Preparation method of noble metal monatomic supported molybdenum disulfide catalyst, catalyst prepared by preparation method and application of catalyst

Abstract

The invention discloses a preparation method of a precious metal monatomic loaded molybdenum disulfide catalyst, the prepared catalyst and application. Comprising the following steps: (1) mixing silicon dioxide, water and sulfydryl silane, stirring for reaction, separating, washing and drying to obtain sulfydryl modified silicon dioxide; (2) mixing the sulfydryl modified silicon dioxide, water, a sulfur source and a molybdenum source, reacting in a closed container, and separating to obtain a black solid; (3) mixing the black solid with a sodium hydroxide solution, treating, separating and washing to obtain a molybdenum disulfide carrier rich in sulfur vacancies; (4) mixing the aqueous solution containing the metal salt and the aqueous solution containing the thiourea, and stirring until the solution is clear to obtain a metal-thiourea complex solution; and (5) mixing a water-alcohol solution containing the molybdenum disulfide carrier rich in sulfur vacancies with a metal-thiourea complex solution, and carrying out heat treatment, separation, washing, drying and roasting to obtain the noble metal monatomic loaded molybdenum disulfide catalyst.

Description

Technical Field

[0001] The present application relates to a method for preparing a noble metal single atom-loaded molybdenum disulfide catalyst, the prepared catalyst and its application, and belongs to the field of chemistry and chemical engineering. Background Art

[0002] Single atom catalysts (SACs) have the characteristics of high atomic utilization and clear active sites. The development of noble metal single atom catalysts can effectively reduce the amount of noble metals used while improving the catalytic efficiency of chemical reactions. (Nature Chemistry, 2011, 3(8): 634-641.) Single atom catalysts have catalytic performance that is completely different from particles due to their unique chemical state. It is of great significance to ensure the stability of the single atom state during preparation and reaction.

[0003] The coordination constraint method is an effective method to prevent the aggregation of noble single atoms during the preparation process. The use of metal complexes as single-atom catalyst precursors is more stable than directly using metal salts. The steric hindrance between complex molecules can inhibit metal aggregation and achieve the preparation of higher-loaded catalysts. In addition, the selection and optimization of support materials can effectively improve the stability of single atoms during the reaction. Defect-rich support materials can stabilize more metal single atoms while effectively preventing the aggregation of metal atoms and improving catalyst stability.

[0004] The reverse water-gas shift reaction is considered to be an effective way to recycle CO2, but due to the poor reaction performance of non-precious metal catalysts, the reverse water-gas shift activity is difficult to further improve. Xie et al. found that single platinum atoms loaded on the surface of ceria can effectively promote the improvement of reverse water-gas shift activity. At the same time, single-atom platinum and platinum particles have different catalytic performances. Single-atom platinum has weak adsorption for CO, so it can reduce the selectivity of over-hydrogenation product CH4 (Applied Catalysis B: Environmental, 2021, 291: 120101.). Li et al. found that molybdenum disulfide, as a two-dimensional transition metal sulfide, has excellent carbon dioxide activation ability and exhibits excellent catalytic activity in carbon dioxide hydrogenation reactions (Applied Surface Science, 2021, 561: 149925.). In addition, compared with metal oxide carriers, the interaction between sulfide carriers and metals is stronger, and the high specific surface area characteristics of two-dimensional materials provide more defect sites for the loading of metal single atoms. Summary of the invention

[0005] The present invention introduces thiol-modified silica as a template into the traditional hydrothermal method for preparing molybdenum disulfide, so that the prepared molybdenum disulfide has a higher specific surface area and vacancy concentration. The noble metal loading adopts metal-thiourea complex to replace metal salt, which can effectively reduce metal aggregation, realize the preparation of high-load single-atom catalysts, and realize the loading of multiple noble metals. The preparation process has universal applicability. The noble metal single-atom loaded molybdenum disulfide prepared in the present invention can effectively improve the activity of the reverse water-gas shift reaction.

