Preparation method and application of pt / c catalyst of dendritic t-nc and ionic liquid

Abstract

The application discloses a preparation method of a dendritic T-NC and ionic liquid Pt / C catalyst and application thereof, and generates a zeolite imidazolate framework material (ZIF-8) by reacting a zinc salt with 2-methyl imidazole, and composites the ZIF-8 with a conductive carbon material. When high-temperature pyrolysis is carried out under an inert atmosphere, zinc species in the ZIF-8 volatilizes, thereby etching out abundant multi-stage pores in the carbon matrix, and forming a unique dendritic nitrogen-doped carbon structure (T-NC). The structure can effectively load and stabilize platinum nanoparticles. Subsequently, by infiltrating ionic liquid, the high ionic conductivity and interface characteristics of the ionic liquid are utilized to enhance the proton conduction of a catalytic layer and optimize a mass transfer process. The method is simple in process, and raw materials are easy to obtain. Through the synergy of the carrier structure and the interface microenvironment, the prepared catalyst realizes comprehensive improvement in oxygen reduction reaction activity, durability and low-humidity adaptability, and provides a feasible material solution for a high-performance, long-life and low-cost proton exchange membrane fuel cell.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalyst preparation for fuel cells, in particular to a preparation method of a Pt / C catalyst of dendritic T-NC and ionic liquid, and a membrane electrode comprising the catalyst. BACKGROUND

[0002] Proton exchange membrane fuel cell (PEMFC) is a high-efficiency clean chemical energy conversion device, however, the performance, cost and durability of fuel cells greatly affect the large-scale commercial use of fuel cell vehicles, among which the catalyst is the most influential. The current mainstream commercial Pt / C catalyst faces three core challenges:

[0003] First, high platinum usage increases system cost, and reducing platinum loading will lead to insufficient active sites and performance decline;

[0004] Second, the traditional carbon carrier is prone to electrochemical corrosion under harsh conditions such as fuel cell start-stop and high potential, leading to platinum particle shedding, agglomeration, catalyst structure damage, and rapid shortening of battery life;

[0005] Third, the transport process of protons, oxygen and water in the catalyst layer is complex, and mass transfer polarization is easily formed under high current density, especially under low humidity conditions, the efficiency of the traditional proton conduction network relying on perfluorosulfonic acid resin is significantly reduced, which restricts the power output of the battery.

[0006] Therefore, a new type of catalyst that can start from the source of structural design and simultaneously achieve stable carrier, efficient mass transfer and controllable cost is urgently needed to support the commercial development of low-platinum, high-durability and complex working conditions of fuel cells. SUMMARY

[0007] The technical problem solved by the present application is to provide a preparation method of a Pt / C catalyst of dendritic T-NC and ionic liquid and its application. By constructing a "dendritic porous carrier-ionic liquid interface" composite structure, the electrochemical activity of the catalyst, the stability of the carrier and the mass transfer efficiency in the catalyst layer are simultaneously improved under the premise of significantly reducing the platinum usage, thereby obtaining a low-platinum fuel cell with high performance, high durability and adaptability to complex working conditions.

[0008] To solve the above technical problems, one technical solution adopted by the present application is to provide a preparation method of a Pt / C catalyst of dendritic T-NC and ionic liquid, comprising the following steps:

[0009] S1: dissolving the zinc salt and the polymer dispersant in a first organic solvent to form a first solution, dissolving 2-methylimidazole in a second organic solvent to form a second solution, mixing the first solution with the second solution, and reacting at 30-50 DEG C, followed by solid-liquid separation and drying to obtain zeolitic imidazolate framework ZIF-8; mixing the ZIF-8 with the conductive carbon material in a third organic solvent, and performing solvothermal treatment at 60-100 DEG C, followed by solid-liquid separation and drying to obtain ZIF-8@C powder;

[0010] S2: under an inert atmosphere (such as argon), the ZIF-8@C powder obtained in step S1 is programmed to increase the temperature to 1100-1300 DEG C at a temperature increasing rate of 5-10 DEG C / min and is kept at this temperature for 1-4 hours; in this process, the organic ligand in the ZIF-8 is carbonized, the zinc species is volatilized, the conductive carbon skeleton is etched and rich micro-mesopores are introduced, and nitrogen atom doping is realized, finally forming a nitrogen-doped carbon carrier with unique connected multi-level pores (i.e. "tree-like" structure), and after cooling, a tree-like nitrogen-doped carbon T-NC powder is obtained;

