Ordering integrated water electrolysis hydrogen production electrode for non-uniformly and directionally supporting catalyst and preparation method of ordering integrated water electrolysis hydrogen production electrode

Abstract

The invention provides an ordered integrated water electrolysis hydrogen production electrode for non-uniformly and directionally supporting a catalyst and a preparation method of the ordered integrated water electrolysis hydrogen production electrode. The ordered integrated water electrolysis hydrogen production electrode consists of an anode, a cathode and a middle film layer, the anode is composed of an anode base layer and an anode catalyst layer, and the cathode is composed of a cathode base layer and a cathode catalyst layer; the anode base layer is an ordered base layer and the anode catalyst layer is a non-uniformly oriented supported layer, and / or the cathode base layer is an ordered base layer and the cathode catalyst layer is a non-uniformly oriented supported layer. The invention further provides a preparation method of the ordered integrated water electrolysis hydrogen production electrode and application of the ordered integrated water electrolysis hydrogen production electrode in water electrolysis hydrogen production. According to the invention, the catalyst is directionally supported in a specific area to form a non-uniform supported catalyst layer, and the non-uniform supported catalyst layer is combined with a film-catalyst layer-electrode substrate / diffusion layer integrated electrode structure by means of hot pressing and the like, so that the utilization rate of the catalyst can be greatly improved, and the impedance can be reduced.

Description

Technical Field

[0001] The invention relates to an ordered integrated water electrolysis hydrogen production electrode with a non-uniform directional catalyst loading and a preparation method thereof, belonging to the technical field of water electrolysis hydrogen production. Background Art

[0002] Hydrogen production by water electrolysis currently mainly includes alkaline electrolysis cells, proton exchange membrane electrolysis cells, and anion exchange membrane electrolysis cells. Among them, alkaline electrolysis cells are mainly composed of diaphragms, electrodes (including electrode substrates and catalysts loaded on the surface), bipolar plates and other components, proton exchange membrane electrolysis cells are mainly composed of proton exchange membranes, catalyst layers (mostly coated on proton exchange membranes), porous transport layers, and bipolar plates, while anion exchange membrane electrolysis cells are mainly composed of anion exchange membranes, catalyst layers (mostly coated on anion exchange membranes), porous transport layers, and bipolar plates. Among them, the electrode substrate / diffusion layer and its contact surface with the catalyst layer and membrane play a key role in constructing proton, electron, water vapor transmission channels and three-phase reaction interfaces. Therefore, constructing a good contact interface is critical to improving the performance of the electrolysis device.

[0003] The porous transmission layers commonly used in electrolysis devices at present include metal felt, foamed metal, powder sintered metal, etc., which have complex manufacturing processes, and the pore size and porosity cannot be accurately controlled. The internal pores are randomly distributed, and it is difficult to form good contact with the catalyst layer and as many reaction sites as possible, so that the utilization rate of a large number of catalysts coated on the membrane that are not in direct contact with the diffusion layer is low, resulting in waste of catalysts and an increase in overall costs; its disordered surface structure is also difficult to achieve precise design of reaction sites and fixed-point coating of catalysts to reduce the amount of precious metal catalysts; in addition, its internal messy and tortuous pore structure is not conducive to the rapid transmission of water vapor, resulting in large ohmic impedance and mass transfer impedance, thus becoming an important factor restricting the improvement of electrolysis efficiency. In addition, the different components in the current electrolysis device only have physical contact, and it is difficult to form a good and stable contact interface, resulting in a large ohmic impedance. Summary of the invention

[0004] To solve the above problems, the purpose of the present invention is to provide a new type of ordered integrated water electrolysis hydrogen production electrode, the catalyst layer of the electrode adopts a non-uniform directional loading method to form a good contact interface and mass transfer channel.

[0005] To achieve the above object, the present invention provides an ordered integrated water electrolysis hydrogen production electrode with non-uniform\directional catalyst loading, wherein the ordered integrated water electrolysis hydrogen production electrode is composed of an anode, a cathode and an intermediate membrane layer;

[0006] The anode is composed of an anode base layer and an anode catalyst layer, and the cathode is composed of a cathode base layer and a cathode catalyst layer;

[0007] The anode base layer is an ordered base layer and the anode catalyst layer is a non-uniformly oriented supported layer, and / or the cathode base layer is an ordered base layer and the cathode catalyst layer is a non-uniformly oriented supported layer.

[0008] In the present invention, ordering means that the pores of the base layer are arranged in order, rather than a disordered random porous structure. The catalyst layer supported on the ordered base layer is also arranged in order, that is, the catalyst is distributed in a specific position of the base layer, rather than the entire surface (i.e., including the exposed pore surface).

[0009] The ordered structure may be a regular mesh structure, and the catalyst layer is distributed on the surface of the wires or threads constituting the mesh structure, etc. The conventional base layer is a disordered porous structure.

