Membrane electrode for hydrogen production by electrolysis of water using an anion exchange membrane and a method for producing the same

Abstract

The application relates to the technical field of hydrogen production devices for electrolysis of water, in particular to a membrane electrode for hydrogen production by water electrolysis through anion exchange membranes and a preparation method thereof. The membrane electrode comprises an anion exchange membrane with two sides, a cathode catalytic layer is arranged on the first side of the anion exchange membrane; and / or an anode catalytic layer is arranged on the second side of the anion exchange membrane; the cathode catalytic layer and the anode catalytic layer are respectively solid-state catalytic layers formed by coating and solidifying cathode catalyst slurry and anode catalyst slurry on the two sides of the anion exchange membrane; the cathode catalyst slurry and the anode catalyst slurry are designed with specific formulations. The membrane electrode has the advantages of low impedance, high catalytic activity, low or no swelling rate, firm combination of the catalytic layer and the anion exchange membrane, simple preparation process flow and the like, and when the membrane electrode is applied to an AEM electrolysis tank, the volume of the electrolysis tank stack will not be expanded, the sealing performance will not be poor, the catalytic layer will not be peeled off and the like during the process of assembling the electrolysis tank stack, and the efficiency of hydrogen production by water electrolysis can be obviously improved.

Description

Technical Field

[0001] This application relates to the technical field of water electrolysis hydrogen production devices, and in particular to a membrane electrode for anion exchange membrane water electrolysis hydrogen production and its preparation method. Background Technology

[0002] After decades of development, several feasible water electrolysis hydrogen production technologies have emerged, mainly including alkaline water electrolysis (ALK), proton exchange membrane (PEM) water electrolysis, anion exchange membrane (AEM) water electrolysis, and solid oxide electrolysis (SOEC). Among these, AEM water electrolysis combines the advantages of low cost of ALK and high efficiency and convenience of PEM water electrolysis, making it the latest and most advanced water electrolysis hydrogen production technology.

[0003] An AEM electrolyzer, a device that converts electrical energy into chemical energy, is the core component of an AEM water electrolysis hydrogen production system. An AEM electrolyzer mainly consists of end plates, bipolar plates, a gas diffusion layer, an AEM, and a membrane electrode assembly. Among these, the membrane electrode assembly is the most important reaction site in the entire water electrolysis hydrogen production device, and it comprises an anode catalyst, a cathode catalyst, and an AEM.

[0004] The fabrication of membrane electrodes mainly includes the catalyst-coated diffusion layer (CCS) method and the catalyst-coated membrane (CCM) method. The difference between the two lies in the location of the catalyst layer; the former involves adhering the catalyst slurry to the surface of the gas diffusion layer, while the latter involves attaching the catalyst slurry to the ion exchange membrane. Due to the swelling problem of AEM membranes, there are few reports on the use of the CCM method to fabricate membrane electrodes on AEM membranes; the CCM method is generally used on proton exchange membranes.

[0005] The CCS method involves directly spraying or coating the active catalyst component onto a diffusion layer. On one hand, the catalyst layer is exposed, making it prone to detachment as hydrogen production from water electrolysis progresses. Furthermore, catalyst particles in the layer gradually agglomerate, reducing the effective active area and catalytic capacity. On the other hand, the delamination between the catalyst layer and the anion exchange membrane results in high impedance at the membrane electrode, impacting hydrogen production efficiency. While the spraying process offers relatively simple parameter control, low equipment cost, and the ability to handle a wide range of slurry viscosities, its drawbacks include significant material waste, low production capacity, and inability to meet the demands of large-scale applications.

[0006] The CCM method results in a smaller contact distance between the catalyst layer and the anion exchange membrane, eliminating the contact gap between them and reducing ion conduction resistance. However, the preparation process is generally complex and can easily cause swelling of the anion exchange membrane, thereby damaging the morphology and structure of the prepared catalyst layer, leading to cracks, peeling, or even complete detachment. This can result in drawbacks such as volume expansion, poor sealing, and unsatisfactory electrochemical performance during the assembly of the electrolyzer stack. Summary of the Invention

