Membrane electrode and hydrogen production electrolytic cell

Abstract

The utility model provides a membrane electrode and a hydrogen production electrolytic tank. The membrane electrode comprises a membrane layer and a membrane electrode, the electrode catalyst layer is formed on one side of the film layer, and a fusion area is arranged between the electrode catalyst layer and the film layer; wherein in the fusion region, a part of the electrode catalyst layer is embedded or fused into the membrane layer. According to the membrane electrode and the hydrogen production electrolytic bath provided by the utility model, the binding force of the electrode catalyst layer and the membrane layer can be improved, the safety of a water electrolysis device is improved, and the service life of the water electrolysis device is prolonged.

Description

[0001] This application claims partial priority to the Chinese patent application filed on June 26, 2024, with application number 202421471546.0 and invention name “A membrane electrode and hydrogen production electrolyzer”, the relevant contents of which are incorporated into this application by reference. Technical Field

[0002] The utility model relates to the technical field of electrode preparation, in particular to a membrane electrode and a hydrogen production electrolyzer. Background Art

[0003] As the core component of water electrolysis hydrogen production technology, the membrane electrode is composed of an electrode catalyst layer, an electrode catalyst layer and a membrane layer. It plays the role of conducting protons, catalyzing reactions and separating gases, and determines the performance, efficiency, life and cost of water electrolysis hydrogen production.

[0004] However, in membrane electrodes, the electrode catalyst layer and membrane layer are prone to delamination, resulting in poor membrane electrode stability. Furthermore, during electrolysis, hydrogen can permeate through the membrane layer from the cathode to the anode. The mixing of hydrogen and oxygen can degrade membrane electrode performance and, in severe cases, cause explosions, raising significant safety concerns. Utility Model Content

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a membrane electrode and a hydrogen production electrolyzer, which can improve the bonding strength of the electrode catalyst layer membrane, improve the safety and stability of the water electrolysis device, and extend the service life of the water electrolysis device.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions.

[0007] The utility model provides a membrane electrode, comprising:

[0008] membrane layer;

[0009] an electrode catalyst layer formed on one side of the membrane layer, wherein a fusion region is provided between the electrode catalyst layer and the membrane layer;

[0010] In the fusion region, a portion of the electrode catalyst layer is embedded in or fused into the membrane layer.

[0011] In one embodiment of the present invention, another electrode catalyst layer is further included, which is formed on the other side of the membrane layer, and a portion of the other electrode catalyst layer is embedded in or integrated into the membrane layer.

[0012] In one embodiment of the present invention, another electrode catalyst layer is further included, formed on the diffusion layer on the other side of the membrane layer.

[0013] In one embodiment of the present invention, the electrode catalyst layer is embedded in the membrane layer to a depth of 10 nm to 7 μm.

[0014] In one embodiment of the present invention, the electrode catalyst layer is an anode catalyst layer, and the anode catalyst layer includes a hydrogen consumption layer and an anode catalyst base layer. The hydrogen consumption layer is formed between the membrane layer and the anode catalyst base layer.

[0015] In one embodiment of the present invention, a portion of the hydrogen consumption layer of the anode catalyst layer is embedded in or integrated into the membrane layer.

[0016] In one embodiment of the present invention, the electrode catalyst layer includes a cathode catalyst layer, which is arranged on the side of the membrane layer opposite to the anode catalyst layer, and the thickness ratio of the membrane layer, the anode catalyst layer and the cathode catalyst layer is 1:0.1:0.1 to 1:10:10.

[0017] In one embodiment of the present invention, the thickness ratio of the hydrogen consumption layer to the anode catalyst substrate is 1:1 to 1:10.

[0018] In one embodiment of the present invention, the porosity of the hydrogen consumption layer is 100-330 m 2 / g;

[0019] And / or, the porosity of the anode catalyst substrate is 100 to 330 m 2 / g;

[0020] And / or, the porosity of the cathode catalyst layer is 100 to 330 m 2 / g.

[0021] The utility model also provides a hydrogen production electrolyzer, comprising the membrane electrode described above.

[0022] In summary, the present invention provides a membrane electrode and a hydrogen production electrolyzer, wherein an electrode catalyst layer and an electrode catalyst layer are respectively arranged on the first surface and the second surface of the membrane layer, which can enhance the bonding force between the electrode catalyst layer and the first surface, as well as the bonding force between the electrode catalyst layer and the second surface, so that the membrane layer and the electrode catalyst layer are tightly bonded, and the electrode catalyst layer and the membrane layer are not easily peeled off, thereby improving the stability of the membrane electrode, improving the utilization rate of the catalyst in the electrode catalyst layer, and improving the efficiency of water electrolysis to produce hydrogen. It can simultaneously improve the purity of hydrogen and oxygen produced by electrolysis of water, and improve the safety of the water electrolysis device. It can increase the number of micropores in the membrane electrode, provide abundant pores for mass transfer, increase the porosity of the catalyst, increase the electrolysis rate, and improve the electrolysis efficiency. It can improve the quality of the membrane electrode. At the same time, the anode catalyst layer and the cathode catalyst layer are aligned on both sides of the membrane layer to ensure the uniformity and stability of the catalysis and extend the service life of the water electrolysis device.

