A catalyst, its preparation method and application

Abstract

This invention relates to the field of catalysts, specifically to a catalyst, its preparation method, and its application. The catalyst has the chemical formula Co3S4 / foam metal; wherein the catalyst has a three-dimensional nanoflower structure. The catalyst of this invention has multiple active sites and a specific structure, increasing the specific surface area and improving the catalytic performance.

Description

Technical Field

[0001] This invention relates to the field of catalysts, and more specifically to a catalyst, its preparation method, and its application. Background Technology

[0002] Rapid industrial development has led to many industries, such as cement, papermaking, mining, and pharmaceuticals, generating large amounts of sulfur-containing pollutants. 2- Sulfur-containing wastewater, containing pollutants such as sulfur dioxide, poses significant threats to the environment and human health. Environmentally, toxic sulfides directly discharged into water can be absorbed by aquatic organisms, leading to serious consequences. Furthermore, sulfides in water bodies cause foul odors and reduce oxygen levels, severely harming aquatic life. Sulfur-containing wastewater also has corrosive properties, potentially damaging pipes over time and impacting the operation and treatment of wastewater treatment equipment. In daily life, exposure to sulfur-containing wastewater can cause H2S gas to leach into the environment at normal temperature and pressure, posing serious health risks to the heart and respiratory system. Therefore, finding an effective method for treating sulfur-containing wastewater is of paramount importance.

[0003] In recent years, methods for treating sulfur-containing wastewater have been continuously developing, mainly including physical, biological, and chemical methods. Electrochemical oxidation is a novel "environmentally friendly" technology. Compared to other methods, electrochemical oxidation typically requires only one treatment cycle. This process usually does not use chemical reagents; it only involves the continuous transfer of electrons between the electrodes and the wastewater. Furthermore, electrochemical oxidation is highly efficient in treating sulfur-containing wastewater, yielding desired chemicals (such as elemental sulfur) and hydrogen at both the anode and cathode. Finally, electrochemical oxidation is not demanding in terms of reaction conditions, operating at room temperature and pressure. The reaction process is flexible, allowing adjustment of parameters such as current and voltage. Moreover, the equipment required for electrochemical oxidation is relatively small, facilitating industrial-scale development.

[0004] The core of electrochemical oxidation is a bifunctional catalyst with hydrogen evolution reaction (HER) and sulfur oxidation reaction (SOR). However, current bifunctional catalysts and their preparation methods for the resource-based treatment of sulfur-containing wastewater have the following problems:

[0005] (1) There is a lack of inexpensive bifunctional catalysts suitable for industrial applications that also have good HER and SOR properties.

[0006] (2) Traditional noble metal catalysts such as Pt / C have good HER activity, but they are expensive and not conducive to industrial application; while traditional Co3S4 catalysts have a small specific surface area and relatively few active sites, resulting in poor HER and SOR performance, which limits their industrial application.

[0007] (3) Most reported bifunctional catalysts are in powder form, making them difficult to recycle;

[0008] (4) The loading of active components in monolithic catalysts prepared by traditional in-situ growth methods is low, and the active components are usually irregular in shape, which is not conducive to the contact between the active sites of the catalyst and the reactant molecules. Although traditional monolithic catalyst preparation methods (such as coating, impregnation, etc.) can easily achieve high loading of active components, the active components are prone to agglomeration into lumps during the catalyst preparation process, and the binder used in the preparation process will coat the active components, which is not conducive to their contact with the reactants. As a result, the catalytic activity of monolithic catalysts prepared by traditional methods is usually lower than that of their corresponding powdered catalysts. At the same time, there are also a series of problems such as the high loading of active components having little impact on catalytic performance and the binder being prone to aging during the catalytic reaction, causing the active components to fall off and be lost. Summary of the Invention

[0009] Therefore, the technical problem to be solved by the present invention is to overcome the following problems in the prior art: easy agglomeration during catalyst preparation; poor catalytic performance when catalysts are used for both hydrogen evolution reaction and sulfur oxidation reaction; small specific surface area and few active sites; easy detachment of active components and difficulty in catalyst recovery after use. The present invention provides a catalyst, its preparation method and application. The catalyst of the present invention can be used for both hydrogen evolution reaction and sulfur oxidation reaction. The catalyst has many active sites and a specific three-dimensional nanoflower structure, which increases the specific surface area of ​​the catalyst and has excellent catalytic performance. The catalyst of the present invention is a monolithic catalyst, which can be easily recovered after use without centrifugation filtration or other operations.