[0007] To address the shortcomings of the prior art mentioned in the background section, this application provides a membrane electrode for hydrogen production via anion exchange membrane electrolysis of water. This electrode possesses advantages such as low impedance, high catalytic activity, low or no swelling ratio, strong bonding between the catalyst layer and the anion exchange membrane, and a simple preparation process. When used in an AEM electrolyzer, it can significantly improve the efficiency of hydrogen production via water electrolysis. The specific technical solution is as follows: This application provides a membrane electrode for hydrogen production via anion exchange membrane electrolysis of water, comprising anion exchange membranes having two sides; a cathode catalyst layer is provided on the first side of the anion exchange membrane; and / or, an anode catalyst layer is provided on the second side of the anion exchange membrane; wherein, the cathode catalyst layer is a solid catalyst layer formed by coating a cathode catalyst slurry onto the first side of the anion exchange membrane and curing it; the anode catalyst layer is a solid catalyst layer formed by coating an anode catalyst slurry onto the second side of the anion exchange membrane and curing it; by mass fraction, the cathode catalyst slurry comprises: 15%–20% cathode catalyst, 35%–40% water, 35%–40% alcohol organic solvent, and 5%–10% ionomer solution; by mass fraction, the anode catalyst slurry comprises: 15%–20% anode catalyst, 35%–40% water, 35%–40% alcohol organic solvent, and 5%–10% ionomer solution.

[0008] In some embodiments, the cathode catalyst slurry is composed of a cathode catalyst, water, an alcohol-based organic solvent, and an ionomer solution, and is obtained by stirring and mixing the cathode catalyst, water, alcohol-based organic solvent, and ionomer solution for 3 to 5 hours; the anode catalyst slurry is composed of an anode catalyst, water, an alcohol-based organic solvent, and an ionomer solution, and is obtained by stirring and mixing the anode catalyst, water, alcohol-based organic solvent, and ionomer solution for 3 to 5 hours.

[0009] In some embodiments, during the coating of the cathode catalyst slurry and the anode catalyst slurry, the coating temperature is controlled by a gradient of 40°C to 100°C, and the coating speed is 0.2 to 0.5 m / min. The process of controlling the coating temperature by a gradient of 40°C to 100°C is as follows: the coating temperature is first raised from room temperature to 40 to 50°C, and after coating is completed, the temperature is further raised to 60°C and held for 15 minutes, then raised to 80 to 100°C and held for 80 to 100°C until the formed cathode catalyst layer or anode catalyst layer is completely dry, and then heating is stopped.

[0010] In some embodiments, the ionomer in the ionomer solution is a polydiphenylene alkylene polymer ionomer, so as to form a robust electrode structure for the cathode catalyst layer or the anode catalyst layer; the support for the cathode catalyst is a porous carbon nanomaterial; and the alcohol organic solvent is isopropanol.

[0011] In some embodiments, the thickness of the anion exchange membrane is 20–160 μm.

[0012] In some embodiments, the thickness of both the cathode catalyst layer and the anode catalyst layer is 0.1–20 μm.

[0013] In some embodiments, the total thickness of the membrane electrode is 0.02 to 0.2 mm.

[0014] This application also provides a method for preparing a membrane electrode for hydrogen production via anion exchange membrane electrolysis of water, which includes the following steps: Cut the anion exchange membrane to the required specifications and dimensions; A cathode catalyst slurry and an anode catalyst slurry are coated on two opposite sides of the anion exchange membrane, respectively, and then dried and cured to form a cathode catalyst layer and an anode catalyst layer on the two sides of the anion exchange membrane, respectively. The cathode catalyst slurry comprises, by mass fraction, 15%–20% cathode catalyst, 35%–40% water, 35%–40% alcohol organic solvent, and 5%–10% ionomer solution; the anode catalyst slurry comprises, by mass fraction, 15%–20% anode catalyst, 35%–40% water, 35%–40% alcohol organic solvent, and 5%–10% ionomer solution.

[0015] In some embodiments, during the coating of the cathode catalyst slurry and the anode catalyst slurry, a gradient-controlled coating temperature of 40°C to 100°C is used, and the coating speed is 0.2 to 0.5 m / min. The gradient-controlled coating temperature of 40°C to 100°C is as follows: the coating temperature is first raised from room temperature to 40 to 50°C, and after coating is completed, the temperature is further raised to 60°C and held for 15 minutes, then raised to 80 to 100°C and held for 80 to 100°C until the formed cathode catalyst layer or anode catalyst layer is completely dry, and then heating is stopped.