[0023] Of course, any one of the methods of implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 Schematic diagram of the process of preparing a membrane electrode in one embodiment of the present invention.

[0026] Figure 2 This is a physical diagram of the membrane electrode in one embodiment of the present invention.

[0027] Figure 3 for Figure 2 Microscopic cross-sectional view of the membrane electrode.

[0028] Figure 4 for Figure 3 Enlarged view of the middle membrane layer and electrode catalyst layer.

[0029] Figure 5 for Figure 2 Stability curve of the membrane electrode.

[0030] Figure 6 This is a schematic diagram of the membrane layer and electrode catalyst layer in one embodiment of the present invention.

[0031] Figure 7 This is a microscopic morphology diagram of the membrane layer and the electrode catalyst layer in one embodiment of the present invention.

[0032] Figure 8 This is a schematic structural diagram of the membrane electrode in one embodiment of the present invention.

[0033] Figure 9 Schematic diagram of the distribution of the hydrogen consumption layer on the film layer in one embodiment of the present invention.

[0034] Figure 10 Schematic diagram of the flow channel in the cathode catalyst layer in one embodiment of the present invention.

[0035] Figure 11 Schematic diagram of the distribution of the hydrogen consumption layer on the membrane layer in another embodiment of the present invention.

[0036] Figure 12 This is a schematic structural diagram of the membrane electrode during transfer in one embodiment of the present invention.

[0037] Figure 13 This is a scanning electron microscope image of an electrode catalyst layer obtained by the transfer method of the present invention in one embodiment.

[0038] Figure 14 This is a scanning electron microscope image of the electrode catalyst layer obtained traditionally.

[0039] Figure 15 Schematic diagram of adhesion test of the membrane electrode obtained in this application and the membrane electrode obtained traditionally.

[0040] Figure 16 This is a schematic diagram of the electrode sheet of this application. DETAILED DESCRIPTION

[0041] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different perspectives and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features within these embodiments may be combined with one another, unless they conflict.

[0042] It should be understood that the present invention can be implemented in different forms and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and will fully convey the scope of the present invention to those skilled in the art.

[0043] The technical solution of the present invention is further described in detail below with reference to the embodiments and accompanying drawings. Obviously, the embodiments described are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] See also Figure 1 As shown, the present invention provides a method for preparing a membrane electrode, which at least includes steps S11-S15.

[0045] S11. Provide a film layer, wherein the film layer includes a first surface and a second surface that are opposite to each other.

[0046] S12, coating the precursor solution on the first surface.

[0047] S13, coating the bonding enhancer on the precursor solution.

[0048] S14, placing the membrane layer in an alkaline solution for growth, so as to in-situ grow an electrode catalyst layer on the first surface.

[0049] S15, repeating the above steps on the second surface using the precursor solution, the binding strength enhancer and the alkaline solution to in-situ grow another electrode catalyst layer on the second surface to obtain a membrane electrode.

[0050] See also Figure 1 As shown, in one embodiment of the present invention, in step S11, the membrane layer 100 is, for example, a diaphragm, a cation exchange membrane, an anion exchange membrane, a proton exchange membrane, a porous membrane, or other membrane layer that can be used for hydrogen electrolysis. The membrane layer 100, for example, includes a first surface and a second surface that are arranged opposite to each other. Furthermore, the membrane layer 100 must be pretreated before use to remove impurities on the first surface and the second surface so that the membrane layer 100 can be closely attached to the subsequently formed electrode catalyst layer 200 and the electrode catalyst layer 300. In one embodiment of the present invention, the pretreatment includes, for example, placing the membrane layer 100 in a solvent at a preset temperature and soaking it for a preset time, then removing the membrane layer 100 and rinsing it with deionized water, and then placing it in an oven to dry. The solvent is, for example, at least one of hydrogen peroxide and sulfuric acid, the preset temperature is, for example, 50°C-90°C, and the preset time is, for example, 0.5h-5h.

