Ionic liquid modification method of hydrogen fuel cell catalyst and slurry and membrane electrode thereof

Abstract

The invention relates to an ionic liquid modification method of a hydrogen fuel cell catalyst and slurry and a membrane electrode thereof, and the ionic liquid modification method of the catalyst comprises the following steps: 1) dissolving an ionic liquid used for modification in an alcoholic solution, and carrying out magnetic stirring or ultrasonic dispersion treatment on the alcoholic solution containing the ionic liquid; 2) fully wetting a catalyst to be modified with ultrapure water, and adding the ionic liquid alcohol solution to obtain a catalyst-ionic liquid mixed solution; 3) performing magnetic stirring or ultrasonic treatment on the catalyst-ionic liquid mixed solution; 4) heating and stirring the catalyst mixed liquid in a water bath environment, or carrying out rotary evaporation treatment under a temperature control condition; 5) taking out the treated substance and putting the substance into a vacuum oven for drying treatment to finish catalyst modification; compared with the prior art, the platinum-based catalyst is modified by using the ionic liquid, so that the performance of the catalyst in practical application can be simply, conveniently and efficiently improved, and the cost is reduced.

Description

[Technical Field]

[0001] The present invention belongs to the technical field of hydrogen fuel cells, and specifically relates to an ionic liquid modification method for a hydrogen fuel cell catalyst, as well as its slurry and membrane electrode. [Background Art]

[0002] In the field of proton exchange membrane fuel cells, the performance of the fuel cell mainly depends on the catalytic activity of the catalyst in the hydrogen oxidation reaction and the oxygen reduction reaction. Due to the excellent oxygen reduction catalyst activity of noble metal materials such as platinum nanoparticles, currently in the application of fuel cells, there is a widespread reliance on high-cost platinum-based catalysts and platinum alloy catalysts. At present, the commonly used platinum-based catalysts in hydrogen fuel cells need to be prepared into catalyst slurries during the application process, and then the catalyst layer is prepared on the proton exchange membrane by spraying, doctor blading, or transfer printing, etc., so as to prepare a membrane electrode for assembling a fuel cell stack. As the core of the fuel cell, the membrane electrode provides a reaction site for the electrochemical reaction and determines the performance of the hydrogen fuel cell; as an important part of the catalyst layer of the membrane electrode, the catalytic activity of the catalyst determines the performance of the membrane electrode.

[0003] Currently, the catalysts used in fuel cells are mainly materials such as platinum nanoparticles or platinum alloys supported on carbon carriers. Among them, the carbon carrier avoids the agglomeration of platinum nanoparticles and helps to disperse the platinum nanoparticles; the platinum nanoparticles are the active sites that provide the catalytic activity and are also the main component of the catalyst cost. In the membrane electrode, the performance mainly depends on the three-phase sites in the catalyst layer, namely the electronic phase, the proton phase, and the reaction gas phase. Among them, the platinum nanoparticles provide the reaction sites, and the conduction of electrons mainly depends on the carbon carrier in the catalyst; the proton conduction mainly depends on the ionomer resin in the catalyst layer. The ionomer resin, as a polymer material, is composed of a long hydrophobic fluorine-containing main chain and a short hydrophilic sulfonic acid group side chain. Due to its structural limitations, it is difficult to penetrate into the pores of the porous carbon carrier and contact the active sites therein, which easily leads to the underutilization of the active sites; the gas conduction mainly depends on the pores in the catalyst layer. Therefore, to improve the performance of the catalyst and the membrane electrode and reduce the cost, it is necessary to construct more three-phase sites in the catalyst layer and improve the utilization rate of platinum nanoparticles in the catalyst.

[0004] However, due to material and technological limitations, it is difficult to precisely control the loading position of platinum nanoparticles on the carbon support. To evenly distribute platinum nanoparticles on the carbon support and improve the utilization rate of platinum nanoparticles, CN118851146A uses plasma to modify the surface of carbon powder to improve its dispersibility, and then makes platinum nanoparticles as evenly distributed as possible on the surface of the carbon support; CN119092719A uses a low-temperature reduction method and optimizes the preparation method of the core-shell structured platinum-based catalyst using components such as surfactants, improving the catalytic activity and stability of the core-shell structured platinum-based catalyst.

