Preparation method of high-temperature proton exchange membrane fuel cell membrane electrode based on zeolite doping regulation

Abstract

The invention discloses a preparation method of a high-temperature proton exchange membrane fuel cell membrane electrode based on zeolite doping regulation, which comprises the following steps: activating zeolite through high-temperature roasting and phosphoric acid treatment, mixing the activated zeolite with a catalyst, a binder and the like to prepare catalyst slurry, and spraying the slurry on a gas diffusion electrode by using an ultrasonic spraying technology; and after heat treatment, assembling the electrode, the high-temperature proton exchange membrane and the polyimide film in sequence, and carrying out hot press molding to finally obtain the optimized membrane electrode of the high-temperature proton exchange membrane fuel cell. The invention provides the membrane electrode assembly with high activity and excellent durability, the introduction of zeolite significantly improves the activity, and in a durability test as long as 500 h, after 8 times of start-stop cycles, the battery voltage is almost not attenuated, and good stability is shown.

Description

Technical Field

[0001] This invention relates to the field of high-temperature proton exchange membrane fuel cell technology. In particular, it relates to a method for preparing a membrane electrode assembly (MEA) for a high-temperature proton exchange membrane fuel cell based on zeolite doping control. Background Technology

[0002] High-temperature proton exchange membrane fuel cells (HT-PEMFCs) can operate under anhydrous conditions above 100°C, exhibiting advantages such as good contaminant tolerance and system simplification. Currently, phosphate-polybenzimidazole (PA-PBI) based HT-PEMFCs are the most widely used. The increased operating temperature enhances tolerance to fuel / air impurities, allowing the use of lower-quality hydrogen (e.g., methanol reformate), significantly reducing hydrogen storage and transportation costs, and enabling HT-PEMFCs to gradually gain market acceptance. Nevertheless, the durability issues under real-world operating conditions remain a significant factor hindering the commercialization of HT-PEMFCs. Data shows that the degradation rate of HT-PEMFCs under dynamic operating conditions is 2-3 times higher than under steady-state conditions, with performance losses due to start-up and shutdown processes accounting for as much as 35%. Zeolite is an ordered three-dimensional porous structure material whose size sieving effect anchors PA molecules; the ordered porous structure also provides rapid channels for gas transport, reducing mass transfer resistance. Meanwhile, the bronsted acidic sites of zeolite can form an electron-proton co-transport mechanism with the proton conduction network, which can reduce the activation energy of the oxygen reduction reaction (ORR). Therefore, the doping and regulation of zeolite is expected to improve the durability decline during the operation of HT-PEMFCs and alleviate the life loss under dynamic operating conditions. However, there is currently a lack of reliable solutions for applying zeolite to high-temperature proton exchange membrane fuel cell membranes.

[0003] The zeolite in the catalyst layer, with its unique pore structure, exhibits a greater adsorption capacity for phosphate species than platinum-based catalysts, thus mitigating their poisoning effect on platinum-based catalysts. Simultaneously, the high specific surface area of ​​zeolite helps optimize the pore structure of the catalyst layer, reducing oxygen mass transfer resistance. This dual optimization mechanism provides an innovative solution for the long-term operation of HT-PEMFCs and has significant engineering application value. Summary of the Invention

[0004] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a method for preparing a high-temperature proton exchange membrane fuel cell membrane electrode based on zeolite doping. This invention innovatively introduces zeolite material with a multi-level porous structure into the membrane electrode, which effectively reduces the influence of phosphate species (H3PO4 and H2PO4). − The poisoning effect on the catalyst reduces the oxygen mass transfer resistance inside the membrane electrode, thereby improving the activity and durability of the high-temperature proton exchange membrane fuel cell.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a method for preparing a high-temperature proton exchange membrane fuel cell membrane electrode based on zeolite doping control, comprising the following steps: S1. Roast the zeolite for preliminary activation; S2. Place the pre-activated zeolite in a phosphoric acid solution and let it stand for a second activation. S3. Mix the zeolite, catalyst, binder, isopropanol and ultrapure water after secondary activation evenly to obtain catalyst slurry; S4. The catalyst slurry is sprayed onto the gas diffusion layer, dried, and then heat-treated to obtain the gas diffusion electrode. S5. The gas diffusion electrode, polyimide film, high-temperature proton exchange membrane, polyimide film, and gas diffusion electrode are sequentially stacked and assembled and hot-pressed to obtain the high-temperature proton exchange membrane fuel cell membrane electrode based on zeolite doping control.

