly improving the selectivity of the product methanol.

[0031] The synthesis method of the present invention specifically comprises the following steps:

[0032] (1) 0.0001 mol of acetylacetonate metal salt A (which may be one of acetylacetonate platinum, acetylacetonate palladium, acetylacetonate rhodium, and acetylacetonate ruthenium) and 0.001-0.005 mol of acetylacetonate metal salt B (which may be one of acetylacetonate manganese, acetylacetonate iron, acetylacetonate nickel, acetylacetonate chromium, acetylacetonate lanthanum, acetylacetonate cerium, acetylacetonate cobalt, acetylacetonate copper, acetylacetonate zinc, acetylacetonate zirconium, acetylacetonate indium, acetylacetonate tin, and acetylacetonate molybdenum) are ground uniformly in a crucible and then placed in a ball mill cavity.

[0033] (2) The powder in step (1) is subjected to mechanical ball milling, the diameter of the agate beads used is 0.5-10 mm, the rotation speed of the mechanical ball mill is 2000-4000 rpm, and the ball milling time is 5-12 h.

[0034] (3) Dry the solid powder obtained in step (2) at 60-80°C for 6-12 hours.

[0035] (4) calcining the solid sample obtained in step (3) at 300-400°C in air atmosphere for 2-3h at a heating rate of 1-2.5°C·min -1 .

[0036] (5) The solid powder obtained in step (4) was dispersed in 30 mL of dimethyl sulfoxide and ultrasonically washed at 40-60° C. After centrifugation, the obtained sample was ultrasonically washed twice with 30-50 mL of an ethanol-deionized water mixed solution (the volume ratio of ethanol to deionized water was 3:1).

[0037] (6) Dry the sample obtained in step (5) at 60-80°C for 6-12 hours.

[0038] (7) The sample obtained in step (6) was calcined at 500-550°C in air atmosphere for 3-4 hours at a heating rate of 1-2°C·min -1 .

[0039] The highly stable single-atom catalyst prepared by the present invention can be used in the CO2 heterogeneous catalytic hydrogenation to methanol reaction. Specifically, at 280 ° C, 3 MPa, and a space velocity of 12,000 h -1 Under the conditions of a gas volume ratio of 70% H2:25% CO2:5% N2, the CO2 conversion efficiency is higher than 8%, and the selectivity of the product methanol is greater than 80%. The efficiency of CO2 hydrogenation to methanol can be stably maintained for more than 100 hours, and can operate stably for more than 200 hours, with excellent stability and catalytic efficiency.

[0040] The following are specific examples.

[0041] Example 1 Preparation of highly stable Pd1-ZnO single atom catalyst

[0042] 0.031g of palladium acetylacetonate and 2.63g of zinc acetylacetonate were weighed and mixed in a mortar. The mixed metal salt precursor was placed in a ball mill chamber and randomly mixed with agate beads of varying sizes, ranging from 0.5 to 10mm in diameter. The sample was mechanically ball milled at 3000rpm for 10 hours. Subsequently, the resulting solid powder was dried at 70°C for 12 hours and then calcined at 300°C in air for 2 hours, with a heating rate of 1°C min. -1 The sample obtained above was dispersed in 30 mL of dimethyl sulfoxide and ultrasonically washed at 50°C. After centrifugation, the sample was ultrasonically washed twice with 30 mL of ethanol-deionized water mixed solution. The obtained solid powder was dried at 70°C for 12 h and then calcined at 500°C in air atmosphere for 4 h with a heating rate of 2°C·min -1 , and finally a highly stable Pd1-ZnO catalyst was obtained.

[0043] See also Figure 1 In (a) and (b), Figure 1 Spherical aberration electron microscopy (STEM) shows that the active components of the highly stable Pd1-ZnO single-atom catalyst maintain atomic-level dispersion before and after the reaction.