[0005] In fuel cell applications, due to the uncertainty of the distribution of platinum nanoparticles, it is difficult for reactants to fully contact all active sites, resulting in the problem that active sites cannot be fully utilized and is difficult to solve. Therefore, there is an urgent need for a convenient method to improve the utilization rate of active sites in the catalyst and reduce the cost of the catalyst material and its preparation. Ionic liquids containing cations with imidazole groups or cations with pyrrolidine groups have the characteristics of high oxygen permeability, high proton conductivity, small molecules and hydrophobicity, which contribute to the transfer of protons in the pores of the catalyst carbon support and can fully improve the utilization rate of active sites in the catalyst in practical applications. Therefore, modifying the catalyst with such ionic liquids can effectively improve the activity of the catalyst and reduce the catalyst material and preparation cost under the same performance requirements. In CN118610498, an organic compound containing a mercapto group and a quaternary ammonium salt ionic liquid are used to modify the catalyst, mainly to improve the hydrophobic effect of the catalyst layer of the membrane electrode to achieve the purpose of improving performance. In this paper, imidazole-based ionic liquids and pyrrolidine-based ionic liquids are used to modify the catalyst, avoiding the introduction of mercapto groups, with simpler and more feasible operations, and more obvious improvement in the utilization rate of platinum in the catalyst and performance. [Summary of the Invention]

[0006] The purpose of the present invention is to solve the above deficiencies and provide an ionic liquid modification method for a hydrogen fuel cell catalyst. By using ionic liquids to modify the platinum-based catalyst, the performance of the catalyst in practical applications can be simply and efficiently improved, the cost can be reduced, and further solve the problem of low utilization rate of platinum nanoparticles in the membrane electrode and difficult full play of performance.

[0007] To achieve the above purpose, an ionic liquid modification method for a hydrogen fuel cell catalyst is designed, including the following steps:

[0008] 1) After dissolving the ionic liquid used for modification in an alcohol solution, perform magnetic stirring or ultrasonic dispersion treatment on the alcohol solution containing the ionic liquid;

[0009] 2) After fully wetting the catalyst to be modified with ultrapure water, add the ionic liquid alcohol solution treated in step 1) to obtain a catalyst-ionic liquid mixed solution;

[0010] 3) Magnetically stir or ultrasonically treat the catalyst-ionic liquid mixed solution obtained in step 2).

[0011] 4) Heat and stir the treated catalyst mixed liquid in a water bath environment, or perform rotary evaporation under temperature control conditions.

[0012] 5) Take out the material treated in step 4), put it into a vacuum oven for drying, and then complete the catalyst modification.

[0013] Further, in step 1), the ionic liquid needs to contain a cation with an imidazole group or a cation with a pyrrolidine group. The alcohol solution is one or more of ethanol, n-propanol, isopropanol, and n-butanol. The concentration of the ionic liquid in the alcohol solution is 0.1%-70% wt. The magnetic stirring speed is 500-2500 rpm, and the dispersion treatment time is 1 min-40 min.

[0014] Further, in step 1), the ionic liquid is any one or more of 1-butyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-methyl-3-hydroxyethylimidazolium nitrate, 1-vinyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, N-ethyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and N-methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)imide.

[0015] Further, in step 2), the mass ratio of the ultrapure water used for catalyst wetting to the catalyst is 0.5:1-5:1. The solid content in the catalyst-ionic liquid mixed solution after adding the ionic liquid alcohol solution is 1%-20% wt.

[0016] Further, in step 4), when heating and stirring the catalyst mixed liquid in a water bath environment, the water bath temperature during stirring is 30°C-80°C, the stirring speed is 1000-3000 rpm, and the treatment time is 120-240 min. Or, when performing rotary evaporation on the catalyst mixed liquid under temperature control conditions, the rotary evaporation temperature ranges from 20°C to 50°C, the rotary evaporation speed ranges from 10 to 50 rpm, and the treatment time is 60-180 min.

[0017] Further, in step 3), the dispersion treatment time is 5-40 min. In step 5), the temperature of the vacuum oven is 30°C-80°C, and the drying time is 4 h-24 h.

