Gas diffusion layer, method for producing the same, membrane electrode, and fuel cell
By introducing a water vapor reaction catalyst into the gas diffusion layer of a high-temperature polymer electrolyte membrane fuel cell, CO is converted into CO2, which solves the problem of CO poisoning of the anode catalyst and improves the performance of the membrane electrode and the stability and efficiency of the fuel cell.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FTXT ENERGY TECH CO LTD
- Filing Date
- 2024-11-29
- Publication Date
- 2026-05-29
AI Technical Summary
The anode catalyst of high-temperature polymer electrolyte membrane fuel cells is susceptible to CO gas poisoning, which leads to performance degradation. Existing solutions are complex, costly, and have poor stability.
A water vapor reaction catalyst, such as Au, Pt, Cu and its oxides, is introduced into the gas diffusion layer to form a composite microporous layer. The water vapor reaction is used to convert CO into CO2, thereby reducing the CO content of the catalyst layer.
It significantly improves the performance and lifespan of the membrane electrode, reduces the adverse effects of CO on the catalyst layer, and enhances the efficiency and stability of the fuel cell.
Smart Images
Figure CN122117980A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fuel cell materials technology, and more specifically, to a gas diffusion layer and its preparation method, a membrane electrode, and a fuel cell. Background Technology
[0002] Compared to traditional low-temperature proton exchange membrane fuel cells (LT-PEMFC), high-temperature polymer electrolyte membrane fuel cells (HT-PEMFC) operate at temperatures between 100-200℃, offering simpler hydrothermal management. Their higher operating temperature significantly improves the electrochemical reaction rate of the electrodes. Furthermore, they exhibit greater resistance to impurity gases and can directly utilize reformed hydrogen produced from biomass or fossil fuels, or even industrial by-product hydrogen, as anode fuel, significantly reducing hydrogen costs.
[0003] Similar to the structure of traditional low-temperature proton exchange membrane fuel cells, the membrane electrode assembly (MEA) is the core component of HT-PEMFCs. It consists of a proton exchange membrane (PEM), anode and cathode catalyst layers (CL), and anode and cathode gas diffusion layers (GDL). The CCM (catalyst-coated membrane) is composed of the PEM and the CL. The catalyst layer, composed of catalyst and ionomers, is the site of electrochemical reactions and directly determines the battery's performance. Adjacent to the catalyst layer is the gas diffusion layer, which supports the CCM and transfers electrons and heat, while also uniformly dispersing reactant gases and dissipating water. Similar to low-temperature proton exchange membrane fuel cells, the anode catalyst in current HT-PEMFCs is still commercially available carbon-supported platinum (Pt / C) electrocatalyst material, which is highly susceptible to CO poisoning, leading to performance degradation, especially when hydrocarbon reforming gas is used as the PEMFC fuel.
[0004] Currently, there are two common solutions to the above problems: First, purify the fuel gas to reduce the content of impurities and reduce the source of CO, which can have a certain effect, but the process is more complex and the cost increases significantly. Second, use a CO-poisoning resistant catalyst in the anode catalyst layer, namely PtM catalysts, represented by PtRu / C alloy catalysts. Due to its unique bifunctional mechanism, it can reduce the adsorption of CO on the Pt surface and complete the oxidation and removal of CO, thereby reducing the impact of CO on electrocatalytic performance. However, the Ru component in the PtRu / C binary alloy catalyst has poor stability under PEMFC operating conditions, and the Ru component is easy to dissolve, which will contaminate the proton exchange membrane and affect the stability of the proton exchange membrane and proton conduction. Summary of the Invention
[0005] The main objective of this invention is to provide a gas diffusion layer and its preparation method, a membrane electrode, and a fuel cell, in order to solve the problem that the anode catalyst of high-temperature polymer electrolyte membrane fuel cells is easily poisoned by CO gas in the prior art.
[0006] To achieve the above objectives, according to one aspect of the present invention, a gas diffusion layer is provided, the gas diffusion layer comprising: a substrate layer and a composite microporous layer disposed on one side surface of the substrate; the composite microporous layer is made of a water vapor reaction catalyst, a carbon material and an ion-conductive binder; the water vapor reaction catalyst comprises a catalyst support and a water vapor reaction catalytically active substance supported on the catalyst support.
