Monatomic cobalt-loaded tungsten disulfide nanosheet catalyst and application thereof
By introducing cobalt single atoms on the tungsten disulfide nanosheets, a single atom cobalt-supported tungsten disulfide catalyst was prepared, which solved the problems of low activity and poor stability of non-precious metal catalysts, and achieved efficient selective quinoline hydrogenation and electrochemical hydrogen evolution reactions, and significantly improved catalytic activity and stability.
Patent Information
- Application Number
- CN202510644271.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-19
- Publication Date
- 2025-08-15
AI Technical Summary
Existing non-precious metal catalysts have low activity and poor stability in hydrogen generation and selective hydrogenation reactions, making it difficult to replace precious metal catalysts, especially in quinoline selective hydrogenation reactions and electrolytic hydrogen production.
The solid-phase ball milling method was used to introduce cobalt single atoms on the tungsten disulfide nanosheets, and a single atom cobalt-supported tungsten disulfide nanosheet catalyst was prepared through solvothermal reaction and heat treatment, and the catalytic activity was improved by strong electron interaction between metal and support.
It has achieved efficient selective quinoline hydrogenation reaction and electrochemical hydrogen evolution reaction, significantly improved catalytic activity and stability, mild reaction conditions, suitable for atmospheric pressure operations, and has good application prospects.
Smart Images
Figure CN120479456A_ABST
Abstract
Description
Technical field:
[0001] The present invention relates to the field of nanomaterial preparation, and in particular to a single-atom cobalt-loaded tungsten disulfide nanosheet catalyst and applications thereof. Background technology:
[0002] Currently, hydrogen energy has a wide range of applications in various fields, including chemical engineering, energy storage, transportation, and power generation. Compared to traditional fossil fuels, hydrogen energy possesses the following characteristics: 1) Cleanliness: Hydrogen is a pollution-free energy source. Its combustion process produces only water vapor and does not release any greenhouse gases or pollutants. This characteristic gives hydrogen energy a unique advantage in addressing global warming and environmental pollution. 2) Renewability: Hydrogen energy can be produced using renewable energy sources (such as solar and wind energy), achieving energy recycling. This not only reduces dependence on fossil fuels but also promotes the optimization of the energy structure and sustainable development. 3) High Energy Density: Hydrogen has an extremely high energy density, which is superior to traditional fossil fuels, making it a promising energy source for long-distance transportation and large-scale applications. 4) Flexibility: Hydrogen energy has diverse applications. It can be burned to generate heat, produce mechanical work in heat engines, be used as an energy material in fuel cells, or be converted into solid hydrogen for use as a structural material. This flexibility allows hydrogen energy to adapt to diverse energy needs and application scenarios.
[0003] Two key hydrogen-related reactions—hydrogen generation and selective hydrogenation—have attracted significant attention due to their central role in energy conversion. Selective catalytic hydrogenation, a crucial reaction in the chemical industry, is a crucial means of producing high-value-added chemical products. 1,2,3,4-Tetrahydroquinoline, a key product produced by the selective hydrogenation of quinoline, serves as a versatile intermediate in the synthesis of alkaloids, pharmaceuticals, agrochemicals, dyes, and many other bioactive molecules. However, achieving these reactions requires addressing key issues such as H2 activation and dissociation, reactant adsorption, and product desorption. Among hydrogen production technologies, water electrolysis is currently a relatively mature method for producing hydrogen, with an efficiency of 75% to 85%. The entire process is environmentally friendly and produces no greenhouse gas emissions. Precious metal platinum-group catalysts are commonly used in water electrolysis for hydrogen production, but their commercialization is limited by low Earth reserves, high cost, and poor durability. A key challenge in water electrolysis for hydrogen production is designing low-cost, highly active, and stable non-precious metal catalysts to replace precious metal-based catalysts. Summary of the invention:
[0004] One object of the present invention is to provide a single-atom cobalt-loaded tungsten disulfide nanosheet catalyst, which is used to solve the problems of low activity and poor stability of non-precious metal catalysts in the prior art; another object of the present invention is to provide an application of this single-atom cobalt-loaded tungsten disulfide nanosheet catalyst.