[0018] The present invention also provides a preparation method for a catalyst slurry, including the following steps:

[0019] (101) Weigh the perfluorosulfonic acid resin solution and the catalyst solid modified by the modification method described in any one of claims 1 to 6 in a certain proportion, and then dissolve them in an aqueous alcohol solution and mix and stir.

[0020] (102) Dispersedly treat the catalyst solution in step (101) by one or a combination of two methods of ultrasonic treatment or ball milling to obtain the required catalyst slurry.

[0021] Further, in step (101), the mass ratio of the dry weight of the perfluorosulfonic acid resin to the mass of carbon in the catalyst is 1:0.3 - 1:1.5; the alcohol is one or more of ethanol, n-propanol, isopropanol, and n-butanol, and the mass proportion of the alcohol in the aqueous alcohol solution in step (101) is 1% - 99%, and the mixing and stirring time is 5 min - 60 min.

[0022] Further, in step (102), the ultrasonic treatment time is 30 min - 180 min, and the ball milling treatment time is 30 min - 180 min.

[0023] The present invention also provides a method for preparing a membrane electrode, including the following steps:

[0024] (201) Load the prepared catalyst slurry on the proton exchange membrane by spraying or doctor blading; or, load the catalyst slurry on the PTFE film substrate by doctor blading, and transfer the catalyst layer to the proton exchange membrane by thermal transfer.

[0025] (202) Package the prepared proton exchange membrane with the catalyst layer loaded with the frame and the gas diffusion layer components to obtain the prepared membrane electrode.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] (1) The method of the present invention uses simple and easy treatment methods such as ultrasonic treatment and stirring to achieve the uniform adsorption effect of the ionic liquid on the catalyst carbon support, and uses the electrostatic adsorption between the negatively charged anions in the ionic liquid and the carbon support to achieve the purpose of modifying the catalyst with the ionic liquid. The process is simple, efficient and easy to control, avoiding complex catalyst synthesis operations, without worrying about catalyst yield, complex preparation process and long time consumption, and has low requirements for operation. An operator without a professional background can also complete it.

[0028] (2) The modification method of using ionic liquid for the catalyst of the present invention has a wide application range and has good performance optimization effects on noble metal catalysts supported on carbon supports.

[0029] (3) The method of the present invention effectively improves the utilization rate of active sites of the catalyst in the membrane electrode, enables the full utilization of the active sites in the catalyst, and reduces the product cost under the same performance;

[0030] (4) The operating principle of the method of the present invention is simple, easy to scale up, not easily limited by production volume, and worthy of popularization and application. [Description of the Drawings]

[0031] Figure 1 It is a performance comparison diagram of Example 1 and Comparative Example 1 (modified platinum carbon and unmodified platinum carbon) of the present invention;

[0032] Figure 2 It is a performance comparison diagram of Example 2 and Comparative Example 2 (modified platinum-cobalt alloy catalyst and unmodified platinum-cobalt alloy catalyst) of the present invention. [Detailed Embodiments]

[0033] One of the purposes of the present invention is to provide a modification method for modifying a platinum-based catalyst with an ionic liquid, which simply and efficiently improves the performance of the catalyst in practical applications and reduces costs.

[0034] Another purpose of the present invention is to provide a high-performance catalyst slurry and membrane electrode to solve the problem of low utilization rate of platinum nanoparticles in the membrane electrode and difficult full play of performance.

[0035] One of the purposes of the present invention includes the following steps:

[0036] Step 1) After dissolving the ionic liquid used for modification in an alcohol solution, perform magnetic stirring or ultrasonic dispersion treatment on the alcohol solution containing the ionic liquid;

[0037] Step 2) After fully wetting the catalyst to be modified with ultrapure water, add the ionic liquid alcohol solution treated in Step 1) to obtain a catalyst-ionic liquid mixed solution;

[0038] Step 3) Perform magnetic stirring or ultrasonic treatment on the catalyst-ionic liquid mixed solution;

[0039] Step 4) Heat and stir the treated catalyst mixed liquid in a water bath environment, or perform rotary evaporation treatment under temperature control conditions; either of the two treatment methods can be selected;

[0040] Step 5) Take out the material treated in Step 4), put it into a vacuum oven for drying treatment, and complete the modification of the catalyst.

