Anode gas diffusion layer for AEM water electrolysis hydrogen production, preparation method and application

Abstract

The invention relates to the technical field of water electrolysis hydrogen production, in particular to an anode gas diffusion layer for AEM water electrolysis hydrogen production and a preparation method and application of the anode gas diffusion layer. The method comprises the following steps: preparing a modification reagent by using an HCl solution, an HNO3 solution and an FeCl3 solution; and modifying the gas diffusion layer body matrix by using a modification reagent, adding lauryl sodium sulfate into the modification reagent, continuously modifying, and placing in a mixed gas of CH4 and Ar2 for high-temperature treatment to obtain the anode gas diffusion layer for AEM water electrolysis hydrogen production. According to the method, the conductivity, the mass transfer efficiency, the corrosion resistance and the like of the gas diffusion layer are further improved through collaborative design of pore structure optimization, chemical etching activation and surface carbon reinforcement on a gas diffusion layer body matrix; the problems that in the prior art, a gas diffusion layer is low in mechanical strength and prone to corrosion, and oxygen bubbles are difficult to discharge are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production by electrolysis of water, and specifically to an anode gas diffusion layer for AEM electrolysis of water to produce hydrogen, a preparation method and an application thereof. Background Technique

[0002] Anion Exchange Membrane Water Electrolysis (AEMWE) technology is a new type of hydrogen production technology based on an anion exchange membrane (AEM) as an ion-conducting separator. By integrating the low-cost advantages of Alkaline Water Electrolysis (ALKWE) and the high current density and fast dynamic response characteristics of Proton Exchange Membrane Water Electrolysis (PEMWE), it shows significant potential in improving hydrogen production efficiency and reducing system costs. As the core component of an AEM electrolyzer, the membrane electrode assembly (MEA) for AEM electrolysis of water to produce hydrogen adopts a sandwich-like hierarchical structure, consisting of a gas diffusion layer (GDL), a catalyst layer (CL) and an AEM. Among them, the reactant water molecules penetrate from the anode side through the anion exchange membrane to the cathode side. In AEM electrolysis technology, the cathode side has high water absorption characteristics, the anode side has low water absorption characteristics, and the anode gas diffusion layer needs to discharge oxygen bubbles. As the core component for reactant transport, electron conduction and bubble management, the anode gas diffusion layer should have characteristics such as efficient mass transfer (oxygen discharge and electrolyte penetration), conductivity, mechanical strength and corrosion resistance. Most of the existing AEM anode gas diffusion layers are made of carbon materials and metal titanium materials. The carbon materials have low mechanical strength, and the titanium materials are prone to corrosion due to their high anodic oxidation potential in an alkaline environment, resulting in easy fracture of the gas diffusion layer of carbon materials, and easy corrosion of the gas diffusion layer of metal titanium materials leading to surface oxidation.

[0003] The Chinese invention with the publication number CN116641086A discloses a highly stable membrane electrode, a preparation method thereof, and a water electrolyzer using the same. The highly stable membrane electrode includes an anode gas diffusion layer, an anode catalyst layer, an anion exchange membrane, a cathode catalyst layer, and a cathode gas diffusion layer that are stacked in sequence. Among them, hydrophobic materials such as polytetrafluoroethylene are added to the anode catalyst layer to achieve the hydrophobic effect of the anode. The prepared membrane electrode has good structural stability and excellent water electrolysis catalytic performance, which can keep the water electrolyzer using the same operating for a long time and has a high hydrogen production efficiency. However, oxygen accumulates on the anode side of the membrane electrode, and it is difficult to discharge oxygen bubbles, which affects the mass transfer effect. Moreover, the problems of insufficient mechanical strength and easy corrosion have not been better solved. Summary of the Invention

[0004] Aiming at the problems of low mechanical strength, easy corrosion, and difficult discharge of oxygen bubbles in the existing technology, the present invention provides an anode gas diffusion layer for AEM water electrolysis hydrogen production, a preparation method, and an application thereof.