[0011] S3: mixing the T-NC powder obtained in step S2 with an ionic liquid in a fourth organic solvent, and stirring and infiltrating at 20-40 DEG C to enable the ionic liquid to be fully adsorbed and enter the pores and surface of the carrier; then washing with a low-boiling-point solvent such as ethanol to remove the excess ionic liquid adsorbed physically, and drying to obtain a TN-C and ionic liquid powder;

[0012] S4: dispersing the TN-C and ionic liquid powder obtained in step S3 in a fifth organic solvent, adding a platinum precursor, and stirring to enable it to be fully adsorbed; under the protection of an inert atmosphere (such as an argon atmosphere), adding a reducing agent to perform a chemical reduction reaction, reducing the platinum ions to metallic platinum nanoparticles, and firmly loading them on the modified carrier; after the reaction is completed, performing solid-liquid separation, washing, and drying to obtain a Pt / TN-C and ionic liquid catalyst; by controlling the amount of platinum precursor added, a catalyst with a platinum mass fraction of 5%-20% can be obtained.

[0013] In a preferred embodiment of the present application, in steps S1-S4, the first organic solvent, the second organic solvent, the third organic solvent, the fourth organic solvent, and the fifth organic solvent are one or more of N-methyl pyrrolidone (NMP), tetrahydrofuran, isopropyl alcohol, or n-butanol. Ensuring that the reactant molecules are in full contact and uniformly mixed creates an ideal liquid phase environment for homogeneous nucleation of ZIF-8, uniform compounding of the carbon material, effective infiltration of the ionic liquid, and sufficient adsorption of the platinum precursor, and is a key process basis for obtaining products with uniform structure and stable performance.

[0014] In a preferred embodiment of the present application, in step S1, the mass ratio of the zinc salt to the polymeric dispersant is preferably 1:2 to 1:6. This preferred ratio helps to obtain uniformly sized and well-dispersed ZIF-8 nanoparticles, laying a structural foundation for subsequent construction of regular dendritic carbon carriers.

[0015] In a preferred embodiment of the present application, in step S1, the mass of the 2-methylimidazole is preferably 5% to 10% of the total mass of the zinc salt and the polymeric dispersant. Controlling the amount of 2-methylimidazole within this range enables optimal matching with zinc ions, ensuring complete formation of the ZIF-8 framework structure, while avoiding waste or subsequent processing difficulties caused by excess ligand. Precise ligand usage is a chemical guarantee for obtaining ZIF-8 precursors with standard channel structures and high nitrogen content.

[0016] In a preferred embodiment of the present application, in step S1, the zinc salt is preferably zinc nitrate hexahydrate Zn(NO3)2·6H2O as the zinc source, and the polymeric dispersant is preferably polyvinylpyrrolidone PVP, which can effectively prevent ZIF-8 particle agglomeration. The conductive carbon material is preferably carbon black, which is highly conductive and low in cost, and can be selected from carbon black XC-72, ECP300, etc. As a composite carbon material, it not only provides an excellent electronic conduction skeleton for the final carrier, but also has abundant surface functional groups that are conducive to binding with ZIF-8 and forming a robust carbon network after pyrolysis, thereby comprehensively ensuring the electrical conductivity, structural stability, and economy of the carrier material.

[0017] In a preferred embodiment of the present application, in step S3, the ionic liquid is preferably a bis-trifluoromethanesulfonylimide salt imidazolyl ionic liquid, and the bis-trifluoromethanesulfonylimide salt imidazolyl ionic liquid is preferably at least one of 1-ethyl-3-methylimidazolium bis-trifluoromethanesulfonylimide [C2mim] + [NTf2] - , 1-butyl-3-methylimidazolium bis-trifluoromethanesulfonylimide [C4mim] + [NTf2] - This helps to form stable proton transport channels in the catalyst layer, especially effectively maintaining proton conduction function at low humidity, and possibly optimizing oxygen dissolution and diffusion, which is a key functional component for significantly improving the low humidity performance and high potential durability of the battery.