[0041] Among them, in step 1), the ionic liquid is composed of a cation containing an imidazole group and an anion containing a perfluoroalkyl chain sulfonamide group, such as any one or more of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HMIM][Tf2N]), 1-ethyl-3-methylimidazolium hexafluorophosphate ([EMIM][PF6]), 1-methyl-3-hydroxyethylimidazolium nitrate ([HEMIM][NO3]), 1-vinyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([VMIM][Tf2N]), N-ethyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([C1C2Pyr][TFSI]), and N-methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([C1C4Pyr][TFSI]); the alcohol solution used contains one or more of ethanol, n-propanol, isopropanol, and n-butanol; the concentration of the ionic liquid in the alcohol solution is between 0.1% - 70% wt; the magnetic stirring speed ranges from 500 - 2500 rpm, and the dispersion treatment time is between 1 min - 40 min.

[0042] In step 2), the mass ratio of the ultrapure water for catalyst wetting to the catalyst is between 0.5:1 - 5:1; the solid content in the catalyst-ionic liquid mixed solution after adding the ionic liquid alcohol solution is between 1% - 20% wt.

[0043] In step 3), the dispersion treatment time is between 5 - 40 min.

[0044] In step 4), the water bath temperature during the stirring process ranges from 30°C - 80°C, the stirring speed ranges from 1000 - 3000 rpm, and the treatment time is between 120 - 240 min; the rotary evaporation treatment temperature ranges from 20°C - 50°C, the rotary evaporation speed ranges from 10 - 50 rpm, and the treatment time is between 60 - 180 min.

[0045] In step 5), the temperature of the vacuum oven is between 30°C - 80°C, and the drying time is between 4 h - 24 h.

[0046] The slurry preparation method provided by the present invention comprises the following steps:

[0047] Step 1. Weigh a fluorosulfonic acid resin solution and the catalyst solid modified by the above modification method in a certain proportion, and then dissolve them in an aqueous alcohol solution and mix and stir.

[0048] Step 2. Disperse the catalyst solution in step 1 by one or a combination of two methods of ultrasonic or ball milling to obtain the required catalyst slurry.

[0049] Among them, in Step 1, the mass ratio of the dry weight of the perfluorosulfonic acid resin to the mass of carbon in the catalyst is between 1:0.3 and 1:1.5; the alcohol is one or more of ethanol, n-propanol, isopropanol, and n-butanol, and the mass proportion of the alcohol in the aqueous alcohol solution in Step 1 is 1%-99%; the mixing and stirring time is between 5 min and 60 min. In Step 2, the ultrasonic treatment time is between 30 min and 180 min, and the ball milling treatment time is between 30 min and 180 min.

[0050] The method for preparing a membrane electrode provided by the present invention comprises the following steps:

[0051] Step 1. Load the prepared catalyst slurry onto the proton exchange membrane by spraying, knife coating, etc.; or load the catalyst slurry onto the PTFE film substrate by knife coating, and transfer the catalyst layer to the proton exchange membrane by thermal transfer;

[0052] Step 2. Package the proton exchange membrane with the loaded catalyst layer with a frame and a gas diffusion layer component to obtain the prepared membrane electrode.

[0053] Among them, in Step 1, when spraying to prepare the catalyst-loaded proton exchange membrane, the loading amount is controlled by the spraying time and the amount of the catalyst slurry used; for knife coating and transfer, different specifications of knife coating tools such as scrapers and wire rollers are used to control the loading amount.