[0006] The object of the present invention is to provide a method for preparing a universal noble metal single-atom supported molybdenum disulfide catalyst, which has the characteristics of high universality, strong repeatability, high activity and high stability for the reverse water gas shift reaction.

[0007] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: preparation of a molybdenum disulfide catalyst loaded with a noble metal single atom, wherein the catalytic material is composed of a carrier molybdenum disulfide and a noble metal single atom, and a series of single-atom catalysts with different loadings can be prepared by changing the type and amount of the noble metal precursor.

[0008] According to one aspect of the present application, a method for preparing a noble metal single atom supported molybdenum disulfide catalyst is provided, comprising the following steps:

[0009] (1) mixing silica, water and mercaptosilane, stirring for reaction, separating, washing and drying to obtain mercapto-modified silica;

[0010] (2) mixing thiol-modified silica, water, a sulfur source and a molybdenum source in a sealed container, reacting and separating to obtain a black solid;

[0011] (3) mixing the black solid with a sodium hydroxide solution, treating, separating, and washing to obtain a molybdenum disulfide carrier rich in sulfur vacancies;

[0012] (4) mixing an aqueous solution containing a metal salt with an aqueous solution containing thiourea, and stirring until clear to obtain a metal-thiourea complex solution;

[0013] (5) Mixing a hydroalcoholic solution containing a molybdenum disulfide carrier rich in sulfur vacancies with a metal-thiourea complex solution, heat treating, separating, washing, drying, and calcining to obtain the noble metal single atom-supported molybdenum disulfide catalyst.

[0014] The size of the silicon dioxide is 30 to 50 nm;

[0015] The mercaptosilane is selected from at least one of 3-mercaptopropyltrimethylsilane (MPTMS), 3-mercaptopropyltriethoxysilane (MPTES), and mercaptoethyltrimethylsilane;

[0016] The usage ratio of silicon dioxide, water and mercaptosilane is 10g:200ml:1-3ml;

[0017] The temperature of the stirring reaction is room temperature;

[0018] The stirring reaction time is 8 to 12 hours;

[0019] The drying temperature is 60-120°C;

[0020] The drying time is 6 to 10 hours.

[0021] The molybdenum source is selected from ammonium molybdate (NH4)6Mo7O 24 At least one of sodium molybdate (Na2MoO4·2H2O) and molybdic acid (H2MoO4);

[0022] The sulfur source is selected from at least one of thiourea (CH4N2S), carbon disulfide (CS2), and thioacetamide (C2H5NS);

[0023] The usage ratio of the mercapto-modified silica, water, sulfur source and molybdenum source is 5g:100ml:5-20mmol:1-5mmol;

[0024] The reaction temperature is 200-220°C;

[0025] The reaction time is 10 to 20 hours.

[0026] The concentration of the sodium hydroxide solution is 2-4 mol / L;

[0027] The molar ratio of the black solid to sodium hydroxide is 4 to 6;

[0028] The treatment temperature is 60-80°C;

[0029] The treatment time is 6 to 12 hours;

[0030] The metal salt is selected from at least one of chloroplatinic acid (H2PtCl6), platinum dichloride (PtCl2), rhodium chloride (RhCl3), rhodium nitrate (Rh(NO3)3), and iridium tetrachloride (IrCl4);

[0031] In the aqueous solution containing metal salt, the concentration of the metal salt is 30 to 60 mg / ml;

[0032] In the aqueous solution containing thiourea, the concentration of thiourea is 120-200 mg / ml;

[0033] The molar ratio of the substance contained in the aqueous solution containing the metal salt to the substance contained in the aqueous solution containing thiourea is 4 to 6;

[0034] The metal-thiourea complex solution is diluted to a total mass concentration of platinum, rhodium and iridium therein of 5-10 mg / ml.