[0010] A first aspect of the present invention protects a catalyst, wherein the chemical formula of the catalyst is Co3S4 / foam metal;

[0011] The catalyst has a three-dimensional nanoflower structure.

[0012] The catalyst in this invention has a large number of active sites and high catalytic activity. The Co3S4 / foam metal exhibits a specific three-dimensional structure and has a large specific surface area, which further improves the catalytic performance of the catalyst.

[0013] According to the present invention, the catalyst has a specific surface area of ​​180-360 m². 2 / g, preferably 280-340m 2 / g.

[0014] In this invention, the specific surface area is tested using a pore structure analyzer.

[0015] According to the present invention, the loading of Co3S4 in the catalyst is 15wt%-35wt%, preferably 21wt%-30wt%.

[0016] In this invention, the load is measured using an inductively coupled plasma spectrometer.

[0017] According to the present invention, the foam metal is selected from at least one of foam nickel, foam copper and foam iron.

[0018] A second aspect of the present invention protects a method for preparing a catalyst, wherein the preparation method comprises:

[0019] S1. Dissolve cobalt salt, precipitant, and regulator in water to obtain a mixed solution, then add foam metal matrix and carry out the first hydrothermal reaction to obtain Co(OH)2 / foam metal;

[0020] S2. Co(OH)2 / foam metal is added to a cobalt cyanide solution to carry out a second hydrothermal reaction to obtain Co-PBA / foam metal;

[0021] S3. Co-PBA / foam metal is added to the sulfide solution to carry out the third hydrothermal reaction, yielding Co3S4 / foam metal.

[0022] The catalyst prepared by the specific method of this invention has a large specific surface area and many active sites; it can be used for hydrogen evolution reaction and sulfur oxidation reaction; in the preparation process, because it is synthesized in situ, no binder needs to be added, and there is no problem of active component loss due to binder aging during use; at the same time, the foam metal has a macroscopic three-dimensional structure, and CoPBA has a highly ordered microscopic three-dimensional structure similar to MOFs. CoPBA grows on the framework of foam metal, and the active components are uniformly dispersed on the support during the preparation process, which is not easy to agglomerate. The structure of the obtained catalyst is a three-dimensional nanoflower structure, which is easier to recover because of its fixed shape compared with general powder catalysts.

[0023] According to the present invention, in S1, the foamed metal matrix is ​​obtained by pretreatment.

[0024] In this invention, the pretreatment process includes: washing the initial foam metal matrix sequentially with hydrochloric acid, ethanol and water, and drying it to obtain the foam metal matrix.

[0025] In this invention, the foamed metal matrix serves only as a carrier, and the metal elements therein do not participate in the catalytic reaction as active components. Typically, without limitation, the foamed metal matrix is ​​in sheet form, with a length of 1-1.5 cm, a width of 0.8-1 cm, and a thickness of 0.05-0.1 cm. The amount of the foamed metal matrix used is 3-5 sheets, and the foamed metal is preferably foamed nickel (NF).

[0026] In this invention, the molar ratio of the cobalt salt, the precipitant, the regulator, and water is the conventional amount used in the art. Typically, without limitation, the molar ratio of the cobalt salt, the precipitant, the regulator, and water is 1:4:3.2:1481. The cobalt salt is a divalent cobalt salt. Preferably, the cobalt salt is selected from at least one of cobalt nitrate, cobalt chloride, and cobalt acetate, and more preferably, cobalt nitrate. The precipitant is urea, and the regulator is ammonium fluoride.

[0027] According to the present invention, in S2, the molar ratio of the cobalt salt to the cobalt cyanide is 0.1-10:1, preferably 1-2:1.

[0028] In this invention, the molar ratio of cobalt salt to cobalt cyanide within the above-mentioned range enables the successful formation of three-dimensional Co-PBA on a foam metal substrate, providing sufficient sites for the production of cobalt sulfide, thereby obtaining a catalyst with a high loading.