[0007] Furthermore, the catalytically active substances for water vapor reaction include at least one of Au and its oxides, Pt and its oxides, Cu and its oxides, and Fe and its oxides;
[0008] The carbon material is selected from one or more of carbon fiber, carbon nanotubes, graphene, graphene oxide, and reduced graphene oxide;
[0009] Ion-conductive binders include one or more of polybenzimidazole, fluorinated ethylene propylene, polytetrafluoroethylene, polyvinylidene fluoride, and perfluorosulfonic acid;
[0010] The catalyst support is selected from any one or more of metal oxide supports, carbon supports, and molecular sieves; the metal oxide supports include any one or more of zirconium oxide, titanium oxide, niobium oxide, and tantalum oxide; the carbon supports include any one or more of mesoporous carbon and Ketjen black; the molecular sieves include any one or more of silica-alumina molecular sieves, alumina-phosphorus molecular sieves, and heteroatom framework molecular sieves.
[0011] Preferably, in the water vapor reaction catalyst, the mass ratio of the water vapor reaction catalytic active material to the catalyst support is 1:5 to 1:1.
[0012] Furthermore, by weight, the composite microporous layer comprises 0.1 to 3 parts of water vapor reaction catalyst, 5 to 9 parts of carbon material, and 0.1 to 2 parts of ion-conductive binder;
[0013] Preferably, the composite microporous layer comprises 0.1 to 2 parts of a water vapor reaction catalyst, 6 to 9 parts of carbon material, and 1 to 2 parts of an ion-conductive binder;
[0014] Furthermore, the thickness of the composite microporous layer is 10-50 μm;
[0015] The thickness of the substrate layer is 150–200 μm.
[0016] Furthermore, the substrate material includes any one or more of carbon paper, carbon cloth, nonwoven fabric, nickel foam, and porous titanium substrate.
[0017] According to another aspect of this application, a method for preparing any of the above-mentioned gas diffusion layers is provided, the method comprising: step S1, mixing a water vapor reaction catalyst, a carbon material, an ion-conductive binder and a solvent to obtain a composite microporous layer slurry; step S2, depositing the composite microporous layer slurry on the surface of a substrate layer to obtain a pre-fabricated gas diffusion layer; and step S3, sintering the pre-fabricated gas diffusion layer in an inert gas atmosphere to obtain a gas diffusion layer.
[0018] Furthermore, the solid content of the composite microporous layer slurry is 5-60%, preferably 6-40%;
[0019] Solvents include any one or more of water, methanol, ethanol, propanol, butanol, pentanol, and hexanol;
[0020] The sintering temperature is 100–500℃ and the time is 0.05–10h.
[0021] According to another aspect of this application, a membrane electrode is provided, comprising an anode gas diffusion layer, an anode catalyst layer, a proton exchange membrane, a cathode catalyst layer, and a cathode gas diffusion layer arranged sequentially, wherein the anode gas diffusion layer is any of the above-mentioned gas diffusion layers or a gas diffusion layer prepared by the above-mentioned gas diffusion layer preparation method, and the composite microporous layer of the gas diffusion layer is in contact with the anode catalyst layer.
[0022] Furthermore, the proton exchange membrane is a high-temperature polymer electrolyte membrane.
[0023] According to another aspect of this application, a high-temperature ionomer fuel cell is provided, including a membrane electrode assembly, wherein the membrane electrode assembly is the membrane electrode assembly described above.
[0024] By applying the technical solution of this invention, the water vapor reaction catalyst is integrated with the microporous layer (MPL) in the gas diffusion layer to form a gas diffusion layer that is resistant to CO poisoning. When hydrogen containing CO passes through the MPL layer, the CO in it will be adsorbed and oxidized into carbon dioxide under the action of the water vapor reaction catalyst, thereby significantly reducing the CO content entering the catalyst layer, effectively mitigating the adverse effects of CO on the electrocatalytic performance of the catalyst layer, and thus significantly improving the performance and service life of the membrane electrode. Attached Figure Description
[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:
[0026] Figure 1 A schematic diagram of a gas diffusion layer structure according to an embodiment of the present invention is shown.