[0005] To achieve the above object, the present invention adopts the following technical solutions: The present invention provides a preparation method for an anode gas diffusion layer for AEM water electrolysis hydrogen production, including: Obtaining a gas diffusion layer body substrate; the porosity of the gas diffusion layer body substrate is 50% - 80%; Preparing a modification reagent using HCl solution, HNO3 solution, and FeCl3 solution; Modifying the gas diffusion layer body substrate with the modification reagent to obtain a first modified gas diffusion layer body substrate; Adding sodium dodecyl sulfate to the modification reagent and continuing to modify the first modified gas diffusion layer body substrate to obtain a second modified gas diffusion layer body substrate; Placing the second modified gas diffusion layer body substrate in a mixed gas of CH4 and Ar2 for high-temperature treatment to obtain an anode gas diffusion layer for AEM water electrolysis hydrogen production.

[0006] Optionally, the gas diffusion layer body substrate is a porous nickel felt, nickel foam, or MOF nickel substrate.

[0007] Optionally, it further includes a pretreatment of the gas diffusion layer body substrate, and the method is: Placing the gas diffusion layer body substrate in acetone and ethanol in sequence and ultrasonically cleaning for 25 - 40 min respectively; Rinsing the ultrasonically cleaned gas diffusion layer body substrate with water and drying it to complete the pretreatment of the gas diffusion layer body substrate.

[0008] Optionally, in the modification reagent, the volume ratio of the HCl solution, the HNO3 solution, and the FeCl3 solution is (40 - 55):(20 - 35):(10 - 25); the concentration of the HCl solution is 8 wt.% - 12 wt.%, the molar concentration of the HNO3 solution is 0.8 - 1.2 M, and the molar concentration of the FeCl3 solution is 0.08 - 0.12 M.

[0009] Optionally, the method for modifying the gas diffusion layer body substrate with the modification reagent to obtain the first modified gas diffusion layer body substrate is as follows: Immerse the gas diffusion layer body substrate in the modification reagent, and react for 8 - 12 min at 55°C - 65°C to obtain the first modified gas diffusion layer body substrate.

[0010] Optionally, the method for adding sodium dodecyl sulfate to the modification reagent and continuing to modify the first modified gas diffusion layer body substrate to obtain the second modified gas diffusion layer body substrate is as follows: Continue to immerse the first modified gas diffusion layer body substrate in the modification reagent added with sodium dodecyl sulfate, react for 15 - 25 min at 35°C - 45°C, and wash to obtain the second modified gas diffusion layer body substrate; wherein, in the modification reagent added with sodium dodecyl sulfate, the mass concentration of the sodium dodecyl sulfate is 0.4% - 0.6%.

[0011] Optionally, the temperature of the high-temperature treatment is 600°C - 800°C, and the time is 1.5 - 2 h.

[0012] Optionally, in the mixed gas of CH4 and Ar2, the flow ratio of CH4 to Ar2 is (1:5) - (1:20).

[0013] An anode gas diffusion layer for AEM electrolytic water hydrogen production is prepared by using the above preparation method of the anode gas diffusion layer for AEM electrolytic water hydrogen production.