[0054] The following further illustrates the present invention with specific embodiments:

[0055] Example 1

[0056] Step 1. Weigh 0.1 g of 1-vinyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([VMIM][Tf2N]) and dissolve it in 9 g of isopropanol, and perform strong ultrasonic treatment for 15 minutes under magnetic stirring (1500 rpm) to obtain an alcohol solution of [VMIM][Tf2N];

[0057] Step 2. Weigh 2 g of 50% Pt C catalyst, add 3.5 g of ultrapure water for wetting, and then add the alcohol solution of [VMIM][Tf2N] treated in Step 1, and perform strong ultrasonic treatment for 15 minutes under magnetic stirring (1500 rpm) to obtain a catalyst mixture;

[0058] Step 3. Place the catalyst mixture in a water bath at 45°C and perform magnetic stirring (2000 rpm) for 180 min;

[0059] Step 4. Place the catalyst solid in an oven, dry it at 40°C for 12 h and then take it out;

[0060] Step 5. Take 0.6 g of the catalyst dried in an oven and mix it with 1 g of perfluorosulfonic acid resin solution, 7 g of n-propanol, and 7 g of ultrapure water and stir for 20 min;

[0061] Step 6. Place the catalyst solution in Step 5 in a high-power ultrasonic bath and perform dispersion treatment for 2 h;

[0062] Step 7. Prepare a membrane electrode by spraying the slurry in Step 6.

[0063] The test performance of the membrane electrode is as shown in the attached Figure 1 Example 1.

[0064] Comparative Example 1

[0065] Step 1. Take 0.6 g of the untreated 50% Pt C catalyst in Step 2 of Example 1 and mix it with 1 g of perfluorosulfonic acid resin solution, 7 g of n-propanol, and 7 g of ultrapure water and stir for 20 min;

[0066] Step 2. Consistent with Step 6 in Example 1, place the catalyst solution in Step 1 in a high-power ultrasonic bath and perform dispersion treatment for 2 h;

[0067] Step 3. Consistent with Step 7 in Example 1, prepare a membrane electrode by spraying the slurry in Step 2.

[0068] The performance of the membrane electrode is as shown in the attached Figure 1 Comparative Example 1. It can be seen that the performance of Example 1 is improved to a certain extent compared with that of Comparative Example 1.

[0069] Example 2

[0070] Step 1. Weigh 0.1 g of N-ethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([C1C2Pyr][TFSI]) and dissolve it in 8 g of isopropanol. Perform high-power ultrasonic treatment for 20 minutes under magnetic stirring (1500 rpm) to obtain an alcohol solution of [C1C2Pyr][TFSI];

[0071] Step 2. Weigh 2 g of 50% PtCo C catalyst, add 4 g of ultrapure water for wetting, and then add the alcohol solution of [C1C2Pyr][TFSI] treated in Step 1. Perform high-power ultrasonic treatment for 20 minutes under magnetic stirring (1500 rpm) to obtain a catalyst mixture;

[0072] Step 3. Place the catalyst mixture in a rotary evaporator, rotate at 10 rpm, and perform vacuum evaporation at a rotary evaporation water bath temperature of 32 °C. Take it out after the catalyst is dried;

[0073] Step 4. Place the catalyst solid in an oven, dry it at 40 °C for 12 h and then take it out;

[0074] Step 5. Take 1.2 g of the catalyst dried in an oven and mix it with 2 g of perfluorosulfonic acid resin solution, 6 g of n-propanol, and 7 g of ultrapure water and stir for 20 min;

[0075] Step 6. Place the catalyst solution in Step 5 in a high-power ultrasonic device for 1 h of dispersion treatment, and then use a ball mill for 1 h of dispersion treatment;

[0076] Step 7. Prepare a membrane electrode by doctor blading and transferring the slurry in Step 6.

[0077] The test performance of the membrane electrode is as shown in Figure 2 Example 2 in the appendix.

[0078] Comparative Example 2

[0079] Step 1. Take 1.2 g of the untreated 50% PtCo C catalyst in Step 2 of Example 2 and mix it with 2 g of perfluorosulfonic acid resin solution, 6 g of n-propanol, and 7 g of ultrapure water and stir for 20 min;

[0080] Step 2. Consistent with Step 6 of Example 2, place the catalyst solution in Step 1 in a high-power ultrasonic device for 1 h of dispersion treatment, and then use a ball mill for 1 h of dispersion treatment;

[0081] Step 3. Consistent with Step 7 of Example 2, prepare a membrane electrode by doctor blading and transferring the slurry in Step 2.

[0082] The performance of the membrane electrode is as shown in Figure 2 Comparative Example 2 in the appendix. It can be seen that the performance of the modified catalyst is significantly improved compared with that of the unmodified catalyst.