[0035] The hydroalcoholic solution is a mixed solution of water and ethanol, wherein the volume ratio of water to ethanol is 0.4 to 0.2;

[0036] In the hydroalcoholic solution containing the molybdenum disulfide carrier rich in sulfur vacancies, the concentration of the molybdenum disulfide carrier rich in sulfur vacancies is 100-200 mg / ml;

[0037] The volume ratio of the aqueous alcohol solution containing the molybdenum disulfide carrier rich in sulfur vacancies to the metal-thiourea complex solution is 1 to 2;

[0038] The temperature of the heat treatment is 60 to 80°C;

[0039] The heat treatment time is 5 to 10 hours;

[0040] The drying temperature is 60-120°C;

[0041] The drying time is 6 to 10 hours;

[0042] The calcination temperature is 200-400°C;

[0043] The calcination time is 2 to 4 hours;

[0044] The calcination atmosphere is a nitrogen atmosphere and / or an inert gas atmosphere.

[0045] Optionally, the following steps are included:

[0046] 1) 10 g of 30-50 nm hydrophilic silica was dispersed in 200 mL of deionized water, and ultrasonic dispersion was performed for 30 min. 1-3 mL of mercaptosilane was added to the dispersed suspension, and the mixture was stirred at room temperature for 10 h. The solid after the reaction was separated by centrifugation, and washed with deionized water and ethanol for 3 times respectively. The collected solid was dried in a vacuum oven at 60° C. for 10 h. The obtained solid was mercapto-modified silica.

[0047] 2) Take 5g of the above-mentioned thiol-modified silica, disperse it in 100mL of deionized water by ultrasonication for 30min, then add 5-20mmol of sulfur source and 1-5mmol of molybdenum source in sequence, ultrasonicate for 30min to fully dissolve the sulfur source and molybdenum source, transfer the fully mixed suspension to 250mL of polytetrafluoroethylene liner, then put it into a hydrothermal kettle, place it in an oven at 200-220°C to react for 10-20h, collect the black solid after the reaction by centrifugation, disperse it in 200mL of 2-4mol / L sodium hydroxide solution, treat the mixture in a water bath at 60°C for 8h, collect the solid after the reaction by suction filtration, and wash it three times alternately with deionized water and ethanol. The obtained solid is a molybdenum disulfide carrier rich in sulfur vacancies;

[0048] 3) The noble metal precursor of the electrostatic adsorption method is coordinated with thiourea before loading to ensure the stable formation of single atoms in the subsequent treatment process. 0.1mmol of metal salt is dissolved in 10mL of deionized water based on the molar amount of the noble metal, and 4mmol of thiourea is dissolved in 10mL of deionized water. The metal salt solution is added dropwise to the thiourea solution, and the mixed solution is stirred at room temperature until it is clear. The obtained clear solution is diluted to a noble metal mass concentration of 5mg / mL based on the metal mass for later use;

[0049] 4) 1 g of molybdenum disulfide carrier is dispersed in a mixed solution of 30 mL of deionized water and 70 mL of ethanol, ultrasonicated in ice water for 1 h, and 0.2 to 2 mL of the above metal-thiourea complex solution is added dropwise to the above mixed solution according to the metal mass loading of 0.1 to 1 wt% under stirring. The mixture is adsorbed in a water bath at 60 to 80 ° C for 5 to 10 h, and the solid is collected by filtration. The solid is washed alternately with deionized water and ethanol for 3 times, and the obtained solid is dried in a vacuum oven at 60 ° C for 8 h. The obtained solid is treated in an inert atmosphere in a tubular furnace for 2 to 4 h. The final solid is a molybdenum disulfide catalyst loaded with metal single atoms.

[0050] According to another aspect of the present application, a noble metal single-atom supported molybdenum disulfide catalyst prepared by the above-mentioned preparation method is provided.

[0051] According to another aspect of the present application, there is provided an application of the above-mentioned noble metal single atom supported molybdenum disulfide catalyst for reverse water gas shift reaction.

