Pt / c catalyst with honeycomb channel structure, preparation method thereof and membrane electrode application

Abstract

The application discloses a Pt / C catalyst with a honeycomb channel structure, and a honeycomb covalent organic framework nanosheet taking graphene oxide as a carrier, wherein the honeycomb covalent organic framework has nanochannels with a pore size of 2-3 nm, and the particle size of Pt nanoparticles is 2-3 nm; the Pt nanoparticles are uniformly and strictly confined in the nanochannels. In the above manner, the migration, agglomeration and Oswald ripening of the Pt nanoparticles under the severe operation conditions of a fuel cell can be fundamentally inhibited, so that the electrochemical stability and durability of the catalyst are significantly improved; the preparation method of the application is simple, controllable and reproducible; and the catalyst of the application applied to a membrane electrode exhibits high activity, high durability and excellent low-humidity adaptability under the premise of maintaining low platinum loading.

Description

Technical Field

[0001] This invention relates to the field of electrochemical catalyst materials, and in particular to a Pt / C catalyst with a honeycomb channel structure for proton exchange membrane fuel cells, its preparation method, and its application in membrane electrode assembly. Background Technology

[0002] Energy crisis and environmental pollution are two major challenges facing the world today. Globally, traditional high-carbon emission and high-pollution fossil fuels are gradually being replaced by low-carbon, clean, and renewable energy sources. Among numerous new energy technologies, proton exchange membrane fuel cells (PEMFCs) are considered one of the most promising energy conversion devices due to their advantages such as zero carbon emissions, high energy conversion efficiency, low noise, and rapid start-up at low temperatures.

[0003] The core component of a proton exchange membrane fuel cell (PEMFC) is the membrane electrode assembly (MEA), and the catalyst is the "heart" of the MEA, its performance directly determining the cell's output power, lifespan, and cost. Currently, platinum (Pt)-based catalysts are indispensable catalysts for the cathode oxygen reduction reaction (ORR) and anolyte hydrogen oxidation reaction (HOR) in PEMFCs. However, the scarcity and high price of Pt severely restrict the commercialization of fuel cells. Therefore, developing highly active and stable low-Pt-loading catalysts, i.e., improving Pt utilization, has become a research hotspot in this field.

[0004] Commercially available Pt / C catalysts are primarily fabricated by supporting Pt nanoparticles on carbon black with a high specific surface area. However, traditional Pt / C catalysts face significant challenges under real-world operating conditions:

[0005] 1. Insufficient durability: Under conditions such as frequent start-stop and load cycling of fuel cells, carbon support is prone to electrochemical corrosion, which leads to the shedding, migration and aggregation of Pt nanoparticles (Oswald curing), resulting in a sharp reduction in active area and rapid performance degradation.

[0006] 2. Poor performance in low humidity: Under low humidity or low humidification conditions, the proton conductivity of the proton exchange membrane and catalyst layer decreases, and reactant transport is hindered, leading to a significant reduction in battery performance. This necessitates the installation of complex humidification equipment, increasing the system's complexity and cost.

[0007] To overcome these shortcomings, researchers have attempted to develop novel carbon supports, such as carbon nanotubes and graphene, hoping to leverage their excellent conductivity and stability to improve catalyst durability. However, Pt nanoparticles on the surface of these supports are still prone to migration and aggregation. On the other hand, materials with regular channels, such as metal-organic frameworks (MOFs) or covalent organic frameworks (COFs), have been used as supports to confine the growth of Pt nanoparticles. However, these materials themselves typically have poor conductivity, and when combined with carbon materials, they often fail to form a uniform and stable composite structure, resulting in non-uniform ion transport channels, especially under high current density and low humidity conditions, where performance improvement is limited. Summary of the Invention

[0008] The main technical problem solved by this invention is to provide a novel Pt / C catalyst and its preparation method, which can significantly improve the stability of platinum nanoparticles, effectively prevent them from undergoing Oswald ripening and agglomeration during fuel cell operation, and optimize the ion and reactant transport channels within the catalyst layer, thereby giving it both excellent durability and superior low-humidity operating performance.

