A membrane electrode for hydrogen production by electrolysis of water, a preparation method thereof, and a water electrolysis apparatus

Abstract

The application belongs to the technical field of membrane electrodes, and discloses a membrane electrode for electrolyzing water to produce hydrogen, a preparation method thereof and a water electrolysis device. The membrane electrode comprises a proton exchange membrane, an anode catalytic layer and a cathode catalytic layer arranged on two sides of the proton exchange membrane, and an anode modification layer; the content of an anode catalyst in the anode catalytic layer increases from the side close to the proton exchange membrane to the direction away from the proton exchange membrane; the content of a cathode catalyst in the cathode catalytic layer increases from the side close to the proton exchange membrane to the direction away from the proton exchange membrane; the anode modification layer is arranged between the anode catalytic layer and the proton exchange membrane, and the anode modification layer contains a molybdenum-based catalyst for catalyzing the oxidation reaction of hydrogen, thereby effectively improving the catalytic performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of membrane electrodes, in particular to a membrane electrode for electrolyzing water to produce hydrogen, a preparation method thereof and a water electrolysis device. BACKGROUND

[0002] With the rapid development of society, the demand for energy is increasing, and the global energy transformation is also underway. Hydrogen energy, as a clean energy with high energy density and no pollution, has been widely concerned. PEM water electrolysis hydrogen production technology can well couple renewable energy hydrogen production and become a research hotspot of hydrogen energy. The PEM water electrolysis membrane electrode is mainly composed of a proton exchange membrane, an anode catalyst layer and a cathode catalyst layer. Among them, the PEM water electrolysis hydrogen production technology is limited by key materials such as proton exchange membranes and noble metal catalysts. In the electrolysis water catalytic reaction, the current still uses platinum and other noble metals as catalysts, and the production cost is high. At the same time, the catalyst particles in the catalyst layer exist in the form of agglomeration during the manufacturing process, and with the increase of the use time, the catalyst layer may crack and fall off, which leads to the reduction of the utilization rate of the catalyst and the low catalytic efficiency. At present, when preparing the catalyst layer, the proton exchange membrane is directly used as the support layer of the catalyst layer, and the catalyst material is attached to both sides of the proton exchange membrane to form a catalyst coating film. However, the polar solvent in the catalyst coating film is easy to contact with the proton exchange membrane during the preparation process, which can easily cause the swelling problem of the proton exchange membrane, thereby affecting the structural stability of the catalyst coating film and the electrolysis efficiency. In the process of electrolysis of water, due to the pressure difference between the hydrogen evolution side and the oxygen evolution side in the electrolytic cell, hydrogen gas is easy to diffuse to the oxygen evolution side. When the mixed concentration of hydrogen and oxygen reaches a certain level, it is easy to cause explosion. With the use of the hydrogen electrolytic cell, scale is easy to form on the cathode catalyst layer, which affects the hydrogen evolution reaction. SUMMARY

[0003] Therefore, the embodiments of the present application provide a membrane electrode for electrolyzing water to produce hydrogen, which improves the hydrogen production efficiency and yield.

[0004] In a first aspect, the present application provides a membrane electrode for electrolyzing water to produce hydrogen.

[0005] The present application is achieved by the following technical solutions:

[0006] A membrane electrode for electrolyzing water to produce hydrogen, the membrane electrode comprising:

[0007] a proton exchange membrane, an anode catalyst layer and a cathode catalyst layer arranged on both sides of the proton exchange membrane, and an anode modification layer;

[0008] The content of the anode catalyst in the anode catalyst layer increases from the side far away from the proton exchange membrane to the side close to the proton exchange membrane;

[0009] The content of the cathode catalyst in the cathode catalytic layer increases from the side far away from the proton exchange membrane to the side close to the proton exchange membrane.

[0010] The anode modification layer is arranged between the anode catalytic layer and the proton exchange membrane, and the anode modification layer contains a molybdenum-based catalyst for catalyzing the oxidation reaction of hydrogen.

[0011] In a preferred example of the present application, the molybdenum-based catalyst in the anode modification layer includes at least one of a MoS2 / C composite material and a MoO2 / C composite material.

[0012] In a preferred example of the present application, the membrane electrode further includes a cathode modification layer; the cathode modification layer is arranged on the outer side of the cathode catalytic layer and is used to adsorb scale-forming ions in electrolytic water.

[0013] In a preferred example of the present application, the cathode catalytic layer includes a first cathode catalytic layer located on the side close to the proton exchange membrane and a second cathode catalytic layer located on the side far away from the proton exchange membrane; the loading amount of the cathode catalyst in the first cathode catalytic layer is greater than the loading amount of the cathode catalyst in the second cathode catalytic layer.

[0014] In a preferred example of the present application, the loading amount of the cathode catalyst in the first cathode catalytic layer is 1.5 mg / cm 2 ~2.0 mg / cm 2 , and the loading amount of the cathode catalyst in the second cathode catalytic layer is 1.0 mg / cm 2 ~1.5 mg / cm 2 .

[0015] In a preferred example of the present application, the first cathode catalytic layer and the second cathode catalytic layer are both prepared from a cathode catalytic slurry.

[0016] The cathode catalytic slurry contains a cathode catalyst, an ionic polymer, a solvent, deionized water, and a dispersant; the cathode catalyst is a Pt / CNT composite material.

[0017] In a preferred example of the present application, the content of Pt is 25%~35% based on the mass of the Pt / CNT composite material; and the average particle size of Pt is 5 nm~20 nm.

[0018] In a preferred example of the present application, the total thickness of the cathode catalytic layer is 5.0 μm~10.0 μm.

