A platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, its preparation method and application

Abstract

This invention discloses a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, its preparation method, and its application, belonging to the field of proton exchange membrane electrolysis for hydrogen production. The catalyst has a layered structure, formed by graphene, a tungsten carbide layer grown in situ on the graphene surface, and noble metal nanoparticles. The graphene forms a two-dimensional conductive network, the tungsten carbide layer is the intermediate layer, and the noble metal nanoparticles are the active centers; wherein the noble metal nanoparticles are Pt nanoparticles, Ru nanoparticles, or Ir nanoparticles. By utilizing the high-speed electron channel provided by graphene, the tungsten carbide layer as the electronic regulation and physical anchoring layer for the noble metal, and the noble metal nanoparticles as the final active centers, the three work synergistically to achieve high activity, high stability, and low noble metal usage.

Description

Technical Field

[0001] This invention belongs to the field of proton exchange membrane electrolysis for hydrogen production technology, specifically relating to a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, its preparation method, and its application. Background Technology

[0002] Hydrogen energy is considered a key secondary energy source for achieving carbon neutrality due to its high energy density and clean, pollution-free nature. Proton exchange membrane electrolysis (PEMWE) for hydrogen production offers advantages such as fast response, high hydrogen purity, and high system integration, making it one of the mainstream technologies for green hydrogen production. However, existing PEMWE cathodes generally use 20wt% Pt / C catalysts, resulting in high precious metal loading and high cost, which severely restricts large-scale commercialization. Tungsten carbide (WC) has d-band centers similar to platinum, near-zero hydrogen adsorption free energy, and is resistant to acid corrosion, but its intrinsic activity is still lower than that of precious metals. Graphene possesses single-atom thickness and ultra-high conductivity (>1000 Scm). -1 It has high strength and mechanical properties, making it an ideal two-dimensional carrier. However, the interfacial bonding between graphene and WC is weak, and it is easy to detach under high temperature and high current density.

[0003] Therefore, how to construct a WC layer with controllable thickness on the graphene surface and achieve uniform loading of noble metal nanoparticles to form a stable layered structure has become the key to reducing the amount of noble metal used while maintaining high activity. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention aims to provide a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, its preparation method and application. The catalyst utilizes graphene to provide a high-speed electron channel, tungsten carbide layer as electronic regulation and physical anchoring layer for noble metals, and noble metal nanoparticles as the final active center. The three work together to achieve high activity, high stability and low noble metal usage.

[0005] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst. The catalyst has a layered structure, which is formed by graphene, a tungsten carbide layer grown in situ on the graphene surface, and noble metal nanoparticles. The graphene is a two-dimensional conductive network, the tungsten carbide layer is an intermediate layer, and the noble metal nanoparticles are active centers. The noble metal nanoparticles are Pt nanoparticles, Ru nanoparticles, or Ir nanoparticles.

[0006] In one embodiment, the graphene has a thickness of 0.34-1.02 nm, a carbon-to-oxygen atomic ratio greater than 8:1, and an electrical conductivity greater than 1000 S / cm; the tungsten carbide layer contains tungsten carbide in the β-WC crystalline phase, with a lattice constant that is less than 5% mismatched with the lattice constant of graphene in a two-dimensional plane, and a thickness of 2-8 nm; the noble metal nanoparticles have a particle size of 1-5 nm.

[0007] In one embodiment, the mass ratio of the noble metal nanoparticles to the tungsten carbide in the tungsten carbide layer is 1:20-1:50; and the mass ratio of tungsten carbide to graphene in the tungsten carbide layer is 1:1-1:3.

[0008] This invention also provides a method for preparing a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, comprising the following steps: A dispersion was prepared by dispersing graphene oxide in deionized water; Ammonium metatungstate was added to the dispersion, and the mixture was ultrasonically mixed to form a tungsten source composite. Then, sodium borohydride aqueous solution was added dropwise at a set rate under ice-water bath conditions, and the mixture was stirred and reduced to obtain a tungsten oxide-graphene precursor. The tungsten oxide-graphene precursor was sequentially filtered, washed until neutral, and vacuum dried to obtain a dry powder. The dried powder was placed in a tube furnace and carbonized by passing in a mixture of hydrogen and methane gas to obtain a tungsten carbide-graphene composite carrier. The tungsten carbide-graphene composite carrier was dispersed in ethylene glycol and then a platinum group noble metal salt was added. After sonication, the mixture was placed in a microwave reactor and microwave reduction was carried out under nitrogen protection to obtain the product. The product was post-processed to obtain a layered catalyst.