[0051] See also Figure 1 As shown, in one embodiment of the present invention, after providing the film layer 100, before applying the precursor solution in step S12, the precursor solution is also subjected to a homogenization treatment to obtain a uniform precursor solution. The homogenization treatment method includes, for example, ultrasonic stirring treatment of the precursor solution, and the ultrasonic stirring time is, for example, 1 min-2 h. In this embodiment, the precursor solution includes, for example, a metal compound and a solution. The metal compound is, for example, selected from at least two of a transition metal compound, a rare earth metal compound and a precious metal compound. The transition metal compound includes, for example, metal compounds such as manganese, chromium, iron, cobalt, nickel, copper, zinc, molybdenum or tungsten. The rare earth metal compound includes, for example, lanthanide rare earth metal compounds. The precious metal compound includes, for example, platinum group precious metal compounds. In this embodiment, the metal compound is, for example, a metal salt or a metal halide. The metal salt is, for example, a metal sulfate, a metal nitrate or a metal chromate. The solvent includes, for example, at least one of an alcohol solvent such as ethanol, ethylene glycol, propanol and isopropanol.

[0052] See also Figure 1As shown in the embodiment of the present application, after the precursor solution is homogenized, the precursor solution is coated on the first surface in step S12. The precursor solution is coated on the first surface by any one of, for example, immersion or ultrasonic spraying. Specifically, when the immersion method is used, first, glue is coated on the second surface, and the second surface is dried to form a protective layer on the second surface, and then the film layer 100 with the protective layer is immersed in the precursor solution. The glue includes at least one of, for example, epoxy resin, acrylic modified epoxy resin, and perfluorosulfonic acid resin. The protective layer is formed on the second surface by coating glue, which can prevent the precursor solution from adhering to the second surface, so that the electrode catalyst layer 200 can be accurately formed on the first surface.

[0053] Referring to Figure 1 As shown in the embodiment of the present application, after the precursor solution is coated on the first surface, the binding strength enhancer is coated on the precursor solution in step S13. The binding strength enhancer is selected from at least one of, for example, potassium borohydride, sodium borohydride, glucose, methanol, diisobutylaluminum hydride, ascorbic acid, hydrazine, and sodium sulfite. The binding strength enhancer is coated on the precursor solution by any one of, for example, immersion or ultrasonic spraying. When the precursor solution is coated on the first surface by the immersion method in step S12, the binding strength enhancer can be added to the precursor solution, and the film layer 100 is continuously immersed in the precursor solution containing the binding strength enhancer.

[0054] Referring to Figure 1 As shown in the embodiment of the present application, after the binding strength enhancer is coated on the precursor solution, the film layer 100 with the binding strength enhancer and the precursor solution is immersed in an alkaline solution to grow in step S14. The pH of the alkaline solution is, for example, 8-14. The alkaline solution is selected from at least one of, for example, sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium carbonate, and potassium bicarbonate. The temperature of the alkaline solution is, for example, 30-90°C. The film layer 100 is immersed in the alkaline solution for, for example, 5-1200 minutes.

[0055] Referring to Figure 1 As shown in the embodiment of the present application, during the process that the film layer 100 is immersed in the alkaline solution in step S14, the precursor solution coated on the film layer 100 grows in situ on the first surface to form the electrode catalyst layer 200. Moreover, during the in-situ growth, the binding strength enhancer coated on the precursor solution can enhance the binding strength between the electrode catalyst layer 200 and the film layer 100, so that the electrode catalyst layer 200 and the film layer 100 can be closely attached, and the stability of the membrane electrode is improved.

[0056] Referring to Figure 1 As shown in the embodiment of the present application, after the step S14, i.e. after the soaking of the film layer 100 in the alkaline solution is completed, the film layer 100 is taken out from the alkaline solution and rinsed to remove the alkaline solution adhered on the first surface. The solvent for rinsing the film layer 100 includes at least one of deionized water and alcohol reagent, for example. Further, when the steps S12 and S13 adopt the soaking method to coat the precursor solution and the binding force enhancer on the first surface, the protective layer on the second surface is removed before rinsing the film layer 100.

[0057] Referring to Figure 1 As shown in the embodiment of the present application, after the film layer 100 is rinsed, in the step S15, the precursor solution, the binding force enhancer and the alkaline solution are used to repeat the steps S12-S14 on the second surface to in-situ grow the electrode catalyst layer 300 on the second surface. Specifically, the precursor solution is coated on the second surface, then the binding force enhancer is coated on the precursor solution, and the film layer 100 is placed in the alkaline solution for growth. After the growth is completed, the film layer 100 is taken out from the alkaline solution and rinsed. Compared with the forming process of the electrode catalyst layer 200, the difference of the forming process of the electrode catalyst layer 300 is that the transition metal compound in the precursor solution includes metal compounds such as manganese, chromium, iron, cobalt, nickel, copper or zinc, and the rest is the same, which is not described here.