[0010] During the preparation of conventional electrodes based on disordered porous base layers, due to the disordered three-dimensional pore structure of the base layer, the catalyst will penetrate into the internal pores during the catalyst loading process, and it is impossible to achieve loading only on the surface. The catalyst that penetrates into the internal pores cannot contact the membrane and cannot form a three-phase interface, resulting in waste. The catalyst layer of this conventional electrode structure is distributed over the entire surface, which is the surface containing exposed pores, while the ordered structure of the present invention achieves loading only on the topmost layer of the base layer that is in direct contact with the membrane.

[0011] In the present invention, non-uniform directional loading means that the catalyst is loaded at a specific position rather than being loaded on the entire surface of the intermediate membrane layer or the base layer; the specific position here refers to the position where the intermediate membrane layer is in direct contact with the base layer.

[0012] The catalyst layer of the conventional catalyst-supported membrane (CCM) configuration is continuous, that is, the entire surface of the intermediate membrane layer is covered with catalyst materials; while the conventional porous electrode based on a disordered porous base layer has catalyst materials covered on the outermost layer of the base layer and the exposed pore surface.

[0013] According to a specific embodiment of the present invention, preferably, in the above-mentioned ordered integrated water electrolysis hydrogen production electrode, the ordered base layer is selected from an ordered electrode substrate and / or an ordered diffusion layer;

[0014] More preferably, the ordered electrode substrate is selected from a metal mesh and an electrode substrate with an ordered structure obtained by 3D printing, laser processing or photolithography. The metal mesh can be a woven mesh or a stretched mesh, etc., preferably an ordered woven nickel mesh and / or an ordered woven titanium mesh; the mesh number of the nickel mesh / titanium mesh is preferably 40 to 200 mesh; wherein, an alkaline electrolytic cell generally uses a nickel mesh, and a proton exchange membrane electrolytic cell generally uses a titanium mesh.

[0015] More preferably, the ordered diffusion layer is selected from a metal mesh and a diffusion layer with an ordered structure obtained by 3D printing, laser processing or photolithography. The specific process of 3D printing is generally to first establish a three-dimensional model of an electrode substrate with ordered pores, and then input it into a 3D printing device for production and preparation; the specific process of laser processing is generally to first prepare a metal plate as a substrate, and then control the power and movement trajectory of the laser to process orderly arranged holes on the substrate; the general process of photolithography is to first prepare a metal plate as a substrate, and then make a mask with ordered holes, and then perform photolithography and etching steps to process orderly arranged holes on the metal plate.

[0016] According to a specific embodiment of the present invention, preferably, in the above-mentioned ordered integrated water electrolysis hydrogen production electrode, the material of the anode catalyst is selected from one or a combination of two or more of Ir, Ru, Pt, Pd, Ir, Cu, Co, Re, Cr, Ni, Mo, Mn, Fe and their oxides.

[0017] According to a specific embodiment of the present invention, preferably, in the above-mentioned ordered integrated water electrolysis hydrogen production electrode, the material of the cathode catalyst is selected from one or a combination of two or more of Pt, Ni, Co, Fe, Cu, Mo, and Au. Among them, the cathode catalyst can use a carbon material as a carrier to load the above-mentioned active metal.

[0018] According to a specific embodiment of the present invention, preferably, in the above-mentioned ordered integrated water electrolysis hydrogen production electrode, the intermediate membrane layer is a diaphragm or an ion exchange membrane. For example, diaphragms suitable for alkaline water electrolysis hydrogen production include polyphenylene sulfide fabric diaphragms (PPS), polysulfone diaphragms (PSF), organic-inorganic composite diaphragms, etc., ion exchange membranes suitable for alkaline water electrolysis hydrogen production include anion exchange membranes, etc., and ion exchange membranes suitable for PEM water electrolysis hydrogen production include proton exchange membranes based on perfluorosulfonic acid (such as Nafion), etc.

[0019] According to a specific embodiment of the present invention, preferably, in the above-mentioned ordered integrated water electrolysis hydrogen production electrode, the thickness of the ordered base layer of the anode is 0.1 mm-2 mm, and the thickness of the non-uniformly directed anode catalyst layer is 0.1 μm-10 μm.

[0020] According to a specific embodiment of the present invention, preferably, in the above-mentioned ordered integrated water electrolysis hydrogen production electrode, the thickness of the ordered base layer of the cathode is 0.1 mm-2 mm, and the thickness of the non-uniformly directed loaded cathode catalyst layer is 0.1 μm-10 μm.

[0021] According to a specific embodiment of the present invention, the cathode and anode of the ordered integrated water electrolysis hydrogen production electrode can simultaneously use an ordered electrode substrate / diffusion layer and a directional supported catalyst layer, or only one electrode can use an ordered structure and a directional supported catalyst layer while the other electrode uses a conventional configuration (i.e., a conventional disordered base layer). That is, the specific structure of the ordered integrated water electrolysis hydrogen production electrode can be selected from one of the following structures:

[0022] The anode is composed of an ordered base layer and a non-uniformly directional supported anode catalyst layer, the cathode is composed of a conventional disordered base layer and a continuously supported cathode catalyst layer, and the intermediate membrane is arranged between the non-uniformly directional supported anode catalyst layer and the continuously supported cathode catalyst layer;

[0023] The anode is composed of a conventional disordered base layer and a continuously loaded anode catalyst layer, the cathode is composed of an ordered base layer and a non-uniformly directional loaded cathode catalyst layer, and the intermediate membrane is arranged between the non-uniformly directional loaded cathode catalyst layer and the continuously loaded anode catalyst layer;

[0024] The anode is composed of an ordered base layer and a non-uniformly oriented anode catalyst layer, the cathode is composed of an ordered base layer and a non-uniformly oriented cathode catalyst layer, and the intermediate membrane is arranged between the non-uniformly oriented anode catalyst layer and the non-uniformly oriented cathode catalyst layer.