[0027] The above figures include the following reference numerals: 001, substrate layer; 002, composite microporous layer. Detailed Implementation
[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0029] As analyzed in the background section of this application, existing technologies suffer from the problem that the anode catalyst in high-temperature polymer electrolyte membrane fuel cells is susceptible to CO gas poisoning. To address this issue, this application provides a gas diffusion layer, its preparation method, a membrane electrode assembly, and a fuel cell.
[0030] According to a typical embodiment of this application, a gas diffusion layer is provided, such as... Figure 1 As shown, the gas diffusion layer includes: a substrate layer 001 and a composite microporous layer 002 disposed on one side surface of the substrate; the composite microporous layer 002 is made of a water vapor reaction catalyst, a carbon material and an ion-conductive binder; the water vapor reaction catalyst includes a catalyst support and a water vapor reaction catalytic active substance supported on the catalyst support.
[0031] This application integrates the water vapor reaction catalyst with the microporous layer (MPL) in the gas diffusion layer to form a gas diffusion layer resistant to CO poisoning. When hydrogen containing CO passes through the MPL layer, the CO in it will be adsorbed and oxidized into carbon dioxide under the action of the water vapor reaction catalyst, thereby significantly reducing the CO content entering the catalyst layer, effectively mitigating the adverse effects of CO on the electrocatalytic performance of the catalyst layer, and thus significantly improving the performance and service life of the membrane electrode.
[0032] The chemical equation for the water vapor conversion reaction (WGS) is CO + H2O → H2 + CO2. During fuel cell operation, water is present at the anode and in the gas diffusion layer, ensuring the smooth progress of the reaction. Furthermore, the water vapor conversion reaction is a process that can both purify CO and produce hydrogen. While eliminating the adverse effects of CO on the membrane electrode assembly, it can also improve the energy efficiency of the fuel cell. Moreover, the water vapor reaction catalysts that can catalyze the water vapor conversion reaction are widely available and easy to obtain, making the gas diffusion layer of this application not only have excellent CO resistance but also low cost.
[0033] The catalytically active material for the water vapor reaction catalyst can be selected from existing technologies. In some embodiments of this application, the catalytically active material for the water vapor reaction includes at least one of Au and its oxides, Pt and its oxides, Cu and its oxides, and Fe and its oxides. Specifically, it can be Au, AuO, Au2O3, Pt, PtO, PtO2, PtO3, Cu, CuO, Cu2O, Fe, FeO, Fe2O3, Fe3O4, etc. This not only has a good catalytic effect on the water vapor reaction, rapidly converting CO and H2O into H2+CO2, but also does not adversely affect the overall performance of the gas diffusion layer and the membrane electrode. Preferably, the catalytically active material for the water vapor reaction is selected from any one or more of Cu, CuO, Cu2O, Fe, FeO, Fe2O3, and Fe3O4. This material exhibits good catalytic effect when applied to the gas diffusion layer of this application, significantly improves the performance of the membrane electrode, and is relatively inexpensive and readily available. In addition, since the gas diffusion layer is in a high-temperature, water-vapor-containing environment when the high-temperature polymer membrane fuel cell is working, some metal elemental water vapor reaction catalytic active materials (such as Cu and Fe) will be converted into their oxides, which can still catalyze water vapor reactions and play a good role in resisting CO poisoning.
[0034] The aforementioned carbon materials, as a common main component of the microporous layer, can be selected from existing technologies. For example, carbon materials include, but are not limited to, one or more of carbon fibers, carbon nanotubes, graphene, graphene oxide, and reduced graphene oxide. Similarly, the specific type of the aforementioned ion-conductive binder can be selected from existing technologies. In some embodiments of this application, the ion-conductive binder includes one or more of polybenzimidazole (PBI), fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and perfluorosulfonic acid (PFSA).
[0035] The water vapor reaction catalyst of this application includes a catalyst support. The addition of the catalyst support facilitates better dispersion and function of the catalytically active substances in the gas diffusion layer, significantly improving the catalytic efficiency of the water vapor reaction. In some embodiments of this application, the catalyst support is selected from any one or more of metal oxide supports, carbon supports, and molecular sieves. Preferably, the metal oxide support includes any one or more of zirconium oxide, titanium oxide, niobium oxide, and tantalum oxide. The carbon support includes any one or more of mesoporous carbon and Ketjen black. Preferably, the molecular sieve includes any one or more of silica-alumina molecular sieves, alumina-phosphorus molecular sieves, and heteroatom framework molecular sieves; for example, SAPO-34, but not limited thereto.