[0016] In some embodiments, the preparation method includes the following steps: The anion exchange membrane is cut to the required size and then placed flat on the substrate; wherein the anion exchange membrane is sealed with tape around its perimeter and vacuum adsorption is maintained to ensure that the anion exchange membrane is flat. Cathode catalyst slurry and anode catalyst slurry are coated on two opposite sides of the anion exchange membrane, respectively, and dried and cured to form cathode catalyst layer and anode catalyst layer. Then the tape around the anion exchange membrane is removed, and the membrane is packaged and stored.

[0017] Based on the above, compared with the prior art, the solution of this application has the following beneficial effects: The membrane electrode for hydrogen production via anion exchange membrane electrolysis provided in this application has advantages such as low impedance, high catalytic activity, low or no swelling rate, strong bonding between the catalyst layer and the anion exchange membrane, and a simple preparation process. When applied in an AEM electrolyzer, it avoids defects such as volume expansion and poor sealing of the electrolyzer stack during assembly, and significantly improves the efficiency of hydrogen production via water electrolysis.

[0018] Other features and beneficial effects of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other beneficial effects of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] Figure 1 This is a microscopic image of the surface of the membrane electrode prepared in Example 1 of this application; Figure 2 This is a cross-sectional scanning electron microscope image of the membrane electrode prepared in Example 1 of this application; Figure 3 This is a scanning electron microscope image of the surface of the membrane electrode prepared in Example 1 of this application; Figure 4 The impedance spectrum (EIS) of the membrane electrode prepared in Example 1 of this application is shown. Figure 5 The polarization curve of the membrane electrode prepared in Example 1 of this application is shown. Figure 6 This is a physical image of the membrane electrode product prepared according to Example 1 of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The technical features designed in the different implementations of this application described below can be combined with each other as long as they do not conflict with each other. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0022] In the description of this application, it should be noted that all terms used in this application (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains, and should not be construed as limiting this application; it should be further understood that the terms used in this application should be understood to have the same meaning as those in the context of this specification and the relevant field, and should not be understood in an idealized or overly formal sense, except as expressly defined in this application.

[0023] An example of the preparation method of the membrane electrode for hydrogen production by anion exchange membrane electrolysis of water provided in this application is as follows: The preparation process of the membrane electrode for hydrogen production via anion exchange membrane electrolysis of water provided in this application includes the following steps: Step 1: Cut the anion exchange membrane to the required size and place it flat on the substrate. Seal the edges of the anion exchange membrane with tape and maintain vacuum adsorption to ensure the membrane is flat. This ensures the flatness of the anion exchange membrane and prevents micropores from forming due to vacuum extraction.

[0024] The surface smoothness of the anion exchange membrane affects the adhesion of the coating and the final membrane electrode smoothness. Therefore, maintaining the smoothness of the anion exchange membrane during this process is beneficial to improving the quality of the membrane electrode.

[0025] Step 2: Coat the cathode catalyst slurry and the anode catalyst slurry on two opposite sides of the anion exchange membrane, respectively, dry and cure to form the cathode catalyst layer and the anode catalyst layer, then remove the tape around the anion exchange membrane and package and store it.

[0026] The membrane electrode prepared by the above method has the following structure: it includes an anion exchange membrane with two sides; the first side and the second side of the anion exchange membrane are respectively provided with an anode catalyst layer and a cathode catalyst layer.

[0027] It should be noted that, depending on the process requirements, only a single-sided film electrode can be coated, that is, only the anode catalytic layer or the cathode catalytic layer can be coated.

[0028] Regarding the slurry formulation and process parameter settings in the preparation process of this membrane electrode: (1) The slurry formula is as follows: Cathode catalyst slurry: The cathode catalyst slurry is composed of cathode catalyst, water, alcohol organic solvent, and ionomer solution. By mass fraction, the cathode catalyst slurry consists of: 15%–20% cathode catalyst, 35%–40% water, 35%–40% alcohol organic solvent, and 5%–10% ionomer solution. The cathode catalyst slurry is obtained by stirring and mixing the cathode catalyst, water, alcohol organic solvent, and ionomer solution for 3–5 hours.