[0009] One technical solution adopted in this invention is to provide a Pt / C catalyst with a honeycomb channel structure, comprising: a honeycomb covalent organic framework nanosheet supported on graphene oxide, wherein the honeycomb covalent organic framework has nanochannels with a pore size of 2-3 nm, and the Pt nanoparticles have a particle size of 2-3 nm, and the Pt nanoparticles are uniformly and strictly confined within the nanochannels. This structure, with particle size matching the channel pore size, effectively immobilizes the Pt nanoparticles, exposes more active sites, and achieves homogenization of the ion transport channels.

[0010] Another technical solution adopted in this invention is to provide a method for preparing the Pt / C catalyst, which is simple and controllable, and achieves the controllable preparation of a honeycomb-like covalent organic framework vertically arranged on graphene oxide through a one-pot colloidal assembly and subsequent heat treatment. The preparation method includes the following steps:

[0011] a. Mix the surfactant, graphene oxide, and organic solvent, and sonicate at room temperature for 30-60 minutes to form a uniform dispersion; this step is the basis of pretreatment. The surfactant, as a mediator, can effectively prevent the aggregation of graphene oxide and provide a template interface for the subsequent assembly of organic monomers; sonication ensures that the components are fully dispersed and uniformly mixed, laying the foundation for subsequent homogeneous reactions and the growth of ordered structures.

[0012] b. First, add 1,2,3,4-phenyltetramine tetrahydrochloride (TAB·4HCl) to the dispersion from step a, and ball mill and disperse for 2-3 hours at room temperature; then add hexakonecyclohexane octahydrate (HKH·8H2O) to the solution and continue to disperse evenly; this step is crucial for the formation of the covalent organic framework. The stepwise addition of the two organic monomers (TAB·4HCl and HKH·8H2O) followed by ball milling and dispersion helps the monomers to be fully adsorbed and pre-assembled on the graphene oxide / surfactant template. By precisely controlling the reaction sequence, it promotes the subsequent formation of a well-structured, uniformly porous covalent organic framework, rather than disordered polymerization.

[0013] c. The solution from step b is reacted in a high-pressure reactor at 110-130℃ for 2-3 hours to allow the covalent organic framework to grow on the surface of graphene oxide, resulting in a honeycomb-shaped covalent organic framework-graphene oxide HCCOF-GO composite material; this step involves crystal growth and composite formation. Under specific temperature and pressure conditions, the pre-assembled monomers undergo a condensation reaction, and through covalent bonds and π-π conjugation, vertically aligned honeycomb-shaped covalent organic frameworks (HCCOF) are grown in situ on the surface of graphene oxide, forming a stable HCCOF-GO composite structure. This structure combines the regular channels of the organic framework with the electrical conductivity of graphene oxide.

[0014] d. The HCCOF-GO composite material is centrifuged, washed, and dried to obtain HCCOF-GO powder; this step is the separation and purification of the product. Centrifugation and washing remove residual monomers, surfactants, and other impurities to obtain pure HCCOF-GO composite material powder; the drying process prepares for subsequent high-temperature heat treatment.

[0015] e. HCCOF-GO powder is blended with a pore-forming agent and heat-treated at 1100-1200℃ under an inert atmosphere to obtain a honeycomb-like HCCOF-GO support; this step optimizes and stabilizes the structure. The high-temperature heat treatment under an inert atmosphere partially reduces graphene oxide, improving the conductivity of the support; furthermore, the decomposition of the pore-forming agent generates gas, which further expands and creates pores, optimizing and stabilizing the honeycomb nanochannel structure. Simultaneously, it removes any potentially residual template agent, ultimately forming a catalyst support with high specific surface area and stable pores.

[0016] f. The honeycomb HCCOF-GO support is mixed with chloroplatinic acid and an organic solvent. The pH is adjusted to 10-12 with an alkaline solution, and microwave reduction is performed for 80-100 seconds. After filtration, washing, and drying, the Pt / C catalyst is obtained. This step is for loading the active sites. Under alkaline conditions, Pt ions in chloroplatinic acid are rapidly reduced to metallic Pt nanoparticles using microwave reduction. The uniformity and speed of microwave heating facilitate the uniform nucleation and growth of Pt nanoparticles within the confined pores of HCCOF, effectively controlling their particle size to 2-3 nanometers and achieving high dispersion, thereby exposing more catalytic active sites.

