An ordered integrated electrolytic water hydrogen production electrode with a non-uniformly oriented supported catalyst and its preparation method

Abstract

The present invention provides an ordered integrated electrolytic water hydrogen production electrode with a non-uniformly oriented supported catalyst and a preparation method thereof. The ordered integrated electrolytic water 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. The present invention also provides a preparation method of the above-mentioned ordered integrated electrolytic water hydrogen production electrode and its application in electrolytic water hydrogen production. The present invention supports the catalyst in a specific area to form a non-uniformly supported catalyst layer, and combines it with a film-catalyst layer-electrode substrate / diffusion layer integrated electrode structure by means of hot pressing and the like, which can greatly improve the utilization rate of the catalyst and reduce the impedance.

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 directionally supported layer, and / or, the cathode base layer is an ordered base layer and the cathode catalyst layer is a non-uniformly directionally supported layer.

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

[0009] Among them, the ordered structure can be a regular network structure, and the catalyst layer is distributed on the surface of the filaments or wires constituting the network structure, etc. The conventional base layer is a disordered porous structure.

[0010] During the preparation of a conventional electrode based on a disordered porous base layer, 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 penetrating 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 on the entire surface, and this surface includes the exposed pore surface, while the ordered structure of the present invention realizes loading only on the outermost layer of the base layer in direct contact with the membrane.

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

[0012] The catalyst layer of a conventional catalyst-coated membrane (CCM) configuration is continuous, that is, the entire surface of the intermediate membrane layer is covered with catalyst material; while a conventional porous electrode based on a disordered porous base layer is covered with catalyst material on both 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 electrolytic water 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 lithographic processing. The above-mentioned metal mesh can be a woven mesh or a drawn 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 mesh to 200 mesh; among them, a nickel mesh is generally used in an alkaline electrolytic cell, and a titanium mesh is generally used in a proton exchange membrane electrolytic cell.

[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. Among them, 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 the substrate, and then control the power and movement trajectory of the laser to process ordered holes on the substrate; the general process of photolithography is to first prepare a metal plate as the substrate, then make a mask with ordered holes, and then perform photolithography and etching steps to process ordered holes on the metal plate.

[0016] According to a specific embodiment of the present invention, preferably, in the above-mentioned ordered integrated electrolytic water 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 electrolytic water 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, 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 electrolytic water hydrogen production electrode, the intermediate film layer is a diaphragm or an ion exchange membrane. For example, diaphragms suitable for alkaline electrolytic water hydrogen production include polyphenylene sulfide fabric diaphragms (PPS), polysulfone diaphragms (PSF), organic-inorganic composite diaphragms, etc., ion exchange membranes suitable for alkaline electrolytic water hydrogen production include anion exchange membranes, etc., and ion exchange membranes suitable for PEM electrolytic water 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 electrolytic water 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 directionally supported 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 electrolytic water 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 directionally supported cathode catalyst layer is 0.1 μm - 10 μm.

[0021] According to the specific embodiments of the present invention, for the cathode and anode of the ordered integrated electrolytic water hydrogen production electrode, an ordered electrode substrate / diffusion layer and a directionally supported catalyst layer can be simultaneously adopted, or only one electrode can adopt an ordered structure and a directionally supported catalyst layer while the other electrode adopts a conventional configuration (i.e., a conventional disordered base layer). That is, the specific structure of the above-mentioned ordered integrated electrolytic water hydrogen production electrode can be selected from one of the following several structures:

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

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

[0025] The present invention also provides a preparation method for the above-mentioned ordered integrated electrolytic water hydrogen production electrode with non-uniformly directionally supported catalysts, which includes the following steps:

[0026] (1) Directionally support an anode catalyst on the surface of the anode ordered base layer to form an anode directionally supported catalyst layer, obtaining a non-uniformly directionally supported anode, or support an anode catalyst on the surface of the intermediate membrane layer to form an anode continuous catalyst layer, obtaining a continuously supported anode;