[0029] According to the present invention, the cobalt cyanide is selected from potassium cobalt cyanide and / or sodium cobalt cyanide.

[0030] According to the present invention, in S3, the molar ratio of the cobalt salt to the sulfide is 1-8:5-40, preferably 3-10:20-35.

[0031] In this invention, when the molar ratio of cobalt salt to sulfide meets the above-mentioned range, the reaction rate can be appropriately moderate, allowing cobalt sulfide to better inherit the morphology of PBA, which in turn facilitates full contact between the reactants and the active sites of the catalyst.

[0032] According to the present invention, the sulfide is selected from sodium sulfide and / or potassium sulfide.

[0033] According to the present invention, the conditions for the first hydrothermal reaction include: the temperature of the first hydrothermal reaction is 100-130°C, and the time of the first hydrothermal reaction is 10-14h.

[0034] According to the present invention, the conditions for the second hydrothermal reaction include: the temperature of the second hydrothermal reaction is 40-90°C, preferably 50-75°C, and the time of the second hydrothermal reaction is 8-16 hours, preferably 10-14 hours.

[0035] According to the present invention, the conditions for the third hydrothermal reaction include: the temperature of the third hydrothermal reaction is 70-130°C, preferably 90-115°C, and the time of the third hydrothermal reaction is 8-15 hours, preferably 9-11 hours.

[0036] In this invention, the products after the first hydrothermal reaction, the products after the second hydrothermal reaction, and the products after the third hydrothermal reaction are respectively subjected to cooling, cleaning, and drying treatments. These treatments are all conventional treatments in the art and do not need to be limited.

[0037] A third aspect of this invention protects a catalyst prepared by the aforementioned method.

[0038] A fourth aspect of this invention protects the use of the aforementioned catalyst in hydrogen evolution reaction and sulfur oxidation reaction.

[0039] According to the present invention, in the hydrogen evolution reaction, when the current density is 100 mA / cm² -2 At that time, the voltage of the catalyst is -0.5 to -0.1V.

[0040] In the hydrogen evolution reaction, at a fixed current density, the smaller the absolute value of the voltage, the better the catalytic reaction performance.

[0041] According to the present invention, in the sulfur oxidation reaction, when the current density is 100 mA / cm² -2 At that time, the voltage of the catalyst is 0.2-0.5V.

[0042] In the sulfur oxidation reaction, at a fixed current density, the smaller the absolute value of the voltage, the better the catalytic reaction performance.

[0043] The excellent catalytic performance in the hydrogen evolution reaction and sulfur oxidation reaction proves that there is no aggregation in the catalyst.

[0044] The technical solution of this invention has the following advantages:

[0045] (1) The catalyst in this invention has many active sites and a specific three-dimensional nanoflower structure, which increases the specific surface area of ​​the catalyst, improves the catalytic performance of the catalyst, is easy to recycle after use, and can be applied to hydrogen evolution reaction and sulfur oxidation reaction.

[0046] (2) The preparation method in this invention adopts an in-situ synthesis method, which avoids the agglomeration of active components, ensures uniform dispersion of active components, and increases the loading of Co3S4 on foam metal. By synthesizing Co-PBA / foam metal with a three-dimensional structure, sites for the growth of Co3S4 are provided. At the same time, because CoPBA has highly ordered metal sites and porous characteristics of MOFs materials, it is beneficial for the Co3S4 active components to be uniformly distributed on the foam metal, so that the catalyst has a high specific surface area and can fully contact the reactants. Furthermore, because no binder is added, the active components will not be lost due to the aging of the binder. Attached Figure Description

[0047] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0048] Figure 1 These are linear sweep voltammetric test graphs of sulfur oxidation reaction (SOR) in Examples 1, 1, and 2 of the present invention.

[0049] Figure 2 These are linear sweep voltammetry results of the hydrogen evolution reaction (HER) in Examples 1, 1, and 2 of this invention.

[0050] Figure 3 This is a test image of the XRD pattern of Embodiment 1 of the present invention;

[0051] Figure 4 This is a test image of SEM from Embodiment 1 of the present invention. Detailed Implementation

[0052] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0053] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0054] The initial foam nickel matrix (Kejing), Pt / C (Guoyao Reagent), and Nafion solution (Guoyao Reagent) are all commercially available.