[0029] Anode catalyst slurry: The anode catalyst slurry consists of anode catalyst, water, alcohol-based organic solvent, and ionomer solution. By mass fraction, the components of the anode catalyst slurry include: 15%–20% anode catalyst, 35%–40% water, 35%–40% alcohol-based organic solvent, and 5%–10% ionomer solution. This anode catalyst slurry is obtained by stirring and mixing the anode catalyst, water, alcohol-based organic solvent, and ionomer solution for 3–5 hours.

[0030] Alternatively, the ionomer in the ionomer solution may be a polydiphenylene alkylene polymer ionomer, the cathode catalyst may be supported by porous carbon nanomaterials, and the alcohol organic solvent may be isopropanol.

[0031] (2) Coating process control is as follows: During the coating process of the cathode catalyst slurry and the anode catalyst slurry, a gradient temperature control method of 40℃~100℃ is adopted for coating, and the coating speed is 0.2~0.5m / min. Specifically, the coating temperature gradient control process of 40℃~100℃ is as follows: the coating temperature is first raised from room temperature to 40~50℃, after coating is completed, the temperature is further raised to 60℃ and held for 15 minutes, then raised to 80~100℃ and held at 80~100℃ until the formed cathode catalyst layer or anode catalyst layer is completely dry, and then heating is stopped.

[0032] This application employs the preparation process described above, and controls the slurry to be formulated with the specific formulation and coating process parameters described above to achieve the desired effect. Its design concept and working principle are as follows: The direct coating technology used in this application involves directly coating the catalyst slurry onto the ion exchange membrane. Since the membrane is prone to swelling when exposed to solvents, the parameters and formulation control of the direct coating process are crucial.

[0033] In the slurry, ionomers primarily function as ion conductors and also act as catalyst binders. Therefore, the proportion of ionomers in the catalyst layer needs to be controlled within a reasonable range. Maintaining the ionomer content within a specific mass ratio in the slurry is crucial to achieving the desired effect. If the ionomer content is too low (below the range defined in this application), the number of three-phase interfaces will be insufficient, preventing ions from fully contacting the catalyst and thus hindering its effective function. However, if the ionomer content is excessive (above the range defined in this application), the porosity of the catalyst layer will decrease, leading to blockage of gas channels in the catalyst layer. This hinders gas transport and water removal, increases concentration polarization, and affects electrolysis efficiency.

[0034] The catalyst support is a porous carbon nanomaterial. Due to its high specific surface area, this porous carbon nanomaterial is prone to agglomeration during the slurry mixing and dispersion process. The slurry, being a non-Newtonian fluid, is dispersed in the solvent as small solid particles. These particles exhibit both adsorption and repulsion. When the adsorption force exceeds the repulsion force, attraction occurs between the particles, leading to agglomeration and affecting subsequent coating operations. Therefore, improper slurry formulation design can cause sedimentation during storage. Controlling the mass ratio of catalysts and other solid substances within a certain range (i.e., limiting the solid content of the slurry to a specific range; this paper uses solid content to characterize the slurry's stability) ensures sufficient catalyst content to maximize its effectiveness while preventing excessive addition of catalysts and other solid substances that could cause agglomeration, resulting in poor slurry dispersibility and affecting subsequent coating operations.

[0035] Furthermore, to achieve crack-free or low-crack coating in the preparation process, the catalyst slurry needs to be designed using an organic alcohol system. However, during direct coating, the anion exchange membrane absorbs alcohols more readily than water, and using only alcohol-based slurries will result in a membrane with severe swelling. Therefore, this application addresses this phenomenon by adding a specific amount of water to control the water-alcohol solvent system within a certain ratio range. Based on this specific water-alcohol system ratio, the coating temperature is controlled in a gradient range of 40℃ to 100℃. In this way, by combining the specific water-alcohol system ratio and the coating temperature process, the severe membrane swelling caused by using only alcohol-based slurries can be avoided. During the curing process, the solvent system and the specific coating temperature range process parameters allow the solvent to evaporate and dry quickly and fully, achieving crack-free or low-crack coating. The reason for controlling the coating temperature within the above range and using the above gradient heating control is that appropriate heating can prevent swelling and wrinkling of the ion exchange membrane. Because alcohols are highly volatile, a coating temperature of 40°C can be used for application, or even without heating, for cost reasons. However, for time efficiency, a coating temperature of 80-100°C can be used to accelerate solvent evaporation. Gradient control of the coating temperature helps improve the quality of the resulting catalyst layer.

