Membrane electrode and preparation method and application thereof

Abstract

The invention provides a membrane electrode as well as a preparation method and application thereof. The membrane electrode comprises a membrane layer; the anode catalyst layer is formed on one side of the film layer, the anode catalyst layer comprises a hydrogen consumption layer and an anode catalyst base layer, the hydrogen consumption layer is formed between the film layer and the anode catalyst base layer, and the cathode catalyst layer is formed on one side of the film layer. According to the membrane electrode as well as the preparation method and the application thereof, the safety of a water electrolysis device can be improved, the electrolysis efficiency can be improved, the uniformity and the stability of catalysis can be ensured, and the service life of the water electrolysis device can be prolonged.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of hydrogen production by water electrolysis, and particularly relates to a membrane electrode and a preparation method and application thereof. BACKGROUND

[0002] With the development of sustainable and renewable clean energy, hydrogen energy is considered as a very potential clean energy because it is not limited by geographical environment and application environment. At present, the most practical and clean method for hydrogen production is hydrogen production by water electrolysis. In the process of hydrogen production by water electrolysis, water is catalyzed by an anode catalyst to produce and release oxygen through an oxygen evolution reaction, and is catalyzed by a cathode catalyst to reduce and release hydrogen through a hydrogen evolution reaction. However, the hydrogen pressure generated by the cathode is higher than the oxygen pressure generated by the anode, hydrogen can penetrate from the cathode to the anode through the membrane layer, and the mixture of hydrogen and oxygen will reduce the performance of the membrane electrode and even cause explosion in a serious case. Meanwhile, the water electrolysis cell also has problems such as alignment of the catalytic layer on both sides of the membrane and slow transmission of the catalytic layer. SUMMARY

[0003] The application provides a membrane electrode and a preparation method and application thereof, which can improve the purity of hydrogen and oxygen produced by water electrolysis, improve the safety of the water electrolysis device, increase the porosity of the catalyst, increase the electrolysis rate, improve the electrolysis efficiency, improve the quality of the membrane electrode, ensure the uniformity and stability of the catalysis, and prolong the service life of the water electrolysis device.

[0004] To solve the above technical problems, the application is realized through the following technical scheme.

[0005] The application provides a membrane electrode, which comprises:

[0006] a membrane layer;

[0007] an anode catalytic layer formed on one side of the membrane layer, wherein the anode catalytic layer comprises a hydrogen consumption layer and an anode catalytic base layer, the hydrogen consumption layer is formed between the membrane layer and the anode catalytic base layer, and

[0008] a cathode catalytic layer formed on one side of the membrane layer.

[0009] In an embodiment of the application, the hydrogen consumption layer comprises a hydrogen consumption catalyst selected from at least one of Pt, Ir or Pd;

[0010] and / or, the anode catalytic base layer comprises a catalyst selected from at least one of Ir, IrO2, Pt, Pd and Ru;

[0011] and / or, the cathode catalytic base layer comprises a catalyst selected from at least one of Ir, IrO2, Pt / C, Pt, Pd and Ru.

[0012] In an embodiment of the present application, the thickness ratio of the membrane layer, the anode catalytic layer and the cathode catalytic layer is 1:0.1:0.1-1:10:10, and the thickness ratio of the hydrogen consumption layer and the anode catalytic base layer is 1:1-1:10.

[0013] In an embodiment of the present application, the porosity of the hydrogen consumption layer is 100-330m 2 / g.

[0014] and / or, the porosity of the anode catalytic base layer is 100-330m 2 / g.

[0015] and / or, the porosity of the cathode catalytic layer is 100-330m 2 / g.

[0016] The present application also provides a preparation method of a membrane electrode, at least comprising:

[0017] forming an anode catalytic layer on one side of the membrane layer, the anode catalytic layer comprising a hydrogen consumption layer and an anode catalytic base layer, the hydrogen consumption layer being formed between the membrane layer and the anode catalytic base layer; and

[0018] forming a cathode catalytic layer on the other side of the membrane layer.

[0019] In an embodiment of the present application, the anode catalytic layer and the cathode catalytic layer are formed by a non-vacuum hot-pressing transfer printing method.