[0027] (2) Directionally support a cathode catalyst on the surface of the cathode ordered base layer to form a cathode directionally supported catalyst layer, obtaining a non-uniformly directionally supported cathode, or support a cathode catalyst on the surface of the intermediate membrane layer to form a cathode continuous catalyst layer, obtaining a continuously supported cathode;

[0028] (3) Clamp the intermediate membrane layer between the anode base layer with the anode catalyst layer directionally supported and the cathode base layer with the cathode catalyst layer directionally supported, or clamp the intermediate membrane layer with the cathode catalyst layer continuously supported on one side between the anode base layer with the anode catalyst layer directionally supported and the cathode base layer, or clamp the intermediate membrane layer with the anode catalyst layer continuously supported on one side between the cathode base layer with the cathode catalyst layer directionally supported and the anode base layer, so that the three are combined together to obtain the above-mentioned ordered integrated electrolytic water hydrogen production module with non-uniformly directionally supported catalysts.

[0029] According to a specific embodiment of the present invention, preferably, in the above preparation method, the directional loading can be carried out by physical or chemical means such as drop coating, spraying, electroplating, sputtering, etc. Through these methods, 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 includes:

[0031] If the drop coating / spraying process is adopted, first prepare the catalyst slurry. The catalyst slurry includes catalyst particles, ionomer (such as Nafion), and solvent (such as water, alcohols). After proper preparation, it is ball milled and dispersed; 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 coating; then the slurry is drop coated on the surface of the ordered base layer with a dropper or sprayed on the surface of the ordered base layer with an ultrasonic sprayer. By controlling the quality of the drop coating / spraying, the loaded catalyst amount is controlled to be within 0.05 mg / cm 2 -0.7 mg / cm 2 , calculated based on the total area of the ordered base layer;

[0032] If the sputtering process is adopted, first place the sample on the sputtering platform of the sputtering equipment (such as a plasma sputtering equipment, a magnetron sputtering equipment), then select the target made of the required catalyst, and control the sputtered catalyst amount by controlling the sputtering power and time, so that the amount is controlled to be within 0.05 mg / cm 2 -0.7 mg / cm 2 , calculated based on the total area of the ordered base layer;

[0033] If the electroplating process is adopted, first physically cover one side of the ordered base layer to isolate this side from the electroplating solution, then place the ordered base layer in a solution containing catalyst ions for electroplating, so that the catalyst is deposited on one side surface of the ordered base layer. By controlling the electroplating time, the deposited catalyst amount is controlled to be within 0.05 mg / cm 2 -0.7 mg / cm 2 , calculated based on the total 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 with reference to the process of forming the anode directionally loaded catalyst layer.

[0035] The three-phase interface refers to the sites that simultaneously meet the conditions for proton, electron, and water-vapor transport, that is, the positions where the membrane is in direct contact with the base layer. The technical solution provided by the present invention can enable the catalyst to be distributed as much as possible at the three-phase interface through directional loading. The specific implementation method is based on the base layer with ordered through-holes. During the loading process, the slurry dropped / sprayed into the pore region will directly pass through the base layer (this part of the slurry can be collected to recover precious metals), so that the catalyst is only loaded on the solid surface of the base layer, and these positions correspond to the positions in direct contact with the membrane; if the sputtering process is used, the catalyst particles sputtered into the pore region can also directly pass through the base layer (this part of the catalyst can be collected to recover precious metals), so that the catalyst is only loaded on the solid surface of the base layer; if processes such as electroplating, hydrothermal treatment, and thermal decomposition are used, physical coverage can be first carried out on one side of the ordered base layer, and then electroplating can be carried out to achieve the loading of the catalyst only on one side surface of the ordered base layer. In short, through the technical solution of the present invention, the low-utilization area of the catalyst can be avoided, so as to improve the catalyst utilization rate while ensuring the electrochemical performance and reducing the catalyst dosage.