[0005] The technical solution adopted by the present invention to solve the technical problem is: the single-atom cobalt-supported tungsten disulfide nanosheet catalyst is prepared by the following method:
[0006] Step (1), dispersing the sulfur-containing precursor and the tungsten salt in deionized water, ultrasonically treating to obtain a uniform mixture solution, transferring the solution to a hydrothermal reactor, performing a solvothermal reaction, washing the obtained solid with deionized water, and drying to obtain WS2 nanosheets;
[0007] Step (2), placing the WS2 nanosheets obtained in step (1) into a ball mill, grinding them thoroughly, adding cobalt salt thereto, and continuing to grind to obtain a black solid;
[0008] Step (3): placing the black solid obtained in step 2 into a magnetic boat, introducing a mixed gas, and then performing heat treatment at a temperature of 100 to 800° C. for 1 to 8 hours to obtain a cobalt-supported tungsten disulfide catalyst; the mixed gas is one of CO / Ar, H2 / Ar, and NH3 / Ar, the volume percentage of CO in the CO / Ar mixed gas is 5%, the volume percentage of H2 in the H2 / Ar mixed gas is 5%, and the volume percentage of NH3 in the NH3 / Ar mixed gas is 5%.
[0009] In step (2) of the above scheme, the cobalt salt is cobalt acetylacetonate, the molar ratio of cobalt acetylacetonate to WS2 nanosheets is 1:50 to 1:200, the ball milling speed is 200 to 800 rpm, and the ball milling time is 30 to 500 min.
[0010] In step (1) of the above scheme, the sulfur-containing precursor is thioacetamide, and the tungsten salt is tungsten chloride.
[0011] In step (1) of the above scheme, the amount of thioacetamide added is 0.5-10 g, the amount of tungsten hexachloride added is 0.5-20 g, and the amount of deionized water added is 30-100 mL.
[0012] The specific conditions of the solvent thermal reaction in step (1) of the above scheme are 60-260° C. and the reaction time is 6-48 h.
[0013] The above-mentioned single-atom cobalt-supported tungsten disulfide nanosheet catalyst is used for the selective hydrogenation reaction of quinoline.
[0014] The method for using the single-atom cobalt-supported tungsten disulfide nanosheet catalyst in the above scheme for the selective hydrogenation reaction of quinoline:
[0015] 4 mg of single-atom cobalt-loaded tungsten disulfide nanosheet catalyst, 500 μmol of quinoline, 10 mg of ammonia borane, and 5 mL of ethanol were placed in a 25 mL reaction tube. The air in the reaction tube was evacuated, and 0.1 MPa of hydrogen was introduced. The reaction temperature was 80°C, and the reaction time was 2.5 hours. The catalyst had a conversion rate of quinoline of 99%, and the selectivity for the product 1,2,3,4-tetrahydroquinoline was as high as 99%.
[0016] In the above scheme, single-atom cobalt-loaded tungsten disulfide nanosheet catalyst is used as a catalyst for electrochemical hydrogen evolution reaction.
[0017] Beneficial effects:
[0018] (1) This invention utilizes solid-phase ball milling to surface-modify tungsten disulfide nanosheets, introducing single cobalt atoms onto the tungsten disulfide. The strong electronic interaction between the metal and the support enhances the material's catalytic activity. This simple synthesis method, with readily available raw materials, has the potential for large-scale production.
[0019] (2) The Co1 / WS2 catalyst provided by the present invention exhibits excellent catalytic activity in the quinoline hydrogenation reaction, with high selectivity for the product 1,2,3,4-tetrahydroquinoline and good stability. The reaction conditions are mild and can be carried out at atmospheric pressure, effectively solving the problem of harsh reaction conditions for existing catalysts and showing promising application prospects in the field of quinoline hydrogenation.
[0020] (3) The Co1 / WS2 catalyst provided by the present invention has an overpotential of only 51 mV for hydrogen evolution reaction in acidic solution, which is close to that of the commercial catalyst Pt / C (21 mV), indicating that it has excellent electrochemical hydrogen evolution activity.