[0020] In an embodiment of the present application, during the transfer printing process, a first transfer printing plate and a second transfer printing plate are arranged on both sides of the membrane layer, and the first transfer printing plate and the second transfer printing plate are provided with openings of the same size and position at the center.

[0021] In an embodiment of the present application, the first transfer printing plate and the second transfer printing plate are provided with positioning holes at the diagonal position, and a positioning member is placed in the positioning hole.

[0022] In an embodiment of the present application, the preparation method further comprises a catalyst pore-forming treatment, and the pore-forming treatment adopts a cold-hot cycle pore-forming method.

[0023] The present application also provides an electrolytic water device comprising the membrane electrode described above or the membrane electrode obtained by the preparation method described above.

[0024] In summary, the application provides a membrane electrode, a preparation method and application thereof, which can improve the purity of hydrogen and oxygen generated by electrolysis of water, and improve the safety of the water electrolysis device. The number of micropores of the membrane electrode can be increased, the mass transfer can be provided by abundant channels, the porosity of the catalyst can be increased, the electrolysis rate can be increased, and the electrolysis efficiency can be improved. In the preparation process, the air in the gap of the middle region of the sheet can be removed, or the generated water vapor can be heated to avoid the generation of large-area bubble defects in the catalyst region after transfer printing, and the quality of the membrane electrode is improved. At the same time, the anode catalyst layer and the cathode catalyst layer are placed on the two sides of the membrane layer, which ensures the uniformity and stability of the catalyst, and prolongs the service life of the water electrolysis device. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0026] Figure 1 It is a structural schematic diagram of the membrane electrode in an embodiment of the application.

[0027] Figure 2 It is a distribution schematic diagram of the hydrogen consumption layer on the membrane layer in an embodiment of the application.

[0028] Figure 3 It is a schematic diagram of the flow channel in the cathode catalyst layer in an embodiment of the application.

[0029] Figure 4 It is a distribution schematic diagram of the hydrogen consumption layer on the membrane layer in another embodiment of the application.

[0030] Figure 5 It is a structural schematic diagram of the membrane electrode in an embodiment of the application during transfer printing.

[0031] Figure 6 It is a scanning electron microscope diagram of the electrode catalyst layer obtained by the transfer printing method in an embodiment of the application.

[0032] Figure 7 It is a scanning electron microscope diagram of the electrode catalyst layer obtained by the traditional method. DETAILED DESCRIPTION

[0033] The embodiments of the application will be described below through specific concrete examples, and those skilled in the art can easily understand other advantages and effects of the application from the disclosure. The application can also be implemented or applied by different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the application.

[0034] It is to be understood that the application can assume various alternative embodiments, and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. Unless otherwise specified, "%" and "parts" shown in the following examples refer to "mass%" and "mass parts", respectively.

[0035] The technical solutions of the present application will be further described in detail below in conjunction with several embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0036] Please refer to Figure 1 As shown in the drawings, in an embodiment of the present application, the membrane electrode provided by the present application can be used in a hydrogen production device for electrolysis of water by proton exchange membrane. The membrane electrode includes a membrane layer 10, an anode catalytic layer 11 and a cathode catalytic layer 12, etc., the anode catalytic layer 11 and the cathode catalytic layer 12 are respectively formed on both sides of the membrane layer 10, the anode catalytic layer 11 includes a hydrogen consumption layer 111 and an anode catalytic base layer 112, and the hydrogen consumption layer 111 is formed between the membrane layer 10 and the anode catalytic base layer 113. By setting the hydrogen consumption layer 111, the hydrogen permeated from the cathode side to the anode can be eliminated in time, the purity of the gas is improved, and the safety of the hydrogen production device for electrolysis of water is improved.

[0037] Please refer to Figure 1 As shown in the drawings, in an embodiment of the present application, the membrane layer 10 is, for example, N115 proton membrane, etc., and the thickness of the membrane layer 10 is, for example, 110 μm to 130 μm, etc., and the thickness of the N115 proton membrane is, for example, 127 μm, to meet the requirements of conduction, isolation and thermal stability, etc.