[0014] The application of the anode gas diffusion layer for AEM electrolytic water hydrogen production as described above in electrolytic water hydrogen production.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method for preparing an anode gas diffusion layer for AEM electrolytic water hydrogen production. This method involves preparing a modification reagent using HCl solution, HNO3 solution, and FeCl3 solution, and modifying the substrate of the gas diffusion layer body with the modification reagent to change the surface chemical properties of the gas diffusion layer body substrate, increasing the active sites. Then, through the synergistic effect of sodium dodecyl sulfate and the modification reagent, a kind of anode gas diffusion layer for AEM electrolytic water hydrogen production is prepared to form a rhombus-like pore structure. The rhombus-like pore structure can provide preferential nucleation sites for oxygen bubbles, and enable the bubbles to grow and detach along the diagonal major axis direction of the rhombus-like pore structure, thereby reducing the residence time of oxygen bubbles, promoting the discharge of oxygen bubbles, and enhancing the mass transfer effect. At the same time, the electrolyte is driven by the surface wetting gradient to flow directionally along the rhombus-like boundary, avoiding the vortex or local liquid accumulation caused by traditional circular pores, and enhancing the water distribution uniformity. Finally, under the protection of Ar2, CH4 is introduced at high temperature to carry out chemical vapor deposition on the anode gas diffusion layer for AEM electrolytic water hydrogen production. While further enhancing the conductivity and hydrophobicity of the gas diffusion layer, the deposited carbon layer is used to delay the oxidation of the pore structure of the diffusion layer, further improving the mechanical properties and corrosion resistance of the gas diffusion layer. This method realizes the further improvement of the core indicators such as conductivity, mass transfer efficiency, and corrosion resistance of the gas diffusion layer through the collaborative design of pore structure optimization, chemical etching activation, and surface carbon strengthening of the gas diffusion layer body substrate. At the same time, it has the advantages of low cost, simple method, and scalable production, which is of great significance for promoting the commercialization process of AEM electrolytic water hydrogen production technology.

[0016] The present invention provides an anode gas diffusion layer for AEM electrolytic water hydrogen production, which is prepared by using the above-mentioned method for preparing an anode gas diffusion layer for AEM electrolytic water hydrogen production. This anode gas diffusion layer for AEM electrolytic water hydrogen production has pores with a rhombus-like structure, forming a gas channel with a low tortuosity, which can greatly reduce the resistance to the discharge of oxygen bubbles and promote the discharge of oxygen bubbles. At the same time, it has a wetting gradient of hydrophilic pores - hydrophobic boundary, which can not only effectively avoid and inhibit flooding and improve the water management ability, but also has better mechanical strength and corrosion resistance. Compared with the traditional gas diffusion layer, it has good mass transfer effect, high mechanical strength, good corrosion resistance, and long service life, and is significantly superior to the existing technology in core indicators such as energy efficiency, service life, and cost, and is expected to promote the commercialization process of AEM electrolyzers.

[0017] Such as the application of the above-mentioned anode gas diffusion layer for AEM electrolytic water hydrogen production in electrolytic water hydrogen production. The anode for AEM electrolytic water hydrogen production prepared by using this anode gas diffusion layer for AEM electrolytic water hydrogen production has the characteristics of high mass transfer efficiency, extremely long service life, and low cost. Its application can not only promote the commercialization process of AEM electrolyzers, but also provide a better solution for the large-scale production of green hydrogen. Description of the Drawings

[0018] Figure 1 Schematic flowchart of the preparation method of the anode gas diffusion layer for AEM electrolytic water hydrogen production according to the present invention.

[0019] Figure 2 SEM image of the anode gas diffusion layer for AEM electrolytic water hydrogen production according to the present invention.

[0020] Figure 3 Schematic diagram of the membrane electrode assembly structure for experimental use provided by the present invention. Detailed implementation manners

[0021] To enable those skilled in the art to understand the features and effects of the present invention, the following provides a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meaning understood by those skilled in the art for the present invention. In case of conflicts, the definitions in this specification shall prevail.

[0022] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall not limit the scope of the present invention in any way, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0023] In this article, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are only for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the ranges (including integers and fractions).

[0024] In this article, unless otherwise specified, terms such as "comprising", "including", "containing", "having", or similar terms cover the meanings of "consisting of" and "consisting essentially of". For example, "A comprises a" covers the meanings of "A comprises a and others" and "A only comprises a".

[0025] In this article, for the sake of brevity, all possible combinations of all technical features in each embodiment or example are not described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered as within the scope described in this specification.

[0026] The following further elaborates the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0027] In the following examples, conventional instruments and equipment in the art are used. For the experimental methods without specific conditions noted in the following examples, they are generally carried out under conventional conditions or according to the conditions recommended by the manufacturers. Various raw materials are used in the following examples. Unless otherwise specified, commercially available products are used, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" represents weight percentage, "parts" represents weight parts, and the ratio represents weight ratio.