[0058] Referring to Figure 1 As shown in the embodiment of the present application, after the electrode catalyst layer 300 is formed on the second surface and the film layer 100 is rinsed, the film layer 100 is dried to obtain a membrane electrode. The film layer 100 is dried in vacuum, for example, and the temperature for drying the film layer 100 in vacuum is 50-150°C, for example. In the preparation method provided by the present application, the precursor solution and the precursor solution are in-situ grown on the first surface and the second surface of the film layer 100 respectively in the alkaline solution to form the electrode catalyst layer 200 on the first surface of the film layer 100 and the electrode catalyst layer 300 on the second surface of the film layer 100. Moreover, in the in-situ growth process, the precursor solution and the binding force enhancer on the precursor solution can enhance the binding force between the electrode catalyst layer 200 and the first surface and the binding force between the electrode catalyst layer 300 and the second surface to improve the quality and stability of the membrane electrode. Moreover, the preparation method provided by the present application can simplify the preparation process of the membrane electrode, reduce the preparation period and cost, and is suitable for large-scale production of the membrane electrode.

[0059] Referring to Figure 1As shown, the present invention also provides a membrane electrode, which is obtained by the above-mentioned membrane electrode preparation method. The membrane electrode, for example, includes a membrane layer 100, an electrode catalyst layer 200, and an electrode catalyst layer 300. Among them, the membrane layer 100 includes a first surface and a second surface arranged opposite to each other, the electrode catalyst layer 200 is arranged on the first surface, and the electrode catalyst layer 300 is arranged on the second surface. In the membrane electrode provided by the present invention, in an alkaline solution, a precursor solution is in situ grown on the first surface or the second surface to form the electrode catalyst layer 200 or the electrode catalyst layer 300. Moreover, during the in situ growth process, the bonding agent can enhance the bonding force between the electrode catalyst layer 200 and the first surface, and the bonding force between the electrode catalyst layer 300 and the second surface, so that the membrane layer 100 and the electrode catalyst layer are tightly bonded, and the electrode catalyst layer and the membrane layer 100 are not easily peeled off, thereby improving the stability of the membrane electrode and the utilization rate of the catalyst in the electrode catalyst layer, and improving the efficiency of hydrogen production by water electrolysis.

[0060] See also Figures 1 to 2 As shown, in one embodiment of the present invention, a membrane electrode is obtained according to the preparation method of the membrane electrode, and the actual image of the membrane electrode is as shown in FIG. Figure 2 shown.

[0061] See also Figures 3 and 4 As shown, in one embodiment of the present invention, Figure 2 The membrane electrode is characterized, for example, by scanning electron microscopy to characterize the cross section of the membrane electrode and to magnify the area between the electrode catalyst layer 200 and the membrane layer 100. Figure 3 The magnification is 100 times, for example. Figure 4 The magnification is, for example, 400 times. Figure 3 and Figure 4 As can be seen, in the membrane electrode, the electrode catalyst layer 300 and the electrode catalyst layer 200 are located on either side of the membrane layer 100, respectively. Furthermore, a fusion region 201 is present between the electrode catalyst layer 200 and the membrane layer 100. In the fusion region 201, the electrode catalyst layer 200 grows on the membrane layer 100 and diffuses toward the membrane layer 100. At this point, a portion of the electrode catalyst layer 200 can be embedded or fused into the membrane layer 100, resulting in a tight bond between the membrane layer 100 and the electrode catalyst layer 200, with good bonding stability. In some embodiments, the depth of the electrode catalyst layer 200 embedded in the membrane layer 100 is, for example, 10 nm to 7 μm.

[0062] It is worth noting that, using the method of the present application, the electrode catalyst layer 200 can be directly grown on opposite sides of the membrane layer 100 to form the membrane electrode of the electrolyzer. However, this is not limiting. In some embodiments, using the method of the present application, the electrode catalyst layer 200 can be grown only on one side of the membrane layer 100, and the electrode catalyst can be formed on the diffusion layer on the other side of the membrane layer 100. That is, in the membrane electrode of the present application, the electrode catalyst layer 200 can be formed on one side or on opposite sides of the membrane layer 100. For example, in an AEM membrane electrode, the electrode catalyst layer 200 can be formed on one side of the membrane layer 100, and the other electrode catalyst layer 200 can be formed on the diffusion layer.

[0063] See also Figure 5 As shown, in one embodiment of the present invention, Figure 2 Specifically, the membrane electrode is loaded to a preset current density and the change in the membrane electrode voltage within 100 hours is measured. The preset current density is, for example, 2A / cm 2 .from Figure 5 It can be seen that within 0-70h, the voltage of the membrane electrode fluctuates stably around 1.94V and tends to 1.94V. Therefore, the stability of the membrane electrode is relatively good.

[0064] See also Figure 6 and Figure 7 As shown, in one embodiment of the present invention, on the anode side of the membrane layer 100, the electrode catalyst layer 300 may include a first metal catalyst layer 301 and a second metal catalyst layer 302. The first metal catalyst layer 301 is formed on the membrane layer 100 and may be partially infiltrated or embedded in the membrane layer 100. The second metal catalyst layer 302 is formed on the first metal catalyst layer 301. The first metal catalyst layer 301 and the second metal catalyst layer 302 may have different metal catalysts. For example, the first metal catalyst layer 301 may include a platinum metal catalyst, and the second metal catalyst layer 302 may include an iridium or iridium oxide metal catalyst. By using different metal catalysts, the use load of precious metal (such as iridium) catalysts can be reduced, thereby reducing costs.