[0006] Preferably, the zeolite has a microporous or mesoporous structure, specifically selected from at least one of the following types of zeolites: NaY type, MCM-41 type, SBA-15 type, Al-MCM-41 type, KIT-6 type, ZSM-5 type, and Beta type.

[0007] Preferably, step S1 specifically includes: In an atmosphere of nitrogen, helium, argon, or a mixture of these gases, the zeolite is heated to 300-550℃ at a heating rate of 2-5℃ / min and calcined for 2-10 hours for preliminary activation.

[0008] Preferably, step S2 specifically involves: placing the pre-activated zeolite in a phosphoric acid solution, allowing it to stand at 4-190℃ for 6-72 hours for secondary activation, filtering, washing and drying the solid product to obtain the secondary activated zeolite; The concentration of the phosphoric acid solution is 50wt%~85wt%, and the solid content of zeolite in the phosphoric acid solution is controlled to be 5%~50%.

[0009] More preferably, after filtering with filter paper in step S2, the zeolite is washed 3-8 times with ultrapure water and ethanol to neutralize the washed solution, and then dried in a vacuum oven for 6-24 hours. Finally, the activated zeolite is stored under negative pressure in a vacuum drying oven for later use.

[0010] Preferably, the catalyst in step S3 is selected from at least one of Pt / C, PtCo / C, PtNi / C, PtFe / C, PtCu / C, Pt / WO3, Pt / SnO2, and Pt / WO3-CNT, and the binder is selected from at least one of PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PBI (polybenzimidazole), and PTFE-PVDF (a mixture of polytetrafluoroethylene and polyvinylidene fluoride).

[0011] Preferably, step S3 specifically involves: mixing the zeolite, catalyst, binder, isopropanol and ultrapure water after secondary activation evenly and then subjecting them to ultrasonic dispersion treatment to obtain a catalyst slurry; The mass ratio of zeolite to catalyst is 1:1 to 1:6, the mass of binder accounts for 10% to 30% of the total mass of catalyst and binder, and the solid content of catalyst slurry is between 1% and 3%.

[0012] Preferably, the mass ratio of ultrapure water to isopropanol is 1:1 to 1:3, more preferably 1:2.

[0013] Preferably, in step S3, the ultrasonic amplitude transformer used for ultrasonic dispersion treatment has a power of 650W and an amplitude of 5-50%, more preferably 10%; the ultrasonic treatment conditions are an ice-water bath and the ultrasonic time is 30-90 min, more preferably 60 min.

[0014] Preferably, step S4 specifically involves: ultrasonically spraying the catalyst slurry onto the gas diffusion layer, drying it at 60-95°C, and then heat-treating it at 180-380°C for 5-60 minutes in a nitrogen atmosphere to obtain the gas diffusion electrode. More preferably, when the binder is PTFE, the heat treatment temperature in step S4 is 320°C-350°C; when the binder is one or more of PVDF, PBI, or PVDF-PBI, the heat treatment temperature in step S4 is 180°C-200°C.

[0015] Preferably, the material of the gas diffusion layer in step S4 is one of carbon paper with a microporous layer, carbon cloth with a microporous layer, carbon paper without a microporous layer, and carbon cloth without a microporous layer, and the thickness of the gas diffusion layer is 200~500μm. The temperature of the vacuum adsorption heating platform in the ultrasonic spraying machine used in the spraying process of step S4 is 60~95℃, more preferably 85℃.