[0025] The present invention also provides a method for preparing the above-mentioned ordered integrated water electrolysis hydrogen production electrode with non-uniform directional catalyst loading, which comprises the following steps:

[0026] (1) Directedly loading an anode catalyst on the surface of an ordered anode base layer to form an anode directed loaded catalyst layer, thereby obtaining an anode with non-uniform directed loading, or, loading an anode catalyst on the surface of an intermediate membrane layer to form an anode continuous catalyst layer, thereby obtaining a continuously loaded anode;

[0027] (2) Directedly loading the cathode catalyst on the surface of the cathode ordered base layer to form a cathode directed loaded catalyst layer to obtain a non-uniform directed loaded cathode, or, loading the cathode catalyst on the surface of the intermediate membrane layer to form a cathode continuous catalyst layer to obtain a continuously loaded cathode;

[0028] (3) The intermediate membrane layer is sandwiched between the anode base layer on which the anode catalyst layer is directionally loaded and the cathode base layer on which the cathode catalyst layer is directionally loaded, or the intermediate membrane layer on one side of which continuously loads the cathode catalyst layer is sandwiched between the anode base layer and the cathode base layer on which the anode catalyst layer is directionally loaded, or the intermediate membrane layer on one side of which continuously loads the anode catalyst layer is sandwiched between the cathode base layer and the anode base layer on which the cathode catalyst layer is directionally loaded, so that the three are composited together to obtain the ordered integrated water electrolysis hydrogen production module with the non-uniform directionally loaded catalyst.

[0029] According to a specific embodiment of the present invention, preferably, in the above-mentioned preparation method, the directional loading can be carried out by physical or chemical means such as drip coating, spraying, electroplating, sputtering, etc., through which the catalyst can be directionally loaded on the surface of the ordered electrode substrate / diffusion layer.

[0030] According to a specific embodiment of the present invention, preferably, in the above preparation method, the process of directionally loading the anode catalyst on the surface of the anode ordered base layer to form the anode directionally loaded catalyst layer comprises:

[0031] If the drip coating / spray coating process is adopted, the catalyst slurry is prepared first, and the catalyst slurry includes catalyst particles, ionomer (such as Nafion), and solvent (such as water, alcohol), which are ball-milled and dispersed after appropriate preparation; then the ordered base layer is placed on a heating platform, and the temperature range of the heating platform is 80°C-100°C, which is used to accelerate the evaporation of the slurry solvent during the coating process; then the slurry is dripped on the surface of the ordered base layer with a dropper or the slurry is sprayed on the surface of the ordered base layer with an ultrasonic sprayer, and the catalyst loading is controlled by controlling the quality of drip coating / spraying, so that the loading is controlled at 0.05 mg / cm 2 -0.7mg / cm 2 , measured in terms of the overall area of ​​the ordered base layer;

[0032] If the sputtering process is used, the sample is first placed on the sputtering platform of the sputtering equipment (such as plasma sputtering equipment, magnetron sputtering equipment), and then a target made of the desired catalyst is selected. The sputtered catalyst loading is controlled by controlling the sputtering power and time to control the loading to 0.05 mg / cm 2 -0.7mg / cm 2 , measured in terms of the overall area of ​​the ordered base layer;

[0033] If the electroplating process is used, one side of the ordered base layer is first physically covered to isolate the side from the electroplating solution, and then the ordered base layer is placed in a solution containing catalyst ions for electroplating, so that the catalyst is deposited on the surface of one side of the ordered base layer. The catalyst loading is controlled by controlling the electroplating time to control the loading at 0.05 mg / cm 2 -0.7mg / cm 2 , based on the overall area of ​​the ordered base layer.

[0034] According to a specific embodiment of the present invention, in the above preparation method, the process of directionally loading the cathode catalyst on the surface of the cathode ordered base layer to form the cathode directionally loaded catalyst layer can be carried out by referring to the process of forming the anode directionally loaded catalyst layer.

[0035] The three-phase interface refers to the site that satisfies the conditions of proton, electron and water vapor transmission at the same time, that is, the position where the membrane is in direct contact with the base layer. The technical solution provided by the present invention can make the catalyst distributed at the three-phase interface as much as possible through directional loading, and the specific implementation method is based on the base layer of ordered through holes. The slurry dripped / sprayed to the pore area during the loading process will directly pass through the base layer (this part of the slurry can be collected to realize the recovery of precious metals), so that the catalyst is only loaded on the physical surface of the base layer, and these positions correspond to the positions directly in contact with the membrane; if a sputtering process is adopted, the catalyst particles sputtered to the pore area can also directly pass through the base layer (this part of the catalyst can be collected to realize the recovery of precious metals), so that the catalyst is only loaded on the physical surface of the base layer; if electroplating, hydrothermal, thermal decomposition and other processes are adopted, physical coverage can be performed on one side of the ordered base layer first, and then electroplating is performed to realize loading catalyst only on the surface of one side of the ordered base layer. In short, the low utilization area of ​​the catalyst can be avoided by the technical solution of the present invention, thereby improving the catalyst utilization rate and reducing the catalyst dosage while ensuring electrochemical performance.