[0028] The present invention will be further described in detail below with specific examples, which are explanations of the present invention rather than limitations.

[0029] See Figure 1 , the present invention discloses a preparation method of an anode gas diffusion layer for AEM electrolytic water hydrogen production, including: S1: Obtain the substrate of the gas diffusion layer body; the porosity of the substrate of the gas diffusion layer body is 50% - 80%; preferably, the substrate of the gas diffusion layer body is porous nickel felt, nickel foam or MOF nickel substrate; Before use, first pre-treat the substrate of the gas diffusion layer body. The method is: Place the substrate of the gas diffusion layer body in acetone and ethanol in sequence, and ultrasonically clean for 25 - 40 min respectively; Rinse the ultrasonically cleaned substrate of the gas diffusion layer body with water and dry it to complete the pre-treatment of the substrate of the gas diffusion layer body. The pre-treatment process can effectively remove oil stains, oxides and impurities on the surface of the substrate of the gas diffusion layer body, laying a foundation for subsequent uniform modification.

[0030] S2: Prepare a modification reagent using HCl solution, HNO3 solution and FeCl3 solution. Among them, the volume ratio of HCl solution, HNO3 solution and FeCl3 solution is (40 - 55):(20 - 35):(10 - 25); the concentration of the HCl solution is 8wt.% - 12wt.%, the molar concentration of the HNO3 solution is 0.8 - 1.2M, and the molar concentration of the FeCl3 solution is 0.08 - 0.12M; S3: Modify the substrate of the gas diffusion layer body with the modification reagent to obtain the first modified substrate of the gas diffusion layer body. Specifically: Immerse the substrate of the gas diffusion layer body in the modification reagent and react at 55°C - 65°C for 8 - 12 min to obtain the first modified substrate of the gas diffusion layer body.

[0031] Using strong oxidative etching with HCl and HNO3 to break the passivation layer on the nickel surface, generating micro-nano scale rough structures, promoting the oxidation and dissolution of Ni, increasing the active sites, and synergistically inducing microbattery corrosion with FeCl3 to accelerate the local corrosion of Ni, forming honeycomb-like micropores.

[0032] S4: Add sodium dodecyl sulfate to the modification reagent and continue to modify the first modified gas diffusion layer body substrate to obtain the second modified gas diffusion layer body substrate. Specifically: Immerse the first modified gas diffusion layer body substrate in the modification reagent added with sodium dodecyl sulfate, react at 35 °C - 45 °C for 15 - 25 min, and wash to obtain the second modified gas diffusion layer body substrate; wherein, in the modification reagent added with sodium dodecyl sulfate, the mass concentration of sodium dodecyl sulfate is 0.4% - 0.6%.

[0033] The addition of sodium dodecyl sulfate forms a hydrophilic-hydrophobic gradient on the first modified gas diffusion layer body substrate. While enhancing the interface stability and synergistically with the action of the modification reagent, the finally obtained second modified gas diffusion layer body substrate forms a rhomboid-like structure. The rhomboid-like pore structure can provide preferential nucleation points for oxygen bubbles, and enable the bubbles to grow and detach along the diagonal major axis direction of the rhomboid-like pore structure, thereby reducing the residence time of oxygen bubbles, promoting the discharge of oxygen bubbles, and improving the mass transfer effect. At the same time, the electrolyte is driven by the surface wetting gradient to flow directionally along the rhomboid-like boundary, avoiding the vortex or local liquid accumulation caused by traditional circular holes, and improving the water distribution uniformity; S5: Place the second modified gas diffusion layer body substrate in a mixed gas of CH4 and Ar2 for high-temperature treatment to obtain the anode gas diffusion layer for AEM electrolytic water hydrogen production. Specifically: Place the second modified gas diffusion layer body substrate in a mixed gas of CH4 and Ar2, and perform high-temperature treatment at 600 °C - 800 °C for 1.5 - 2 h to obtain the anode gas diffusion layer for AEM electrolytic water hydrogen production, wherein in the mixed gas of CH4 and Ar2, the flow ratio of CH4 to Ar2 is (1:5) - (1:20).