[0016] Preferably, in step S4, the spraying method is horizontal and vertical cross-spraying.

[0017] Preferably, during ultrasonic spraying, the Pt loading on the gas diffusion layer is controlled to be 0.5-1.0 mg using a weighing method. Pt / cm 2 .

[0018] Preferably, the parameters for hot pressing in step S5 are: hot pressing temperature 130℃~150℃, pressure 0.4MPa~2MPa, and hot pressing time 0.5~5min.

[0019] The beneficial effects of this invention are: This invention provides a method for preparing a membrane electrode assembly (MEA) for a high-temperature proton exchange membrane fuel cell (HT-PEMFC) based on zeolite doping. This invention innovatively applies zeolite through a specific process to the preparation of the MEA, achieving at least the following unexpected technical effects: First, the zeolite in the catalyst layer of the MEA exhibits a greater adsorption capacity for phosphoric acid species (currently, widely used high-temperature proton exchange membranes are typically phosphoric acid-doped polybenzimidazole membranes) than platinum-based catalysts, effectively reducing the poisoning effect of phosphoric acid on the catalyst and thus improving the overall intrinsic activity. Second, the higher specific surface area of ​​zeolite helps to increase the pore size and specific surface area of ​​the catalyst layer, reducing oxygen mass transfer resistance. This invention provides an innovative solution for the long-term operation of HT-PEMFCs, possessing significant engineering application value and broad market application prospects. Attached Figure Description

[0020] Figure 1 This is a flowchart of an optimization method for membrane electrode assembly of a high-temperature proton exchange membrane fuel cell based on zeolite doping control; Figure 2 These are the nitrogen adsorption-desorption curves and BET specific surface area test results of the membrane electrode cathode catalysis of Examples 1-3 and Comparative Example 1 of this invention. Figure 3 These are the pore size distribution curves of the membrane electrode cathode catalysis in Examples 1-3 and Comparative Example 1 of this invention; Figure 4 The NaY-type zeolite and PtCo / C in this invention are effective against H3PO4 and H2PO4. − The adsorption energy test results; Figure 5 These are the polarization curves of the membrane electrodes of Embodiment 1 and Comparative Example 1 of the present invention under simulated reformed gas / air conditions; Figure 6 These are the long-term durability curves of the membrane electrodes of Embodiment 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0021] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0023] This invention provides a method for preparing a membrane electrode assembly (MEA) for a high-temperature proton exchange membrane fuel cell (HT-PEMFC) based on zeolite doping. Zeolite doping is directly introduced into the catalyst layer to regulate the internal structure of the MEA, optimizing the MEA assembly and improving the durability of HT-PEMFCs. The process is as follows: Figure 1 As shown, the specific steps include: S1. Prepare zeolite, then roast it at high temperature for preliminary activation; S2. Phosphoric acid pretreatment and activation: The pre-activated zeolite is placed in a phosphoric acid solution and allowed to stand to obtain activated zeolite. S3. Prepare catalyst slurry: Mix the activated zeolite, catalyst, binder, isopropanol and ultrapure water evenly to obtain catalyst slurry; S4. Preparation of Gas Diffusion Electrode (GDE): The catalyst slurry is sprayed onto the gas diffusion layer, dried, and then heat-treated to obtain the gas diffusion electrode; and the relevant properties of GDE are characterized. S5. Membrane electrode assembly: The gas diffusion electrode, polyimide film, high-temperature proton exchange membrane, polyimide film, and gas diffusion electrode are sequentially stacked and assembled and hot-pressed to obtain the high-temperature proton exchange membrane fuel cell membrane electrode based on zeolite doping control, and HT-PEMFCs testing and membrane electrode related performance characterization are performed.

[0024] In this invention, the zeolite in the catalyst layer with its unique pore structure has a greater adsorption capacity for phosphate species than platinum-based catalysts, thereby mitigating its poisoning effect on platinum-based catalysts. Simultaneously, the high specific surface area of ​​zeolite helps optimize the pore structure of the catalyst layer, reducing oxygen mass transfer resistance. This dual optimization mechanism provides an innovative solution for the long-term operation of HT-PEMFCs and has significant engineering application value.