[0055] Example 1

[0056] This embodiment provides a catalyst, the specific preparation steps and operating parameters of which are as follows:

[0057] Pretreatment of the nickel foam matrix:

[0058] Under ultrasonic conditions, the initial nickel foam matrix was sequentially cleaned with 100 mL of 3 mol / L hydrochloric acid solution, 100 mL of ethanol, and 100 mL of water for 30 min each to remove surface oxides and impurities. Then, it was dried in a vacuum oven to obtain the nickel foam matrix, which has a length of 1 cm, a width of 1 cm, and a thickness of 0.6 cm.

[0059] S1. Measure 40 mL of deionized water using a graduated cylinder and 750 μL of 2 mol / L cobalt nitrate solution using a pipette. Place both solutions in a polytetrafluoroethylene (PTFE) reactor. Accurately weigh 0.36 g of urea and 0.18 g of ammonium fluoride using an analytical balance and add them to the reactor (molar ratio of cobalt nitrate, urea, ammonium fluoride, and water is 1:4:3.2:1481). Add a clean magnetic stir bar and stir for 10 min. Remove the magnetic stir bar with a magnet and use tweezers to place three pieces of nickel foam matrix in the reactor. After sealing the reactor, initiate the first hydrothermal reaction at 120 °C for 12 h. After the reaction is complete, open the hydrothermal reactor and wash the product three times with distilled water and ethanol, then dry it at 25 °C to obtain Co(OH)₂ / NF.

[0060] S2. Disperse 0.25g of potassium cobalt cyanide in 35mL of water, add a clean magnetic stir bar and stir for 10min. Remove the magnetic stir bar with a magnet to obtain a potassium cobalt cyanide solution. Then, transfer the Co(OH)2 / NF and potassium cobalt cyanide solution prepared in S1 to the inner liner of a stainless steel autoclave (the molar ratio of cobalt nitrate to potassium cobalt cyanide is 2:1) for a second hydrothermal reaction. The temperature of the second hydrothermal reaction is 60℃ and the reaction time is 12h. After the reaction is completed, wash the product three times with distilled water and ethanol, and dry it at 25℃ to obtain Co-PBA / NF.

[0061] S3. Accurately measure 40 mL of 0.4 mol / L sodium sulfide solution using a graduated cylinder and place it in a clean polytetrafluoroethylene hydrothermal reactor. Use tweezers to pick up 3 pieces of Co-PBA / NF prepared in S2 and place them flat in the reactor. After the reactor is fitted with an outer casing (the molar ratio of cobalt nitrate to sodium sulfide is 3:32), carry out the third hydrothermal reaction at a temperature of 100℃ for 10 h. Wash the product after the reaction three times with distilled water and ethanol, and dry it at 25℃ to obtain Co3S4 / NF.

[0062] from Figure 3 It can be seen that Co3S4 / NF has a distinct crystal form, indicating that Co3S4 / NF was successfully prepared with high purity; from Figure 4 It is clear that the structure of Co3S4 / NF is a three-dimensional nanoflower structure.

[0063] Example 2

[0064] This embodiment provides a catalyst that differs from Example 1 in that, in S2, the molar ratio of cobalt nitrate to potassium cobalt cyanide is 3:1, resulting in Co3S4 / NF-2.

[0065] Example 3

[0066] This embodiment provides a catalyst that differs from Example 1 in that, in S2, a second hydrothermal reaction is carried out at a temperature of 70°C for 14 hours to obtain Co3S4 / NF-3.

[0067] Example 4

[0068] This embodiment provides a catalyst that differs from Example 1 in that, in S3, the molar ratio of cobalt nitrate to sodium sulfide is 3:22, resulting in Co3S4 / NF-4.

[0069] Example 5

[0070] This embodiment provides a catalyst that differs from Example 1 in that, in S3, "the temperature of the third hydrothermal reaction is 120°C and the time of the third hydrothermal reaction is 8 hours", thus obtaining Co3S4 / NF-5.