[0036] If the traditional catalyst-coated membrane (CCM) process is used, since the surface of the membrane is continuous, only a continuous catalyst layer can be formed on the membrane surface. In this way, there is also catalyst loading at the positions that are not in direct contact after being combined with the electrode substrate / diffusion layer, and it is impossible to make the catalyst only distributed at the three-phase interface; if the traditional disordered electrode substrate / diffusion layer is used, due to its disordered three-dimensional pore structure, during the catalyst loading process, the catalyst will penetrate into the internal pores, and it is impossible to achieve loading only on the surface. The catalyst penetrating into the internal pores cannot contact the membrane and cannot form a three-phase interface, resulting in waste.

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

[0038] In the ordered integrated electrolytic water 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 at the same time provide a substrate for the directional loading of the catalyst; the catalyst layer directionally loaded on the ordered substrate can effectively avoid the low-utilization catalyst layer that does not directly contact the diffusion layer compared with the traditional CCM membrane electrode, thereby improving the catalyst utilization rate while ensuring the electrochemical performance, reducing the catalyst dosage; further combined with an integration means (such as hot pressing), the bonding strength between different components is improved, and the integration means can improve the contact interface, embed a part of the ordered electrode with a non-uniformly loaded catalyst layer into 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 an application of the above-mentioned ordered integrated electrolytic water hydrogen production electrode with non-uniform directional loading of the catalyst in electrolytic water hydrogen production.

[0040] According to a specific embodiment of the present invention, preferably, the above-mentioned ordered integrated electrolytic water hydrogen production electrode is placed in an electrolytic cell for use 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 electrolytic water hydrogen production electrolysis unit provided by the present invention is based on an ordered electrode substrate / diffusion layer, directionally loads a catalyst in a specific area to form a non-uniformly loaded catalyst layer, and combines with a diaphragm / ion exchange membrane through means such as hot pressing to form a membrane-catalyst layer-electrode substrate / diffusion layer integrated electrode structure, which can greatly improve the catalyst utilization rate and reduce the impedance. Description of the Drawings

[0043] Figure 1 Schematic diagram of the structure of the ordered integrated electrolytic water hydrogen production electrode provided for Example 1.

[0044] Figure 2 Schematic diagram of the structure of the ordered integrated electrolytic water hydrogen production electrode provided for Example 2.

[0045] Figure 3 Scanning electron microscope picture of the integrated electrolytic water hydrogen production electrode of Example 2.

[0046] Figure 4 Comparison result of polarization curves between the integrated electrolytic water hydrogen production electrode of Example 2 and the traditional CCM membrane electrode.

[0047] Figure 5Comparison results of Ohmic impedance between the integrated electrolytic water hydrogen production electrode of Example 2 and the traditional CCM membrane electrode.

[0048] Figure 6 Comparison results of catalyst utilization rate between the integrated electrolytic water hydrogen production electrode of Example 2 and the traditional CCM membrane electrode.

[0049] Figure 7 The ordered integrated electrolytic water hydrogen production electrode with non-uniformly oriented supported catalyst provided in Example 3.

[0050] Figure 8 The ordered integrated electrolytic water hydrogen production electrode with non-uniformly oriented supported catalyst provided in Example 4. Detailed implementation manners

[0051] For a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below, but it should not be construed as a limitation on the implementable scope of the present invention.

[0052] Example 1

[0053] This example provides an ordered integrated electrolytic water hydrogen production electrode with non-uniformly oriented supported catalyst, which is an integrated electrolytic water hydrogen production electrode for an alkaline electrolytic cell, and the structure is as Figure 1 shown.

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

[0055] The anode is composed of an anodic ordered electrode substrate and an anodic oriented supported catalyst layer. Among them, the anodic oriented supported catalyst layer is oriented and supported on the surface of the anodic ordered electrode substrate. The anodic ordered electrode substrate is a 60-mesh nickel mesh, and the catalytic material of the catalyst layer is Ir, and this catalytic material is distributed on the surface of the nickel wires constituting the nickel mesh;

[0056] The cathode is composed of a cathodic ordered electrode substrate and a cathodic oriented supported catalyst layer. Among them, the cathodic oriented supported catalyst layer is oriented and supported on the surface of the cathodic ordered electrode substrate. The cathodic ordered electrode substrate is a 60-mesh nickel mesh, and the catalytic material of the catalyst layer is Pt, and this catalytic material 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 moreover, the anodic oriented supported catalyst layer and the cathodic oriented supported catalyst layer are respectively combined with the diaphragm.