[0036] In some embodiments of this application, in order to further improve the performance of the gas diffusion layer against CO poisoning and to better utilize the role of the water vapor reaction catalytic active material, the mass ratio of the water vapor reaction catalytic active material to the catalyst support in the water vapor reaction catalyst is 1:5 to 1:1, specifically 1:1, 1:2, 1:3, 1:4, 1:4.5, etc., but not limited to this.
[0037] In some typical embodiments of this application, the composite microporous layer comprises, by weight, 0.1 to 3 parts of water vapor reaction catalyst, 5 to 9 parts of carbon material and 0.1 to 2 parts of ion-conductive binder, which is beneficial for each component to better exert synergistic effects and improve the overall performance of the gas diffusion layer; preferably, the composite microporous layer comprises 0.1 to 2 parts of water vapor reaction catalyst, 6 to 9 parts of carbon material and 1 to 2 parts of ion-conductive binder.
[0038] In order to better utilize the anti-CO poisoning properties of the composite microporous layer, in some embodiments of this application, the thickness of the composite microporous layer is 10-50 μm and the thickness of the substrate layer is 150-200 μm.
[0039] The material of the substrate layer can be selected from the prior art. This application does not have any special requirements. For example, the material of the substrate layer includes, but is not limited to, any one or more of carbon paper, carbon cloth, non-woven fabric, nickel foam and porous titanium substrate.
[0040] In some embodiments of this application, the porosity of the composite microporous layer of the gas diffusion layer is 40%–70%, and the electrical conductivity is 10. -2 ~10 -1 The S / cm ratio of the gas diffusion layer in this application not only enables the membrane electrode to resist CO poisoning, but also provides excellent gas diffusion rate and uniformity, which is beneficial to improving the output power of the battery.
[0041] According to another typical embodiment of this application, a method for preparing a gas diffusion layer is provided, the method comprising: step S1, mixing a water vapor reaction catalyst, a carbon material, an ion-conductive binder and a solvent to obtain a composite microporous layer slurry; step S2, depositing the composite microporous layer slurry on the surface of a substrate layer to obtain a pre-prepared gas diffusion layer; and step S3, sintering the pre-prepared gas diffusion layer in an inert gas atmosphere to obtain a gas diffusion layer.
[0042] The gas diffusion layer prepared by the above method integrates the water vapor reaction catalyst with the microporous layer (MPL) in the gas diffusion layer, forming a gas diffusion layer resistant to CO poisoning. When hydrogen containing CO passes through the MPL layer, the CO in it will be adsorbed and oxidized into carbon dioxide under the action of the water vapor reaction catalyst, thereby significantly reducing the CO content entering the catalyst layer, effectively mitigating the adverse effects of CO on the electrocatalytic performance of the catalyst layer, and thus significantly improving the performance and service life of the membrane electrode.
[0043] In some embodiments of this application, the above-mentioned water vapor reaction catalyst, carbon material, ion-conductive binder, and solvent are mixed and then stirred and ultrasonically treated to ensure uniform mixing of the components, resulting in a more uniform and stable composite microporous layer slurry, thereby further improving the performance of the gas diffusion layer. Preferably, the stirring time is 5–300 min and the ultrasonic treatment time is 0.1–2 h, which provides a better mixing effect for the slurry.
[0044] In some embodiments of this application, the solid content of the composite microporous layer slurry is 5%-60%, where the solid content represents the mass percentage of solid components in the composite microporous layer slurry. Preferably, the solid content of the composite microporous layer slurry is 6%-40%, specifically 6%, 10%, 15%, 20%, 25%, 30%, 35%, 38%, etc.