[0017] The surfactant mentioned in step a includes one or more of sodium citrate, sodium dodecylbenzenesulfonate (SDBS), and hexadecyltrimethylammonium bromide (CTAB). Different types of surfactants can provide different template effects and steric hindrances, which help to regulate the dispersion state of graphene oxide and the subsequent growth morphology of the organic framework, thereby affecting the uniformity of the final honeycomb structure.

[0018] The organic solvent includes one or more of isopropanol, N-methylpyrrolidone (NMP), and tetrahydrofuran. Ensuring good solubility and dispersion stability of graphene oxide, surfactants, and organic monomers is a prerequisite for successful assembly.

[0019] The mass ratio of graphene oxide to organic solvent is 1:2-5. Controlling the appropriate solid-liquid ratio is a key parameter for achieving controllable synthesis, ensuring sufficient concentration in the reaction system to promote the reaction while avoiding problems such as increased viscosity and uneven dispersion caused by excessive concentration.

[0020] In step b, the total mass of TAB·4HCl and HKH·8H2O added is 5%-10% of the mass of graphene oxide. Precisely controlling the amount of monomers added directly determines the thickness and coverage of the covalent organic framework grown on the surface of graphene oxide, avoiding bulk polymerization due to excessive amounts or incomplete coverage due to insufficient amounts, which is the key to obtaining the ideal composite structure.

[0021] In step d, the composite material is centrifuged at 6000-10000 rpm for 3-10 minutes to obtain black HCCOF-GO powder. The powder is then washed with ethanol and deionized water at 70-90°C. Finally, the washed powder is dried in an oven at 70-90°C for 18-30 hours to obtain HCCOF-GO powder. Optimized centrifugation parameters ensure complete product separation; washing with warm solvents more effectively removes organic impurities; and suitable drying temperature and time thoroughly remove moisture without damaging the material structure, providing qualified raw materials for the next high-temperature processing.

[0022] The pore-forming agent mentioned in step e includes one or more of ammonium bicarbonate, ammonium carbonate, ammonium bioxate, and ammonium oxalate. The pore-forming agent can decompose at high temperatures to generate gas, creating more micropores and mesopores in the support, effectively increasing the specific surface area and optimizing mass transfer channels. This is crucial for improving the accessibility of active sites on the catalyst and the efficiency of reactant transport.

[0023] The organic solvent mentioned in step f includes deionized water, isopropanol, and mixtures thereof; the microwave reduction temperature is 80-120 degrees Celsius. The solvent system can effectively dissolve chloroplatinic acid; the microwave reduction temperature range ensures that the Pt precursor is rapidly and uniformly reduced into metal nanoparticles, which is a key process condition for achieving uniform Pt nanoparticle size and high dispersion.

[0024] One technical solution adopted by this invention is to provide a fuel cell membrane electrode assembly, comprising the aforementioned Pt / C catalyst, wherein the catalyst is loaded onto both sides of a proton exchange membrane by spraying, wherein the cathode catalyst loading is 0.2-0.4 mg / cm³. 2 The anode catalyst loading is 0.05-0.15 mg / cm³. 2 .

[0025] When the high-performance catalyst prepared in this invention is applied to the membrane electrode, the excellent structural stability and high activity of the catalyst itself can reduce the performance degradation of the membrane electrode and fuel cell in durability tests under low platinum loading, and maintain a high current density under low humidity conditions, thus significantly improving the overall performance and practicality of the fuel cell.

[0026] The beneficial effects of this invention are as follows: The honeycomb covalent organic framework-graphene oxide composite support structure of this invention provides an ideal confinement space for Pt nanoparticles with its 2-3 nm regular channels. This structure fundamentally inhibits the migration, aggregation, and Oswald ripening of Pt nanoparticles under the harsh operating conditions of fuel cells, thereby significantly improving the electrochemical stability and durability of the catalyst. Simultaneously, the uniform nanochannels optimize proton and water transport, greatly enhancing the battery's performance in low-humidity environments.