[0036] If the traditional catalyst loaded membrane (CCM) process is adopted, since the surface of the membrane is continuous, only a continuous catalyst layer can be formed on the membrane surface. In this way, the catalyst is also loaded in the position that is not in direct contact with the electrode substrate / diffusion layer after compounding, and the catalyst cannot be distributed only at the three-phase interface. If the traditional disordered electrode substrate / diffusion layer is adopted, due to the disordered three-dimensional pore structure, the catalyst will penetrate into the internal pores during the catalyst loading process, and it is impossible to achieve loading only on the surface. The catalyst penetrated in the internal pores cannot contact the membrane and cannot form a three-phase interface, which causes waste.

[0037] According to a specific embodiment of the present invention, preferably, in the above preparation method, the compounding method is selected from hot pressing, the hot pressing pressure is 1MPa-10MPa, the temperature is 100℃-150℃, and the time is 2min-10min.

[0038] In the ordered integrated water electrolysis hydrogen production electrode provided by the present invention, the ordered electrode substrate / diffusion layer can construct an ordered mass transfer channel, reduce the mass transfer impedance, and provide a substrate for the directional loading of the catalyst; the catalyst layer directional loaded on the ordered substrate can effectively avoid the low-utilization catalyst layer that is not directly in contact with the diffusion layer compared to the traditional CCM membrane electrode, thereby improving the catalyst utilization and reducing the catalyst dosage while ensuring the electrochemical performance; further combined with the integration means (such as hot pressing), the bonding strength between different components is improved, and the integration means can improve the contact interface, so that a part of the ordered electrode with an unevenly loaded catalyst layer is embedded in the membrane, so that the catalyst on the contact interface can form a three-dimensional distribution, improve the contact interface, enhance the stability of the contact interface, strengthen the proton and electron transfer channels, reduce the ohmic impedance, and improve the electrolysis performance.

[0039] The present invention also provides the use of the ordered integrated water electrolysis hydrogen production electrode with the above-mentioned non-uniform directional catalyst loading in water electrolysis hydrogen production.

[0040] According to a specific embodiment of the present invention, preferably, the ordered integrated water electrolysis hydrogen production electrode is placed in an electrolytic cell and used as an electrode.

[0041] According to a specific embodiment of the present invention, preferably, the electrolytic cell is one of an alkaline electrolytic cell, a proton exchange membrane electrolytic cell, and an anion exchange membrane electrolytic cell.

[0042] The integrated design scheme for the electrolysis unit for producing hydrogen by electrolysis of water provided by the present invention is based on an ordered electrode substrate / diffusion layer, directionally loads the catalyst in a specific area to form a non-uniformly loaded catalyst layer, and is combined with a diaphragm / ion exchange membrane by means of hot pressing and the like to form an integrated electrode structure of membrane-catalyst layer-electrode substrate / diffusion layer, which can greatly improve the catalyst utilization rate and reduce the impedance. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic diagram of the structure of the ordered integrated water electrolysis hydrogen production electrode provided in Example 1.

[0044] Figure 2 This is a schematic diagram of the structure of the ordered integrated water electrolysis hydrogen production electrode provided in Example 2.

[0045] Figure 3 This is a scanning electron microscope image of the integrated water electrolysis hydrogen production electrode of Example 2.

[0046] Figure 4 The polarization curves of the integrated water electrolysis hydrogen production electrode of Example 2 and the traditional CCM membrane electrode are compared.

[0047] Figure 5The ohmic impedance comparison results of the integrated water electrolysis hydrogen production electrode of Example 2 and the traditional CCM membrane electrode.

[0048] Figure 6 The results are a comparison of the catalyst utilization of the integrated water electrolysis hydrogen production electrode of Example 2 and the traditional CCM membrane electrode.

[0049] Figure 7 This is the ordered integrated water electrolysis hydrogen production electrode with non-uniform directional catalyst loading provided in Example 3.

[0050] Figure 8 This is the ordered integrated water electrolysis hydrogen production electrode with non-uniform directional catalyst loading provided in Example 4. DETAILED DESCRIPTION

[0051] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0052] Example 1

[0053] This embodiment provides an ordered integrated water electrolysis hydrogen production electrode with non-uniform directional catalyst loading, which is an integrated water electrolysis hydrogen production electrode for alkaline electrolysis cells, and has a structure as shown in FIG. Figure 1 shown.