[0021] (4) The present invention provides a new approach for the design and synthesis of catalytic materials for transition metal sulfide compounds. Description of the drawings:
[0022] Figure 1 This is an AC-STEM image of the catalyst prepared in Example 1 of the present invention;
[0023] Figure 2 This is an AC-STEM image of the catalyst prepared in Example 2 of the present invention;
[0024] Figure 3 This is a SEM image of the catalyst prepared in Example 1 of the present invention;
[0025] Figure 4 TEM image of the catalyst prepared in Example 1 of the present invention;
[0026] Figure 5 The XRD patterns of the catalysts prepared in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention are shown;
[0027] Figure 6 This is a graph showing the conversion frequencies of the catalysts prepared in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention in the hydrogenation reaction of quinoline;
[0028] Figure 7 This is a comparison chart of the linear sweep voltammetry curves of the catalysts prepared in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention. Specific implementation method:
[0029] The present invention will be further described below with reference to the accompanying drawings:
[0030] Example 1:
[0031] This single-atom cobalt-supported tungsten disulfide nanosheet catalyst was prepared by the following method:
[0032] (1) 1.19 g of thioacetamide and 2.28 g of tungsten hexachloride were dispersed in 60 mL of deionized water and ultrasonically treated to obtain a uniform mixture solution. The resulting reaction system was transferred to a hydrothermal reactor and subjected to a hydrothermal reaction at 220 °C for 24 h. The resulting solid was washed with deionized water and dried to obtain WS2 nanosheets.
[0033] (2) Place 2 g of WS2 nanosheets in a ball mill and grind them thoroughly at 400 rpm for 30 min. Then add 40 mg of cobalt acetylacetonate (cobalt acetylacetonate to tungsten disulfide nanosheets in a molar ratio of 1:72). Continue grinding at 400 rpm for 1 h to obtain a black solid.
[0034] (3) The black solid obtained in (2) was placed in a magnetic boat and heat-treated at 280°C in a H2 / Ar (5% H2) environment for 3 h to obtain a single-atom cobalt-supported tungsten disulfide nanosheet catalyst (Co1 / WS2).
[0035] Example 2:
[0036] The only difference between this single-atom cobalt-supported tungsten disulfide nanosheet catalyst and Example 1 is that the amount of cobalt acetylacetonate added is 57 mg. The molar ratio of cobalt acetylacetonate to tungsten disulfide is 1:50. The cobalt in this example is supported on the tungsten disulfide nanosheet in the form of single atoms.
[0037] Comparative Example 1:
[0038] A method for preparing a tungsten disulfide nanocatalyst, the specific steps are as follows:
[0039] 1.19 g of thioacetamide and 2.28 g of tungsten hexachloride were dispersed in 60 mL of deionized water and ultrasonically treated to obtain a uniform mixture solution. The resulting reaction system was transferred to a hydrothermal reactor and subjected to a hydrothermal reaction at 220 °C for 24 h. The resulting solid was washed with deionized water and dried to obtain WS2 nanosheets.
[0040] Comparative Example 2:
[0041] The only difference between this comparative example and Example 1 is that the amount of cobalt acetylacetonate added is 100 mg, and the molar ratio of cobalt acetylacetonate to tungsten disulfide nanosheets is 1:28. In this comparative example, the cobalt is not supported on the tungsten disulfide nanosheets in the form of single atoms, but rather forms nanoclusters (Co clusters / WS2).
[0042] A series of characterizations were performed on the catalysts prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2.
[0043] Figure 1 The AC-STEM image of the single-atom cobalt-supported tungsten disulfide nanosheet catalyst prepared in Example 1 is shown. It is observed that cobalt is supported on the tungsten disulfide nanosheet in the form of a single atom. Figure 2 The AC-STEM image of the catalyst prepared in Example 2 is shown, which shows that when the molar ratio of cobalt acetylacetonate to tungsten disulfide nanosheets is 1:50, cobalt exists in the form of single atoms and does not form clusters. Figure 3 This is an SEM image of the catalyst prepared in Example 1, which shows that it has a self-assembled nanosheet structure. Figure 4 This is a TEM image, where the nanosheet morphology can be observed. Figure 5 The XRD patterns of Example 1, Comparative Example 1, and Comparative Example 2 indicate that the dispersion of metallic Co is relatively high, and the particles of the Co clusters are relatively small.