[0034] Using the in-situ growth mechanism of the carbon layer, under the protection of Ar2 and at high temperature, CH4 is cracked to form a carbon layer covering the surface of the anode gas diffusion layer for electrolytic water hydrogen production and forming a chemical bond with the anode gas diffusion layer for electrolytic water hydrogen production. While enhancing the structural stability, the deposited carbon layer is used to delay the oxidation of the pore structure of the diffusion layer, further improving the mechanical properties and corrosion resistance of the gas diffusion layer.

[0035] Through the collaborative design of optimizing the pore structure, chemically etching and activating, and surface carbon strengthening of the gas diffusion layer body substrate, this method realizes further improvement in the core indicators such as conductivity, mass transfer efficiency, and corrosion resistance of the gas diffusion layer. At the same time, it has the advantages of low cost, simple method, and scalable production, which is of great significance for promoting the commercialization process of AEM electrolytic water hydrogen production technology.

[0036] Example 1 Select a porous nickel felt as the gas diffusion layer body substrate with a porosity of 70%. First, ultrasonically clean the porous nickel felt with acetone for 30 min, then ultrasonically clean it with ethanol for 30 min, and finally rinse it repeatedly with water 5 times. After that, place it in a drying oven at 60 °C and dry it for 4 h for standby.

[0037] Prepare 50 ml of 10 wt.% HCl solution respectively, and then prepare 30 ml of 1 M HNO3 and 20 ml of 0.1 M FeCl3, and mix them as the modification reagent; Completely immerse the porous nickel felt in the modification reagent, first corrode it at 60 °C for 10 min to obtain the first modified gas diffusion layer body substrate. Subsequently, add sodium dodecyl sulfate (SDS) to the modification reagent, where the mass concentration of sodium dodecyl sulfate is 0.5%. Stir and mix it at 60 °C until it is completely dissolved. When the temperature of the whole modification reagent drops to 40 °C, then completely immerse the first modified gas diffusion layer body substrate in the modification reagent added with sodium dodecyl sulfate and corrode it for 20 min to make it grow into a rhombic pore structure, obtaining the second modified gas diffusion layer body substrate.

[0038] Take out the obtained second modified gas diffusion layer body substrate, ultrasonically clean it with deionized water for 3 - 5 min, and cycle three times until the pH value of the cleaned aqueous solution is neutral, indicating that the corrosion by-products have been completely removed. After preliminary drying, put it into a tube sintering furnace and introduce a mixed gas of CH4 and Ar2, and treat it at a high temperature of 600 °C for 2 h to obtain the anode gas diffusion layer for AEM electrolytic water hydrogen production.

[0039] Example 2 Select a MOF nickel substrate as the gas diffusion layer body substrate with a porosity of 70%. First, ultrasonically clean the MOF nickel substrate with acetone for 25 min, then ultrasonically clean it with ethanol for 25 min, and finally rinse it repeatedly with water 5 times. After that, place it in a drying oven at 60 °C and dry it for 4 h for standby.

[0040] Prepare 45 ml of 8 wt.% HCl solution respectively, and then prepare 35 ml of 1.1 M HNO3 and 20 ml of 0.08 M FeCl3, and mix them as the modification reagent; The MOF nickel substrate was completely immersed in the modification reagent, first corroded at 65 °C for 8 min to obtain the first modified gas diffusion layer body substrate. Subsequently, sodium dodecyl sulfate (SDS) was added to the modification reagent, where the mass concentration of sodium dodecyl sulfate was 0.4%. It was mixed and stirred at 60 °C until completely dissolved. When the temperature of the overall modification reagent dropped to 45 °C, the first modified gas diffusion layer body substrate was completely immersed in the modification reagent containing sodium dodecyl sulfate and corroded for 15 min to grow into a rhombic pore structure, obtaining the second modified gas diffusion layer body substrate.