[0027] The preparation method provided by this invention is simple, controllable, and highly reproducible. Through a one-pot colloidal assembly and interface engineering, the vertical growth of covalent organic frameworks on graphene oxide is achieved; combined with high-temperature heat treatment, the honeycomb structure is stabilized.

[0028] The membrane electrode assembly using the catalyst of this invention exhibits high activity, high durability, and excellent low-humidity adaptability while maintaining a low platinum loading. When assembled into a fuel cell, it can significantly extend service life and reduce reliance on system humidification while maintaining high power density, demonstrating broad commercial prospects. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0030] Figure 1 This is the Pt nanoparticle size distribution diagram of Example 1 of the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0033] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0034] In the description of this invention, it should be noted that the terms "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is conventionally placed during use. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] In this invention, unless otherwise expressly specified and limited, "above or below" a first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] The embodiments of the present invention include:

[0038] Example 1: A method for preparing a Pt / C catalyst with a honeycomb channel structure, comprising the following steps:

[0039] a. Weigh 0.2g sodium dodecylbenzenesulfonate (SDBS) and 2g graphene oxide, place them in a beaker, add 2g ethanol and 8g N-methylpyrrolidone (NMP), and sonicate at room temperature (25℃) for 40 minutes to form a uniform dispersion.

[0040] b. First, add 0.08 g of 1,2,3,4-phenyltetramine tetrahydrochloride (TAB·4HCl) to the dispersion in step a, and disperse by ball milling at room temperature for 2 h; then add 0.08 g of hexadecimenone cyclohexane octahydrate (HKH·8H2O) to the solution, and break the cells for 20 min to make them evenly dispersed.

[0041] c. Transfer the solution from step b to a high-pressure reactor and react at 120°C for 2 hours to allow the covalent organic framework to grow on the surface of graphene oxide, thus obtaining a honeycomb covalent organic framework-graphene oxide HCCOF-GO composite material.

[0042] d. The HCCOF-GO composite material was centrifuged (8000 rpm, 5 min), washed 5 times with ethanol and deionized water at 80 °C, and then dried at 80 °C for 24 h to obtain HCCOF-GO powder.

[0043] e. Take 1.5g of HCCOF-GO powder and mix it with 0.2g of ammonium bicarbonate in a tube furnace, heat treat it at 1100℃ for 1h under an argon atmosphere, and after cooling, take it out to obtain a honeycomb HCCOF-GO carrier.

[0044] f. Take 0.5g of honeycomb HCCOF-GO support, 0.76g of chloroplatinic acid, 2g of deionized water, and 2g of isopropanol. Adjust the pH to 11 with 0.1mol / L NaOH. Microwave the resulting solution for 90s to bring the microwave temperature to 120℃. Filter, wash, and dry the resulting catalyst slurry to obtain a 60% Pt / C catalyst.

[0045] g. Membrane electrode preparation: Take 0.2g of Pt / C catalyst, mix it with 2g of water, 2g of isopropanol and 0.2g of Nafion 520 solution and sonicate it. Spray it onto both sides of the GORE 8μm membrane (cathode 0.3 mg / cm², anode 0.1 mg / cm²). Assemble the sprayed membrane CCM with the gas diffusion layer to form a membrane electrode.

[0046] Example 2: A method for preparing a Pt / C catalyst with a honeycomb channel structure, comprising the following steps:

[0047] a. Weigh 0.3g cetyltrimethylammonium bromide (CTAB) and 3g graphene oxide, place them in a beaker, add 3.2g ethanol and 5.8g tetrahydrofuran, and sonicate at room temperature (25℃) for 40 minutes to form a uniform dispersion.

[0048] b. First, add 0.08 g of 1,2,3,4-phenyltetramine tetrahydrochloride (TAB·4HCl) to the dispersion in step a, and ball mill and disperse for 2 h at room temperature; then add 0.07 g of hexadecimenone cyclohexane octahydrate (HKH·8H2O) to the solution, and break the cells for 20 min to make them evenly dispersed.

[0049] c. The solution from step b was reacted in a high-pressure reactor at 120°C for 3 hours to allow the covalent organic framework to grow on the surface of graphene oxide, resulting in a honeycomb covalent organic framework-graphene oxide HCCOF-GO composite material.