[0065] In one embodiment, the thickness of the first metal catalyst layer 301 is, for example, 5 nm to 200 nm, and the thickness of the second metal catalyst layer 302 is, for example, 50 nm to 5 μm.

[0066] In one embodiment, the size of the nanoparticles of the metal catalyst in the first metal catalyst layer 301 is, for example, 1 nm to 15 nm, and the size of the nanoparticles of the metal catalyst in the second metal catalyst layer 302 is, for example, 10 nm to 200 nm.

[0067] See also Figure 8As shown, in another embodiment of the present invention, the membrane electrode provided by the present invention includes a membrane layer 100, an anode catalyst layer 11, and a cathode catalyst layer 12. The anode catalyst layer 11 and the cathode catalyst layer 12 are respectively formed on both sides of the membrane layer 100. The anode catalyst layer 11 includes a hydrogen consumption layer 111 and an anode catalyst base layer 112. The hydrogen consumption layer 111 is formed between the membrane layer 100 and the anode catalyst base layer 112. By providing the hydrogen consumption layer 111, hydrogen that penetrates from the cathode side to the anode can be promptly eliminated, thereby improving the purity of the gas and enhancing the safety of the water electrolysis hydrogen production device.

[0068] See also Figure 8 As shown, in one embodiment of the present invention, the membrane layer 100 is, for example, an N115 proton membrane, and the thickness of the membrane layer 100 is, for example, 110 μm to 130 μm, and the thickness of the N115 proton membrane is, for example, 127 μm, to meet the requirements of conduction, isolation and thermal stability.

[0069] See also Figure 8 As shown, in one embodiment of the present invention, the hydrogen-scavenging catalyst in the hydrogen-consuming layer 111 is selected from a highly active, acid-resistant, and stable material such as Pt, Ir, or Pd. The anode catalyst in the anode catalyst substrate 112 is selected from a catalyst for catalyzing oxygen reactions, and is further selected from at least one of Ir, IrO2, Pt, Pd, or Ru. The hydrogen-scavenging catalyst in the hydrogen-consuming layer 111 can convert hydrogen diffused from the cathode into hydrogen ions, and a portion of the oxygen generated on the anode side diffuses into the hydrogen-scavenging layer 111. The hydrogen-scavenging catalyst in the hydrogen-consuming layer 111 can also convert the oxygen diffused into the hydrogen-consuming layer 111 into oxygen ions, causing the hydrogen ions and oxygen ions to react to form water. Thus, the hydrogen and oxygen react to form 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. This can simultaneously improve the purity of hydrogen and oxygen generated by water electrolysis, thereby improving the safety of the water electrolysis device.

[0070] See also Figure 8 As shown, in one embodiment of the present invention, the cathode catalyst in the cathode catalyst layer 12 is, for example, a catalyst that catalyzes hydrogen reaction, and for example, at least one of Ir, IrO2, Pt / C, Pt, Pd or Ru is selected.

[0071] See also Figure 8In an embodiment of the present application, the thickness ratio of the membrane layer 100, the anode catalytic layer 11 and the cathode catalytic layer 12 is, for example, 1:0.1:0.1-1:10:10, and for example, 1:1.5:1.5, and the thickness ratio of the hydrogen consumption layer 111 and the anode catalytic base layer 112 is, for example, 1:1-1:10, and for example, 1:5. In an embodiment of the present application, the total thickness of the membrane electrode is, for example, 154 μm. The membrane electrode is in this thickness range, and the thickness of the different layers is matched, so that the efficiency of the membrane electrode in electrolyzing water can be improved.

[0072] Referring to Figure 8 In an embodiment of the present application, the porosity of the hydrogen consumption layer 111 is, for example, 1 m 2 / g, the porosity of the anode catalytic base layer 112 is, for example, 100-330 m 2 / g, and the porosity of the cathode catalytic layer 12 is, for example, 100-330 m 2 / g. In an embodiment of the present application, the porosity of the hydrogen consumption layer 111 is, for example, 130 m 2 / g, the porosity of the anode catalytic base layer 112 is, for example, 160 m 2 / g, and the porosity of the cathode catalytic layer 12 is, for example, 180 m 2 / g. The porosity of the anode catalytic layer 11 and the cathode catalytic layer 12 on both sides of the membrane layer 100 is large, which can increase the number of channels of the membrane electrode, provide abundant channels for mass transfer, and thus improve the electrolysis rate.