[0036] Furthermore, since the coating speed directly affects the thickness and uniformity of the coating, this application also designs and adapts a specific range of coating speed process parameters based on a specific slurry formulation. During the fabrication of the membrane electrode, the coating speed is controlled at 0.2–0.5 m / min according to the specific slurry formulation. Using excessively high or low coating speeds will lead to a decrease in coating quality. Moreover, in this application's solution, the coating speed and blade height can be flexibly adjusted to obtain the desired catalyst layer thickness.

[0037] In summary, this application utilizes a catalyst-coated membrane (CCM) method, which reduces the contact distance between the CCM catalyst layer and the anion exchange membrane, eliminating contact gaps and lowering ion conduction resistance. It is evident that in this application, because the cathode and anode catalyst layers are directly connected to the anion exchange membrane, the membrane electrode impedance is low, which is beneficial for improving the efficiency of hydrogen production through water electrolysis. Furthermore, the preparation process is simple to operate. Through slurry formulation design and process parameter matching, swelling of the ion exchange membrane is prevented during preparation, thus avoiding damage to the morphology and structure of the prepared catalyst layer. The catalyst layer will not crack or detach, preventing defects such as volume expansion and poor sealing of the electrolyzer stack during assembly.

[0038] Based on the above examples, the following design is preferred for the slurry formulation and layer dimensions of the above membrane electrode: (1) The thickness of the anion exchange membrane is 20–160 μm; The preparation method provided in this application can be used for anion exchange membranes of all thicknesses, but it is preferred to set the thickness of the anion exchange membrane to 20–160 μm. This design allows the anion exchange membrane to effectively conduct OH- anions. - This also prevents the anion exchange membrane from rupturing during the electrolysis of water to produce hydrogen.

[0039] When the thickness of the anion exchange membrane is less than 20 μm, for example, 10 μm, the anion exchange membrane is too thin. During the AEM water electrolysis hydrogen production process, a locally strongly alkaline environment will form on the surface of the anion exchange membrane, which will affect the OH... - Under the influence of certain substances, the membrane is easily degraded, causing it to perforate and rupture, leading to a short circuit in the AEM electrolyzer, affecting the operation of hydrogen production through water electrolysis and the lifespan of the AEM electrolyzer. When the thickness of the anion exchange membrane is greater than 160 μm, for example, when the thickness of the anion exchange membrane is 170 μm, the excessive thickness of the anion exchange membrane can cause OH... - The slow conduction reduces the efficiency of AEM water electrolysis for hydrogen production.

[0040] (2) The thickness of both the cathode catalyst layer and the anode catalyst layer is 0.1 to 20 μm.

[0041] Depending on the application scenario, the thickness of the cathode catalyst layer and the anode catalyst layer can be adjusted adaptively, with a preferred thickness of 0.1–20 μm. This design ensures good catalytic performance without affecting OH. - Conduction.

[0042] When the thickness of the catalyst layer is less than 0.1 μm, for example, when the thickness of the cathode catalyst layer is 0.05 μm, the catalytic activity is low due to the thinness of the cathode catalyst layer, affecting the amount of hydrogen evolved at the cathode and thus the water electrolysis efficiency. When the thickness of the catalyst layer is greater than 20 μm, for example, when the thickness of the cathode catalyst layer is 25 μm, the excessive thickness of the cathode catalyst layer is unfavorable for the formation of OH-. - Conduction, causing OH - Reduced and slowed conduction from the cathode to the anode ultimately affects the efficiency of AEM water electrolysis.

[0043] (4) The total thickness of the membrane electrode is 0.02 to 0.2 mm.

[0044] Depending on the application scenario, the thickness of the membrane electrode can be adjusted adaptively, and the total thickness of the membrane electrode is preferably 0.02–0.2 mm. Using the above-mentioned preferred range for the total thickness of the membrane electrode ensures the strength of the membrane electrode while reducing its impedance, thereby improving the service life of the electrolyzer and the efficiency of hydrogen production from water electrolysis.