[0052] The beneficial effects of the present invention are as follows: the method is reliable, has strong universality, and is conducive to large-scale production and use. The catalyst prepared by the present invention uses defect-rich molybdenum disulfide as a carrier and a metal complex as a precursor, which can effectively avoid the aggregation of metals during preparation and use. A series of noble metal single-atom catalysts can be prepared by changing the type and amount of the metal precursor. The catalyst provided by the present invention is used for the reverse water-gas shift reaction. Under the test conditions of 450 to 550°C, the introduction of single atoms can effectively improve the catalyst activity. The CO selectivity in the catalytic process is maintained at more than 99%, and it has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a spherical aberration electron microscope image of the platinum-supported single-atom molybdenum disulfide catalyst in Example 1.

[0054] Figure 2 The catalytic activity comparison chart of the noble metal single-atom molybdenum disulfide catalyst and the pure molybdenum disulfide catalyst in Examples 2 and 3 and Comparative Example 1. Reaction conditions: 450-550°C, 0.1 MPa, GHSV=36000 ml g -1 h -1 ;

[0055] Figure 3 This is the infrared image of CO adsorption of noble metal single-atom molybdenum disulfide loaded in Example 2.

[0056] Figure 4 This is the infrared image of CO adsorption of noble metal single-atom molybdenum disulfide loaded in Example 3.

[0057] Figure 5 This is the XPS result of the noble metal single atom molybdenum disulfide loaded in Example 2. DETAILED DESCRIPTION

[0058] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0059] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0060] Example 1

[0061] Take 10g of hydrophilic silica spheres with a particle size of 50nm, disperse them in 200mL of deionized water, ultrasonically disperse them for 30min, add 1mL of 3-mercaptopropyltriethoxysilane (MPTES), and stir them at room temperature for 10h. Centrifuge to separate the solid, wash it with deionized water and ethanol three times respectively, and then vacuum dry it at 60℃ for 10h. Take 5g of thiol-modified silica spheres, disperse them in 100mL of deionized water and ultrasonically disperse them for 30min, add 5mmol of thioacetamide (C2H5NS) and 1mmol of ammonium molybdate ((NH4)6Mo7O24 ·4H2O), ultrasonically treated for 30 min, transferred to a 250 mL polytetrafluoroethylene liner, and hydrothermally reacted at 220 ° C for 10 h. The black solid was collected by centrifugation, dispersed in 200 mL 4 mol / L NaOH solution, treated in a water bath at 60 ° C for 8 h, filtered and washed with deionized water and ethanol three times to obtain a MoS2 carrier rich in sulfur vacancies.

[0062] Take 0.1mmol of platinum dichloride (PtCl2) and dissolve it in 10mL of deionized water, add it dropwise to 4mmol of thiourea solution, and stir until it is clear. Disperse 1g of MoS2 carrier in a mixed solution of 30mL of deionized water and 70mL of ethanol, and ultrasonicate it in ice water for 1h. According to the metal loading of 0.1wt%, add the platinum-thiourea complex solution dropwise, and adsorb it in a water bath at 60℃ for 10h. Collect the solid by suction filtration, wash it with deionized water and ethanol 3 times, vacuum dry it at 60℃ for 8h, and finally treat it under argon atmosphere at 200℃ for 2h to obtain MoS2 catalyst loaded with single atomic platinum.

[0063] Example 2

[0064] Take 10g of hydrophilic silica spheres with a particle size of 50nm, disperse them in 200mL of deionized water, ultrasonically disperse them for 30min, add 1mL of 3-mercaptopropyltriethoxysilane (MPTES), and stir and react at room temperature for 10h. Centrifuge to separate the solid, wash it with deionized water and ethanol three times each, and then vacuum dry it at 60℃ for 10h. Take 5g of thiol-modified silica spheres and disperse them in 100mL of deionized water. After ultrasonication for 30min, add 10mmol of thioacetamide (C2H5NS) and 1mmol of sodium molybdate (Na2MoO4·2H2O), ultrasonically mix for 30min, transfer to 250mL of polytetrafluoroethylene liner, and hydrothermally react at 220℃ for 10h. After the reaction, centrifuge to collect the black solid, disperse it in 200mL of 4mol / L NaOH solution, treat it in a water bath at 60℃ for 8h, filter and wash it, and obtain a MoS2 carrier rich in sulfur vacancies.