[0071] Comparative Example 1

[0072] This comparative example provides a catalyst, the specific preparation steps and operating parameters of which are as follows:

[0073] S1. Measure 40 mL of deionized water using a graduated cylinder and 750 μL of 2 mol / L cobalt nitrate solution using a pipette. Place both solutions in a polytetrafluoroethylene (PTFE) reactor. Accurately weigh 0.36 g of urea and 0.18 g of ammonium fluoride using an analytical balance and add them to the reactor (molar ratio of cobalt nitrate, urea, ammonium fluoride, and water is 1:4:3.2:1481). Add a clean magnetic stir bar and stir for 10 min. Remove the magnetic stir bar with a magnet, cover the reactor, and proceed with the first hydrothermal reaction at 120 °C for 12 h. After the reaction is complete, open the hydrothermal reactor and wash the powder three times with distilled water and ethanol, then centrifuge. Collect the lower solid powder and dry it at 25 °C to obtain Co(OH)₂.

[0074] S2. Disperse 0.25g of potassium cobalt cyanide in 35mL of water, add a clean magnetic stir bar and stir for 10min. Remove the magnetic stir bar with a magnet to obtain a potassium cobalt cyanide solution. Then, transfer the Co(OH)2 and potassium cobalt cyanide solution prepared in S1 to the inner liner of a stainless steel autoclave (the molar ratio of cobalt nitrate to potassium cobalt cyanide is 2:1) for a second hydrothermal reaction. The temperature of the second hydrothermal reaction is 60℃ and the reaction time is 12h. After the reaction is completed, wash the product three times with distilled water and ethanol, and centrifuge. Collect the lower solid powder and dry it at 25℃ to obtain Co-PBA.

[0075] S3. Accurately measure 40 mL of 0.4 mol / L sodium sulfide solution using a graduated cylinder and place it in a clean polytetrafluoroethylene hydrothermal reactor. Place the Co-PBA obtained in S2 into the reactor. After fitting the outer casing of the reactor (the molar ratio of cobalt nitrate to sodium sulfide is 3:32), carry out the third hydrothermal reaction at a temperature of 100℃ for 10 h. Wash the product after the reaction three times with distilled water and ethanol, and centrifuge. Collect the lower solid powder, dry it at 25℃ to obtain Co3S4. Drop-coat the catalyst onto carbon paper to obtain the Co3S4 / CP catalyst.

[0076] Comparative Example 2

[0077] This comparative example provides a commercial catalyst, Pt / C powder, denoted as catalyst Pt / C.

[0078] Test case

[0079] The catalysts prepared in each embodiment and comparative example were tested for specific surface area, loading, hydrogen evolution reaction activity, and sulfur oxidation reaction activity. The specific test methods are as follows:

[0080] The specific surface area of ​​the catalyst was tested using a pore structure analyzer.

[0081] The catalyst loading was tested using an inductively coupled plasma optical transilluminator (ICP-ORT).

[0082] The method for testing the hydrogen evolution reaction activity of the catalyst is as follows: using a three-electrode system, in a 0.1 mol / L NaOH solution, the linear sweep voltammetry method is employed.

[0083] The sulfur oxidation activity of the catalyst was tested using a three-electrode system in a mixed solution of 0.1 mol / L NaOH and 0.1 mol / L Na2S, by linear sweep voltammetry.

[0084] The specific test results are shown in Table 1.

[0085] Table 1

[0086]

[0087]

[0088] Note: The specific surface area in the table refers to the surface area of ​​sheet-like structures.

[0089] In summary, as can be seen from Table 1:

[0090] Comparative Example 1 did not add foamed metal and was a powdered material. Comparative Example 2 was also a powdered material. The specific surface area reference systems for sheet materials and powdered materials are different, so there is no significance for comparison. No carrier was added in Comparative Example 1, so there is no loading parameter.

[0091] (1) Compared with Examples 2-5, the absolute values ​​of the voltages corresponding to SOR and HER of the Co3S4 / NF catalyst prepared in Example 1 are the smallest, indicating that Co3S4 / NF has the best SOR and HER activity. This is because the catalyst of Example 1 has the highest specific surface area and the highest loading.