[0044] Example 3:
[0045] The application of the above-mentioned single-atom cobalt-supported tungsten disulfide nanosheet catalyst in the selective hydrogenation reaction of quinoline comprises the following steps:
[0046] (1) 4 mg of the catalyst prepared in Example 1, 500 μmol of quinoline, 10 mg of ammonia borane, and 5 mL of ethanol were placed in a 25 mL reaction tube. The air in the container was evacuated, and 0.1 MPa of hydrogen was introduced. The reaction temperature was 80° C., and the reaction time was 2.5 hours. The reagent amounts and experimental methods used in Comparative Examples 1 and 2 were the same as above.
[0047] Table 1. Catalytic effects of catalysts prepared in different examples or comparative examples in the selective hydrogenation of quinoline
[0048]
[0049] The selectivity of quinoline hydrogenation refers to the selectivity for 1,2,3,4-tetrahydroquinoline in the product.
[0050] Table 1 shows that the introduction of metallic cobalt improves the catalytic activity and selectivity of WS2 in the selective hydrogenation of quinoline. The conversion rate of quinoline by Co1 / WS2 can reach 99%, and it has a high selectivity for 1,2,3,4-tetrahydroquinoline. Figure 6 It can be seen that compared with Co clusters / WS2, Co1 / WS2 has a higher conversion frequency, which can reach 3371h -1 .
[0051] (2) The catalyst after the reaction is centrifuged, washed, and dried. The corresponding reagents are added according to the proportions in step (1) and a cyclic stability test is performed.
[0052] Table 2. Catalytic effect of Co1 / WS2 in selective hydrogenation of quinoline after different cycle times
[0053]
[0054] It can be seen from Table 2 that the Co1 / WS2 catalyst has good cycle stability.
[0055] Example 4:
[0056] The application of the above-mentioned single-atom cobalt-supported tungsten disulfide nanosheet catalyst in the electrochemical hydrogen evolution reaction comprises the following steps:
[0057] (1) All electrochemical tests were performed on an electrochemical workstation using a standard three-electrode system, with carbon paper coated with catalyst as the working electrode, platinum as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The electrolyte was a 0.5MH2SO4 solution. The electrode potential was obtained by comparing the silver / silver chloride potential and converted to the electrode potential relative to the reversible hydrogen electrode (vs RHE). The conversion equation is as follows: E RHE =E Ag / AgCl +0.059pH+0.197.
[0058] (2) Weigh 5 mg of the catalyst obtained in Example 1, add 960 μL of isopropyl alcohol, and sonicate for 2 hours. Then, add 40 μL of nafion and sonicate for half an hour to obtain a uniform ink. 80 μL of the catalyst was drop-coated on carbon paper and allowed to dry naturally. The treatment methods for Comparative Examples 1 and 2 were the same as above.
[0059] (3) In the potential range of 0 to -0.7 V (vs RHE), the -1 The catalyst was activated by CV at a scan rate of .
[0060] (4) The activity of the catalyst was tested using linear voltammetry with a scan rate of 5 mV s -1 , scanning range 0~-0.7V (vs RHE).
[0061] Performance comparison:
[0062] Depend on Figure 7 It can be seen that at a current density of 10 mA cm -2 When , the overpotential of Co1 / WS2 is only 51mV, which is much lower than that of WS2 (233mV), indicating that the introduction of cobalt improves the electrochemical hydrogen evolution performance of WS2 nanosheets, while the overpotential of Co clusters / WS2 is 142mV. In comparison, the electrochemical hydrogen evolution performance of single-atom catalysts is better.
[0063] Transition metal sulfide compounds have a lamellar structure similar to graphite, with a metallic luster on the surface and good chemical and thermal stability. Among them, there are very weak van der Waals forces between the layers of transition metal sulfide compounds, very strong covalent bonds within the layers, and the layers are easily peeled off. WS2 is a typical representative of transition metal sulfide compounds, with the characteristics of simple preparation method and strong chemical stability. Its edge-exposed S sites are highly active and have shown great potential in catalytic reactions. However, the active sites are unevenly distributed and it is difficult to accurately control their specific position and number, which has certain limitations in practical applications. At present, their catalytic performance is mainly optimized through methods such as defect engineering, doping modification and morphology regulation. Cobalt, as a transition metal combined with a carrier, has an adjustable coordination environment and electronic structure and is commonly used in various catalytic reactions. The present invention prepares a single-atom cobalt-supported tungsten disulfide catalyst, and introduces metallic cobalt on WS2 nanosheets by solid-phase ball milling. Compared to tungsten disulfide nanosheets, single-atom cobalt-supported tungsten disulfide catalysts exhibit superior catalytic activity and stability in both the thermal quinoline hydrogenation reaction and the electrochemical hydrogen evolution reaction. Due to the simplicity, high efficiency, and low energy consumption of this preparation method, it has promising application prospects in catalyst preparation and the potential for large-scale production.