[0025] In the following examples and comparative examples, the single-cell test temperature of HT-PEMFCs was 160–170 °C, the anode reactant gas was simulated methanol reformate (H2-79%, CO2-20%, CO-1%), the cathode reactant gas was air, and the excess coefficients of the anode and cathode gases were 2.0 and 5.0, respectively. The start-up / shutdown test procedures of HT-PEMFCs are shown in Table 1 to simulate real operating conditions in fuel cell systems (e.g., without nitrogen purging).

[0026] Table 1. Start-stop cycle test procedure steps for HT-PEMFCs Initially, the fuel cell temperature is below 50°C and the inlet and outlet gas valves are closed. The system first raises the temperature to 120°C through a heating program to induce vaporization of liquid water, and then continues to raise the temperature to 160°C. At 120°C, the anode operates at a rate of 200 N / ml / min. −1 The flow rate was purged for 30 seconds to remove impurities. Before reaching 160°C, the system switched to stoichiometric control mode (anode λ=1.25, cathode λ=2.5) and loaded with 0.1 A cm⁻¹. −2 The initial current density is adjusted to avoid catalyst corrosion caused by open-circuit voltage (OCV). When the temperature exceeds 157°C, steady-state operation is determined, and the current density is increased to 0.2 A cm⁻¹. −2 The gas flow rate is dynamically adjusted according to the stoichiometric ratio, and this condition is maintained for 30 minutes to monitor performance. During shutdown, heating is turned off and forced air cooling is activated, with the current density set to 0.1 A cm⁻¹. −2 Continue until the temperature drops below 120°C, then stop the air supply and reduce the anode flow rate to 50 Nml·min. −1 Loading 0.05 A cm −2 To consume residual reactants. After shutting off the gas, if the voltage exceeds 0.5V, apply 0.01 A cm⁻¹. −2 The "discharge current" is used to slowly consume the remaining hydrogen and oxygen and reduce the electrochemical potential. The entire cycle includes heating to 160°C, constant load operation for 30 minutes, cooling to below 50°C, and standby for 5 minutes, with nitrogen purging prohibited throughout to simulate real-world conditions. Through stepped temperature control, dynamic gas regulation, and discharge current design, material stability and system efficiency are effectively balanced, providing a standardized testing framework for evaluating the dynamic decay mechanism of membrane electrodes.

[0027] The following detailed embodiments and comparative examples are provided to further illustrate the present invention.

[0028] Example 1 S1. Prepare 2g of NaY type zeolite (SiO2 / Al2O3=12, average pore size=0.75nm), place it in a tube muffle furnace under nitrogen atmosphere, and hold it at 400 ℃ for 4 h with a heating rate of 3 ℃ min. −1 After cooling to room temperature, the zeolite is removed and ground in an agate mortar for 2 minutes to obtain preliminarily activated zeolite.

[0029] S2. Place the pre-activated zeolite in an 85 wt% concentrated phosphoric acid solution, control the solid content to 15%, let it stand for 24 h, control the temperature of the phosphoric acid solution to 60 ℃, filter it, wash it 4 times with ultrapure water, and dry it in a vacuum oven for 12 h to obtain the zeolite after secondary activation. Store it in a vacuum desiccator under negative pressure for later use.

[0030] S3. Mix the NaY type zeolite, catalyst, polytetrafluoroethylene (PTFE) concentrated dispersion (60 wt%, Sigma-Aldrich), isopropanol and ultrapure water in a certain proportion, and sonicate them for 60 min under ice-water bath conditions to obtain catalyst slurry. The mass ratio of isopropanol to ultrapure water is 2:1, and the solid content of the catalyst slurry is 1%.