[0009] In one embodiment, the concentration of graphene oxide in the dispersion is 1 mg / mL; the mass ratio of ammonium metatungstate to graphene oxide is 4:1; the temperature of the ice-water bath is 0°C; the set rate is 1 mL / min; the concentration of the sodium borohydride aqueous solution is 0.1 mol / L; the molar amount of sodium borohydride in the sodium borohydride aqueous solution is 5 times that of ammonium metatungstate; and the stirring and reduction time is 2 h.

[0010] In one embodiment, the washing uses deionized water, and the washing continues until the conductivity of the filtrate is <10 μS / cm; the vacuum drying temperature is 80°C, and the time is 12 hours.

[0011] In one embodiment, the volume ratio of hydrogen to methane in the hydrogen-methane mixture is 1:10, and the total flow rate of the hydrogen-methane mixture is 100 mL / min; the carbonization process involves raising the temperature to 900°C at a rate of 5°C / min and holding it at that temperature for 2 hours.

[0012] In one embodiment, the concentration of the tungsten carbide-graphene composite carrier dispersed in ethylene glycol is 10 mg / mL; the platinum group noble metal salt is one of chloroplatinic acid, ruthenium trichloride, or iridium trichloride; the mass ratio of the platinum group noble metal salt to tungsten carbide is 1:30; the microwave reduction power is 800 W and the time is 5 min.

[0013] In one embodiment, the post-processing procedure is as follows: the product is filtered, washed three times each with deionized water and ethanol, and then vacuum dried at 60°C for 24 hours.

[0014] The present invention also provides a proton exchange membrane water electrolysis device, wherein the cathode catalyst layer of the proton exchange membrane water electrolysis device comprises a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, the thickness of the cathode catalyst layer is 5 micrometers to 15 micrometers, the proton exchange membrane of the proton exchange membrane water electrolysis device is a perfluorosulfonic acid membrane, and the anode of the proton exchange membrane water electrolysis device is an iridium black catalyst.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, constructing a layered structure in which graphene, tungsten carbide layers, and noble metal nanoparticles are grown in situ sequentially. The three elements work synergistically to achieve high catalytic activity with low noble metal usage. Graphene, as a two-dimensional conductive network, provides high-speed electron channels; the tungsten carbide layer, as an intermediate layer, acts as a physical anchor and modulates the electronic structure of the noble metal nanoparticles; the noble metal nanoparticles, as active centers, participate in the hydrogen evolution reaction. The synergistic effect of these three elements optimizes the catalytic performance. The catalyst structure of this invention exhibits excellent structural stability. The high lattice matching between the tungsten carbide layer and graphene results in a tight bond through in-situ growth; the physical anchoring effect of the tungsten carbide layer on the noble metal nanoparticles inhibits their aggregation, ensuring the stability of the active centers. This invention significantly reduces the amount of noble metal used, thus lowering the catalytic cost. Through the electronic regulation and physical anchoring effect of the tungsten carbide layer, uniform loading of the noble metal nanoparticles is achieved, improving the utilization rate of the noble metal, reducing the amount of noble metal used, and lowering the catalyst preparation cost. The aforementioned cathode hydrogen evolution catalyst mainly comprises graphene, tungsten carbide, and noble metals. The graphene is a single-layer or few-layer reduced graphene oxide with a thickness of 0.34-1.02 nm, a carbon-to-oxygen atomic ratio >8:1, and an electrical conductivity >1000 S / cm. The tungsten carbide exists in a β-WC crystalline phase with a lattice constant and a mismatch of <5% with the two-dimensional plane of graphene, and a thickness of 2-8 nm, providing active sites for hydrogen adsorption while preventing noble metal agglomeration. The noble metal is selected from Pt, Ru, or Ir, with a particle size of 1-5 nm, and its loading is controlled according to a noble metal to tungsten carbide mass ratio of 1:20-1:50 to ensure maximum atom utilization.

[0016] This invention provides a method for preparing a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst. The process is controllable, simple to operate, and allows for precise control of the properties and structure of each component. During the preparation process, the properties of graphene, the thickness and crystal phase of the tungsten carbide layer, and the particle size of the noble metal nanoparticles can all be precisely adjusted through process parameters. The process has good repeatability and is easy to scale up for production.