[0083] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art. The standard parts used can be purchased from the market. The special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, and welding in the prior art. The machines, parts, and equipment all adopt conventional models in the prior art. The circuit connections adopt conventional connection methods in the prior art, and will not be elaborated here.

[0084] The present invention is not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. An ionic liquid modification method for a hydrogen fuel cell catalyst, characterized in that, It includes the following steps: 1) After dissolving the ionic liquid used for modification in an alcohol solution, magnetically stir or ultrasonically disperse the alcohol solution containing the ionic liquid; 2) After fully wetting the catalyst to be modified with ultrapure water, add the ionic liquid alcohol solution treated in step 1) to obtain a catalyst-ionic liquid mixed solution; 3) Magnetically stir or ultrasonically treat the catalyst-ionic liquid mixed solution obtained in step 2); 4) Heat and stir the catalyst mixed liquid treated in step 3) in a water bath environment, or perform rotary evaporation treatment under temperature control conditions; 5) Take out the substance treated in step 4) and put it into a vacuum oven for drying to complete the modification of the catalyst.

2. The method according to claim 1, characterized in that: In step 1), the ionic liquid needs to contain a cation of the imidazole group type or a cation of the pyrrolidine group type. The alcohol solution is one or more of ethanol, n-propanol, isopropanol, and n-butanol. The concentration of the ionic liquid in the alcohol solution is 0.1%-70% wt. The magnetic stirring speed is 500-2500 rpm, and the dispersion treatment time is 1 min-40 min.

3. The method according to claim 2, wherein: In step 1), the ionic liquid is any one or more of 1-butyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-methyl-3-hydroxyethylimidazolium nitrate, 1-vinyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, N-ethyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and N-methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)imide.

4. The method according to claim 1, wherein: In step 2), the mass ratio of the ultrapure water used to wet the catalyst to the catalyst is 0.5:1-5:1; the solid content in the catalyst-ionic liquid mixed solution after adding the ionic liquid alcohol solution is 1%-20% wt.

5. The method according to claim 1, characterized in that: In step 4), when heating and stirring the catalyst mixed liquid in a water bath environment, the water bath temperature during the stirring process is 30°C-80°C, the stirring speed is 1000-3000 rpm, and the treatment time is 120-240 min; alternatively, when performing rotary evaporation treatment on the catalyst mixed liquid under temperature control conditions, the rotary evaporation treatment temperature is in the range of 20°C-50°C, the rotary evaporation speed is in the range of 10-50 rpm, and the treatment time is 60-180 min.

6. The method according to claim 1, wherein: In step 3), the dispersion treatment time is 5-40 min; In step 5), the temperature of the vacuum oven is 30°C-80°C, and the drying time is 4 h-24 h.

7. A method for preparing a catalyst slurry, characterized in that, It includes the following steps: (101) Weigh a fluorosulfonic acid resin solution and the catalyst solid modified by the modification method described in any one of claims 1 to 6 in a certain proportion, and then dissolve them in an aqueous alcohol solution and mix and stir; (102) Disperse the catalyst solution in step (101) by one or a combination of two methods of ultrasonic or ball milling to obtain the required catalyst slurry.

8. The method according to claim 7, characterized in that: In step (101), the mass ratio of the dry weight of the perfluorosulfonic acid resin to the mass of carbon in the catalyst is 1:0.3 - 1:1.5; the alcohol is one or more of ethanol, n-propanol, isopropanol, and n-butanol, and the mass percentage of the alcohol in the aqueous alcohol solution in step (101) is 1% - 99%, and the mixing and stirring time is 5 min - 60 min.

9. The method according to claim 7, wherein: In step (102), the ultrasonic treatment time is 30 min - 180 min, and the ball milling treatment time is 30 min - 180 min.

10. A method for preparing a membrane electrode, characterized in that, It includes the following steps: (201) Load the prepared catalyst slurry onto the proton exchange membrane by spraying or scraping; or, load the catalyst slurry onto the PTFE film substrate by scraping, and transfer the catalyst layer to the proton exchange membrane by thermal transfer; (202) Package the prepared proton exchange membrane with the catalyst layer loaded with the frame and the gas diffusion layer components to obtain the prepared membrane electrode.

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