[0045] The solvents mentioned above can be selected from existing technologies. In some embodiments of this application, the solvent includes any one or more of water, methanol, ethanol, propanol, butanol, pentanol, and hexanol, wherein the alcohols (methanol, ethanol, propanol, butanol, pentanol, and hexanol) include various structural isomers and stereoisomers. In some typical embodiments of this application, the solvent is any one or more of methanol, ethanol, propanol, butanol, pentanol, and hexanol mixed with water.
[0046] The catalyst for the aforementioned water vapor reaction comprises a water vapor reaction catalytically active substance and a catalyst support, which can be prepared using existing methods or purchased as commercially available products. Pre-compositing the water vapor reaction catalytically active substance with the catalyst support allows for better dispersion of the active substance within the composite microporous layer, thereby improving the catalytic effect.
[0047] In some embodiments of this application, the catalytically active material for water vapor reaction includes at least one of Au and its oxides, Pt and its oxides, Cu and its oxides, and Fe and its oxides, specifically Au, AuO, Au2O3, Pt, PtO, PtO2, PtO3, Cu, CuO, Cu2O, Fe, FeO, Fe2O3, Fe3O4, etc.
[0048] In some embodiments of this application, the catalyst support is selected from any one or more of metal oxide supports, carbon supports, and molecular sieves. Preferably, the metal oxide support includes any one or more of zirconium oxide, titanium oxide, niobium oxide, and tantalum oxide. The carbon support includes any one or more of mesoporous carbon and Ketjen black. Preferably, the molecular sieve includes any one or more of silica-alumina molecular sieves, alumina-phosphorus molecular sieves, and heteroatom framework molecular sieves; for example, the molecular sieve can be SAPO-34, but it is not limited thereto.
[0049] The type of carbon material can be selected from existing technologies. For example, carbon materials include, but are not limited to, one or more of carbon fibers, carbon nanotubes, graphene, graphene oxide, and reduced graphene oxide. In some embodiments of this application, the solid content of the carbon material in the above-mentioned composite microporous layer slurry is 1-30%.
[0050] Those skilled in the art can apply the aforementioned composite microporous layer slurry to the surface of the substrate using existing methods, and this application does not limit this. For example, coating methods such as blade coating or slot coating can be used. After blade coating, the resulting pre-formed gas diffusion layer is sintered in an inert gas atmosphere to obtain the aforementioned gas diffusion layer. The inert gas can be selected from existing technologies, such as nitrogen, helium, or argon.
[0051] In some embodiments of this application, the sintering temperature is 100–500°C and the time is 0.05–10 h, which is beneficial for further improving the performance of the gas diffusion layer. Preferably, the sintering temperature is 300–500°C and the time is 0.1–3 h.
[0052] According to another typical embodiment of this application, a membrane electrode is provided, comprising an anode gas diffusion layer, an anode catalyst layer, a proton exchange membrane, a cathode catalyst layer and a cathode gas diffusion layer arranged sequentially, wherein the anode gas diffusion layer is the aforementioned gas diffusion layer, and the composite microporous layer of the gas diffusion layer is in contact with the anode catalyst layer.
[0053] Because of the gas diffusion layer mentioned above, the CO in the hydrogen gas can be adsorbed and oxidized into carbon dioxide under the action of water vapor reaction catalyst in the gas diffusion layer. This significantly reduces the CO content entering the catalyst layer, effectively mitigating the adverse effects of CO on the electrocatalytic performance of the catalyst layer, and thus significantly improving the performance and service life of the membrane electrode.
[0054] The anode catalyst layer, proton exchange membrane, cathode catalyst layer and cathode gas diffusion layer in the membrane electrode can all be selected from the prior art, and the membrane electrode of this application does not have any special requirements in this regard.
[0055] Since the gas diffusion layer catalyst of this application also has good stability at high temperatures, in some preferred embodiments of this application, the proton exchange membrane is a polybenzimidazole membrane (PBI membrane). The PBI membrane is a special electrolyte membrane for high-temperature polymer fuel cells. By using the above-mentioned gas diffusion layer, the problem that the catalyst (such as Pt / C) in the high-temperature polymer electrolyte membrane is easily poisoned by CO can be solved. Even if hydrocarbon reforming gas is used as fuel, the damage of CO to the membrane electrode can be significantly reduced, and the efficiency of the fuel cell can also be increased.