[0017] This invention provides a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst that can be applied to a proton exchange membrane water electrolysis device. Its cathode catalyst layer contains the catalyst of this invention and exhibits good compatibility with the proton exchange membrane and anode catalyst of the device. Through rational component design and structural optimization, graphene, tungsten carbide layers, and noble metal nanoparticles each exert their advantages and synergistically complement each other, resulting in overall performance superior to similar catalysts in the prior art. Detailed Implementation

[0018] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0019] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0020] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0021] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0022] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0023] This invention provides a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, which is a "graphene-tungsten carbide-noble metal" sandwich layered cathode hydrogen evolution catalyst. The catalyst has graphene as a two-dimensional conductive framework, tungsten carbide as the middle layer, and noble metal nanoparticles as the active center. The catalyst also includes its preparation method and its direct application in a proton exchange membrane water electrolysis device.

[0024] One aspect provides a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, which is a cathode hydrogen evolution catalyst for proton exchange membrane electrolysis of water to produce hydrogen. The catalyst is a layered structure formed by sequentially growing a tungsten carbide intermediate layer and noble metal nanoparticles on the surface of a two-dimensional conductive graphene network. The noble metal is selected from platinum, ruthenium, or iridium. The thickness of the tungsten carbide layer is 2 nm to 8 nm. The average particle size of the noble metal nanoparticles is 1 nm to 5 nm. The mass ratio of the noble metal to tungsten carbide is 1:20 to 1:50. The mass ratio of tungsten carbide to graphene is 1:1 to 1:3.

[0025] The graphene used is a single-layer or few-layer reduced graphene oxide with a carbon-oxygen atom ratio greater than 8:1 and an electrical conductivity greater than 1000 S / cm.

[0026] The tungsten carbide exists in a face-centered cubic β-WC phase, and the mismatch between its lattice constant and the graphene lattice constant in the two-dimensional plane is less than 5%, thereby ensuring interfacial electronic coupling.

[0027] On the other hand, a method for preparing the catalyst is also provided, comprising the following steps: Step 1: Ultrasonically disperse graphene oxide in deionized water for 30 minutes to obtain a uniform dispersion with a concentration of 1 mg / mL. Step 2: Add ammonium metatungstate to the dispersion from step (1) to make the mass ratio of ammonium metatungstate to graphene oxide 4:1, and continue sonication for 30 minutes. Step 3: Under 0 degrees Celsius conditions, add 0.1 mol / L sodium borohydride aqueous solution to the mixture in step (2) at a rate of 1 mL per minute. The total amount added is 5 times the molar amount of ammonium metatungstate. Stir and reduce for 2 hours to obtain tungsten oxide-graphene precursor. Step 4: After filtering and washing the precursor obtained in step (3) until it is neutral, dry it in a vacuum at 80 degrees Celsius for 12 hours. Step 5: Place the dried precursor in a tube furnace and heat it to 900 degrees Celsius at a heating rate of 5 degrees Celsius per minute in an atmosphere of hydrogen and methane mixed gas with a volume ratio of 1:10. Carbonize for 2 hours to obtain tungsten carbide-graphene composite carrier. Step 6: The tungsten carbide-graphene composite carrier obtained in step (5) is redispersed in ethylene glycol, and one of the noble metal salts, chloroplatinic acid, ruthenium trichloride or iridium trichloride, is added so that the mass ratio of the noble metal to tungsten carbide is 1:30. After sonication for 20 minutes, it is placed in a microwave reactor and microwaved for 5 minutes at 800 watts under nitrogen protection. Step 7: Filter the product obtained in step (6), wash it three times with deionized water and three times with ethanol, and dry it under vacuum at 60 degrees Celsius for 24 hours to obtain the layered catalyst.

[0028] In step (5), the total flow rate of the hydrogen and methane mixture is 100 mL per minute to ensure that the tungsten carbide grain size is controlled between 2 nm and 8 nm.

[0029] In the microwave reduction process described in step (6), ethylene glycol serves as both a solvent and a reducing agent. Its boiling point is 198 degrees Celsius, and the microwave power density is 5 watts per mL of solution, ensuring that the noble metal crystal nuclei are formed instantaneously and deposited uniformly.

[0030] Another aspect provides a proton exchange membrane electrolysis water device, wherein the cathode catalytic layer of the device contains the catalyst, the thickness of the catalytic layer is 5 micrometers to 15 micrometers, the proton exchange membrane is a perfluorosulfonic acid membrane, and the anode is an iridium black catalyst.