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

[0059] 1. Orientedly load an anode catalyst on the surface of an anodically ordered electrode substrate to form an anodically oriented loaded catalyst layer, thereby obtaining an anode. The specific method is as follows:

[0060] Prepare the anode catalyst layer by sputtering: Place the nickel mesh substrate on the sputtering device platform, install the Ir target, and control the sputtering power and time to make the sputtering loading 0.1 mg / cm 2 , based on the total area of the nickel mesh substrate; due to the ordered weaving structure of the nickel mesh, the catalyst is only loaded on the surface of the nickel wire, thereby obtaining a non-uniformly loaded catalyst layer;

[0061] 2. Orientedly load a cathode catalyst on the surface of a cathodically ordered electrode substrate to form a cathodically oriented loaded catalyst layer, thereby obtaining a cathode. The specific method is as follows:

[0062] Prepare the cathode catalyst layer by sputtering: Place the nickel mesh substrate on the sputtering device platform, install the Pt target, and control the sputtering power and time to make the sputtering loading 0.05 mg / cm 2 , based on the total area of the nickel mesh substrate; due to the ordered weaving structure of the nickel mesh, the catalyst is only loaded on the surface of the nickel wire, thereby obtaining a non-uniformly loaded catalyst layer;

[0063] 3. Sandwich a diaphragm (zirfion diaphragm, with a thickness of 500 μm) between the anodically oriented loaded catalyst layer and the cathodically oriented loaded catalyst layer, and bond them together by hot pressing. The hot pressing temperature is 100 °C and the pressure is 3 MPa to form an integrated electrolytic water hydrogen production electrode.

[0064] Example 2

[0065] This example provides an ordered integrated electrolytic water hydrogen production electrode with non-uniformly oriented loaded catalysts, which is an integrated electrolytic water hydrogen production electrode for a proton exchange membrane electrolyzer / anion exchange membrane electrolyzer, and its structure is as Figure 2 shown.

[0066] This integrated electrolytic water hydrogen production electrode consists of an anode, an ion exchange membrane, and a cathode;

[0067] The anode consists of an anodic ordered diffusion layer and an anodically oriented loaded catalyst layer. Among them, the anodically oriented loaded catalyst layer is orientedly loaded on the surface of the anodically ordered electrode substrate. The anodic ordered diffusion layer is a titanium mesh with a thickness of 0.2 mm and a mesh number of 200. The material of the catalyst layer is IrO2 catalyst and ionomer Nafion;

[0068] The cathode consists of a conventional diffusion layer and a cathode catalyst layer. The conventional diffusion layer has a disordered porous structure, and the cathode catalyst layer is a continuous layer supported on the surface of the ion exchange membrane. Among them, the material of the diffusion layer of the cathode is sintered titanium powder, with a size of 2 cm × 2 cm and a thickness of 0.5 mm; the material of the cathode catalyst layer is platinum supported on carbon and Nafion ionomer;

[0069] The anode and the cathode are respectively located on both sides of the proton exchange membrane (the material is 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 electrolytic water hydrogen production electrode of this embodiment is prepared through the following steps:

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

[0072] 2. Prepare the anode non-uniformly supported catalyst layer: Spray the catalyst slurry on the surface of the titanium mesh through an ultrasonic sprayer. The loading of the anode catalyst is 0.5 mg / cm 2 , calculated based on the total area of the titanium mesh substrate; due to the ordered woven structure of the titanium mesh, the catalyst is only supported on the surface of the titanium wire, thereby obtaining a non-uniformly supported catalyst layer;

[0073] 3. Prepare the cathode single-sided CCM membrane electrode: The formation of the cathode catalyst layer on the surface of the cathode diffusion layer is specifically carried out in the following manner:

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

[0075] Then spray the cathode catalyst slurry on the surface of the proton exchange membrane to form a uniform cathode catalyst layer, and the loading of the cathode catalyst is 0.2 mg / cm 2 ;

[0076] 4. Prepare the integrated electrode: Integrate the ordered titanium mesh electrode with non-uniformly supported anode catalyst, the single-sided CCM membrane electrode with the cathode platinum supported on carbon catalyst layer, and the cathode diffusion layer into one body by hot pressing. The hot pressing temperature is 130 °C and the pressure is 5 MPa; among them, during the hot pressing process, a part of the titanium mesh will be embedded in the proton exchange membrane, so that the non-uniformly supported catalyst layer can fully contact the proton membrane and form a three-dimensional distribution.