[0018] In a preferred embodiment of the present application, in step S4, the platinum precursor is preferably chloroplatinic acid H2PtCl6 as the platinum source, and the reducing agent is preferably at least one of sodium borohydride and sodium citrate, providing a flexible and reliable chemical reduction route for preparing platinum nanoparticles with high dispersion and high activity.

[0019] Another technical solution adopted by the present application is to provide a membrane electrode, comprising the catalyst prepared by any of the above preparation methods, and the preparation method of the membrane electrode comprises the following steps: mixing the catalyst, isopropyl alcohol, deionized water and a perfluorosulfonic acid resin solution in a certain proportion, and ultrasonic dispersion to form a uniform membrane electrode catalyst slurry; using a spraying, doctor blade coating or other coating process to uniformly coat the catalyst slurry on both sides of the proton exchange membrane, respectively as the cathode and the anode, and after drying, assembling into a three-in-one membrane electrode.

[0020] In a preferred embodiment of the present application, the perfluorosulfonic acid resin solution is one or more of Nafion 520, Nafion 1010 or Nafion 2020, which can flexibly adjust the viscosity and rheology of the catalyst slurry to adapt to different coating processes (such as spraying, doctor blade coating), and at the same time, different concentrations of Nafion solution will affect the morphology and distribution of the ionomer network in the catalyst layer after drying, thereby optimizing the three-phase interface, proton conduction channel and gas diffusion path in the catalyst layer, which is an important process parameter to balance the conductivity, mass transfer capacity and mechanical strength of the catalyst layer.

[0021] In a preferred embodiment of the present application, the thickness of the proton exchange membrane is 8-15 microns, which enhances the thinness of the proton exchange membrane, can significantly reduce the ohmic resistance of the membrane, and improve the cell voltage and power density. The catalyst loading of the cathode is 0.05-0.15 mg Pt / cm², and the catalyst loading of the anode is 0.01-0.05 mg Pt / cm². While ensuring sufficient active sites, the platinum usage is greatly reduced, which directly points to the goal of low cost.

[0022] The present application has the following advantages: by constructing a unique "tree-like nitrogen-doped carbon T-NC" carrier, the present application reduces the platinum loading while achieving a comprehensive breakthrough in catalyst performance, achieving extraordinary durability; by introducing "ionic liquid" interface modification, a humidity-independent proton conduction channel is formed in the pores of the carrier, making the output performance of the battery under low humidity far superior to that of traditional catalysts, achieving excellent low humidity adaptability; through the synergy of the carrier structure and the interface microenvironment, the catalyst is comprehensively improved in oxygen reduction reaction activity, durability and low humidity adaptability, providing a feasible material solution for high-performance, long-life and low-cost proton exchange membrane fuel cells. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows:

[0024] Figure 1is a TEM particle size distribution chart of the catalyst prepared in Example 1 of the present application. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application.

[0026] Therefore, the detailed description of the embodiments of the present application is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0027] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms “arranged”, “connected” should be understood broadly, for example, can be fixedly connected, or detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] In the present application, unless otherwise explicitly specified and limited, the first feature above or below the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature above, above and above the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature below, below and below the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0029] The present application comprises:

[0030] Example 1

[0031] A preparation method of a Pt / C catalyst of a dendritic T-NC and ionic liquid, comprising the following steps:

[0032] S1: weigh 0.2 g of Zn(NO3)2·6H2O and 0.5 g of PVP, dissolve in 100 mL of NMP to form a first solution. Weigh 0.07 g of 2-methylimidazole, dissolve in 50 mL of NMP to form a second solution.

[0033] The first solution and the second solution were mixed and reacted at 40°C for 36 hours. After the reaction, the solid product was collected by centrifugation and washed with methanol, and then dried to obtain the zeolitic imidazolate framework material ZIF-8.

[0034] 0.5 g of the ZIF-8 powder prepared in the above step and 0.4 g of conductive carbon black XC-72 were weighed and dissolved in 100 mL of NMP. The mixture was transferred to a 150 mL reactor and subjected to solvothermal treatment at 80°C for 24 hours. After the treatment, the ZIF-8@C powder was obtained by centrifugation, washing and drying.

[0035] S2: 0.6 g of the ZIF-8@C powder obtained in step S1 was weighed and placed in a tube furnace. The temperature was programmed to rise to 1200°C at a rate of 8°C / min under an argon atmosphere, and the temperature was maintained at 1200°C for 2 hours. Then, the temperature was naturally cooled to room temperature to obtain the T-NC powder.