[0092] (2) Compared with Comparative Example 2 (Pt / C), the Co3S4 / NF catalyst prepared in Example 1 has better SOR performance, while the Pt / C catalyst has better HER performance than the Co3S4 / NF catalyst. Considering cost factors, the Pt / C catalyst is not only expensive and scarce, but also difficult to achieve excellent dual SOR and HER performance.

[0093] (3) Compared with Comparative Example 1 (Co3S4 / CP), the Co3S4 / NF catalyst prepared in Example 1 has better SOR and HER performance, indicating that the monolithic catalyst can not only inherit the three-dimensional framework of foam metal to achieve rapid mass transfer and separation of reactants and products, but also has better performance because the three-dimensional structure is conducive to the full exposure of active sites, which in turn is conducive to the catalytic reaction.

[0094] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a catalyst, characterized in that, The preparation method includes: S1. Dissolve cobalt salt, precipitant, and regulator in water to obtain a mixed solution, then add foam metal matrix and carry out the first hydrothermal reaction to obtain Co(OH)2 / foam metal; S2. Co(OH)2 / foam metal is added to a cobalt cyanide solution to carry out a second hydrothermal reaction to obtain Co-PBA / foam metal; S3. Co-PBA / foam metal is added to the sulfide solution to carry out the third hydrothermal reaction, yielding Co3S4 / foam metal.

2. The preparation method according to claim 1, characterized in that, In S2, the molar ratio of the cobalt salt to the cobalt cyanide is 0.1-10:1; And / or, the cobalt cyanide is selected from potassium cobalt cyanide and / or sodium cobalt cyanide.

3. The preparation method according to claim 2, characterized in that, The molar ratio of the cobalt salt to the cobalt cyanide is 1-2:

1.

4. The preparation method according to claim 1, characterized in that, In S3, the molar ratio of the cobalt salt to the sulfide is 1-8:5-40; And / or, the sulfide is selected from sodium sulfide and / or potassium sulfide.

5. The preparation method according to claim 4, characterized in that, In S3, the molar ratio of the cobalt salt to the sulfide is 3-8:20-35.

6. The preparation method according to claim 1, characterized in that, The conditions for the first hydrothermal reaction include: the temperature of the first hydrothermal reaction is 100-130℃, and the time of the first hydrothermal reaction is 10-14h; And / or, the conditions for the second hydrothermal reaction include: the temperature of the second hydrothermal reaction is 40-90°C, and the time of the second hydrothermal reaction is 8-16 hours; And / or, the conditions for the third hydrothermal reaction include: the temperature of the third hydrothermal reaction is 70-130°C, and the time of the third hydrothermal reaction is 8-15 hours.

7. The preparation method according to claim 6, characterized in that, The conditions for the second hydrothermal reaction include: the temperature of the second hydrothermal reaction is 50-75℃, and the time of the second hydrothermal reaction is 10-14h; And / or, the conditions for the third hydrothermal reaction include: the temperature of the third hydrothermal reaction is 90-115°C, and the time of the third hydrothermal reaction is 9-11 hours.

8. A catalyst prepared by the method according to any one of claims 1-7.

9. The catalyst according to claim 8, characterized in that, The chemical formula of the catalyst is Co3S4 / foam metal; The catalyst has a three-dimensional nanoflower structure.

10. The catalyst according to claim 9, characterized in that, The catalyst has a specific surface area of ​​180-360 m². 2 / g; And / or, the loading of Co3S4 in the catalyst is 15wt%-35wt%; And / or, the foam metal is selected from at least one of foam nickel, foam copper and foam iron.

11. The catalyst according to claim 10, characterized in that, The catalyst has a specific surface area of ​​280-340 m². 2 / g; And / or, the loading of Co3S4 in the catalyst is 21wt%-30wt%.

12. The use of the catalyst according to any one of claims 8-11 in the hydrogen evolution reaction and the sulfur oxidation reaction.

13. The application according to claim 12, characterized in that, In the hydrogen evolution reaction, when the current density is 100 mA / cm² -2 At that time, the voltage of the catalyst is -0.5 to -0.1V.

14. The application according to claim 12 or 13, characterized in that, In the sulfur oxidation reaction, when the current density is 100 mA / cm² -2 At that time, the voltage of the catalyst is 0.2-0.5V.

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