[0073] Referring to Figure 9 In an embodiment of the present application, a distribution diagram of the hydrogen consumption layer 111 on the membrane layer 100 is provided. In the electrolysis process, the hydrogen gas permeating through the membrane layer 100 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 catalytic layer. Therefore, on the anode side of the membrane layer 100, from the end of the membrane electrode far away from the water flow direction to the end close to the water flow direction, the hydrogen consumption layer 111 on the membrane layer 100 is increased, such as increasing the width, loading and density of the hydrogen consumption catalyst of the hydrogen consumption layer 111, and the like. Figure 9 In part a of FIG. 8, the hydrogen consumption layer 111 includes a plurality of arranged strip structures, and the width of the strip structure of the hydrogen consumption layer 111 is sequentially increased from the end far away from the water flow direction to the end close to the water flow direction. Figure 9 In part b of FIG. 8, the loading of the hydrogen consumption layer 111 is sequentially increased from the end far away from the water flow direction to the end close to the water flow direction, such as increasing the thickness of the hydrogen consumption layer 111. Figure 9In section c, the density of hydrogen-scavenging catalyst within hydrogen-consuming layer 111 increases gradually toward the water flow direction. By providing different amounts of hydrogen-scavenging layer 111 in different regions of membrane layer 100, the efficiency of hydrogen removal on the anode side can be improved while reducing the amount of hydrogen-scavenging catalyst used and lowering costs.

[0074] See also Figure 10 and Figure 11 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 100 is provided. The electrolyzer includes a membrane electrode 10 and a diode 20, and the diode 20 is located on the outside of the anode catalyst layer and the cathode catalyst layer of the membrane electrode, respectively. During the electrolysis process, since the position of the cathode flow field ridge 2011 of the diode 20 on the cathode catalyst layer side is compressed with the membrane layer 100 at the contact position of the membrane layer 100, it is not conducive to hydrogen permeation, the hydrogen content is low, the membrane layer 100 at the flow channel 2022 position swells, and there are more microporous channels, which is conducive to hydrogen permeation. In some embodiments, the hydrogen consumption layer 111 can be provided with a bending structure (such as Figure 11 As shown, the curved structure of the hydrogen consumption layer 111 can be consistent with the flow field distribution of the electrode plate outside the cathode catalyst layer. It can consume the hydrogen diffused from the flow channel 2022, improve the removal efficiency of hydrogen on the anode side, and enhance the safety of electrolysis.

[0075] In one embodiment of the present invention, the present invention further provides a method for preparing a membrane electrode, comprising steps S11 - S12 .

[0076] Step S11: forming an anode catalyst layer on one side of the membrane layer. The anode catalyst layer includes a hydrogen consumption layer and an anode catalyst base layer. The hydrogen consumption layer is formed between the membrane layer and the anode catalyst base layer.

[0077] Step S12: forming a cathode catalyst layer on the other side of the membrane layer.

[0078] In one embodiment of the present invention, the electrode catalyst layer (anode catalyst layer and / or cathode catalyst layer) can be formed by transfer, for example. During the transfer, the anode catalyst layer and the cathode catalyst layer can be transferred simultaneously or in steps. The hydrogen consumption layer and the anode catalyst base layer in the anode catalyst layer are transferred simultaneously or in steps. When the transfer is performed synchronously, the anode catalyst base layer is formed on the transfer film. After the hydrogen consumption layer is formed on the anode catalyst base layer, it is transferred to the membrane layer. When the transfer is performed in steps, the hydrogen consumption layer is first transferred to the membrane layer, and then the anode catalyst base layer is transferred to the anode catalyst base layer. In this embodiment, for example, a non-vacuum hot pressing transfer method is used for transfer.

[0079] See also Figure 12The 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 comprises an anode catalyst and a resin, etc., the anode catalyst comprises a carrier and a component comprising an active metal element substance supported on the carrier, and the mass ratio of the anode catalyst and the resin is, for example, 1:0.1-1:3. The anode catalytic slurry layer is formed, for example, by means of scraping, roller coating or spraying, etc. The hydrogen consumption slurry layer comprises a hydrogen consumption catalyst and a resin, etc., the hydrogen consumption catalyst comprises a carrier and a component comprising an active metal element substance supported on the carrier, and the mass ratio of the hydrogen consumption catalyst and the resin is, for example, 1:0.5-1:3. The hydrogen consumption slurry layer is formed, for example, by means of scraping, roller coating or spraying, etc.

[0080] Please refer to Figure 12 The cathode catalytic slurry layer is formed on the transfer film to form a second transfer film 16. The cathode catalytic slurry layer comprises a cathode catalyst and a resin, etc., the cathode catalyst comprises a carrier and a component comprising an active metal element substance supported on the carrier, and the mass ratio of the cathode catalyst and the resin is, for example, 1:0.7-1:2. The cathode catalytic slurry layer is formed, for example, by means of scraping, roller coating or spraying, etc.