[0054] The integrated water electrolysis hydrogen production electrode is composed of an anode, a diaphragm and a cathode;

[0055] The anode is composed of an anode ordered electrode substrate and an anode directional supported catalyst layer, wherein the anode directional supported catalyst layer is directionally supported on the surface of the anode ordered electrode substrate, the anode ordered electrode substrate is a 60-mesh nickel mesh, and the catalytic material of the catalyst layer is Ir, which is distributed on the surface of the nickel wires constituting the nickel mesh;

[0056] The cathode is composed of a cathode ordered electrode substrate and a cathode directional supported catalyst layer, wherein the cathode directional supported catalyst layer is directionally supported on the surface of the cathode ordered electrode substrate, the cathode ordered electrode substrate is a 60-mesh nickel mesh, and the catalytic material of the catalyst layer is Pt, which is distributed on the surface of the nickel wires constituting the nickel mesh;

[0057] The anode and the cathode are respectively located on both sides of the diaphragm, and the anode-oriented catalyst-supported layer and the cathode-oriented catalyst-supported layer are respectively combined with the diaphragm.

[0058] The integrated water electrolysis hydrogen production electrode of this embodiment is prepared by the following steps:

[0059] 1. Directly load the anode catalyst on the surface of the anode ordered electrode substrate to form an anode directed catalyst layer to obtain the anode, which is specifically carried out in the following manner:

[0060] The anode catalyst layer was prepared by sputtering: the nickel mesh substrate was placed on the sputtering device platform, the Ir target was installed, and the sputtering load was 0.1 mg / cm by controlling the sputtering power and time. 2 , based on the overall area of ​​the nickel mesh substrate; since the nickel mesh has an ordered woven structure, the catalyst is only loaded on the surface of the nickel wire, thereby obtaining a non-uniformly loaded catalyst layer;

[0061] 2. Directly load the cathode catalyst on the surface of the cathode ordered electrode substrate to form a cathode directed catalyst layer to obtain the cathode, which is specifically carried out in the following manner:

[0062] The cathode catalyst layer was prepared by sputtering: the nickel mesh substrate was placed on the sputtering device platform, the Pt target was installed, and the sputtering load was controlled to 0.05 mg / cm by controlling the sputtering power and time. 2 , based on the overall area of ​​the nickel mesh substrate; since the nickel mesh has an ordered woven structure, the catalyst is only loaded on the surface of the nickel wire, thereby obtaining a non-uniformly loaded catalyst layer;

[0063] 3. The diaphragm (zirfion diaphragm, 500 μm thick) is sandwiched between the anode-oriented catalyst layer and the cathode-oriented catalyst layer, and they are combined together by hot pressing at a temperature of 100°C and a pressure of 3 MPa to form an integrated water electrolysis hydrogen production electrode.

[0064] Example 2

[0065] This embodiment provides an ordered integrated water electrolysis hydrogen production electrode with non-uniform directional catalyst loading, which is an integrated water electrolysis hydrogen production electrode for proton exchange membrane electrolysis cell / anion exchange membrane electrolysis cell, and has a structure as shown in FIG. Figure 2 shown.

[0066] The integrated water electrolysis hydrogen production electrode is composed of an anode, an ion exchange membrane and a cathode;

[0067] The anode is composed of an anode ordered diffusion layer and an anode directional supported catalyst layer, wherein the anode directional supported catalyst layer is directionally supported on the surface of the anode ordered electrode substrate, the anode ordered diffusion layer is a titanium mesh with a thickness of 0.2 mm and a mesh number of 200, and the material of the catalyst layer is IrO2 catalyst and ionomer Nafion;

[0068] The cathode is composed of a conventional diffusion layer and a cathode catalyst layer. The conventional diffusion layer is a disordered porous structure, and the cathode catalyst layer is a continuous layer supported on the surface of the ion exchange membrane. The cathode diffusion layer is made of powdered sintered titanium with a size of 2 cm×2 cm and a thickness of 0.5 mm. The cathode catalyst layer is made of carbon-supported platinum and Nafion ionomer.

[0069] The anode and the cathode are respectively located on both sides of a proton exchange membrane (made of perfluorosulfonic acid (PFSA) with a thickness of 100 μm), and the anode and the cathode are respectively combined with the proton exchange membrane.

[0070] The integrated water electrolysis hydrogen production electrode of this embodiment is prepared by the following steps:

[0071] 1. Prepare anode catalyst slurry: The catalyst slurry is composed of IrO2 catalyst particles, 5% Nafion solution, pure water and n-propanol in a mass ratio of 1:5:5:50, and the catalyst particles are evenly dispersed in the slurry by combining ball milling and ultrasonic dispersion;

[0072] 2. Preparation of anode non-uniform catalyst layer: Spray the catalyst slurry on the surface of the titanium mesh by ultrasonic spraying, and the anode catalyst loading is 0.5 mg / cm 2 , based on the overall area of ​​the titanium mesh substrate; since the titanium mesh has an ordered woven structure, the catalyst is only loaded on the surface of the titanium wire, thereby obtaining a non-uniformly loaded catalyst layer;

[0073] 3. Preparation of cathode single-side CCM membrane electrode: The cathode catalyst layer is formed on the surface of the cathode diffusion layer by the following methods:

[0074] First, the catalyst slurry is prepared. The specific preparation process is the same as that of the anode catalyst slurry, except that the carbon-supported platinum catalyst is used to replace the IrO2 particles, wherein the mass ratio of the carbon-supported platinum catalyst (Pt loading is 60wt%), 5% concentration Nafion solution, deionized water, and n-propanol is 1:10:10:50;

[0075] Then the cathode catalyst slurry was sprayed on the surface of the proton exchange membrane to form a uniform cathode catalyst layer. The cathode catalyst loading was 0.2 mg / cm 2 ;

[0076] 4. Preparation of integrated electrodes: The ordered titanium mesh electrode with non-uniformly loaded catalyst at the anode, the single-sided CCM membrane electrode with a cathode carbon-supported platinum catalyst layer, and the cathode diffusion layer are combined into one by hot pressing at a temperature of 130°C and a pressure of 5 MPa. During the hot pressing process, a portion of the titanium mesh will be embedded in the proton exchange membrane, so that the non-uniformly loaded catalyst layer will fully contact the proton membrane to form a three-dimensional distribution.

[0077] Comparative Example 1

[0078] This comparative example provides a conventional CCM-configured water electrolysis hydrogen production membrane electrode, which is a proton exchange membrane with catalyst layers uniformly coated on both sides. It is specifically prepared by the following steps:

[0079] 1. Prepare anode catalyst slurry: The catalyst slurry is composed of IrO2 catalyst particles, 5% Nafion solution, pure water and n-propanol in a mass ratio of 1:5:5:50, and the catalyst particles are evenly dispersed in the slurry by combining ball milling and ultrasonic dispersion;

[0080] 2. Preparation of uniform anode catalyst layer: Spray the anode catalyst slurry onto the surface of the proton exchange membrane by ultrasonic spraying to form a uniform anode catalyst layer with a catalyst loading of 2 mg / cm 2 ;

[0081] 3. Prepare cathode catalyst slurry: The specific preparation process is the same as that of anode catalyst slurry, except that carbon-supported platinum catalyst is used to replace IrO2 particles, wherein the mass ratio of carbon-supported platinum catalyst (Pt loading is 60wt%), 5% concentration Nafion solution, deionized water, and n-propanol is 1:10:10:50;

[0082] 4. Preparation of uniform cathode catalyst layer: The cathode catalyst slurry is sprayed on the other side of the proton exchange membrane by ultrasonic spraying to form a uniform cathode catalyst layer. The cathode catalyst loading is 0.2 mg / cm 2 .

[0083] During the performance test, an anode diffusion layer and a cathode diffusion layer are arranged on the anode and cathode sides of the CCM membrane electrode respectively. The anode diffusion layer is titanium felt with a size of 2cm×2cm and a thickness of 0.4mm; the cathode diffusion layer is made of powdered sintered titanium with a size of 2cm×2cm and a thickness of 0.5mm.

[0084] Figure 3 The scanning electron microscope image of the integrated water electrolysis hydrogen production electrode obtained by directional loading on the ordered titanium mesh substrate in this embodiment is shown. Figure 4 The polarization curve comparison results of the integrated water electrolysis hydrogen production electrode of this embodiment and the traditional CCM membrane electrode (Comparative Example 1) are shown.

[0085] according to Figure 4 The results show that the catalyst loading of the integrated water electrolysis hydrogen production electrode of this embodiment is reduced by 75% (the catalyst loading of the CCM membrane electrode of comparative example 1 is 2 mg / cm 2 The catalyst loading of the integrated water electrolysis hydrogen production electrode of this embodiment is 0.5 mg / cm 2), but the performance is improved by 39% (at 2V, the current density of the CCM membrane electrode of Comparative Example 1 is 2.8A / cm 2 The current density of the integrated water electrolysis hydrogen production electrode of this embodiment is 3.9A / cm 2 ), the ohmic impedance is reduced by 43% (such as Figure 5 As shown in Figure 2), the catalyst utilization rate increased by 5.6 times (expressed in terms of current per unit mass of catalyst, as shown in Figure 2). Figure 6 shown).

[0086] Example 3

[0087] This embodiment provides an ordered integrated water electrolysis hydrogen production electrode with non-uniform directional catalyst loading, which is an integrated water electrolysis hydrogen production electrode for proton exchange membrane electrolysis cell / anion exchange membrane electrolysis cell, and has a structure as shown in FIG. Figure 7 shown.

[0088] The integrated water electrolysis hydrogen production electrode is composed of an anode, an ion exchange membrane and a cathode;

[0089] The cathode is composed of a cathode ordered diffusion layer and a cathode directional supported catalyst layer, wherein the cathode directional supported catalyst layer is directionally supported on the surface of the cathode ordered diffusion layer, the cathode ordered diffusion layer is a titanium mesh with a thickness of 0.2 mm and a mesh size of 200 meshes, and the material of the catalyst layer is a carbon-supported platinum catalyst (Pt loading is 60 wt%) and ionomer Nafion;

[0090] The anode is composed of a conventional diffusion layer and an anode catalyst layer. The conventional diffusion layer is a disordered porous structure, and the anode catalyst layer is a continuous layer supported on the surface of the ion exchange membrane. The diffusion layer of the anode is a titanium felt with a size of 2cm×2cm and a thickness of 0.4mm. The material of the anode catalyst layer is IrO2 catalyst and Nafion ionomer.