[0038] Please refer to Figure 1As shown, in one embodiment of the present invention, the hydrogen removal catalyst in the hydrogen consumption layer 111 is selected from highly active, acid-resistant, and highly stable materials such as Pt, Ir, or Pd. The anode catalyst in the anode catalyst substrate 112 is selected from catalysts used for catalyzing oxygen reactions, such as at least one of Ir, IrO2, Pt, Pd, or Ru. Through the hydrogen removal catalyst in the hydrogen consumption layer 111, the hydrogen gas diffused from the cathode can be converted into hydrogen ions. Some of the oxygen generated on the anode side diffuses into the hydrogen consumption layer 111. The hydrogen removal catalyst in the hydrogen consumption layer 111 can also convert the oxygen diffused into oxygen ions, so that the hydrogen ions and oxygen ions react to generate water, thereby eliminating hydrogen on the anode side, improving the purity of oxygen on the anode side, and preventing oxygen from diffusing to the cathode. That is, it can simultaneously improve the purity of hydrogen and oxygen generated by water electrolysis and improve the safety of the water electrolysis device.

[0039] Please see Figure 1 As shown, in one embodiment of the present invention, the cathode catalyst in the cathode catalyst layer 12 is, for example, a catalyst for catalyzing hydrogen reaction, or at least one of Ir, IrO2, Pt / C, Pt, Pd or Ru.

[0040] Please see Figure 1 As shown, in one embodiment of the present invention, the thickness ratio of the membrane layer 10, the anode catalyst layer 11, and the cathode catalyst layer 12 is, for example, 1:0.1:0.1 to 1:10:10, or, for example, 1:1.5:1.5, and the thickness ratio of the hydrogen consumption layer 111 and the anode catalyst layer 112 is, for example, 1:1 to 1:10, or 1:5, etc. In a specific embodiment of the present invention, the total thickness of the membrane electrode is, for example, 154 μm. With the membrane electrode within this thickness range, and the thicknesses of different layers being coordinated, the efficiency of water electrolysis by the membrane electrode can be improved.

[0041] Please see Figure 1 As shown, in one embodiment of the present invention, the porosity of the hydrogen consumption layer 111 is, for example, 1 m. 2 / g, the porosity of the anode catalyst substrate 112 is, for example, 100–330 μm. 2 / g, the porosity of the cathode catalyst layer 12 is, for example, 100–330 μm. 2 / g. In a specific embodiment of the present invention, the porosity of the hydrogen-consuming layer 111 is, for example, 130 μm. 2 / g, the porosity of the anode catalyst substrate 112 is, for example, 160m. 2 / g, the porosity of the cathode catalyst layer 12 is, for example, 180m. 2 / g. Among them, the anode catalyst layer 11 and cathode catalyst layer 12 on both sides of the membrane layer 10 have large porosity, which can increase the number of membrane electrode channels, provide abundant channels for mass transfer, and thus improve the electrolysis rate.

[0042] Please see Figure 2 As shown in one embodiment of the present invention, a schematic diagram of the distribution of the hydrogen consumption layer 111 on the membrane layer 10 is provided. During electrolysis, hydrogen gas permeating through the membrane layer 10 gradually accumulates from the inlet to the outlet of the anode layer flow field. In some embodiments, the loading of the hydrogen consumption layer can be increased along the water flow direction of the anode catalyst layer. Therefore, on the anode side of the membrane layer 10, the hydrogen consumption layer 111 on the membrane layer 10 increases from the end of the membrane electrode away from the water flow direction to the end closer to the water flow direction, such as by increasing the width, loading, and density of the hydrogen consumption layer 111. Figure 2 In part a, the hydrogen consumption layer 111 comprises multiple arranged strip-like structures, with the width of the strip-like structures of the hydrogen consumption layer 111 increasing sequentially towards the end closer to the water flow direction. Figure 2 In part b, towards the end closer to the water flow direction, the loading of the hydrogen consumption layer 111 increases sequentially, as does the thickness of the hydrogen consumption layer 111. Figure 2 In section c of the membrane 10, the density of the hydrogen-absorbing catalyst in the hydrogen-consuming layer 111 increases sequentially towards the end closer to the water flow. By setting different amounts of hydrogen-consuming layer 111 in different regions of the membrane 10, the hydrogen removal efficiency on the anode side can be improved, while reducing the amount of hydrogen-absorbing catalyst used and lowering costs.