[0081] 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 perfluororesin solution (D2020) and the like.

[0082] Please refer to Figure 12 In an embodiment of the present application, when the film electrode is formed by the transfer assembly, the film layer 100 is placed in the middle position to ensure that the film layer 100 is flat and has no folding. The transfer plates are arranged on both sides of the film layer 100, for example, comprising a first transfer plate 131 and a second transfer plate 132, the first transfer plate 131 and the second transfer plate 132 are the same in size, and the openings with the same size are arranged at the centers of the first transfer plate 131 and the second transfer plate 132 to determine the transfer area, so as to ensure that the sizes of the catalytic layer areas on both sides of the film layer 100 after transfer are the same, and the catalytic layer areas are aligned. The air or water vapor generated by heating in the transfer process 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 the larger film electrode.

[0083] Please refer to Figure 12Said, in an embodiment of the utility model, the diagonal position of first transfer form 131 and second transfer form 132 is provided with positioning hole 141, and the position of positioning hole 141 on first transfer form 131 and second transfer form 132 is same. When transferring, film layer 100 is placed in the middle of first transfer form 131 and second transfer form 132, and positioning member 14 is placed in diagonal positioning hole 141, and positioning member 14 is for example fluorine rubber etc., to fix and position the film layer of membrane electrode, so that subsequent transfer process is convenient.

[0084] Please refer to Figure 12 Said, in an embodiment of the utility model, first transfer film 15 is set on the side of first transfer form 131 away from film layer 100, and the slurry layer on first transfer film 15 is opposite to film layer 100. Second transfer film 16 is set on the side of second transfer form 132 away from film layer 100, and the slurry layer on second transfer film 16 is opposite to film layer 100. Positioning member 14 defines the position of first transfer film 15 and second transfer film 16, and the slurry layer on transfer film is transferred to film layer by simultaneously applying pressure on the side of first transfer film 15 away from film layer 100 and the side of second transfer film 16 away from film layer 100 under the condition of temperature for example 130 DEG C ~ 180 DEG C, pressure for example 0.5MPa ~ 4MPa and hot-pressing time for example 10s ~ 600s, and then removing transfer film, to form anode catalyst layer and cathode catalyst layer. By setting transfer form and positioning member, air in the gap of sheet middle area can be removed when forming, or water vapor generated by heating is removed, to avoid large-area bubble defects in catalyst area after transfer, improve the quality of membrane electrode, and ensure the uniformity and stability of anode catalyst layer and cathode catalyst layer on both sides of film layer, to prolong the service life of electrolytic water device.

[0085] As Figures 13 to 15 Indicated, by the manufacturing method of the membrane electrode of the application, compared with the traditional electrode catalyst layer (such as Figure 14 ), the electrode catalyst layer (such as Figure 13 ) with good surface uniformity can be obtained. In some embodiments, the surface roughness Ra of the electrode catalyst layer (anode catalyst layer and / or cathode catalyst layer) of the application can be less than or equal to 0.15 μm, for example 0.08 μm ~ 0.15. Furthermore, as Figure 15 Indicated, by the manufacturing method of the membrane electrode of the application (such as Figure 15 a), compared with the traditional electrode catalyst layer (such as Figure 15 b and c), after different adhesion force (for example 1N / cm 2 and 4N / cm 2 ) test, the membrane electrode (such as Figure 15The catalyst layer in a) will not peel off and has good stability. The bonding force between the electrode catalyst layer and the membrane layer can be greater than 0.8N / cm 2 , for example, 1 to 10 N / cm 2 .

[0086] It is worth noting that in the present application, the electrode catalyst layer of the membrane electrode can be formed on the membrane layer by in-situ growth or transfer methods, and the hydrogen consumption layer of the anode catalyst layer can also be formed on the membrane layer by in-situ growth or transfer methods. In one embodiment, a portion of the hydrogen consumption layer of the anode catalyst layer can be embedded or fused into the membrane layer.

[0087] See also Figure 8 and Figure 12 As mentioned above, in one embodiment of the present invention, 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 hot and cold cycle pore-forming method is used for pore-forming treatment. 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, kept warm for 12 hours, and then slowly heated 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, 80KPa, the cooling rate is, for example, 0.5°C / min to 3°C / min, and the heating rate is, for example, 0.5°C / min to 3°C / min. The pore-forming treatment method improved in this application is simple and easy 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 one embodiment, the pore size of the catalyst pore is, for example, 1μm to 200μm.

[0088] The present invention also provides a water electrolysis device, such as a proton exchange membrane water electrolysis hydrogen production device, comprising the membrane electrode described above. When applied to the hydrogen production device, the membrane electrode can react with hydrogen and oxygen on the anode side to produce water, thereby achieving the purpose of eliminating hydrogen on the anode side, thereby increasing the purity of oxygen on the anode side and improving the safety of the water electrolysis device. At the same time, the quality of the membrane electrode is improved, ensuring the uniformity and stability of the catalytic reaction, and extending the service life of the water electrolysis device. It can also increase the electrolysis rate and improve the electrolysis efficiency, which is conducive to promoting the development of water electrolysis hydrogen production technology.