[0041] The obtained second modified gas diffusion layer body substrate was taken out and ultrasonically cleaned with deionized water for 3 - 5 min, and the cycle was repeated three times until the pH value of the aqueous solution after cleaning was neutral, indicating that the corrosion by-products had been completely removed. After preliminary drying, it was placed in a tube furnace and a mixed gas of CH4 and Ar2 was introduced, and heat-treated at 650 °C for 1.5 h to obtain the anode gas diffusion layer for AEM electrolytic water hydrogen production.

[0042] Example 3 Foam nickel was selected as the gas diffusion layer body substrate with a porosity of 80%. The foam nickel was first ultrasonically cleaned with acetone for 25 min, then ultrasonically cleaned with ethanol for 25 min, and finally repeatedly rinsed with water 5 times, and then placed in a drying oven at 60 °C and dried for 4 h for standby.

[0043] 40 ml of 12 wt.% HCl solution was prepared respectively, and then 35 ml of 0.8 M HNO3 and 25 ml of 0.12 M FeCl3 were prepared and mixed into the modification reagent; The foam nickel was completely immersed in the modification reagent, first corroded at 55 °C for 12 min to obtain the first modified gas diffusion layer body substrate. Subsequently, sodium dodecyl sulfate (SDS) was added to the modification reagent, where the mass concentration of sodium dodecyl sulfate was 0.6%. It was mixed and stirred at 60 °C until completely dissolved. When the temperature of the overall modification reagent dropped to 45 °C, the first modified gas diffusion layer body substrate was completely immersed in the modification reagent containing sodium dodecyl sulfate and corroded for 15 min to grow into a rhombic pore structure, obtaining the second modified gas diffusion layer body substrate.

[0044] The obtained second modified gas diffusion layer body substrate was taken out and ultrasonically cleaned with deionized water for 3 - 5 min, and the cycle was repeated three times until the pH value of the aqueous solution after cleaning was neutral, indicating that the corrosion by-products had been completely removed. After preliminary drying, it was placed in a tube furnace and a mixed gas of CH4 and Ar2 was introduced, and heat-treated at 700 °C for 1 h to obtain the anode gas diffusion layer for AEM electrolytic water hydrogen production.

[0045] Example 4 Select porous nickel felt as the matrix of the gas diffusion layer body, with a porosity of 75%. First, ultrasonically clean the porous nickel felt with acetone for 30 min, then ultrasonically clean it with ethanol for 30 min. Finally, rinse it repeatedly with water 5 times and place it in a drying oven at 60 °C for 4 h for standby.

[0046] Prepare 55 ml of 9 wt.% HCl solution respectively, and then prepare 30 ml of 1.2 M HNO3 and 15 ml of 0.09 M FeCl3, and mix them as the modification reagent; Completely immerse the porous nickel felt in the modification reagent. First, corrode it at 60 °C for 10 min to obtain the first modified matrix of the gas diffusion layer body. Subsequently, add sodium dodecyl sulfate (SDS) to the modification reagent, where the mass concentration of sodium dodecyl sulfate is 0.5%. Stir and mix at 60 °C until completely dissolved. When the temperature of the overall modification reagent drops to 40 °C, completely immerse the first modified matrix of the gas diffusion layer body in the modification reagent added with sodium dodecyl sulfate and corrode it for 20 min to grow it into a rhombic pore structure, obtaining the second modified matrix of the gas diffusion layer body.

[0047] Take out the obtained second modified matrix of the gas diffusion layer body and ultrasonically clean it with deionized water for 3 - 5 min, and cycle three times until the pH value of the aqueous solution after cleaning is neutral, indicating that the corrosion by-products have been completely removed. After preliminary drying, put it into a tube furnace and introduce a mixed gas of CH4 and Ar2, and treat it at 800 °C for 1 h to obtain the anode gas diffusion layer for AEM electrolytic water hydrogen production.

[0048] Comparative Example 1 Select porous nickel felt as the matrix of the gas diffusion layer body, with a porosity of 70%. First, ultrasonically clean the porous nickel felt with acetone for 30 min, then ultrasonically clean it with ethanol for 30 min. Finally, rinse it repeatedly with water 5 times and place it in a drying oven at 60 °C for 4 h for standby.