[0036] S3: 0.5 g of the T-NC powder obtained in step S2 and 2.0 g of [C2mim] + [NTf2] - ionic liquid were weighed and added to 100 mL of NMP. The mixture was stirred at 30°C for 24 hours. Then, a large amount of ethanol was used for washing to remove the excess physically adsorbed ionic liquid, and the TN-C and ionic liquid powder was obtained by filtration and drying.

[0037] S4: 0.2 g of the TN-C and ionic liquid powder obtained in step (3) and 0.04 g of H2PtCl6 were weighed and added to 100 mL of NMP, and stirred to fully mix and adsorb. Under an argon atmosphere, 0.36 g of sodium borohydride was added as a reducing agent to the system to perform a chemical reduction reaction. After the reaction, the Pt / TN-C and ionic liquid catalyst was obtained by filtration, washing and drying, and the platinum mass fraction was 20%, and the yield was about 0.18 g.

[0038] S5: Membrane electrode preparation: 0.1 g of the 20% Pt / TN-C and ionic liquid catalyst was weighed, mixed with 20 mL of isopropyl alcohol, 10 mL of deionized water and 0.03 g of Nafion 520 solution with a mass concentration of about 5%, and ultrasonic dispersion was performed to form a uniform catalyst slurry. The slurry was uniformly sprayed on both sides of a 25 cm², 8 μm thick proton exchange membrane using a spraying method. The catalyst loading (calculated as platinum) on the cathode side was controlled to be 0.1 mg / cm², and the catalyst loading on the anode side was controlled to be 0.03 mg / cm². The sprayed membrane was dried under suitable conditions to form a three-in-one membrane electrode.

[0039] Example 2:

[0040] A method for preparing a Pt / C catalyst of a dendritic T-NC and ionic liquid, comprising the following steps:

[0041] S1: 0.15 g of Zn(NO3)2·6H2O and 0.6 g of PVP were weighed and dissolved in 80 mL of tetrahydrofuran to form a first solution. 0.08 g of 2-methylimidazole was weighed and dissolved in 50 mL of tetrahydrofuran to form a second solution.

[0042] The first solution was mixed with the second solution and reacted at 40°C under water bath conditions for 36 hours. After the reaction was completed, the solid product was collected by centrifugal separation and washed with ethanol, and then dried to obtain a zeolitic imidazolate framework material ZIF-8.

[0043] 0.5 g of the ZIF-8 powder prepared above and 0.4 g of conductive carbon black ECP300 were weighed and dissolved in 80 mL of tetrahydrofuran. The mixed solution was transferred to a 150 mL reaction kettle and subjected to solvothermal treatment at 80°C for 24 hours. After the treatment was completed, the ZIF-8@C powder was obtained by centrifugation, washing and drying.

[0044] S2: 0.5 g of the ZIF-8@C powder obtained in step S1 was weighed and placed in a tube furnace. Under the protection of argon atmosphere, the temperature was programmed to rise to 1200°C at a rate of 8°C / min, and then kept at this temperature for 2 hours. Subsequently, it was naturally cooled to room temperature to obtain a T-NC powder.

[0045] S3: 0.4 g of the T-NC powder obtained in step S2 and 1.5 g of [C4mim] + [NTf2] - ionic liquid were weighed and added to 80 mL of tetrahydrofuran. The mixture was stirred and infiltrated at 30°C under water bath conditions for 24 hours. Then, a large amount of ethanol was used for washing to remove the excess ionic liquid physically adsorbed, and the TN-C and ionic liquid powder was obtained by filtration and drying.

[0046] S4: 0.2 g of the TN-C and ionic liquid powder obtained in step S3 and 0.04 g of H2PtCl6 were weighed and added to 80 mL of tetrahydrofuran, and stirred to fully mix and adsorb. Under the protection of argon atmosphere, 0.32 g of sodium citrate was added to the system as a reducing agent to carry out a chemical reduction reaction. After the reaction was completed, the Pt / TN-C and ionic liquid catalyst was obtained by filtration, washing and drying, and the mass fraction of platinum was 20%, and the yield was about 0.15 g.