[0091] The anode and cathode are respectively located on both sides of a proton exchange membrane (made of perfluorosulfonic acid (PFSA) with a thickness of 100 μm), and the cathode and anode are respectively combined with the proton exchange membrane.

[0092] The integrated water electrolysis hydrogen production electrode of this embodiment is prepared by the following steps:

[0093] 1. Prepare cathode catalyst slurry: The catalyst slurry is composed of carbon-supported platinum catalyst particles, 5% Nafion solution, pure water and n-propanol in a mass ratio of 1:10:10:50, and the catalyst particles are evenly dispersed in the slurry by combining ball milling and ultrasonic dispersion;

[0094] 2. Preparation of cathode non-uniform catalyst layer: Spray the catalyst slurry on the surface of the titanium mesh by ultrasonic spraying, with a loading of 0.1 mg / cm2 , based on the overall area of ​​the titanium mesh substrate; since the titanium mesh has an ordered woven structure, the catalyst is only loaded on the surface of the titanium wire, thereby obtaining a non-uniformly loaded catalyst layer;

[0095] 3. Preparation of anode single-side CCM membrane electrode: The anode catalyst layer is formed on the surface of the anode diffusion layer by the following methods:

[0096] First, the catalyst slurry is prepared. The specific preparation process is the same as that of the cathode catalytic slurry, except that the carbon-supported platinum particles are replaced by IrO2 catalyst, wherein the mass ratio of IrO2 catalyst, 5% concentration Nafion solution, deionized water, and n-propanol is 1:5:5:50;

[0097] Then the anode catalyst slurry was sprayed on the surface of the proton exchange membrane to form a uniform anode catalyst layer with a catalyst loading of 2 mg / cm 2 ;

[0098] 4. Preparation of integrated electrodes: The ordered titanium mesh electrode with non-uniformly loaded catalyst at the cathode, the single-sided CCM membrane electrode with an anode IrO2 catalyst layer, and the anode diffusion layer are combined into one by hot pressing at a temperature of 130°C and a pressure of 5 MPa. During the hot pressing process, a portion of the titanium mesh will be embedded in the proton exchange membrane, so that the non-uniformly loaded catalyst layer can fully contact the proton membrane to form a three-dimensional distribution.

[0099] Example 4

[0100] This embodiment provides an ordered integrated water electrolysis hydrogen production electrode with non-uniform directional catalyst loading, which is an integrated water electrolysis hydrogen production electrode for proton exchange membrane electrolysis cell / anion exchange membrane electrolysis cell, and has a structure as shown in FIG. Figure 8 shown.

[0101] The integrated water electrolysis hydrogen production electrode is composed of an anode, an ion exchange membrane and a cathode;

[0102] The anode is composed of an anode ordered diffusion layer and an anode directional supported catalyst layer, wherein the anode directional supported catalyst layer is directionally supported on the surface of the anode ordered diffusion layer, the anode ordered diffusion layer is a titanium mesh with a thickness of 0.2 mm and a mesh number of 200 meshes, and the material of the catalyst layer is IrO2 catalyst and ionomer Nafion;

[0103] The cathode is composed of a cathode ordered diffusion layer and a cathode directional supported catalyst layer, wherein the cathode directional supported catalyst layer is directionally supported on the surface of the cathode ordered diffusion layer, the cathode ordered diffusion layer is a titanium mesh with a thickness of 0.2 mm and a mesh size of 200 meshes, and the material of the catalyst layer is a carbon-supported platinum catalyst (Pt loading is 60 wt%) and ionomer Nafion;

[0104] The anode and cathode are respectively located on both sides of a proton exchange membrane (made of perfluorosulfonic acid (PFSA) with a thickness of 100 μm), and the anode-oriented catalyst layer and the cathode-oriented catalyst layer are respectively combined with the proton exchange membrane.

[0105] The integrated water electrolysis hydrogen production electrode of this embodiment is prepared by the following steps:

[0106] 1. Prepare anode catalyst slurry: The catalyst slurry is composed of IrO2 catalyst particles, 5% Nafion solution, pure water and n-propanol in a mass ratio of 1:5:5:50, and the catalyst particles are evenly dispersed in the slurry by combining ball milling and ultrasonic dispersion;

[0107] 2. Preparation of anode non-uniform catalyst layer: Spray the catalyst slurry on the surface of the titanium mesh using an ultrasonic sprayer with a loading of 0.5 mg / cm 2 , based on the overall area of ​​the titanium mesh substrate; since the titanium mesh has an ordered woven structure, the catalyst is only loaded on the surface of the titanium wire, thereby obtaining a non-uniformly loaded catalyst layer;

[0108] 3. Prepare cathode catalyst slurry: The catalyst slurry is composed of carbon-supported platinum catalyst particles, 5% Nafion solution, pure water and n-propanol in a mass ratio of 1:10:10:50, and the catalyst particles are evenly dispersed in the slurry by combining ball milling and ultrasonic dispersion;