[0044] Example 2 Preparation of Highly Stable Pd1-In2O3 Single Atom Catalyst

[0045] 0.031g of palladium acetylacetonate and 4.12g of indium acetylacetonate were weighed and mixed in a mortar. The mixed metal salt precursor was placed in a ball mill chamber and randomly mixed with agate beads of varying sizes, ranging from 0.5 to 10mm in diameter. The sample was mechanically ball milled at 3000rpm for 10 hours. Subsequently, the resulting solid powder was dried at 70°C for 12 hours and then calcined at 300°C in air for 2 hours, with a heating rate of 1°C min. -1 The sample obtained above was dispersed in 30 mL of dimethyl sulfoxide and ultrasonically washed at 50°C. After centrifugation, the sample was ultrasonically washed twice with 30 mL of ethanol-deionized water mixed solution. The obtained solid powder was dried at 70°C for 12 h and then calcined at 500°C in air atmosphere for 4 h with a heating rate of 2°C·min -1 , and finally a highly stable Pd1-In2O3 catalyst was obtained.

[0046] See also Figure 2 In (a) and (b), Figure 2Spherical aberration electron microscopy (STEM) shows that the active components of the highly stable Pd1-In2O3 single-atom catalyst maintain atomic-level dispersion before and after the reaction.

[0047] Example 3 Preparation of Highly Stable Rh1-ZnO Single Atom Catalyst

[0048] 0.040g of palladium acetylacetonate and 2.63g of zinc acetylacetonate were weighed and mixed in a mortar. The mixed metal salt precursor was placed in a ball mill chamber and randomly mixed with agate beads of varying sizes, ranging from 0.5 to 10mm in diameter. The sample was mechanically ball milled at 3000rpm for 10 hours. Subsequently, the resulting solid powder was dried at 70°C for 12 hours and then calcined at 300°C in air for 2 hours, with a heating rate of 1°C min. -1 The sample obtained above was dispersed in 30 mL of dimethyl sulfoxide and ultrasonically washed at 50°C. After centrifugation, the sample was ultrasonically washed twice with 30 mL of ethanol-deionized water mixed solution. The obtained solid powder was dried at 70°C for 12 h and then calcined at 500°C in air atmosphere for 4 h with a heating rate of 2°C·min -1 , and finally a highly stable Rh1-ZnO catalyst was obtained.

[0049] See also Figure 3 In (a) and (b), Figure 3 Spherical aberration electron microscopy (STEM) shows that the active components of the highly stable Rh1-ZnO single-atom catalyst maintain atomic-level dispersion before and after the reaction.

[0050] Example 4 Preparation of Highly Stable Rh1-In2O3 Single Atom Catalyst

[0051] 0.040g of palladium acetylacetonate and 4.12g of indium acetylacetonate were weighed and mixed in a mortar. The mixed metal salt precursor was placed in a ball mill chamber and randomly mixed with agate beads of varying sizes, ranging from 0.5 to 10mm in diameter. The sample was mechanically ball milled at 3000rpm for 10 hours. Subsequently, the resulting solid powder was dried at 70°C for 12 hours and then calcined at 300°C in air for 2 hours, with a heating rate of 1°C min. -1 The sample obtained above was dispersed in 30 mL of dimethyl sulfoxide and ultrasonically washed at 50°C. After centrifugation, the sample was ultrasonically washed twice with 30 mL of ethanol-deionized water mixed solution. The obtained solid powder was dried at 70°C for 12 h and then calcined at 500°C in air atmosphere for 4 h with a heating rate of 2°C·min -1 , and finally a highly stable Rh1-In2O3 catalyst was obtained.

[0052] See also Figure 4In (a) and (b), Figure 4 The spherical aberration electron microscopy (STEM) and EDS-mapping images show that the active components of the highly stable Rh1-In2O3 single-atom catalyst maintain atomic-level dispersion before and after the reaction.

[0053] Example 5 Catalytic CO2 Hydrogenation Activity and Stability Test

[0054] The heterogeneous catalytic hydrogenation of CO2 was carried out in a fixed-bed tubular reactor (304.8 mm in total length and 9.1 mm in inner diameter). Before activity testing, the catalyst (150 mg) was pretreated in H2 at 300°C for 60 min. The gas mixture ratio was H2 / CO2 / N2 = 3 / 1 / 1 (N2 was used as an internal standard), and the gas flow rate was 30 mL / min. -1 The reaction was carried out at 200-280°C and 30 bar, and the products were analyzed online by gas chromatography (Clarus 580; PerkinElmer) equipped with a TCD and flame ionization detector. The specific calculation formula for catalytic activity is as follows:

[0055]

[0056]

[0057]

[0058]

[0059] Where CO2 conversion is the carbon dioxide concentration, n CO2,in is the input carbon dioxide molar amount, n CO2,out To output the molar amount of carbon dioxide, MeOH selectivity is the methanol selectivity, n MeOH,out is the molar amount of methanol output, n CO,out is the molar amount of carbon monoxide output, MeOH specific yield is the methanol yield, F CO2 is the partial pressure of CO2, M MeOH is the output mass of methanol, m cat is the mass of the catalyst, w m is the metal loading.