[0050] d. The HCCOF-GO composite material was centrifuged (8000 rpm, 5 min), washed 5 times with ethanol and deionized water at 80 °C, and then dried at 80 °C for 24 h to obtain HCCOF-GO powder.

[0051] e. Take 2g of HCCOF-GO powder and mix it with 0.4g of ammonium oxalate in a tube furnace. Heat treat it at 1100℃ for 1h under an argon atmosphere. After cooling, take it out to obtain a honeycomb-shaped HCCOF-GO carrier.

[0052] f. Take 0.8g of honeycomb HCCOF-GO support, 0.74g of chloroplatinic acid, 1.5g of deionized water, and 2g of isopropanol. Adjust the pH to 10 with 0.1mol / L NaOH. Microwave the resulting solution for 100s to reach a microwave temperature of 110℃. Filter, wash, and dry the resulting catalyst slurry to obtain a 60% Pt / C catalyst.

[0053] g. Membrane electrode preparation: 0.24 g of Pt / C catalyst was mixed with 2 g of water, 2 g of isopropanol, and 0.2 g of Nafion 520 solution, and ultrasonically sprayed onto both sides of a GORE 12 μm membrane (cathode 0.3 mg / cm). 2 Anode 0.1 mg / cm 2 The sprayed CCM membrane and the gas diffusion layer are assembled into a membrane electrode.

[0054] Comparative Example 1: A GORE 8µm proton exchange membrane was cut. The anode and cathode used JM 60% Pt / C catalyst, with water / isopropanol as the dispersion. The catalyst was uniformly dispersed using a crusher and then sprayed evenly onto both sides of the proton exchange membrane using a sprayer, resulting in an anode catalyst loading of 0.3 mg / cm³. 2 The cathode catalyst loading is 0.1 mg / cm³. 2 The sprayed CCM film and the gas diffusion layer are assembled into a membrane electrode.

[0055] The membrane electrode assemblies obtained in Examples 1 and 2 and Comparative Example 1 were tested for Pt durability and low humidity performance in a fuel cell test fixture. The results are shown in Tables 1 and 2.

[0056] Durability testing method: The test was conducted in a fuel cell environment with a constant temperature of 80°C, 100% relative humidity at the anode / cathode, and a hydrogen / air back pressure of 200 kPa. The hydrogen metering ratio at the anode was 1.2, and the air metering ratio at the cathode was 2.5.

[0057] Under hydrogen pump conditions with nitrogen at the cathode and hydrogen at the anode, scanning cycles were performed within the potential range of 0.6 V to 0.95 V (e.g., scan rate 50 mV / s). After 0, 10,000, and 30,000 cycles, the operation was switched to hydrogen / air, and the current density of the cell at the operating potential of 0.65 V was measured and recorded to quantify the performance degradation rate of the catalyst. The final data are shown in Table 1.

[0058] Different humidity test methods: During the test, keep the humidity of the anode and cathode consistent, and run the test under conditions of 100% RH, 80% RH and 40% RH in sequence. Measure and record the current density at 0.8 V. The data are shown in Table 2.

[0059] Table 1. Comparison of carbon carrier durability tests:

[0060]

[0061] Table 2. Performance comparison under different humidity levels:

[0062]

[0063] As shown in Table 1, after 30,000 potential cycles, the catalyst performance degradation rates of Examples 1 and 2 were approximately 24% and 28%, respectively, significantly lower than the 42% degradation rate of the commercial catalyst in Comparative Example 1. This fully demonstrates that the unique honeycomb support structure of this invention can effectively inhibit the migration, aggregation, and Oswald ripening of Pt nanoparticles during long-term operation, thereby significantly improving the electrochemical stability and lifespan of the catalyst.

[0064] As shown in Table 2, under different humidity conditions, especially at a low humidity of 40%, the current density of the catalyst in the embodiments of the present invention at 0.8V (Example 1: 0.16 A / cm²; Example 2: 0.17 A / cm²) is more than twice that of the commercial catalyst in Comparative Example 1 (0.08 A / cm²). Even at 100% relative humidity, the performance of the catalyst of the present invention still maintains a significant advantage.