[0049] Put the porous nickel felt into a tube furnace and introduce a mixed gas of CH4 and Ar2, and treat it at 600 °C for 2 h to obtain the anode gas diffusion layer.

[0050] Comparative Example 2 Select porous nickel felt as the matrix of the gas diffusion layer body, with a porosity of 75%. First, ultrasonically clean the porous nickel felt with acetone for 30 min, then ultrasonically clean it with ethanol for 30 min. Finally, rinse it repeatedly with water 5 times and place it in a drying oven at 60 °C for 4 h for standby.

[0051] Prepare 50 ml of 10 wt.% HCl solution respectively, and then prepare 30 ml of 1 M HNO3 and 20 ml of 0.1 M FeCl3, and mix them as the modification reagent; The porous nickel felt was completely immersed in the modifying reagent, corroded at 60 °C for 10 min first, and then reacted at 40 °C for 20 min to obtain the modified porous nickel felt. The obtained porous nickel felt was taken out and ultrasonically cleaned with deionized water for 3 - 5 min, and the cycle was repeated three times until the pH value of the aqueous solution after cleaning was neutral, indicating that the corrosion by-products had been completely removed. After preliminary drying, it was placed in a tube furnace and a mixed gas of CH4 and Ar2 was introduced, and heat-treated at 600 °C for 2 h to obtain the anode gas diffusion layer.

[0052] See Figure 3 , Example 1, Comparative Example 1, and Comparative Example 2 were assembled. Among them, the anode gas diffusion layer was a porous nickel felt with a thickness of 0.25 mm, the cathode diffusion layer was a porous nickel felt with a thickness of 0.25 mm, the membrane electrode was a CCM type membrane electrode, and its electrochemically active effective area was 25 cm 2 , 1 mol / L KOH was used as the electrolyte, the temperature of the alkaline solution was 60 °C, and the flow rate was 110 ml / min. An AEM test bench was used to test the performance of the relevant membrane electrode. The test results are shown in the following table:

[0053] It can be seen that the overall resistance of the anode gas diffusion layer for AEM electrolytic water hydrogen production prepared in Example 1 of the present invention is the smallest, the interfacial contact resistance is lower, the cell voltage is low, and the range of cell voltage fluctuation is smaller, indicating that the performance of the electrolytic cell prepared by using this anode gas diffusion layer for AEM electrolytic water hydrogen production is stable.

[0054] The present invention also provides an anode gas diffusion layer for AEM electrolytic water hydrogen production, which is prepared by using the preparation method of the above-mentioned anode gas diffusion layer for AEM electrolytic water hydrogen production. This anode gas diffusion layer for AEM electrolytic water hydrogen production has holes with a similar rhombic structure, forming gas channels with a low tortuosity, which can greatly reduce the resistance to the discharge of oxygen bubbles and promote the discharge of oxygen bubbles; at the same time, it has a wetting gradient of hydrophilic pores - hydrophobic boundary, which can not only effectively avoid and inhibit flooding and improve water management ability, but also has better mechanical strength and corrosion resistance. Compared with the traditional gas diffusion layer, it has good mass transfer effect, high mechanical strength, good corrosion resistance, and long service life, and is significantly superior to the existing technology in core indicators such as energy efficiency, service life, and cost, and is expected to promote the commercialization process of AEM electrolytic cells.

[0055] The application of the anode gas diffusion layer for AEM electrolytic water hydrogen production as described above in electrolytic water hydrogen production. The anode for AEM electrolytic water hydrogen production prepared by using this anode gas diffusion layer for AEM electrolytic water hydrogen production has the characteristics of high mass transfer efficiency, extremely long service life, and low cost. Its application can not only promote the commercialization process of AEM electrolytic cells, but also provide a better solution for large-scale green hydrogen production.

[0056] The above are only the preferred embodiments of the present invention, and are not intended to limit the technical solutions of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solutions can be subject to several simple modifications and substitutions, and these modifications and substitutions also fall within the protection scope covered by the claims.