[0047] S5: Membrane electrode preparation: 0.1 g of the above 20% Pt / TN-C catalyst with ionic liquid was weighed and mixed with 30 mL of isopropanol, 15 mL of deionized water and 0.02 g of Nafion 2020 solution, and then ultrasonically dispersed to form a uniform catalyst slurry. The slurry was uniformly sprayed on both sides of a 25 cm2proton exchange membrane with a thickness of 12 μm using a spray coating method. The catalyst loading (in terms of platinum) on the cathode side was controlled to be 0.1 mg / cm2, and that on the anode side was 0.03 mg / cm2. The sprayed membrane was dried under suitable conditions, and then assembled into a three-in-one membrane electrode.

[0048] Comparative Example 1:

[0049] A 25 cm2composite proton membrane with a thickness of 8 μm from the American Gore Company was cut. Commercial JM 20% Pt / C catalyst was used for both the anode and the cathode. The catalyst was uniformly dispersed with a solution of perfluorosulfonic acid resin (Nafion) using a cell crusher with a water / isopropanol mixture as a dispersant to form a slurry. The slurry was uniformly sprayed on both sides of the proton membrane using a spray coater, and the platinum loading on the anode was controlled to be 0.03 mg / cm2, and that on the cathode was 0.1 mg / cm2. The sprayed membrane was dried under suitable conditions, and then assembled into a membrane electrode.

[0050] Performance test:

[0051] The membrane electrodes assembled in Examples 1, 2 and Comparative Example 1 were respectively loaded into a fuel cell test system, hydrogen was introduced into the anode, and air or nitrogen was introduced into the cathode, and the performance test was carried out. At the same time, the catalyst prepared in Example 1 was subjected to TEM particle size analysis, and the distribution is shown in Figure 1

[0052] The durability test conditions were: the cell temperature was 80°C, the humidity of the anode and the cathode was both 100% RH, and the hydrogen / air back pressure was both 200 kPa. The accelerated stress test was carried out in the potential range of 1.0 V to 1.5 V (nitrogen was introduced into the cathode), and the current density was tested at 0.65 V working potential after 0 cycles, 2000 cycles and 5000 cycles.

[0053] Table a: Comparison table of durability test data of Example 1, Example 2 and Comparative Example 1:

[0054]

[0055] Different humidity test: The current density was tested at 0.8 V working potential when the humidity of the anode and the cathode was 40% RH, 80% RH and 100% RH, respectively.

[0056] Table b: Comparison table of different humidity data of Example 1, Example 2 and Comparative Example 1: ​

[0057]

[0058] As shown in Table a, after 5000 cycles of high-potential accelerated stress testing, the catalyst performance degradation rates of Example 1 and Example 2 were approximately 22% and 32%, respectively, while the performance degradation rate of Comparative Example 1 was as high as 86%. This fully demonstrates that the dendritic nitrogen-doped carbon support (T-NC) prepared in this invention has significantly better electrochemical corrosion resistance than the traditional commercial carbon black support (Comparative Example 1), effectively inhibiting the aggregation and loss of platinum nanoparticles at high potentials, thus exhibiting extremely excellent durability.

[0059] As shown in Table b, under different humidity conditions, especially in low humidity (40% RH) environments, the current densities of Examples 1 and 2 (approximately 0.07-0.08 A / cm²) are significantly higher than those of Comparative Example 1 (0.02 A / cm²). This indicates that the ionic liquid supported on the catalyst support of the present invention can effectively maintain proton conduction under low humidity conditions, significantly improving the mass transfer within the catalyst layer and giving the battery excellent adaptability to low humidity operating conditions.

[0060] Depend on Figure 1 As shown in the particle size distribution diagram, the size of the platinum particles in the catalyst prepared in Example 1 is mainly distributed between 1.5 nm and 3.5 nm, with the peak value located near 3 nm, exhibiting a concentrated and uniform distribution pattern.

[0061] These results demonstrate that this invention, by constructing a unique "dendritic nitrogen-doped carbon T-NC" support, achieves a comprehensive breakthrough in catalyst performance while reducing platinum loading, resulting in exceptional durability. By introducing "ionic liquid" interface modification, a humidity-independent proton conduction channel is formed within the support pores, enabling the battery's output performance under low humidity conditions to far exceed that of traditional catalysts, achieving superior low-humidity adaptability. Through the synergy between the support structure and the interfacial microenvironment, the catalyst's oxygen reduction reaction activity, durability, and low-humidity adaptability are comprehensively improved, providing a feasible material solution for high-performance, long-life, and low-cost proton exchange membrane fuel cells.