[0031] The catalyst is used in the process of hydrogen production by proton exchange membrane electrolysis of water, and the application conditions are as follows: the membrane electrode assembly is assembled into a single cell, the electrolyte is 0.5 mol / L sulfuric acid, the temperature is 60 to 80 degrees Celsius, the current density is 0.2 amperes per square centimeter to 2 amperes per square centimeter, and the operating pressure is 0.1 MPa to 3 MPa.

[0032] In one specific embodiment, the preparation method of the platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst includes the following steps: Step 1, Graphene Oxide Dispersion. Graphene oxide was ultrasonically dispersed in deionized water at a concentration of 1 mg / mL for 30 minutes to form a homogeneous colloid.

[0033] Step 2, tungsten source composite. Add ammonium metatungstate to the above colloid, with a mass ratio of ammonium metatungstate to graphene oxide of 4:1, and continue sonication for 30 minutes to allow tungstate ions to be electrostatically adsorbed onto the surface of graphene oxide.

[0034] Step 3, low-temperature reduction. Under ice-water bath conditions, add 0.1 mol / L sodium borohydride aqueous solution dropwise at a rate of 1 mL / min, with a total amount 5 times the molar amount of ammonium metatungstate. Stir for 2 hours to reduce tungsten oxide in situ and anchor it to the graphene surface, thus obtaining the tungsten oxide-graphene precursor.

[0035] Step 4, drying. Filter the precursor, wash with deionized water until the conductivity of the filtrate is <10 μS / cm, and vacuum dry at 80℃ for 12 hours.

[0036] Step 5, carbonization. Place the dried powder in a tube furnace and introduce a mixture of hydrogen and methane gas (volume ratio 1:10) at a total flow rate of 100 mL / min. Increase the temperature to 900℃ at a rate of 5℃ / min and hold for 2 hours to complete the reduction carbonization and obtain the tungsten carbide-graphene composite carrier.

[0037] Step 6, Noble Metal Loading. The tungsten carbide-graphene composite carrier is redispersed in ethylene glycol at a concentration of 10 mg / mL. Chloroplatinic acid, ruthenium trichloride, or iridium trichloride are added to make the mass ratio of noble metal to tungsten carbide 1:30. After sonication for 20 minutes, the mixture is placed in a microwave reactor under nitrogen protection and microwaved at 800W for 5 minutes. Ethylene glycol serves as both a solvent and a reducing agent.

[0038] Step 7, Post-processing. The product was filtered, washed three times each with deionized water and ethanol, and dried under vacuum at 60°C for 24 hours to obtain a layered catalyst.

[0039] The catalyst layer is prepared as follows: The above catalyst was mixed with 5 wt% Nafion solution and isopropanol at a mass ratio of 1:5:20 and ball-milled for 2 hours to obtain a uniform slurry. An 8-micrometer-thick cathode catalyst layer was formed on the surface of the Nafion115 membrane by ultrasonic spraying. An iridium black catalyst was used as the anode to prepare the membrane electrode assembly.

[0040] The application method is as follows: The membrane electrode assembly was assembled into a single cell, with 0.5 mol / L sulfuric acid as the electrolyte, at a temperature of 70℃, and a current density of 0.2-2 A / cm². 2 The operating pressure is 0.1-3MPa, and the voltage rise is less than 30mV after 1000 hours of continuous operation.

[0041] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0042] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0043] Example 1 Step 1, Graphene oxide dispersion. Add 200 mg of monolayer graphene oxide (carbon-oxygen ratio ≈ 9.2:1) to 200 mL of deionized water and sonicate for 30 min to obtain a 1 mg / mL homogeneous colloid.

[0044] Step 2, weigh 800 mg of ammonium metatungstate ((NH4)6W) 12 O 39 Add xH2O to the above colloid and continue sonication for 30 minutes.

[0045] Step 3, low-temperature reduction. The system was placed in an ice-water bath at 0°C, and 0.1 mol / L NaBH4 aqueous solution (64 mL in total) was added dropwise at 1 mL / min. The mixture was stirred for 2 h to obtain the tungsten oxide-graphene precursor.

[0046] Step 4, drying. Filter by suction, wash with deionized water until the conductivity of the filtrate is <10 μS / cm, and dry under vacuum at 80℃ for 12 h.