[0031] S4. Apply the catalyst slurry to the gas diffusion layer using an ultrasonic sprayer at a flow rate of 0.3 mL / min. −1 The temperature of the vacuum adsorption heating platform of the ultrasonic spraying machine is 85 ℃. The spraying method is cross spraying. After the spraying is completed, it is placed in a vacuum drying oven at 60 ℃ for complete drying. Then it is placed in a nitrogen atmosphere at 350 ℃ for 30 min to temper and form a catalyst layer on the gas diffusion layer, thereby obtaining a gas diffusion electrode (GDE). The gas diffusion electrode includes an anode and a cathode. For both the anode and cathode, in step S3, the mass ratio of NaY-type zeolite to catalyst is 1:3. For the cathode, the catalyst used in step S3 was a commercial PtCo / C (47.1 wt% Pt, 4.5 wt% Co, Tanaka), and the PTFE mass percentage in the catalyst layer formed in step S4 was 20%; the Pt loading in the cathode was controlled to be 0.85 mg using a weighing method. Pt cm −2 , For the anode, the catalyst used in step S3 is a commercial Pt / C (40 wt% Pt, Johnson Matthey), and the PTFE mass percentage in the catalyst layer formed in step S4 is 10%; the Pt loading in the anode is controlled to be 0.5 mg using a weighing method. Pt cm −2 .

[0032] S5. According to GDE, PI membrane (polyimide film, 50μm thick), high-temperature proton exchange membrane (phosphoric acid-doped polybenzimidazole membrane, Celtec) ®The membrane electrode assembly (MEA) of a high-temperature proton exchange membrane fuel cell based on zeolite doping was obtained by sequentially stacking and hot-pressing the PI membrane (50 μm thick) and GDE. The hot-pressing parameters were: hot-pressing temperature 140 ℃, pressure 0.4 MPa, and hot-pressing time 1 min.

[0033] The membrane electrode was then placed in the HT-PEMFCs single-cell test fixture, and a high-purity nitrogen gas leak detection device was used to ensure that the gas leakage rate did not exceed 1%. The HT-PEMFCs single-cell start-up / shutdown test procedure is shown in Table 1. The test lasted for 500 hours and underwent 8 start-ups and shutdowns, during which the voltage remained basically unchanged.

[0034] Example 2 S1. Prepare 2g of NaY type zeolite (SiO2 / Al2O3=12, average pore size=0.75nm), place it in a tube muffle furnace under nitrogen atmosphere, and hold it at 400 ℃ for 4 h with a heating rate of 3 ℃ min. −1 After cooling to room temperature, the zeolite is removed and ground in an agate mortar for 2 minutes to obtain preliminarily activated zeolite.

[0035] S2. Place the pre-activated zeolite in an 85 wt% concentrated phosphoric acid solution, control the solid content to 15%, let it stand for 24 h, control the temperature of the phosphoric acid solution to 60 ℃, filter it, wash it 4 times with ultrapure water, and dry it in a vacuum oven for 12 h to obtain the zeolite after secondary activation. Store it in a vacuum desiccator under negative pressure for later use.

[0036] S3. Mix the NaY type zeolite, catalyst, polytetrafluoroethylene (PTFE) concentrated dispersion (60 wt%, Sigma-Aldrich), isopropanol and ultrapure water in a certain proportion, and sonicate them for 60 min under ice-water bath conditions to obtain catalyst slurry. The mass ratio of isopropanol to ultrapure water is 2:1, and the solid content of the catalyst slurry is 1%.