[0060] The stability test of the catalytic reaction was carried out under the following conditions: the catalyst mass was 150 mg, the mixed gas ratio was H2 / CO2 / N2=3 / 1 / 1 (N2 was used as the internal standard), and the gas flow rate was 30 mL min -1The stability test was carried out at 280 °C and 30 bar, and the products were analyzed online by gas chromatography (Clarus 580; PerkinElmer) equipped with TCD and flame ionization detector.

[0061] See also Figure 5 ,Depend on Figure 5 The activity test results show that the high-stable single-atom catalyst prepared by the present invention has a high stability at 280°C, 3Mpa, and a space velocity of 12,000h -1 Under the conditions of gas ratio of 70% H2:25% CO2:5% N2, the CO2 conversion efficiency is higher than 8%, and the selectivity of product methanol is greater than 80%.

[0062] Example 6

[0063] 0.0001 mol of palladium acetylacetonate and 0.005 mol of zinc acetylacetonate were weighed and mixed in a mortar. The mixed metal salt precursor was placed in a ball mill chamber and randomly mixed with agate beads of varying sizes, ranging from 0.5 to 10 mm in diameter. The sample was mechanically ball milled at 2000 rpm for 12 hours. Subsequently, the resulting solid powder was dried at 60°C for 12 hours and then calcined at 400°C in air for 2 hours, with a heating rate of 2°C / min. -1 The sample obtained above was dispersed in 30 mL of dimethyl sulfoxide and ultrasonically washed at 40°C. After centrifugation, the sample was ultrasonically washed twice with 40 mL of ethanol-deionized water mixed solution. The obtained solid powder was dried at 60°C for 12 h and then calcined at 520°C in air atmosphere for 3 h with a heating rate of 1°C·min -1 , and finally a highly stable single-atom catalyst was obtained.

[0064] Example 7

[0065] 0.0001 mol of palladium acetylacetonate and 0.001 mol of zinc acetylacetonate were weighed and mixed in a mortar. The mixed metal salt precursor was placed in a ball mill chamber and randomly mixed with agate beads of varying sizes, ranging from 0.5 to 10 mm in diameter. The sample was mechanically ball milled at 2500 rpm for 8 hours. Subsequently, the resulting solid powder was dried at 65°C for 10 hours and then calcined at 350°C in air for 2.5 hours, with a heating rate of 2.5°C / min. -1 The sample was dispersed in 30 mL of dimethyl sulfoxide and ultrasonically washed at 60°C. After centrifugation, the sample was ultrasonically washed twice with 50 mL of ethanol-deionized water mixed solution. The solid powder was dried at 70°C for 8 h and then calcined at 550°C in air atmosphere for 3 h at a heating rate of 2°C min -1, and finally a highly stable single-atom catalyst was obtained.

[0066] Example 8

[0067] 0.0001 mol of palladium acetylacetonate and 0.003 mol of zinc acetylacetonate were weighed and mixed in a mortar. The mixed metal salt precursor was placed in a ball mill chamber and randomly mixed with agate beads of varying sizes, ranging from 0.5 to 10 mm in diameter. The sample was mechanically ball milled at 4000 rpm for 5 hours. Subsequently, the resulting solid powder was dried at 80°C for 68 hours and then calcined at 320°C in air for 3 hours, with a heating rate of 1.5°C / min. -1 The sample obtained above was dispersed in 30 mL of dimethyl sulfoxide and ultrasonically washed at 50°C. After centrifugation, the sample was ultrasonically washed twice with 30 mL of ethanol-deionized water mixed solution. The solid powder obtained was dried at 80°C for 6 h and then calcined at 500°C in air atmosphere for 4 h with a heating rate of 1.5°C·min -1 , and finally a highly stable single-atom catalyst was obtained.