[0056] According to another typical embodiment of this application, a fuel cell is provided, including a membrane electrode assembly (MEA), wherein the MEA is the aforementioned membrane electrode assembly. Fuel cells using the aforementioned MEA exhibit better stability, longer service life, and higher fuel efficiency. In particular, when the fuel cell is a high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC), the battery's lifespan and stability can be significantly improved.
[0057] The beneficial effects that this application can achieve will be further illustrated below with reference to embodiments and comparative examples.
[0058] Example 1
[0059] 0.286 g of Au / TiO2 (50% Au by mass) catalyst, 2 g of vapor-grown carbon fiber reinforcement (VGCF), 1.112 g of deionized water, 26.621 g of isopropanol, and 1.836 g of polytetrafluoroethylene solution (wt% = 25%) were mixed thoroughly and stirred for 30 minutes, followed by sonication for 2 hours to prepare a mixed MPL slurry. The mixed MPL slurry was then coated onto a 180-micron thick base layer of carbon fiber paper (commercially purchased, brand: Toray), with a final thickness of 80 microns. After coating, the pre-prepared gas diffusion layer was sintered in an inert gas atmosphere at 200°C for 60 minutes to obtain a 200-micron thick gas diffusion layer.
[0060] Example 2
[0061] A mixed MPL slurry was prepared by mixing 0.286 g of Cu / TiO2 (Cu mass fraction 50%) catalyst, 2 g of vapor-grown carbon fiber reinforcement (VGCF), 1.112 g of deionized water, 26.621 g of isopropanol, and 1.836 g of polytetrafluoroethylene solution (wt% = 25%). The mixture was stirred for 30 minutes and then sonicated for 2 hours. The mixed MPL slurry was then coated onto a 180 μm thick base layer of carbon fiber paper (commercially purchased, brand: Toray). The thickness was set to 80 μm. After coating, the pre-prepared gas diffusion layer was sintered in an inert gas atmosphere at 180 °C for 60 minutes to obtain a 200 μm thick gas diffusion layer.
[0062] Comparative Example 1
[0063] The commercially available gas diffusion layer is model H23C6.
[0064] Comparative Example 2
[0065] A mixed MPL slurry was prepared by mixing 0.143 g of Fe2O3 catalyst, 2 g of vapor-grown carbon fiber reinforcement (VGCF), 1.112 g of deionized water, 26.621 g of isopropanol, and 1.836 g of polybenzimidazole solution (wt% = 25) thoroughly for 30 minutes, followed by sonication for 2 hours. The mixed MPL slurry was then coated onto a 180 μm thick base layer of carbon fiber paper (commercially purchased, Toray brand), with an initial thickness of 80 μm. After coating, the pre-prepared gas diffusion layer was sintered in an inert gas atmosphere at 200°C for 60 minutes, resulting in a 200 μm thick gas diffusion layer.
[0066] A cathode and anode slurries were prepared by mixing Pt / C catalyst, polytetrafluoroethylene solution (wt.%) = 25%, isopropanol, and water in a ratio of 1:2.5:5:5, and then coated. The slurries were then subjected to an induction heating process at 130°C and 10 kgf / cm². 2 CCMs were prepared by transfer printing onto a proton exchange membrane under specific conditions. The gas diffusion layers prepared in the above examples and comparative examples were then assembled with CCMs to form membrane electrodes, and tests were performed. The Pt loadings at the anode and cathode were 0.2 mg / cm³, respectively. -2 and 0.07mg cm -2 .
[0067] The specific testing methods are as follows, and the test results are listed in Table 1.
[0068] The membrane electrode assembly was tested under the following conditions: temperature 160℃, anode and cathode pressure 150 / 160 kPa, anode and cathode humidity 40 / 50%, and anode / cathode stoichiometry ratio 3 / 4. During the test, hydrogen gas and hydrogen gas containing 1.5% CO were introduced into the anode, and air was introduced into the cathode. The voltage was tested at different current densities.