[0043] Please see Figure 3 and Figure 4 As shown, in another embodiment of the present invention, a schematic diagram of the distribution of the hydrogen consumption layer 111 on the membrane layer 10 is provided. The electrolyzer includes a membrane electrode 10 and a diode 20, which are respectively located outside the anode catalyst layer and the cathode catalyst layer of the membrane electrode. During electrolysis, because the position of the cathode flow field ridge 201 of the electrode 20 on the cathode catalyst layer side is pressed at the contact point with the membrane layer 10, it is not conducive to hydrogen permeation, resulting in a low hydrogen content. The membrane layer 10 at the flow channel 202 position swells, resulting in more micropores, which is conducive to hydrogen permeation. In some embodiments, the hydrogen consumption layer 111 may be provided with a bent structure (e.g., Figure 4 As shown, the bent structure of the hydrogen consumption layer 111 can be consistent with the flow field distribution of the electrode plate outside the cathode catalyst layer. This can consume the hydrogen diffused from the flow channel 202, improve the hydrogen removal efficiency on the anode side, and enhance the safety of electrolysis.

[0044] In one embodiment of the present invention, the present invention also provides a method for preparing a membrane electrode, including steps S11-S12.

[0045] Step S11, forming an anode catalytic layer on one side of the film layer, the anode catalytic layer including a hydrogen consumption layer and an anode catalytic base layer, the hydrogen consumption layer being formed between the film layer and the anode catalytic base layer.

[0046] Step S12, forming a cathode catalytic layer on the other side of the film layer.

[0047] In an embodiment of the present application, the anode catalytic layer and the cathode catalytic layer are formed by, for example, a transfer printing method. In the transfer printing, the anode catalytic layer and the cathode catalytic layer can be transferred simultaneously or in steps. In the case of simultaneous transfer, the anode catalytic base layer is formed on the transfer film, and the hydrogen consumption layer is formed on the anode catalytic base layer, and then the anode catalytic layer is transferred to the film layer. In the case of step-by-step transfer, the hydrogen consumption layer is first transferred to the film layer, and then the anode catalytic base layer is transferred to the hydrogen consumption layer. In this embodiment, the transfer printing is performed by, for example, a non-vacuum hot-press transfer printing method.

[0048] Referring to Figure 5 In an embodiment of the present application, the anode catalytic slurry layer and the hydrogen consumption slurry layer are formed on the transfer film to form a first transfer film 15. The anode catalytic slurry layer includes an anode catalyst and a resin, etc. The anode catalyst includes a carrier and a component including an active metal element-containing substance supported on the carrier. The mass ratio of the anode catalyst to the resin is, for example, 1:0.1 to 1:3. The anode catalytic slurry layer is formed by, for example, a doctor blade coating, a roll coating, or a spray coating, etc.

[0049] Referring to Figure 5 In an embodiment of the present application, the cathode catalytic slurry layer is formed on the transfer film to form a second transfer film 16. The cathode catalytic slurry layer includes a cathode catalyst and a resin, etc. The cathode catalyst includes a carrier and a component including an active metal element-containing substance supported on the carrier. The mass ratio of the cathode catalyst to the resin is, for example, 1:0.7 to 1:2. The cathode catalytic slurry layer is formed by, for example, a doctor blade coating, a roll coating, or a spray coating, etc.

[0050] In an embodiment of the present application, the resins in the anode catalytic slurry layer, the hydrogen consumption slurry layer, and the cathode catalytic slurry layer can be the same or different. The resin is, for example, selected from at least one of a perfluoro resin solution (D2020), etc.

[0051] Referring to Figure 5In an embodiment of the present application, the film layer 10 is placed in the middle position during the film electrode formation by the transfer assembly to ensure that the film layer 10 is flat and free of folding. The transfer plates are provided on both sides of the film layer 10, for example, including a first transfer plate 131 and a second transfer plate 132, which have the same size. Openings with the same size are provided at the centers of the first transfer plate 131 and the second transfer plate 132 to determine the transfer area, so that the sizes of the areas where the catalytic layers are located on both sides of the film layer 10 after the transfer are the same, and the areas where the catalytic layers are located are aligned. The air in the transfer process or the water vapor generated by heating can be discharged from the edges of the openings. In the present application, the size of the opening is not limited and can be set according to the size of the film electrode to meet the preparation requirements of forming a larger film electrode.