[0045] It should be noted that: The theoretical formula for calculating solid content is: Solid content = solid mass / (solid mass + solvent mass); In practice, the raw material ratio of the slurry can be adjusted adaptively within the above formula ratio range. Depending on the type of catalyst, the alcohol-to-water ratio and solid content in the slurry can be adjusted appropriately to make the total amount 100% by mass, including but not limited to the specific formula scheme provided in Example 1 below. This application uses direct coating technology to directly coat the catalyst slurry onto the ion exchange membrane. The specific workflow and working principle of the direct coating technology are existing technologies and will not be described in detail here.

[0046] To verify the effectiveness of the proposed solution, the following embodiments and comparative examples are also provided: Example 1 The fabrication process of this membrane electrode includes the following steps: Step 1: Cut the anion exchange membrane to the required size and place it flat on the substrate. Seal the anion exchange membrane with tape around its perimeter and maintain vacuum adsorption to ensure the membrane is flat. Step 2: Coat the cathode catalyst slurry and the anode catalyst slurry on two opposite sides of the anion exchange membrane, respectively, dry and cure to form the cathode catalyst layer and the anode catalyst layer, then remove the tape around the anion exchange membrane and package and store it.

[0047] The coating speed is 0.35 m / min, and the gradient control process of the coating temperature is as follows: the coating temperature is first raised from room temperature to 40°C, and after coating is completed, the temperature is raised to 60°C and kept constant for 15 min, then raised to 80°C and kept constant at 80°C until the formed cathode catalyst layer or anode catalyst layer is completely dry, then heating is stopped and the material is allowed to cool naturally.

[0048] Specifically, the coating temperature refers to the temperature at which the anion exchange membrane is placed on the substrate and heated to a set temperature.

[0049] The cathode catalyst slurry, by mass fraction, consists of 15% cathode catalyst, 40% deionized water, 35% alcohol-based organic solvent, and 10% ionomer solution. The anode catalyst slurry consists of 20% anode catalyst, 35% deionized water, 40% alcohol-based organic solvent, and 5% ionomer solution. The ionomer in the ionomer solution is a polydiphenylene alkylene polymer ionomer. The cathode catalyst support is porous carbon nanomaterials, specifically Pt / C; the anode catalyst is RuO2; and isopropanol is used as the alcohol-based organic solvent.

[0050] The membrane electrode fabricated by the above method has the following structure: it includes an anion exchange membrane with two sides. An anode catalyst layer and a cathode catalyst layer are respectively provided on the first and second sides of the anion exchange membrane. The thickness of the anion exchange membrane (AEM membrane) is approximately 95 micrometers, and the thicknesses of the anode and cathode catalyst layers are approximately 13.5 micrometers.

[0051] The product obtained in Example 1 was characterized and tested. The results and analysis are as follows: Figure 1 This is a microscopic image of the surface of the membrane electrode prepared in Example 1. Figure 1 It can be seen that the catalytic layer on the surface of the membrane electrode has low porosity, is very uniform and has no cracks.

[0052] Figure 2 This is a cross-sectional scanning electron microscope (SEM) image of the membrane electrode fabricated in Example 1 of this application. Position 1 represents the catalyst layer, position 2 represents the AEM film, and position 3 represents the interface between the catalyst layer and the AEM film. The catalyst layer has a thickness of approximately 13.5 micrometers, and the AEM film has a thickness of approximately 95 micrometers. Position 3 shows that the AEM film and the catalyst layer are firmly bonded; therefore, the thicknesses of the AEM film and the catalyst layer can be flexibly adjusted during the implementation of this application.

[0053] Figure 3 This is a scanning electron microscope (SEM) image of the surface of the membrane electrode prepared in Example 1 of this application. Figure 3 It can be seen that the particles on the surface of the membrane electrode are evenly distributed.

[0054] Figure 4 The impedance spectrum (EIS) of the membrane electrode prepared in Example 1 of this application is obtained from... Figure 4 It can be seen that when operating at a current density of 1A / cm², its EIS impedance is measured to be 0.0165Ω.

[0055] Figure 5 The polarization curve of the membrane electrode prepared in Example 1 of this application is shown below. Figure 5 It can be seen that under a constant voltage of 1.8V, the current density reaches 2.4A / cm². 2 .

[0056] Figure 6 The membrane electrode product prepared in Example 1 of this application, from Figure 6 It can be seen that the product surface is smooth, without peeling or swelling.