[0077] Comparative Example 1

[0078] This comparative example provides a proton exchange membrane for electrolytic water hydrogen production with a traditional CCM configuration, whose structure is a proton exchange membrane uniformly coated with catalyst layers on both sides. Specifically, it is prepared through the following steps:

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

[0080] 2. Prepare the anode uniformly supported catalyst layer: The anode catalyst slurry is sprayed on the surface of the proton exchange membrane through an ultrasonic sprayer to form a uniform anode catalyst layer, and the catalyst loading is 2mg / cm 2 ;

[0081] 3. Prepare the cathode catalyst slurry: 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. Among them, 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;

[0082] 4. Prepare the cathode uniformly supported catalyst layer: The cathode catalyst slurry is sprayed on the other surface of the proton exchange membrane through an ultrasonic sprayer to form a uniform cathode catalyst layer, and the cathode catalyst loading is 0.2mg / cm 2 。

[0083] During performance testing, an anode diffusion layer and a cathode diffusion layer are respectively arranged on both sides of the anode and cathode of the CCM membrane electrode. 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 diffusion layer of the cathode is sintered titanium powder, with a size of 2cm×2cm and a thickness of 0.5mm.

[0084] Figure 3 shows the scanning electron microscope image of the integrated electrolytic water hydrogen production electrode obtained by directional loading based on the ordered titanium mesh substrate in this example, Figure 4 shows the comparison result of the polarization curves between the integrated electrolytic water hydrogen production electrode in this example and the traditional CCM membrane electrode (Comparative Example 1).

[0085] According to Figure 4 the results shown, it can be seen that: the catalyst loading of the integrated electrolytic water hydrogen production electrode in this example is reduced by 75% (the catalyst loading of the CCM membrane electrode in Comparative Example 1 is 2mg / cm 2 , and the catalyst loading of the integrated electrolytic water hydrogen production electrode in this example is 0.5mg / cm 2), but the performance has been improved by 39% (at 2V, the current density of the CCM membrane electrode in Comparative Example 1 is 2.8 A / cm 2 , and the current density of the integrated electrolytic water hydrogen production electrode in this example is 3.9 A / cm 2 ), the ohmic impedance has been reduced by 43% (as shown in Figure 5 ), and the catalyst utilization rate has been increased by 5.6 times (expressed by the current corresponding to unit mass of the catalyst, as shown in Figure 6 ).

[0086] Example 3

[0087] This example provides an ordered integrated electrolytic water hydrogen production electrode with non-uniformly oriented supported catalysts, which is an integrated electrolytic water hydrogen production electrode for proton exchange membrane electrolytic cells / anion exchange membrane electrolytic cells, and the structure is as shown in Figure 7 .

[0088] The integrated electrolytic water 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 directionally supported catalyst layer. Among them, the cathode directionally 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 number of 200. The material of the catalyst layer is carbon-supported platinum catalyst (Pt loading is 60 wt%) and ionomer Nafion;

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

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

[0092] The integrated electrolytic water hydrogen production electrode in this example is prepared by the following steps:

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

[0094] 2. Prepare the cathode non-uniformly supported catalyst layer: Spray the catalyst slurry on the surface of the titanium mesh through an ultrasonic sprayer, and the loading is 0.1 mg / cm2 , based on the total area of the titanium mesh substrate; since the titanium mesh has an ordered weaving structure, the catalyst is only supported on the surface of the titanium wire, thus obtaining a non-uniformly supported catalyst layer;