[0064] The single-atom cobalt-loaded tungsten disulfide nanosheet catalyst of the present invention has greatly improved the performance of the catalyst through comparison of experimental results, and achieved efficient quinoline hydrogenation and electrochemical hydrogen evolution.
Claims
1. A single-atom cobalt-supported tungsten disulfide nanosheet catalyst, characterized by: This single-atom cobalt-supported tungsten disulfide nanosheet catalyst was prepared by the following method: Step (1), dispersing the sulfur-containing precursor and the tungsten salt in deionized water, ultrasonically treating to obtain a uniform mixture solution, transferring the solution to a hydrothermal reactor, performing a solvothermal reaction, washing the obtained solid with deionized water, and drying to obtain WS2 nanosheets; Step (2), placing the WS2 nanosheets obtained in step (1) into a ball mill, grinding them thoroughly, adding cobalt salt thereto, and continuing to grind to obtain a black solid; Step (3), placing the black solid obtained in step 2 into a magnetic boat, introducing a mixed gas, and then performing a heat treatment at a temperature of 100-800°C for a treatment time of 1-8 h to obtain a cobalt-supported tungsten disulfide catalyst; the mixed gas is one of CO / Ar, H2 / Ar, and NH3 / Ar, the volume percentage of CO in the CO / Ar mixed gas is 5%, the volume percentage of H2 in the H2 / Ar mixed gas is 5%, and the volume percentage of NH3 in the NH3 / Ar mixed gas is 5%.
2. The single-atom cobalt-supported tungsten disulfide nanosheet catalyst according to claim 1, characterized in that: In the step (2), the cobalt salt is cobalt acetylacetonate, the molar ratio of cobalt acetylacetonate to WS2 nanosheets is 1:50-1:200, the ball milling speed is 200-800 rpm, and the ball milling time is 30-500 min.
3. The single-atom cobalt-supported tungsten disulfide nanosheet catalyst according to claim 2, characterized in that: In step (1), the sulfur-containing precursor is thioacetamide, and the tungsten salt is tungsten chloride.
4. The single-atom cobalt-supported tungsten disulfide nanosheet catalyst according to claim 3, characterized in that: In the step (1), the amount of thioacetamide added is 0.5-10 g, the amount of tungsten hexachloride added is 0.5-20 g, and the amount of deionized water added is 30-100 mL.
5. The single-atom cobalt-supported tungsten disulfide nanosheet catalyst according to claim 4, characterized in that: The specific conditions of the solvent thermal reaction in step (1) are 60~260 ºC and the reaction time is 6~48 h.
6. Use of the single-atom cobalt-supported tungsten disulfide nanosheet catalyst according to claim 5, characterized in that: The single-atom cobalt-supported tungsten disulfide nanosheet catalyst is used for the selective hydrogenation reaction of quinoline.
7. The use of the single-atom cobalt-supported tungsten disulfide nanosheet catalyst according to claim 6, characterized in that: The method for using the single-atom cobalt-supported tungsten disulfide nanosheet catalyst for the selective hydrogenation reaction of quinoline: 4 mg of single-atom cobalt-supported tungsten disulfide nanosheet catalyst, 500 μmol of quinoline, 10 mg of ammonia borane, and 5 mL of ethanol were placed in a 25 mL reaction tube. The air in the reaction tube was evacuated, and 0.1 MPa of hydrogen was introduced. The reaction temperature was 80 ºC, and the reaction time was 2.5 hours. The conversion rate of quinoline to the catalyst reached 99%.
8. Use of the single-atom cobalt-supported tungsten disulfide nanosheet catalyst according to claim 5, characterized in that: The single-atom cobalt-loaded tungsten disulfide nanosheet catalyst is used as a catalyst for electrochemical hydrogen evolution reaction.