[0109] 4. Preparation of non-uniform cathode catalyst layer: Spray the catalyst slurry on the surface of the titanium mesh using an ultrasonic sprayer with a loading of 0.1 mg / cm 2 , based on the overall area of ​​the titanium mesh substrate; since the titanium mesh has an ordered woven structure, the catalyst is only loaded on the surface of the titanium wire, thereby obtaining a non-uniformly loaded catalyst layer;

[0110] 5. Preparation of integrated electrodes: The ordered titanium mesh electrode with non-uniform catalyst loading at the anode, the ordered titanium mesh electrode with non-uniform catalyst loading at the cathode, and the ion exchange membrane are combined into one by hot pressing at a temperature of 130°C and a pressure of 5 MPa. During the hot pressing process, a portion of the titanium mesh will be embedded in the proton exchange membrane, so that the non-uniform catalyst loading layer is fully in contact with the proton membrane, forming a three-dimensional distribution.

Claims

1. An ordered integrated water electrolysis hydrogen production electrode with non-uniform directional catalyst loading, wherein: The ordered integrated water electrolysis hydrogen production electrode is composed of an anode, a cathode and an intermediate membrane layer; The anode is composed of an anode base layer and an anode catalyst layer, and the cathode is composed of a cathode base layer and a cathode catalyst layer; The anode base layer is an ordered base layer and the anode catalyst layer is a non-uniformly oriented supported layer, and / or the cathode base layer is an ordered base layer and the cathode catalyst layer is a non-uniformly oriented supported layer.

2. The ordered integrated water electrolysis hydrogen production electrode according to claim 1, wherein: The ordered base layer is selected from an ordered electrode substrate and / or an ordered diffusion layer.

3. The ordered integrated water electrolysis hydrogen production electrode according to claim 2, wherein: The ordered electrode substrate is selected from a metal mesh and an electrode substrate with an ordered structure obtained by 3D printing, laser processing or photolithography processing; The ordered electrode diffusion layer is selected from a metal mesh and a diffusion layer with an ordered structure obtained by 3D printing, laser processing or photolithography processing.

4. The ordered integrated water electrolysis hydrogen production electrode according to claim 3, wherein: The metal mesh is selected from an ordered woven nickel mesh and / or an ordered woven titanium mesh.

5. The ordered integrated water electrolysis hydrogen production electrode according to claim 4, wherein: The mesh number of the nickel mesh and / or the titanium mesh is 40 meshes to 200 meshes.

6. The ordered integrated water electrolysis hydrogen production electrode according to claim 1, wherein: The intermediate membrane layer is a diaphragm or an ion exchange membrane.

7. A method for preparing an ordered integrated water electrolysis hydrogen production electrode with a non-uniform directional catalyst support according to any one of claims 1 to 6, comprising the following steps: (1) Directly loading the anode catalyst on the surface of the anode ordered base layer to form an anode directed loaded catalyst layer to obtain an anode with non-uniform directed loading, or, loading the anode catalyst on the surface of the intermediate membrane layer to form an anode continuous catalyst layer; (2) Directly loading the cathode catalyst on the surface of the cathode ordered base layer to form a cathode directed loaded catalyst layer to obtain a non-uniform directed loaded cathode, or, loading the cathode catalyst on the surface of the intermediate membrane layer to form a cathode continuous catalyst layer; (3) The intermediate membrane layer is sandwiched between the anode base layer on which the anode catalyst layer is directionally loaded and the cathode base layer on which the cathode catalyst layer is directionally loaded, or the intermediate membrane layer on one side of which continuously loads the cathode catalyst layer is sandwiched between the anode base layer and the cathode base layer on which the anode catalyst layer is directionally loaded, or the intermediate membrane layer on one side of which continuously loads the anode catalyst layer is sandwiched between the cathode base layer and the anode base layer on which the cathode catalyst layer is directionally loaded, so that the three are composited together to obtain the ordered integrated water electrolysis hydrogen production electrode with the non-uniform directionally loaded catalyst.

8. The preparation method according to claim 7, wherein: The process of directionally loading the anode catalyst on the surface of the anode ordered base layer is achieved by drip coating, spray coating, electroplating or sputtering; The process of directionally loading the cathode catalyst on the surface of the cathode ordered base layer is achieved by drip coating, spray coating, electroplating or sputtering.

9. The preparation method according to claim 7, wherein: The compounding method is selected from hot pressing, the hot pressing pressure is 1MPa-10MPa, the temperature is 100℃-150℃, and the time is 2min-10min.

10. Use of the ordered integrated water electrolysis hydrogen production electrode with non-uniform directional catalyst loading according to any one of claims 1 to 6 in water electrolysis hydrogen production; Preferably, the ordered integrated water electrolysis hydrogen production electrode is placed in an electrolytic cell and used as an electrode; Preferably, the electrolytic cell is one of an alkaline electrolytic cell, a proton exchange membrane electrolytic cell, and an anion exchange membrane electrolytic cell.

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