[0095] 3. Preparation of an anode single-sided CCM membrane electrode: The formation of the anode catalyst layer on the surface of the anode diffusion layer is carried out in the following way:

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

[0097] Then, spray the anode catalyst slurry on the surface of the proton exchange membrane to form a uniform anode catalyst layer, and the catalyst loading is 2mg / cm 2 ;

[0098] 4. Preparation of an integrated electrode: Integrate the ordered titanium mesh electrode with non-uniformly supported catalyst on the cathode, the single-sided CCM membrane electrode with the anode IrO2 catalyst layer, and the anode diffusion layer by hot pressing. The hot pressing temperature is 130°C and the pressure is 5MPa; among them, during the hot pressing process, a part of the titanium mesh will be embedded in the proton exchange membrane, so that the non-uniformly supported catalyst layer can fully contact the proton membrane to form a three-dimensional distribution.

[0099] Example 4

[0100] This example provides an ordered integrated electrolytic water hydrogen production electrode with non-uniform directional catalyst loading, which is an integrated electrolytic water hydrogen production electrode for a proton exchange membrane electrolyzer / anion exchange membrane electrolyzer, and the structure is as Figure 8 shown.

[0101] This integrated electrolytic water hydrogen production electrode consists of an anode, an ion exchange membrane, and a cathode;

[0102] The anode consists of an anode ordered diffusion layer and an anode directionally supported catalyst layer. Among them, the anode directionally 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 0.2mm and a mesh number of 200. The material of the catalyst layer is the IrO2 catalyst and the ionomer Nafion;

[0103] The cathode consists of a cathode ordered diffusion layer and a cathode directionally supported catalyst layer. Among them, the cathode directionally 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 0.2mm and a mesh number of 200. The material of the catalyst layer is the carbon-supported platinum catalyst (Pt loading is 60wt%) and the ionomer Nafion;

[0104] 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-oriented supported catalyst layer and the cathode-oriented supported catalyst layer are respectively combined with the proton exchange membrane.

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

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

[0107] 2. Prepare the anode non-uniformly supported catalyst layer: Spray the catalyst slurry on the surface of the titanium mesh through an ultrasonic sprayer, with a loading of 0.5 mg / cm 2 , calculated based on the total area of the titanium mesh substrate; due to the ordered woven structure of the titanium mesh, the catalyst is only supported on the surface of the titanium wires, thereby obtaining a non-uniformly supported catalyst layer;

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

[0109] 4. Prepare the cathode non-uniformly supported catalyst layer: Spray the catalyst slurry on the surface of the titanium mesh through an ultrasonic sprayer, with a loading of 0.1 mg / cm 2 , calculated based on the total area of the titanium mesh substrate; due to the ordered woven structure of the titanium mesh, the catalyst is only supported on the surface of the titanium wires, thereby obtaining a non-uniformly supported catalyst layer;

[0110] 5. Prepare the integrated electrode: Thermally press the ordered titanium mesh electrode with the anode non-uniformly supported catalyst, the ordered titanium mesh electrode with the cathode non-uniformly supported catalyst, and the ion exchange membrane into one body. The thermal pressing temperature is 130 °C and the pressure is 5 MPa; among them, during the thermal pressing process, a part of the titanium mesh will be embedded in the proton exchange membrane, so that the non-uniformly supported catalyst layer can fully contact the proton membrane to form 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; The ordered base layer is selected from an ordered woven nickel mesh and / or an ordered woven titanium mesh.

2. The ordered integrated water electrolysis hydrogen production electrode according to claim 1, wherein: The mesh number of the nickel mesh and / or the titanium mesh is 40 meshes to 200 meshes.

3. 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.

4. 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 3, 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 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.

5. The preparation method according to claim 4, 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.

6. The preparation method according to claim 4, 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.

7. Use of the ordered integrated water electrolysis hydrogen production electrode with non-uniform directional catalyst support as described in any one of claims 1 to 3 in water electrolysis hydrogen production.

8. The use according to claim 7, wherein: The ordered integrated water electrolysis hydrogen production electrode is placed in an electrolytic cell and used as an electrode; 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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