[0047] Step 5, carbonization. Spread the dry powder evenly on a quartz boat and place it in a tube furnace; introduce H2 / CH2 = 1:10 (total flow rate 100 mL / min), heat to 900℃ at 5℃ / min, hold for 2 hours, and cool naturally to obtain the WC-rGO composite carrier.

[0048] Step 6, Noble Metal Loading. Disperse 100 mg WC-rGO in 10 mL of ethylene glycol, add 3.3 mg H2PtCl6·6H2O (Pt:WC mass ratio ≈ 1:30), sonicate for 20 min, then place in a microwave reactor under nitrogen protection and microwave reduction at 800 W (5 W / mL) for 5 min.

[0049] Step 7, filtration. Wash three times each with deionized water and ethanol, and dry under vacuum at 60°C for 24 hours to obtain the Pt / WC-rGO layered catalyst.

[0050] Example 2 Step 1, Graphene oxide dispersion. Add 200 mg of monolayer graphene oxide (carbon-oxygen ratio ≈ 9.2:1) to 200 mL of deionized water and sonicate for 30 min to obtain a 1 mg / mL homogeneous colloid.

[0051] Step 2, weigh 800 mg of ammonium metatungstate ((NH4)6W) 12 O 39 Add xH2O to the above colloid and continue sonication for 30 minutes.

[0052] Step 3, low-temperature reduction. The system was placed in an ice-water bath at 0°C, and 0.1 mol / L NaBH4 aqueous solution (64 mL in total) was added dropwise at 1 mL / min. The mixture was stirred for 2 h to obtain the tungsten oxide-graphene precursor.

[0053] Step 4, drying. Filter by suction, wash with deionized water until the conductivity of the filtrate is <10 μS / cm, and dry under vacuum at 80℃ for 12 h.

[0054] Step 5, carbonization. Spread the dry powder evenly on a quartz boat and place it in a tube furnace; introduce H2 / CH2 = 1:10 (total flow rate 100 mL / min), heat to 900℃ at 5℃ / min, hold for 2 hours, and cool naturally to obtain the WC-rGO composite carrier.

[0055] Step 6, Noble Metal Loading. Disperse 100 mg WC-rGO in 10 mL of ethylene glycol, add 3.3 mg RuCl3 (Ru:WC mass ratio ≈ 1:30), sonicate for 20 min, then place in a microwave reactor under nitrogen protection and microwave reduction at 800 W (5 W / mL) for 5 min.

[0056] Step 7, filtration. Wash three times each with deionized water and ethanol, and dry under vacuum at 60°C for 24 hours to obtain the Ru / WC-rGO layered catalyst.

[0057] Example 3 Step 1, Graphene oxide dispersion. Add 200 mg of monolayer graphene oxide (carbon-oxygen ratio ≈ 9.2:1) to 200 mL of deionized water and sonicate for 30 min to obtain a 1 mg / mL homogeneous colloid.

[0058] Step 2, weigh 800 mg of ammonium metatungstate ((NH4)6W) 12 O 39 Add xH2O to the above colloid and continue sonication for 30 minutes.

[0059] Step 3, low-temperature reduction. The system was placed in an ice-water bath at 0°C, and 0.1 mol / L NaBH4 aqueous solution (64 mL in total) was added dropwise at 1 mL / min. The mixture was stirred for 2 h to obtain the tungsten oxide-graphene precursor.

[0060] Step 4, drying. Filter by suction, wash with deionized water until the conductivity of the filtrate is <10 μS / cm, and dry under vacuum at 80℃ for 12 h.

[0061] Step 5, carbonization. Spread the dry powder evenly on a quartz boat and place it in a tube furnace; introduce H2 / CH2 = 1:10 (total flow rate 100 mL / min), heat to 900℃ at 5℃ / min, hold for 2 hours, and cool naturally to obtain the WC-rGO composite carrier.

[0062] Step 6, Noble Metal Loading. Disperse 100 mg WC-rGO in 10 mL of ethylene glycol, add 3.3 mg IrCl3 (Ir:WC mass ratio ≈ 1:30), sonicate for 20 min, then place in a microwave reactor under nitrogen protection and microwave reduction at 800 W (5 W / mL) for 5 min.

[0063] Step 7, filtration. Wash three times each with deionized water and ethanol, and dry under vacuum at 60°C for 24 hours to obtain the Ir / WC-rGO layered catalyst.