[0037] S4. Apply the catalyst slurry to the gas diffusion layer using an ultrasonic sprayer at a flow rate of 0.3 mL / min. −1 The temperature of the vacuum adsorption heating platform of the ultrasonic spraying machine is 85 ℃. The spraying method is cross spraying. After the spraying is completed, it is placed in a vacuum drying oven at 60 ℃ for complete drying. Then it is placed in a nitrogen atmosphere at 350 ℃ for 30 min to temper and form a catalyst layer on the gas diffusion layer, thereby obtaining a gas diffusion electrode (GDE). The gas diffusion electrode includes an anode and a cathode. For both the anode and cathode, in step S3, the mass ratio of NaY-type zeolite to catalyst is 1:4; For the cathode, the catalyst used in step S3 was a commercial PtCo / C (47.1 wt% Pt, 4.5 wt% Co, Tanaka), and the PTFE mass percentage in the catalyst layer formed in step S4 was 20%; the Pt loading in the cathode was controlled to be 0.85 mg using a weighing method. Pt cm −2 , For the anode, the catalyst used in step S3 is a commercial Pt / C (40 wt% Pt, Johnson Matthey), and the PTFE mass percentage in the catalyst layer formed in step S4 is 10%; the Pt loading in the anode is controlled to be 0.5 mg using a weighing method. Pt cm −2 .

[0038] S5. According to GDE, PI membrane (polyimide film, 50μm thick), high-temperature proton exchange membrane (phosphoric acid-doped polybenzimidazole membrane, Celtec) ® The membrane electrode assembly (MEA) of a high-temperature proton exchange membrane fuel cell based on zeolite doping was obtained by sequentially stacking and hot-pressing the PI membrane (50 μm thick) and GDE. The hot-pressing parameters were: hot-pressing temperature 140 ℃, pressure 0.4 MPa, and hot-pressing time 1 min.

[0039] The membrane electrode was then placed in the HT-PEMFCs single-cell test fixture, and a high-purity nitrogen gas leak detection device was used to ensure that the gas leakage rate did not exceed 1%.

[0040] Example 3 S1. Prepare 2g of NaY type zeolite (SiO2 / Al2O3=12, average pore size=0.75nm), place it in a tube muffle furnace under nitrogen atmosphere, and hold it at 400 ℃ for 4 h with a heating rate of 3 ℃ min. −1 After cooling to room temperature, the zeolite is removed and ground in an agate mortar for 2 minutes to obtain preliminarily activated zeolite.

[0041] S2. Place the pre-activated zeolite in an 85 wt% concentrated phosphoric acid solution, control the solid content to 15%, let it stand for 24 h, control the temperature of the phosphoric acid solution to 60 ℃, filter it, wash it 4 times with ultrapure water, and dry it in a vacuum oven for 12 h to obtain the zeolite after secondary activation. Store it in a vacuum desiccator under negative pressure for later use.

[0042] S3. Mix the NaY type zeolite, catalyst, polytetrafluoroethylene (PTFE) concentrated dispersion (60 wt%, Sigma-Aldrich), isopropanol and ultrapure water in a certain proportion, and sonicate them for 60 min under ice-water bath conditions to obtain catalyst slurry. The mass ratio of isopropanol to ultrapure water is 2:1, and the solid content of the catalyst slurry is 1%.

[0043] S4. Apply the catalyst slurry to the gas diffusion layer using an ultrasonic sprayer at a flow rate of 0.3 mL / min. −1 The temperature of the vacuum adsorption heating platform of the ultrasonic spraying machine is 85 ℃. The spraying method is cross spraying. After the spraying is completed, it is placed in a vacuum drying oven at 60 ℃ for complete drying. Then it is placed in a nitrogen atmosphere at 350 ℃ for 30 min to temper and form a catalyst layer on the gas diffusion layer, thereby obtaining a gas diffusion electrode (GDE). The gas diffusion electrode includes an anode and a cathode. For both the anode and cathode, in step S3, the mass ratio of NaY-type zeolite to catalyst is 1:2. For the cathode, the catalyst used in step S3 was a commercial PtCo / C (47.1 wt% Pt, 4.5 wt% Co, Tanaka), and the PTFE mass percentage in the catalyst layer formed in step S4 was 20%; the Pt loading in the cathode was controlled to be 0.85 mg using a weighing method. Pt cm −2 , For the anode, the catalyst used in step S3 is a commercial Pt / C (40 wt% Pt, Johnson Matthey), and the PTFE mass percentage in the catalyst layer formed in step S4 is 10%; the Pt loading in the anode is controlled to be 0.5 mg using a weighing method. Pt cm −2 .