[0089] In some embodiments, the electrode catalyst layer may include nanoparticles, nanowires, nanochains, or other nanostructures.

[0090] In some embodiments, when the electrode catalyst layer 200 or 300 is formed on the diffusion layer, an electrode sheet can be formed. In this case, the coverage of the electrode catalyst layer on one side of the diffusion layer can be greater than or equal to 70%, for example. Figure 16In this way, the high coverage of the electrode catalyst layer on the diffusion layer can improve the catalyst performance of the electrode. In one embodiment, the coverage of the electrode catalyst layer on one surface of the diffusion layer can be, for example, 75% to 99%. In one embodiment, the electrode catalyst layer can be formed on two opposing surfaces of the diffusion layer, and the coverage of the electrode catalyst layer on one surface of the diffusion layer can be, for example, greater than or equal to 70%, for example, 75% to 99%.

[0091] It is worth noting that the membrane electrode of the present application can be used in suitable electrolyzers, such as proton exchange membrane (PEM) electrolyzers, anion exchange membrane (AEM) electrolyzers, alkaline solution electrolyzers, solid oxide electrolytic cell (SOEC) or other electrolyzers.

[0092] In summary, the present invention provides a membrane electrode and a hydrogen production electrolyzer, wherein an electrode catalyst layer and an electrode catalyst layer are respectively arranged on the first surface and the second surface of the membrane layer, which can enhance the bonding force between the electrode catalyst layer and the first surface, as well as the bonding force between the electrode catalyst layer and the second surface, so that the membrane layer and the electrode catalyst layer are tightly bonded, and the electrode catalyst layer and the membrane layer are not easily peeled off, thereby improving the stability of the membrane electrode, improving the utilization rate of the catalyst in the electrode catalyst layer, and improving the efficiency of water electrolysis to produce hydrogen. It can simultaneously improve the purity of hydrogen and oxygen produced by electrolysis of water and improve the safety of the water electrolysis device. It can increase the number of micropores in the membrane electrode, provide abundant pores for mass transfer, increase the porosity of the catalyst, increase the electrolysis rate, and improve the electrolysis efficiency. It can improve the quality of the membrane electrode. At the same time, the anode catalyst layer and the cathode catalyst layer are aligned on both sides of the membrane layer to ensure the uniformity and stability of the catalysis and extend the service life of the water electrolysis device.

[0093] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed in the present invention are intended to be covered by the claims of the present invention.

Claims

1. A membrane electrode, characterized in that include: membrane layer; an electrode catalyst layer formed on one side of the membrane layer, wherein a fusion region is provided between the electrode catalyst layer and the membrane layer; In the fusion region, a portion of the electrode catalyst layer is embedded in or fused into the membrane layer.

2. The membrane electrode according to claim 1, characterized in that The invention also includes another electrode catalyst layer formed on the other side of the membrane layer, and a portion of the another electrode catalyst layer is embedded in or integrated into the membrane layer.

3. The membrane electrode according to claim 1, characterized in that The invention also includes another electrode catalyst layer formed on the diffusion layer on the other side of the membrane layer.

4. The membrane electrode according to claim 1, characterized in that The electrode catalyst layer is embedded in the membrane layer to a depth of 10 nm to 7 μm.

5. The membrane electrode according to claim 1, characterized in that The electrode catalyst layer is an anode catalyst layer, which includes a hydrogen consumption layer and an anode catalyst base layer. The hydrogen consumption layer is formed between the membrane layer and the anode catalyst base layer.

6. The membrane electrode according to claim 5, characterized in that Part of the hydrogen consumption layer of the anode catalyst layer is embedded or fused into the membrane layer.

7. The membrane electrode according to claim 5, characterized in that The electrode catalyst layer includes a cathode catalyst layer, which is arranged on a side of the membrane layer opposite to the anode catalyst layer. The thickness ratio of the membrane layer, the anode catalyst layer and the cathode catalyst layer is 1:0.1:0.1 to 1:10:

10.

8. The membrane electrode according to claim 5, characterized in that The thickness ratio of the hydrogen consumption layer to the anode catalyst substrate is 1:1 to 1:

10.

9. The membrane electrode according to claim 7, characterized in that The porosity of the hydrogen consumption layer is 100 to 330 m 2 / g; And / or, the porosity of the anode catalyst substrate is 100 to 330 m 2 / g; And / or, the porosity of the cathode catalyst layer is 100 to 330 m 2 / g.

10. A hydrogen production electrolyzer, characterized in that: Comprising the membrane electrode according to claim 1.

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