[0062] 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 method for preparing a Pt / C catalyst based on a dendritic T-NC ionic liquid, characterized in that, Includes the following steps: S1: Zinc salt and polymer dispersant are dissolved in a first organic solvent to form a first solution, and 2-methylimidazole is dissolved in a second organic solvent to form a second solution. The first solution and the second solution are mixed and reacted at 30-50°C. After solid-liquid separation and drying, zeolite imidazole ester framework material ZIF-8 is obtained. ZIF-8 is mixed with conductive carbon material in a third organic solvent and subjected to solvothermal treatment at 60-100°C. After solid-liquid separation and drying, ZIF-8@C powder is obtained. S2: Under an inert atmosphere, the ZIF-8@C powder obtained in step S1 is heated to 1100-1300℃ at a heating rate of 5-10℃ / min and held for 1-4 hours, and then cooled to obtain dendritic nitrogen-doped carbon T-NC powder. S3: The T-NC powder obtained in step S2 is mixed with the ionic liquid in a fourth organic solvent, stirred and impregnated at 20-40°C, and then washed with ethanol and dried to obtain TN-NC and ionic liquid powder. S4: Disperse the TN-C ionic liquid powder obtained in step S3 in the fifth organic solvent, add platinum precursor, and stir to allow it to be fully adsorbed; add reducing agent under inert atmosphere to carry out chemical reduction reaction, and after the reaction is completed, separate solid and liquid, wash and dry to obtain Pt / TN-C ionic liquid catalyst.

2. The method for preparing the Pt / C catalyst of the dendritic T-NC ionic liquid according to claim 1, characterized in that, In steps S1-S4, the first organic solvent, the second organic solvent, the third organic solvent, the fourth organic solvent, and the fifth organic solvent are one or more of N-methylpyrrolidone, tetrahydrofuran, isopropanol, or n-butanol.

3. The method for preparing the Pt / C catalyst of the dendritic T-NC ionic liquid according to claim 1, characterized in that, In step S1, the mass ratio of the zinc salt to the polymer dispersant is 1:2 to 1:

6.

4. The method for preparing the Pt / C catalyst of the dendritic T-NC ionic liquid according to claim 1, characterized in that, In step S1, the mass of the 2-methylimidazole is 5% to 10% of the total mass of the zinc salt and the polymer dispersant.

5. The method for preparing the Pt / C catalyst of the dendritic T-NC ionic liquid according to claim 1, characterized in that, In step S1, the zinc salt is zinc nitrate hexahydrate, the polymer dispersant is polyvinylpyrrolidone, and the conductive carbon material is carbon black.

6. The method for preparing the Pt / C catalyst of the dendritic T-NC ionic liquid according to claim 1, characterized in that, In step S3, the ionic liquid is a bis(trifluoromethanesulfonyl)imide salt imidazole-based ionic liquid, wherein the bis(trifluoromethanesulfonyl)imide salt imidazole-based ionic liquid is at least one of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt or 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt.

7. The method for preparing the Pt / C catalyst of the dendritic T-NC ionic liquid according to claim 1, characterized in that, In step S4, the platinum precursor is chloroplatinic acid, and the reducing agent is at least one of sodium borohydride and sodium citrate.

8. A membrane electrode, characterized in that, include: The catalyst prepared by any one of claims 1-7, wherein the preparation method of the membrane electrode comprises: mixing the catalyst, isopropanol, deionized water and perfluorosulfonic acid resin solution to form a membrane electrode catalyst slurry; The catalyst slurry was uniformly coated on both sides of the proton exchange membrane, serving as the cathode and anode respectively. After drying, the membrane was assembled into a three-in-one membrane electrode.

9. The membrane electrode according to claim 8, characterized in that, The perfluorosulfonic acid resin solution is one or more of Nafion 520, Nafion 1010, or Nafion 2020.

10. The membrane electrode according to claim 8, characterized in that, The thickness of the proton exchange membrane is 8 micrometers to 15 micrometers, the catalyst loading of the cathode is 0.05 mg Pt / cm² to 0.15 mg Pt / cm², and the catalyst loading of the anode is 0.01 mg Pt / cm² to 0.05 mg Pt / cm².

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