[0069] Table 1
[0070]
[0071]
[0072] As can be seen from the above description, the above embodiments of the present invention achieve the following technical effects: This application integrates the water vapor reaction catalyst with the microporous layer (MPL) in the gas diffusion layer to form a gas diffusion layer that can resist CO poisoning. When hydrogen containing CO passes through the MPL layer, the CO in it will be adsorbed and oxidized into carbon dioxide under the action of the water vapor reaction catalyst, thereby significantly reducing the CO content entering the catalyst layer, effectively mitigating the adverse effects of CO on the electrocatalytic performance of the catalyst layer, and thus significantly improving the performance and service life of the membrane electrode.
[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A gas diffusion layer, characterized in that, include: The substrate layer and a composite microporous layer disposed on one side surface of the substrate; the composite microporous layer is made of a water vapor reaction catalyst, a carbon material and an ion-conductive binder; the water vapor reaction catalyst includes a catalyst support and a water vapor reaction catalytic active substance supported on the catalyst support.
2. The gas diffusion layer according to claim 1, characterized in that, The water vapor reaction catalytic active material includes at least one of Au and its oxides, Pt and its oxides, Cu and its oxides, and Fe and its oxides; The carbon material is selected from one or more of carbon fiber, carbon nanotubes, graphene, graphene oxide, and reduced graphene oxide. The ion-conductive binder includes one or more of polybenzimidazole, fluorinated ethylene propylene, polytetrafluoroethylene, polyvinylidene fluoride, and perfluorosulfonic acid; The catalyst support is selected from any one or more of metal oxide supports, carbon supports, and molecular sieves; the metal oxide support includes any one or more of zirconium oxide, titanium oxide, niobium oxide, and tantalum oxide; the carbon support includes any one or more of mesoporous carbon and Ketjen black; the molecular sieve includes any one or more of silica-alumina molecular sieves, alumina-phosphorus molecular sieves, and heteroatom framework molecular sieves. Preferably, in the water vapor reaction catalyst, the mass ratio of the water vapor reaction catalytic active material to the catalyst support is 1:5 to 1:
1.
3. The gas diffusion layer according to claim 1 or 2, characterized in that, By weight, the composite microporous layer comprises 0.1 to 3 parts of water vapor reaction catalyst, 5 to 9 parts of carbon material, and 0.1 to 2 parts of ion-conductive binder; Preferably, the composite microporous layer comprises 0.1 to 2 parts of a water vapor reaction catalyst, 6 to 9 parts of carbon material, and 1 to 2 parts of an ion-conductive binder.
4. The gas diffusion layer according to claim 1 or 2, characterized in that, The thickness of the composite microporous layer is 10-50 μm; The thickness of the substrate layer is 150–200 μm.
5. The gas diffusion layer according to claim 1 or 2, characterized in that, The substrate material includes any one or more of carbon paper, carbon cloth, non-woven fabric, nickel foam, and porous titanium substrate.
6. A method for preparing a gas diffusion layer according to any one of claims 1 to 5, characterized in that, include: Step S1: Mix the water vapor reaction catalyst, carbon material, ion-conductive binder and solvent to obtain a composite microporous layer slurry; Step S2: The composite microporous layer slurry is applied to the surface of the substrate layer to obtain a pre-fabricated gas diffusion layer; Step S3: Sinter the pre-fabricated gas diffusion layer in an inert gas atmosphere to obtain the gas diffusion layer.
7. The method for preparing the gas diffusion layer according to claim 6, characterized in that, The solid content of the composite microporous layer slurry is 5-60%, preferably 6-40%; The solvent includes any one or more of water, methanol, ethanol, propanol, butanol, pentanol, and hexanol; The sintering temperature is 100–500℃, and the time is 0.05–10h.
8. A membrane electrode, comprising an anode gas diffusion layer, an anode catalyst layer, a proton exchange membrane, a cathode catalyst layer, and a cathode gas diffusion layer arranged sequentially, characterized in that, The anode gas diffusion layer is the gas diffusion layer according to any one of claims 1 to 5 or the gas diffusion layer prepared by the method of the gas diffusion layer according to claim 6 or 7, and the composite microporous layer of the gas diffusion layer is in contact with the anode catalyst layer.
9. The membrane electrode according to claim 8, characterized in that, The proton exchange membrane is a high-temperature polymer electrolyte membrane.
10. A high-temperature ionomer fuel cell, comprising a membrane electrode assembly, characterized in that, The membrane electrode is the membrane electrode as described in claim 8.