[0065] Take 0.1mmol chloroplatinic acid (H2PtCl6) and dissolve it in 10mL deionized water, add it dropwise to the solution of 4mmol thiourea and stir until it is clear. Disperse 1g MoS2 carrier in a mixed solution of 30mL deionized water and 70mL ethanol, ultrasonicate in ice water for 1h, add the above metal-thiourea complex solution dropwise at a metal loading of 1wt%, and adsorb it in a water bath at 60℃ for 10h. Collect the solid by suction filtration, wash it with deionized water and ethanol three times in turn, vacuum dry it at 60℃ for 8h, and finally treat it in a nitrogen atmosphere at 300℃ for 2h to obtain a MoS2 catalyst loaded with single atomic platinum.

[0066] Example 3

[0067] Take 10g of hydrophilic silica spheres with a particle size of 40nm, disperse them in 200mL of deionized water, ultrasonically disperse them for 30min, add 2mL of mercaptoethyltrimethylsilane (ETMS), and stir and react at room temperature for 10h. Centrifuge to separate the solid, wash it with deionized water and ethanol three times respectively, and then vacuum dry it at 60℃ for 10h. Take 5g of thiol-modified silica spheres, disperse them in 100mL of deionized water, ultrasonically disperse them for 30min, add 15mmol of carbon disulfide (CS2) and 3mmol of ammonium molybdate ((NH4)6Mo7O 24 ·4H2O), ultrasonically mixed for 30 min, transferred to a 250 mL polytetrafluoroethylene liner, and hydrothermally reacted at 210 ° C for 15 h. The black solid after the reaction was collected by centrifugation, dispersed in 200 mL 3 mol / L NaOH solution, treated in a water bath at 60 ° C for 8 h, filtered and washed with deionized water and ethanol three times to obtain a MoS2 carrier rich in sulfur vacancies.

[0068] Take 0.1mmol rhodium chloride (RhCl3) and dissolve it in 10mL deionized water, and add 4mmol thiourea solution dropwise, and stir until clear. Disperse 1g MoS2 carrier in a mixed solution of 30mL deionized water and 70mL ethanol, and ultrasonicate in ice water for 1h. According to 1wt% metal loading, add the above rhodium-thiourea complex solution dropwise, and adsorb in 70℃ water bath for 8h. Filter and collect solid, wash with deionized water and ethanol 3 times respectively, and vacuum dry at 60℃ for 8h. Finally, treat it under 300℃ helium atmosphere for 3h to obtain MoS2 catalyst loaded with single atom rhodium.

[0069] Example 4

[0070] Take 10g of hydrophilic silica spheres with a particle size of 40nm, disperse them in 200mL of deionized water, ultrasonically disperse them for 30min, add 2mL of 3-mercaptopropyltrimethylsilane (MPTMS), and stir them at room temperature for 10h. Centrifuge to separate the solid, wash it with deionized water and ethanol three times respectively, and then vacuum dry it at 60℃ for 10h. Take 5g of thiol-modified silica spheres, disperse them in 100mL of deionized water and ultrasonically disperse them for 30min, add 10mmol of thiourea (CH4N2S) and 3mmol of ammonium molybdate ((NH4)6Mo7O 24 ·4H2O), after ultrasonic treatment for 30 min, it was transferred to a 250 mL polytetrafluoroethylene liner and hydrothermally reacted at 200 °C for 10 h. The black solid was collected by centrifugation, dispersed in 200 mL 3 mol / L NaOH solution, treated in a water bath at 60 °C for 8 h, filtered and washed with deionized water and ethanol three times to obtain a MoS2 carrier rich in sulfur vacancies.