Claims

1. A preparation method of an anode gas diffusion layer for AEM electrolytic water hydrogen production, characterized in that, Including: Obtain the substrate of the gas diffusion layer body; the porosity of the substrate of the gas diffusion layer body is 50% - 80%; Prepare a modification reagent using HCl solution, HNO3 solution, and FeCl3 solution; Modify the substrate of the gas diffusion layer body with the modification reagent to obtain the first modified substrate of the gas diffusion layer body; Add sodium dodecyl sulfate to the modification reagent and continue to modify the first modified substrate of the gas diffusion layer body to obtain the second modified substrate of the gas diffusion layer body; Place the second modified substrate of the gas diffusion layer body in a mixed gas of CH4 and Ar2 for high-temperature treatment to obtain the anode gas diffusion layer for AEM water electrolysis hydrogen production.

2. The preparation method of the anode gas diffusion layer for AEM electrolytic water hydrogen production according to claim 1, wherein The substrate of the gas diffusion layer body is porous nickel felt, nickel foam, or MOF nickel substrate.

3. The preparation method of the anode gas diffusion layer for AEM electrolytic water hydrogen production according to claim 1, wherein, It also includes the pretreatment of the substrate of the gas diffusion layer body. The method is: Place the substrate of the gas diffusion layer body in acetone and ethanol in sequence, and ultrasonically clean for 25 - 40 min respectively; Rinse the ultrasonically cleaned substrate of the gas diffusion layer body with water and dry it to complete the pretreatment of the substrate of the gas diffusion layer body.

4. The preparation method of the anode gas diffusion layer for AEM electrolytic water hydrogen production according to claim 1, characterized in that, In the modification reagent, the volume ratio of HCl solution, HNO3 solution, and FeCl3 solution is (40 - 55):(20 - 35):(10 - 25); the concentration of the HCl solution is 8 wt.% - 12 wt.%, the molar concentration of the HNO3 solution is 0.8 - 1.2 M, and the molar concentration of the FeCl3 solution is 0.08 - 0.12 M.

5. The preparation method of the anode gas diffusion layer for AEM electrolytic water hydrogen production according to claim 1, characterized in that, The method of modifying the substrate of the gas diffusion layer body with the modification reagent to obtain the first modified substrate of the gas diffusion layer body is: Immerse the substrate of the gas diffusion layer body in the modification reagent, and react for 8 - 12 min at 55°C - 65°C to obtain the first modified substrate of the gas diffusion layer body.

6. The preparation method of the anode gas diffusion layer for AEM electrolytic water hydrogen production according to claim 1, wherein The method of adding sodium dodecyl sulfate to the modification reagent and continuing to modify the first modified substrate of the gas diffusion layer body to obtain the second modified substrate of the gas diffusion layer body is: Continue to immerse the first modified substrate of the gas diffusion layer body in the modification reagent added with sodium dodecyl sulfate, react for 15 - 25 min at 35°C - 45°C, and wash to obtain the second modified substrate of the gas diffusion layer body; wherein, in the modification reagent added with sodium dodecyl sulfate, the mass concentration of sodium dodecyl sulfate is 0.4% - 0.6%.

7. The preparation method of the anode gas diffusion layer for AEM electrolytic water hydrogen production according to claim 1, wherein The temperature of the high-temperature treatment is 600°C - 800°C, and the time is 1.5 - 2 h.

8. The preparation method of the anode gas diffusion layer for AEM electrolytic water hydrogen production according to claim 1, characterized in that, In the mixed gas of CH4 and Ar2, the flow ratio of CH4 to Ar2 is (1:5) - (1:20).

9. An anode gas diffusion layer for AEM electrolytic water hydrogen production, characterized in that, Prepared by the preparation method of the anode gas diffusion layer for AEM water electrolysis hydrogen production according to any one of claims 1 - 8.

10. Application of the anode gas diffusion layer for AEM water electrolysis hydrogen production according to claim 9 in water electrolysis hydrogen production.

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