[0057] The above Figure 1-6 The results show that the membrane electrode prepared in Example 1 of this application has advantages such as low impedance, high catalytic activity, low swelling rate, and strong bonding between the catalytic layer and the anion exchange membrane.

[0058] It should be noted that: In this article, “~” is used to represent the range of values, and the range of values ​​represented by this expression includes two endpoint values.

[0059] The specific parameters or some commonly used reagents or raw materials in the above embodiments are specific embodiments or preferred embodiments under the concept of this application, and are not intended to limit them; those skilled in the art can make adaptive adjustments within the concept and protection scope of this application.

[0060] In addition, unless otherwise specified, the raw materials used may be commercially available products in the field or prepared by conventional methods in the field; that is, the reagents and instruments used in this embodiment do not specify the manufacturer or other information, and are all conventional products that can be purchased from the market.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A membrane electrode for hydrogen production via anion exchange membrane electrolysis of water, characterized in that: Including anion exchange membranes with two sides; The anion exchange membrane has a cathode catalytic layer on its first side and an anode catalytic layer on its second side. Wherein, the cathode catalyst layer is a solid catalyst layer formed by coating the first side of the anion exchange membrane with cathode catalyst slurry and curing it; the anode catalyst layer is a solid catalyst layer formed by coating the second side of the anion exchange membrane with anode catalyst slurry and curing it; the membrane electrode for anion exchange membrane electrolysis of water to produce hydrogen is an integrated CCM structure composed of anion exchange membrane and catalyst layers directly coated on both sides thereon. The cathode catalyst slurry, by mass fraction, consists of 15%–20% cathode catalyst, 35%–40% water, 35%–40% alcohol organic solvent, and 5%–10% ionomer solution; the cathode catalyst slurry is obtained by stirring and mixing the cathode catalyst, water, alcohol organic solvent, and ionomer solution for 3–5 hours. The anode catalyst slurry, by mass fraction, consists of 15%–20% anode catalyst, 35%–40% water, 35%–40% alcohol organic solvent, and 5%–10% ionomer solution. The anode catalyst slurry is obtained by stirring and mixing the anode catalyst, water, alcohol organic solvent, and ionomer solution for 3–5 hours. Wherein, the ionomer in the ionomer solution is a polydiphenylene alkylene polymer ionomer, so as to form a robust electrode structure for the cathode catalyst layer or the anode catalyst layer; the support for the cathode catalyst is a porous carbon nanomaterial; and the alcohol organic solvent is isopropanol. The thickness of the anion exchange membrane is 20–160 μm; The thickness of both the cathode catalyst layer and the anode catalyst layer is 0.1–20 μm; The total thickness of the membrane electrode is 0.02–0.2 mm; The method for preparing the membrane electrode includes the following steps: Cut the anion exchange membrane to the required specifications and dimensions; A cathode catalyst slurry and an anode catalyst slurry are coated on two opposite sides of the anion exchange membrane, respectively, and then dried and cured to form a cathode catalyst layer and an anode catalyst layer on the two sides of the anion exchange membrane, respectively. During the coating process of the cathode catalyst slurry and the anode catalyst slurry, a coating temperature of 40℃~100℃ is controlled by gradient, and the coating speed is 0.2~0.5m / min; The process of gradient control of coating temperature from 40°C to 100°C is as follows: the coating temperature is first raised from room temperature to 40-50°C. After coating is completed, the temperature is raised to 60°C and held constant for 15 minutes. Then the temperature is raised to 80-100°C and held constant at 80-100°C until the formed cathode catalyst layer or anode catalyst layer is completely dry, and then heating is stopped.

2. The membrane electrode for hydrogen production via anion exchange membrane electrolysis of water according to claim 1, characterized in that, The method for preparing the membrane electrode further includes the following steps: The anion exchange membrane is cut to the required size and then placed flat on the substrate; wherein the anion exchange membrane is sealed with tape around its perimeter and vacuum adsorption is maintained to ensure that the anion exchange membrane is flat. Cathode catalyst slurry and anode catalyst slurry are coated on two opposite sides of the anion exchange membrane, respectively, and dried and cured to form cathode catalyst layer and anode catalyst layer. Then the tape around the anion exchange membrane is removed, and the membrane is packaged and stored.

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