[0071] Take 0.1mmol iridium tetrachloride (IrCl4) and dissolve it in 10mL deionized water, add it dropwise to 4mmol thiourea solution, and stir until it is clear. Disperse 1g MoS2 carrier in a mixed solution of 30mL deionized water and 70mL ethanol, and ultrasonicate in ice water for 1h. According to the metal loading of 1wt%, add 2mL iridium-thiourea complex solution dropwise, and adsorb it in a 60℃ water bath for 10h. Collect the solid by suction filtration, wash it with deionized water and ethanol 3 times, vacuum dry it at 60℃ for 8h, and finally treat it under 300℃ argon atmosphere for 2h to obtain MoS2 catalyst loaded with single atomic iridium.

[0072] Comparative Example 1

[0073] Take 10g of hydrophilic silica spheres with a particle size of 30nm, disperse them in 200mL of deionized water, ultrasonically disperse them for 30min, add 3mL of 3-mercaptopropyltrimethylsilane (MPTMS), and stir and react at room temperature for 10h. Centrifuge to separate the solid, wash it with deionized water and ethanol three times each, and then vacuum dry it at 60oC for 10h. Take 5g of thiol-modified silica spheres and disperse them in 100mL of deionized water. After ultrasonication for 30min, add 20mmol of thiourea (CH4N2S) and 5mmol of molybdic acid (H2MoO4), ultrasonically mix for 30min, transfer to 250mL of polytetrafluoroethylene liner, and hydrothermally react at 200℃ for 20h. Collect the black solid by centrifugation, disperse it in 200mL of 2mol / L NaOH solution, treat it in a water bath at 60℃ for 8h, filter it and wash it with deionized water and ethanol three times to obtain a pure MoS2 carrier.

[0074] Catalyst performance test

[0075] 0.2 g of the catalysts prepared in Examples 1 to 3 and Comparative Example 1 were respectively loaded into a quartz tube fixed bed reactor to evaluate the catalytic performance of the reverse water-gas shift reaction. First, H2 reduction treatment was performed at a temperature of 550°C and a pressure of normal pressure. The reverse water-gas shift reaction conditions were: reaction temperature 450-550°C, reaction pressure 0.1 MPa, synthesis gas volume space velocity 36000 ml / g -1 h -1 , the molar ratio of H2 to CO2 is 3. The raw gas and gas products were analyzed online using an Agilent 7890B gas chromatograph equipped with a TCD detector.

[0076] Figure 1 This is a spherical aberration electron microscope image of the platinum-supported single-atom molybdenum disulfide catalyst in Example 1.

[0077] Figure 2The catalytic activity comparison chart of the noble metal single-atom molybdenum disulfide catalyst and the pure molybdenum disulfide catalyst in Examples 2 and 3 and Comparative Example 1. Reaction conditions: 450-550°C, 0.1 MPa, GHSV=36000 ml g -1 h -1 ;

[0078] Figure 3 This is the infrared image of CO adsorption of noble metal single-atom molybdenum disulfide loaded in Example 2.

[0079] Figure 4 This is the infrared image of CO adsorption of noble metal single-atom molybdenum disulfide loaded in Example 3.

[0080] Figure 5 This is the XPS result of the noble metal single atom molybdenum disulfide loaded in Example 2.

[0081] Depend on Figure 1 It can be seen that platinum does exist in the form of single atoms on the molybdenum disulfide support.

[0082] Depend on Figure 2 It can be seen that the catalytic activity of molybdenum disulfide is improved after loading single atoms, and the catalytic activity can be further improved with the increase of metal loading.

[0083] Depend on Figure 3 , 4 It can be seen that the CO adsorption peak on the noble metal is concentrated at 2090 cm -1 This is consistent with the linear adsorption results of CO on single atoms.

[0084] Depend on Figure 5 It can be seen that the valence state of the loaded metal is positive, indicating that even if the loading amount is 1 wt%, the precious metal does not exist in the form of particles on the surface of molybdenum disulfide.