[0044] S5. According to GDE, PI membrane (polyimide film, 50μm thick), high-temperature proton exchange membrane (phosphoric acid-doped polybenzimidazole membrane, Celtec) ® The membrane electrode assembly (MEA) of a high-temperature proton exchange membrane fuel cell based on zeolite doping was obtained by sequentially stacking and hot-pressing the PI membrane (50 μm thick) and GDE. The hot-pressing parameters were: hot-pressing temperature 140 ℃, pressure 0.4 MPa, and hot-pressing time 1 min.

[0045] The membrane electrode was then placed in the HT-PEMFCs single-cell test fixture, and a high-purity nitrogen gas leak detection device was used to ensure that the gas leakage rate did not exceed 1%.

[0046] Comparative Example 1 The only difference from Example 1 is that no zeolite is added to the catalyst slurry in this example.

[0047] Performance testing Reference Figure 2 The figures show the nitrogen adsorption-desorption curves and BET specific surface area test results for the membrane electrode cathode catalysis of Examples 1-3 and Comparative Example 1. It can be seen that the introduction of zeolite significantly increased the specific surface area of ​​the membrane electrode catalytic layer: the BET specific surface area of ​​Examples 1-3 was higher than that of the control group (Comparative Example 1) without zeolite. Among them, Example 1 (zeolite to catalyst mass ratio of 1:3) showed the most optimized zeolite addition ratio, achieving the highest specific surface area of ​​549.1 m². 2 g −1 This result is in Figure 3 The pore size distribution curves further validated this finding, showing that the catalyst layer in Example 1 exhibited the largest pore size, thus effectively reducing oxygen mass transfer resistance. Density functional theory was used to calculate the compatibility of PtCo / C and NaY zeolite with H3PO4 and H2PO4. − The adsorption energy between them, the results are as follows Figure 4 As shown: NaY zeolite with H3PO4 and H2PO4 − The adsorption energies are -63.1 kcal / mol. −1 and −67.1 kcal mol −1 PtCo / C with H3PO4 and H2PO4 − The adsorption energies are -31.8 kcal / mol. −1 and −45.6 kcal mol −1 The results showed that H3PO4 and H2PO4 − It is easier to adsorb onto the surface of NaY zeolite, thereby reducing the coverage of PtCo / C and lowering its poisoning effect.

[0048] Figure 5 The polarization curves of the membrane electrodes prepared in Example 1 and Comparative Example 1 under simulated reformed gas / air conditions are shown. The results indicate that Example 1 exhibits significantly better performance than Comparative Example 1, with a peak power density of 0.334 W·cm⁻¹. −2 This exceeds the 0.364 W·cm⁻¹ of Comparative Example 1. −2 This indicates that the addition of NaY zeolite improved the performance of HT-PEMFC. Figure 6 The membrane electrodes prepared in Example 1 and Comparative Example 1 are shown to operate under simulated reformed gas / air conditions at 0.2 A cm⁻¹. −2Durability test curves under operating conditions. Example 1 underwent a test duration of approximately 500 hours, including 8 start-stop cycles, with almost no voltage decay. In contrast, Comparative Example 1, under a test duration of 200 hours, including 3 start-stop cycles, showed a voltage decay of 14.3%.

[0049] As described above, the zeolite-doped membrane electrode prepared by this invention exhibits high activity and excellent stability. In a durability test lasting 500 hours, after eight start-stop cycles, the battery voltage showed almost no decay, demonstrating outstanding stability.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a membrane electrode assembly (MEA) for a high-temperature proton exchange membrane fuel cell based on zeolite doping, characterized in that, Includes the following steps: S1. Roast the zeolite for preliminary activation; S2. Place the pre-activated zeolite in a phosphoric acid solution and let it stand for a second activation. S3. Mix the zeolite, catalyst, binder, isopropanol and ultrapure water after secondary activation evenly to obtain catalyst slurry; S4. The catalyst slurry is sprayed onto the gas diffusion layer, dried, and then heat-treated to obtain the gas diffusion electrode. S5. The gas diffusion electrode, polyimide film, high-temperature proton exchange membrane, polyimide film, and gas diffusion electrode are sequentially stacked and assembled and hot-pressed to obtain the high-temperature proton exchange membrane fuel cell membrane electrode based on zeolite doping control.