[0064] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst, characterized in that, The catalyst has a layered structure, which is formed by graphene, a tungsten carbide layer grown in situ on the surface of graphene, and noble metal nanoparticles. The graphene is a two-dimensional conductive network, the tungsten carbide layer is an intermediate layer, and the noble metal nanoparticles are active centers. The noble metal nanoparticles are Pt nanoparticles, Ru nanoparticles, or Ir nanoparticles.

2. The platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst according to claim 1, characterized in that, The graphene has a thickness of 0.34-1.02 nm, a carbon-oxygen atomic ratio greater than 8:1, and an electrical conductivity greater than 1000 S / cm; the tungsten carbide layer contains tungsten carbide in the β-WC crystalline phase, with a lattice constant that is less than 5% mismatched with the lattice constant of graphene in a two-dimensional plane, and a thickness of 2-8 nm; the noble metal nanoparticles have a particle size of 1-5 nm.

3. The platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst according to claim 1, characterized in that, The mass ratio of the noble metal nanoparticles to the tungsten carbide in the tungsten carbide layer is 1:20-1:50; the mass ratio of tungsten carbide to graphene in the tungsten carbide layer is 1:1-1:

3.

4. The method for preparing a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst as described in any one of claims 1 to 3, characterized in that, Includes the following steps: A dispersion was prepared by dispersing graphene oxide in deionized water; Ammonium metatungstate was added to the dispersion, and the mixture was ultrasonically mixed to form a tungsten source composite. Then, sodium borohydride aqueous solution was added dropwise at a set rate under ice-water bath conditions, and the mixture was stirred and reduced to obtain a tungsten oxide-graphene precursor. The tungsten oxide-graphene precursor was sequentially filtered, washed until neutral, and vacuum dried to obtain a dry powder. The dried powder was placed in a tube furnace and carbonized by passing in a mixture of hydrogen and methane gas to obtain a tungsten carbide-graphene composite carrier. The tungsten carbide-graphene composite carrier was dispersed in ethylene glycol and then a platinum group noble metal salt was added. After sonication, the mixture was placed in a microwave reactor and microwave reduction was carried out under nitrogen protection to obtain the product. The product was post-processed to obtain a layered catalyst.

5. The method for preparing a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst according to claim 4, characterized in that, The concentration of graphene oxide in the dispersion is 1 mg / mL; the mass ratio of ammonium metatungstate to graphene oxide is 4:1; the temperature of the ice-water bath is 0℃; the set rate is 1 mL / min; the concentration of the sodium borohydride aqueous solution is 0.1 mol / L; the molar amount of sodium borohydride in the sodium borohydride aqueous solution is 5 times that of ammonium metatungstate; and the stirring and reduction time is 2 h.

6. The method for preparing a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst according to claim 4, characterized in that, The washing process uses deionized water and continues until the conductivity of the filtrate is <10 μS / cm; the vacuum drying process is carried out at 80°C for 12 hours.

7. The method for preparing a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst according to claim 4, characterized in that, The volume ratio of hydrogen to methane in the hydrogen-methane mixture is 1:10, and the total flow rate of the hydrogen-methane mixture is 100 mL / min; the carbonization process involves raising the temperature to 900°C at a rate of 5°C / min and holding it at that temperature for 2 hours.

8. The method for preparing a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst according to claim 4, characterized in that, The concentration of the tungsten carbide-graphene composite carrier dispersed in ethylene glycol is 10 mg / mL; the platinum group noble metal salt is one of chloroplatinic acid, ruthenium trichloride, or iridium trichloride; the mass ratio of the platinum group noble metal salt to tungsten carbide is 1:30; the microwave reduction power is 800 W and the time is 5 min.

9. The method for preparing a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst according to claim 4, characterized in that, The post-processing procedure is as follows: filter the product, wash it three times each with deionized water and ethanol, and vacuum dry it at 60°C for 24 hours.

10. A proton exchange membrane water electrolysis device, characterized in that, The cathode catalyst layer of the proton exchange membrane water electrolysis device comprises a platinum-tungsten carbide-graphene layered cathode hydrogen evolution catalyst as described in any one of claims 1 to 3, wherein the thickness of the cathode catalyst layer is 5 micrometers to 15 micrometers, the proton exchange membrane of the proton exchange membrane water electrolysis device is a perfluorosulfonic acid membrane, and the anode of the proton exchange membrane water electrolysis device is an iridium black catalyst.