[0085] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing a noble metal single atom supported molybdenum disulfide catalyst, characterized in that: The following steps are involved: (1) mixing silica, water and mercaptosilane, stirring for reaction, separating, washing and drying to obtain mercapto-modified silica; (2) mixing thiol-modified silica, water, a sulfur source and a molybdenum source in a sealed container, reacting and separating to obtain a black solid; (3) mixing the black solid with a sodium hydroxide solution, treating, separating, and washing to obtain a molybdenum disulfide carrier rich in sulfur vacancies; (4) mixing an aqueous solution containing a metal salt with an aqueous solution containing thiourea, and stirring until clear to obtain a metal-thiourea complex solution; (5) Mixing a hydroalcoholic solution containing a molybdenum disulfide carrier rich in sulfur vacancies with a metal-thiourea complex solution, heat treating, separating, washing, drying, and calcining to obtain the noble metal single atom-supported molybdenum disulfide catalyst.

2. The preparation method according to claim 1, characterized in that: The size of the silicon dioxide is 30 to 50 nm; The mercaptosilane is selected from at least one of 3-mercaptopropyltrimethylsilane, 3-mercaptopropyltriethoxysilane, and mercaptoethyltrimethylsilane; The usage ratio of silicon dioxide, water and mercaptosilane is 10g:200ml:1-3ml; The temperature of the stirring reaction is room temperature; The stirring reaction time is 8 to 12 hours; The drying temperature is 60-120°C; The drying time is 6 to 10 hours.

3. The preparation method according to claim 1, characterized in that: The molybdenum source is selected from at least one of ammonium molybdate, sodium molybdate and molybdic acid; The sulfur source is selected from at least one of thiourea, carbon disulfide, and thioacetamide; The usage ratio of the mercapto-modified silica, water, sulfur source and molybdenum source is 5g:100ml:5-20mmol:1-5mmol; The reaction temperature is 200-220°C; The reaction time is 10 to 20 hours.

4. The preparation method according to claim 1, characterized in that: The concentration of the sodium hydroxide solution is 2-4 mol / L; The molar ratio of the black solid to sodium hydroxide is 4 to 6; The treatment temperature is 60-80°C; The treatment time is 6 to 12 hours.

5. The preparation method according to claim 1, characterized in that: The metal salt is selected from at least one of chloroplatinic acid, platinum dichloride, rhodium chloride, rhodium nitrate, and iridium tetrachloride; In the aqueous solution containing metal salt, the concentration of the metal salt is 30 to 60 mg / ml; In the aqueous solution containing thiourea, the concentration of thiourea is 120-200 mg / ml; The molar ratio of the substance contained in the aqueous solution containing the metal salt to the substance contained in the aqueous solution containing thiourea is 4 to 6; The metal-thiourea complex solution is diluted to a total mass concentration of platinum, rhodium and iridium therein of 5-10 mg / ml.

6. The preparation method according to claim 1, characterized in that: The hydroalcoholic solution is a mixed solution of water and ethanol, wherein the volume ratio of water to ethanol is 0.4 to 0.2; In the hydroalcoholic solution containing the molybdenum disulfide carrier rich in sulfur vacancies, the concentration of the molybdenum disulfide carrier rich in sulfur vacancies is 100-200 mg / ml; The volume ratio of the aqueous alcohol solution containing the molybdenum disulfide carrier rich in sulfur vacancies to the metal-thiourea complex solution is 1 to 2; The temperature of the heat treatment is 60-80°C; The heat treatment time is 5 to 10 hours; The drying temperature is 60-120°C; The drying time is 6 to 10 hours; The calcination temperature is 200-400°C; The calcination time is 2 to 4 hours; The calcination atmosphere is a nitrogen atmosphere and / or an inert gas atmosphere.

7. A noble metal single atom supported molybdenum disulfide catalyst prepared by the preparation method according to any one of claims 1 to 6.

8. An application of the noble metal single atom supported molybdenum disulfide catalyst according to claim 7, characterized in that: Used for reverse water gas shift reaction.

Images