[0052] Referring to Figure 5 In an embodiment of the present application, positioning holes 141 are provided at the diagonal positions of the first transfer plate 131 and the second transfer plate 132, and the positions of the positioning holes 141 on the first transfer plate 131 and the second transfer plate 132 are the same. During the transfer, the film layer 10 is placed in the middle of the first transfer plate 131 and the second transfer plate 132, and the positioning member 14, for example, fluorine rubber, is placed in the diagonal positioning holes 141 to fix and position the film layer of the film electrode for subsequent transfer processes.

[0053] Referring to Figure 5 In an embodiment of the present application, the first transfer film 15 is provided on the side of the first transfer plate 131 away from the film layer 10, and the slurry layer on the first transfer film 15 faces the film layer 10. The second transfer film 16 is provided on the side of the second transfer plate 132 away from the film layer 10, and the slurry layer on the second transfer film 16 faces the film layer 10. The positioning member 14 defines the positions of the first transfer film 15 and the second transfer film 16. The slurry layer on the transfer film is transferred to the film layer by simultaneously applying pressure to the side of the first transfer film 15 away from the film layer 10 and the side of the second transfer film 16 away from the film layer 10 at a temperature of, for example, 130-180°C, a pressure of, for example, 0.5-4 MPa, and a hot pressing time of, for example, 10-600 s, and then the transfer film is removed to form the anode catalyst layer and the cathode catalyst layer. By providing the transfer plates and the positioning member, the air in the gap in the middle of the sheet during the formation of the film electrode or the water vapor generated by heating can be removed, and large-area bubble defects in the catalytic layer after the transfer can be avoided, thereby improving the quality of the film electrode. In addition, the anode catalyst layer and the cathode catalyst layer are placed and aligned on both sides of the film layer, which ensures the uniformity and stability of the catalysis and prolongs the service life of the water electrolysis device.

[0054] Referring to Figure 6 and Figure 7 By the transfer method of the present application, compared with the traditional electrode catalytic layer (for example,Figure 7 ), the electrode catalyst layer with good surface uniformity can be obtained (e.g. Figure 6 In some embodiments, the thickness of the electrode catalyst layer of the present application can be less than or equal to 0.15 μm, for example, 0.15-0.08 μm.

[0055] Please refer to Figure 1 and Figure 5 In an embodiment of the present application, after the transfer is completed, the anode catalyst layer 11 and / or the cathode catalyst layer 12 can also be subjected to a catalyst pore-forming treatment, for example, a cold and hot cycle pore-forming method. Specifically, the membrane electrode is immersed in water in a negative pressure environment, and after the membrane electrode is fully swollen, the membrane electrode is slowly cooled, for example, to -50°C, and after 12 h of incubation, the temperature is slowly increased to 70°C, and the cycle is repeated, to increase the pore distribution of the catalyst. In this embodiment, the pressure of the negative pressure environment is, for example, 80 KPa, the cooling rate is, for example, 0.5°C / min-3°C / min, and the heating rate is, for example, 0.5°C / min-3°C / min. The improved pore-forming treatment method of the present application is simple and convenient to operate, and after the pore-forming treatment, the pore distribution of the catalyst can be increased, the porosity of the catalyst can be increased, the electrolysis rate can be increased, and the electrolysis efficiency can be improved. In an embodiment, the pore size of the catalyst is, for example, 1 μm-200 μm.

[0056] The present application also provides an electrolytic water device, for example, a proton exchange membrane electrolytic water hydrogen production device, comprising the membrane electrode as described above. When the membrane electrode is applied to the hydrogen production device, water can be obtained by the reaction of hydrogen and oxygen on the anode side, thereby achieving the purpose of hydrogen consumption on the anode side, improving the purity of oxygen on the anode side, and improving the safety of the electrolytic water device. At the same time, the quality of the membrane electrode is improved, the uniformity and stability of the catalyst are ensured, and the service life of the electrolytic water device is prolonged. The electrolysis rate can be increased, the electrolysis efficiency can be improved, and the development of electrolytic water hydrogen production technology is promoted.