2. The method for preparing a high temperature zeolite doped regulated proton exchange membrane fuel cell membrane electrode according to claim 1, characterized in that, The zeolite is selected from at least one of the following types of zeolites: NaY type, MCM-41 type, SBA-15 type, Al-MCM-41 type, KIT-6 type, ZSM-5 type, and Beta type.

3. The method for preparing a high temperature zeolite doped regulated proton exchange membrane fuel cell membrane electrode according to claim 1, characterized in that, Step S1 is as follows: In an atmosphere of nitrogen, helium, argon, or a mixture of these gases, the zeolite is heated to 300-550℃ at a heating rate of 2-5℃ / min and calcined for 2-10 hours for preliminary activation.

4. The method for preparing a high temperature zeolite doped regulated proton exchange membrane fuel cell membrane electrode according to claim 1, characterized in that, Step S2 specifically involves placing the pre-activated zeolite in a phosphoric acid solution and allowing it to stand at 4-190℃ for 6-72 hours for secondary activation. The zeolite is then filtered, washed, and dried to obtain the secondary activated zeolite. The concentration of the phosphoric acid solution is 50wt%~85wt%, and the solid content of zeolite in the phosphoric acid solution is controlled to be 5%~50%.

5. The method for preparing a high temperature zeolite doped regulated proton exchange membrane fuel cell membrane electrode according to claim 1, characterized in that, The catalyst in step S3 is selected from at least one of Pt / C, PtCo / C, PtNi / C, PtFe / C, PtCu / C, Pt / WO3, Pt / SnO2, and Pt / WO3-CNT, and the binder is selected from at least one of PTFE, PVDF, PBI, and PVDF-PBI.

6. The method for preparing a high temperature zeolite doped regulated proton exchange membrane fuel cell membrane electrode according to claim 5, characterized in that, Step S3 specifically involves: mixing the zeolite, catalyst, binder, isopropanol, and ultrapure water after secondary activation evenly, followed by ultrasonic dispersion treatment to obtain a catalyst slurry; The mass ratio of zeolite to catalyst is 1:1 to 1:6, the mass of binder accounts for 10% to 30% of the total mass of catalyst and binder, and the solid content of catalyst slurry is between 1% and 3%.

7. The method for preparing a zeolite-doping-regulated high-temperature PEM fuel cell membrane electrode according to claim 1, characterized in that, Step S4 specifically involves ultrasonically spraying the catalyst slurry onto the gas diffusion layer, drying it at 60~95℃, and then heat-treating it at 180~380℃ for 5~60 minutes in a nitrogen atmosphere to obtain the gas diffusion electrode.

8. The method for preparing a zeolite-doping-regulated high-temperature PEM fuel cell membrane electrode according to claim 7, characterized in that, When the binder is PTFE, the heat treatment temperature in step S4 is 320℃~350℃; when the binder is one or more of PVDF, PBI, and PTFE-PVDF, the heat treatment temperature in step S4 is 180℃~200℃.

9. The method for preparing the membrane electrode of a high-temperature proton exchange membrane fuel cell based on zeolite doping control according to claim 1, characterized in that, The gas diffusion layer in step S4 is made of one of the following materials: carbon paper with a microporous layer, carbon cloth with a microporous layer, carbon paper without a microporous layer, and carbon cloth without a microporous layer. The thickness of the gas diffusion layer is 200~500μm.

10. The method for preparing a zeolite doped regulated high temperature proton exchange membrane fuel cell membrane electrode according to claim 1, characterized in that, The parameters for hot pressing in step S5 are: hot pressing temperature 130℃~150℃, pressure 0.4MPa~2MPa, and hot pressing time 0.5~5min.

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