[0065] This fully demonstrates that the honeycomb nanochannel structure of the catalyst of the present invention optimizes the water management and proton transport process within the catalyst layer, ensuring efficient proton and reactant transport even under low humidity conditions, greatly enhancing the environmental adaptability of the fuel cell and reducing the dependence on complex humidification systems.

[0066] Furthermore, characterization of the catalyst in Example 1 showed that ( Figure 1 The Pt nanoparticles exhibited a stable particle size distribution in the 1.5-3.5 nm range, confirming the confinement effect of the HCCOF-GO support. Examples 1 and 2 consistently yielded excellent results under different process parameters, demonstrating the good reproducibility and process controllability of the preparation method of this invention.

[0067] Both Examples 1 and 2, using different surfactants, solvent ratios, and slight adjustments to process parameters, produced catalysts that exhibited excellent and consistent performance. This demonstrates that the one-pot colloidal assembly combined with heat treatment method provided by this invention is process-controllable, highly reproducible, and suitable for the controllable preparation of high-performance catalysts.

[0068] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A Pt / C catalyst with a honeycomb channel structure, characterized in that, include: A honeycomb covalent organic framework nanosheet with graphene oxide as a carrier, wherein the honeycomb covalent organic framework has nanochannels with a pore size of 2-3 nm, and the Pt nanoparticles have a particle size of 2-3 nm, wherein the Pt nanoparticles are uniformly and strictly confined within the nanochannels.

2. A method for preparing the Pt / C catalyst as described in claim 1, characterized in that, Includes the following steps: a. Mix a surfactant, graphene oxide, and an organic solvent, and sonicate at room temperature for 30-60 minutes to form a uniform dispersion. The surfactant includes one or more of sodium citrate, sodium dodecylbenzene sulfonate (SDBS), and hexadecyltrimethylammonium bromide (CTAB). The organic solvent includes one or more of isopropanol, N-methylpyrrolidone (NMP), and tetrahydrofuran. The mass ratio of graphene oxide to organic solvent is 1:2-5. b. First, add 1,2,3,4-phenyltetramine tetrahydrochloride (TAB·4HCl) to the dispersion from step a, and ball mill and disperse at room temperature for 2-3 hours; then add hexakonecyclohexane octahydrate (HKH·8H2O) to the solution, and continue to disperse evenly. The total mass of TAB·4HCl and HKH·8H2O should be 5%-10% of the mass of graphene oxide. c. The solution from step b is reacted in a high-pressure reactor at 110-130℃ for 2-3 hours to allow the covalent organic framework to grow on the surface of graphene oxide, thus obtaining a honeycomb covalent organic framework-graphene oxide HCCOF-GO composite material. d. The composite material is centrifuged at 6000-10000 rpm for 3-10 minutes to obtain black HCCOF-GO powder; then the powder is washed with ethanol and deionized water at 70-90℃; finally, the washed powder is dried in an oven at 70-90℃ for 18-30 hours to obtain HCCOF-GO powder. e. HCCOF-GO powder is mixed with a pore-forming agent and heat-treated at 1100-1200℃ under an inert atmosphere to obtain a honeycomb HCCOF-GO carrier. The pore-forming agent includes one or more of ammonium bicarbonate, ammonium carbonate, ammonium bioxate, and ammonium oxalate. f. The honeycomb HCCOF-GO support is mixed with chloroplatinic acid and an organic solvent. The pH value is adjusted to 10-12 with an alkaline solution. The microwave reduction temperature is 80-120 degrees Celsius and the time is 80-100 seconds. After filtration, washing and drying, the Pt / C catalyst is obtained. The organic solvent includes deionized water, isopropanol and mixtures thereof.

3. A fuel cell membrane electrode assembly, characterized in that, The catalyst includes the Pt / C catalyst as described in claim 1, wherein the catalyst is loaded onto both sides of a proton exchange membrane by spraying, wherein the cathode catalyst loading is 0.2-0.4 mg / cm³. 2 The anode catalyst loading is 0.05-0.15 mg / cm³. 2 .

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