[0068] Example 9

[0069] Same as Example 8, except that zinc acetylacetonate is replaced by manganese acetylacetonate.

[0070] Example 10

[0071] Same as Example 8, except that zinc acetylacetonate is replaced by ferric acetylacetonate.

[0072] Example 11

[0073] Same as Example 8, except that zinc acetylacetonate is replaced by nickel acetylacetonate.

[0074] Example 12

[0075] Same as Example 8, except that zinc acetylacetonate is replaced by chromium acetylacetonate.

[0076] Example 13

[0077] Same as Example 8, except that zinc acetylacetonate is replaced by lanthanum acetylacetonate.

[0078] Example 14

[0079] Same as Example 8, except that zinc acetylacetonate is replaced by cerium acetylacetonate.

[0080] Example 15

[0081] Same as Example 8, except that zinc acetylacetonate is replaced by cobalt acetylacetonate.

[0082] Example 16

[0083] Same as Example 8, except that zinc acetylacetonate is replaced by copper acetylacetonate.

[0084] Example 17

[0085] Same as Example 8, except that zinc acetylacetonate is replaced by zirconium acetylacetonate.

[0086] Example 18

[0087] Same as Example 8, except that zinc acetylacetonate is replaced by tin acetylacetonate.

[0088] Example 19

[0089] Same as Example 8, except that zinc acetylacetonate is replaced by molybdenum acetylacetonate.

[0090] The foregoing description is merely a description of the preferred embodiments of the present invention and is not to be construed as limiting the scope of the claims. The present invention is not limited to the foregoing embodiments, and variations in the specific structure are permitted. Any variations within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

[0091] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

Claims

1. A method for synthesizing a highly stable single-atom catalyst, characterized in that: The following steps are involved: Acetylacetonate metal salt A and acetylacetonate metal salt B are mechanically ground and then calcined twice to obtain a highly stable single-atom catalyst; solvent thermal washing is performed between the two calcinations; The acetylacetonate metal salt A is platinum acetylacetonate, palladium acetylacetonate, rhodium acetylacetonate or ruthenium acetylacetonate; The acetylacetonate metal salt B is manganese acetylacetonate, iron acetylacetonate, nickel acetylacetonate, chromium acetylacetonate, lanthanum acetylacetonate, cerium acetylacetonate, cobalt acetylacetonate, copper acetylacetonate, zinc acetylacetonate, zirconium acetylacetonate, indium acetylacetonate, tin acetylacetonate or molybdenum acetylacetonate; The primary roasting temperature is 300-400 ºC and the roasting time is 3-4 h; The secondary calcination temperature is 500-550 ºC and the calcination time is 3-4 h.

2. The method for synthesizing a highly stable single-atom catalyst according to claim 1, wherein: The molar ratio of acetylacetonate metal salt A to acetylacetonate metal salt B is 1:10-50.

3. The method for synthesizing a highly stable single-atom catalyst according to claim 1, wherein: The ball milling speed is 2000-4000 rpm, and the ball milling time is 5-12 h.

4. The method for synthesizing a highly stable single-atom catalyst according to claim 1, wherein: The sample after mechanical ball milling is dried at a temperature of 60-80 ºC and a drying time of 6-12 h.

5. The method for synthesizing a highly stable single-atom catalyst according to claim 1, wherein: 3-5 ºC∙min -1 The temperature is raised to 300-400 ºC at a heating rate of 100 ℃.

6. The method for synthesizing a highly stable single-atom catalyst according to claim 1, wherein: 1-2 ºC∙min -1 The temperature was raised to 500-550 ºC at a heating rate of 100 ℃.

7. A highly stable single-atom catalyst prepared by the synthesis method according to any one of claims 1 to 6, characterized in that: The noble metal active sites in the catalyst are dispersed at the atomic level on the surface of the metal oxide support.

8. Use of a highly stable single-atom catalyst prepared by the synthesis method according to any one of claims 1 to 6 in the CO2 heterogeneous catalytic hydrogenation reaction to produce methanol.

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