[0057] In summary, the present application provides a membrane electrode and a preparation method and application thereof, which can simultaneously improve the purity of hydrogen and oxygen produced by electrolytic water, and improve the safety of the electrolytic water device. The number of micropores of the membrane electrode can be increased, the mass transfer can be provided by abundant pores, the porosity of the catalyst can be increased, the electrolysis rate can be increased, and the electrolysis efficiency can be improved. In the preparation process, the air in the gap in the middle region of the sheet can be removed, or the water vapor generated by heating can be removed, to avoid the generation of large-area bubble defects in the catalyst region after transfer, and to improve the quality of the membrane electrode. At the same time, the anode catalyst layer and the cathode catalyst layer are placed in alignment on both sides of the membrane layer, to ensure the uniformity and stability of the catalyst, and to prolong the service life of the electrolytic water device.

[0058] The above embodiments are only illustrative of the principles of the present application and its efficacy, and are not intended to limit the present application. Any modification or change made by any person skilled in the art without departing from the spirit and scope of the present application shall be covered by the claims of the present application.

Claims

1. A membrane electrode, characterized by, The membrane electrode comprises: a membrane layer; an anode catalytic layer formed on one side of the membrane layer, the anode catalytic layer comprising a hydrogen consumption layer and an anode catalytic base layer, the hydrogen consumption layer being formed between the membrane layer and the anode catalytic base layer, and a cathode catalytic layer formed on the other side of the membrane layer.

2. The membrane electrode according to claim 1, characterized in that, The hydrogen consumption layer comprises a hydrogen consumption catalyst selected from at least one of Pt, Ir or Pd; and / or, the anode catalytic base layer comprises a catalyst selected from at least one of Ir, IrO2, Pt, Pd, Ru; and / or, the cathode catalytic base layer comprises a catalyst selected from at least one of Ir, IrO2, Pt / C, Pt, Pd, Ru.

3. The membrane electrode according to claim 1, characterized in that, The thickness ratio of the membrane layer, the anode catalytic layer and the cathode catalytic layer is 1:0.1:0.1-1:10:10, and the thickness ratio of the hydrogen consumption layer and the anode catalytic base layer is 1:1-1:

10.

4. The membrane electrode of claim 1, wherein The hydrogen-consuming layer has a porosity of 100 to 330 m 2 / g; and / or the porosity of the anode catalytic base layer is 100-330 m 2 / g; and / or the porosity of the cathode catalytic layer is 100-330 m 2 / g.

5. A method for preparing a membrane electrode, characterized by, The membrane electrode comprises: an anode catalytic layer formed on one side of the membrane layer, the anode catalytic layer comprising a hydrogen consumption layer and an anode catalytic base layer, the hydrogen consumption layer being formed between the membrane layer and the anode catalytic base layer; and a cathode catalytic layer formed on the other side of the membrane layer.

6. The method of claim 5, wherein the membrane electrode is prepared by the steps of: The anode catalytic layer and the cathode catalytic layer are formed by a non-evacuation hot pressing transfer printing method.

7. The method of claim 6, wherein the membrane electrode is prepared by the steps of: During the transfer printing process, a first transfer printing plate and a second transfer printing plate are arranged on both sides of the membrane layer, and the first transfer printing plate and the second transfer printing plate are provided with openings of the same size and position at the center.

8. The method of claim 7, wherein the membrane electrode is prepared by the steps of: The first transfer printing plate and the second transfer printing plate are provided with positioning holes at the diagonal position, and the positioning holes are placed with positioning members.

9. The method of claim 5, wherein the membrane electrode is prepared by the steps of: The manufacturing method further comprises a catalyst pore-forming treatment, and the pore-forming treatment adopts a cold and hot cycle pore-forming method.

10. An apparatus for electrolyzing water, characterized by comprising: The membrane electrode obtained by the manufacturing method of any one of claims 5-9. The membrane electrode obtained by the manufacturing method of any one of claims 5-9.

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