[0019] In a preferred example of the present application, the anode catalytic layer can be further provided as including a first anode catalytic layer located close to the proton exchange membrane and a second anode catalytic layer located away from the proton exchange membrane; the loading amount of the anode catalyst in the first anode catalytic layer is higher than the loading amount of the anode catalyst in the second anode catalytic layer.

[0020] In a preferred example of the present application, the loading amount of the anode catalyst in the first anode catalytic layer can be further provided as 2.5-3.5 mg / cm 2 ; and the loading amount of the second anode catalyst can be further provided as 2.0-2.5 mg / cm 2 .

[0021] In a preferred example of the present application, the first anode catalytic layer and the second anode catalytic layer can be further provided as both prepared from an anode catalytic slurry; the anode catalytic slurry includes an anode catalyst, an ionic polymer, a solvent, deionized water and a dispersant; the anode catalyst includes one or more of Ir, IrO2, Ru, RuO2, IrRuOx.

[0022] In a preferred example of the present application, the total thickness of the anode catalytic layer can be further provided as 10-20 μm.

[0023] In a preferred example of the present application, the proton exchange membrane can be further provided as selected from at least one of a perfluorosulfonic acid proton exchange membrane, an organic / inorganic nanocomposite proton exchange membrane and a fluorine-free proton exchange membrane.

[0024] In a second aspect, the present application provides a preparation method of a membrane electrode for hydrogen production by water electrolysis.

[0025] The present application is achieved by the following technical solutions:

[0026] A preparation method of a membrane electrode for hydrogen production by water electrolysis, the preparation method being used to prepare the membrane electrode of the first aspect, and the preparation method including:

[0027] Preparation of an anode catalytic slurry: mixing an anode catalyst with an ionic polymer, a solvent, deionized water and a dispersant, and performing ultrasonic dispersion to obtain a uniform first anode catalytic slurry and a second anode catalytic slurry;

[0028] Preparation of a cathode catalytic slurry: mixing a cathode catalyst with an ionic polymer, a solvent, deionized water and a dispersant, and stirring and dispersing in a planetary ball mill to obtain a first cathode catalytic slurry and a second cathode catalytic slurry;

[0029] Preparation of an anode modification layer slurry: mixing a molybdenum-based catalyst, a porous carbon material, a binder and a viscosity regulator to form an anode modification layer slurry;

[0030] The anode modification layer slurry is coated on one surface of the proton exchange membrane, and dried to obtain an anode modification layer attached to the proton exchange membrane;

[0031] The first anode catalyst slurry is coated on the surface of the anode modification layer by the transfer printing method, and placed on a vacuum adsorption heating plate for heating to form a first anode catalyst layer; the second anode catalyst slurry is coated on the surface of the first anode catalyst layer by the transfer printing method, and placed on a vacuum adsorption heating plate for heating to form a second anode catalyst layer.

[0032] The first cathode catalyst slurry is coated on the other surface of the proton exchange membrane by the transfer printing method, and placed on a vacuum adsorption heating plate for heating to form a first cathode catalyst layer; the second cathode catalyst slurry is coated on the other surface of the proton exchange membrane by the transfer printing method, and placed on a vacuum adsorption heating plate for heating to form a second cathode catalyst layer.

[0033] In a preferred example of the present application, a detachable cathode modification layer can be further provided on the surface of the second cathode catalyst layer.

[0034] In a preferred example of the present application, the step of preparing the anode catalyst slurry can further include mixing anode catalyst, ionic polymer, solvent, deionized water, and dispersant in a mass ratio of (20% to 30%):(3% to 8%):(30% to 50%):(20% to 45%):(1% to 2%), and performing ultrasonic dispersion to obtain a uniform first anode catalyst slurry.

[0035] In a preferred example of the present application, the step of preparing the anode catalyst slurry can further include mixing anode catalyst, ionic polymer, solvent, deionized water, and dispersant in a mass ratio of (20% to 30%):(3% to 8%):(30% to 50%):(20% to 45%):(1% to 2%), and performing ultrasonic dispersion to obtain a uniform first anode catalyst slurry.

[0036] In a preferred example of the present application, the step of preparing the anode catalyst slurry can further include mixing anode catalyst, ionic polymer, solvent, deionized water, and dispersant in a mass ratio of (20% to 30%):(3% to 8%):(30% to 50%):(20% to 45%):(1% to 2%), and performing ultrasonic dispersion to obtain a uniform first anode catalyst slurry.

[0037] In a preferred example of the present application, the step of preparing the cathode catalyst slurry can further include mixing cathode catalyst, ionic polymer, solvent, deionized water, and dispersant in a mass ratio of (15% to 20%):(3% to 8%):(30% to 50%):(25% to 45%):(1% to 2%), and stirring and dispersing in a planetary ball mill to obtain a first cathode catalyst slurry.

[0038] In a preferred example of the present application, the mass ratio of the cathode catalyst, the ionomer, the solvent, the deionized water and the dispersant can be (10-15) : (3-8) : (30-50) : (25-45) : (1-2), and the mixture is placed in a planetary ball mill for stirring and dispersion to obtain the second cathode catalyst slurry.

[0039] In a preferred example of the present application, the thickness of the anode modification layer is 0.5-1.0 μm.

[0040] In a third aspect, the present application provides an electrolytic water device.

[0041] The present application is achieved by the following technical solutions:

[0042] An electrolytic water device includes an electrolytic cell, and the electrolytic cell includes the membrane electrode for electrolytic water hydrogen production according to the first aspect.

[0043] Compared with the prior art, the technical solutions provided in the embodiments of the present application have at least the following beneficial effects:

[0044] The membrane electrode provided in the present application includes a proton exchange membrane, an anode catalyst layer and a cathode catalyst layer disposed on both sides of the proton exchange membrane, and an anode modification layer; the content of the anode catalyst in the anode catalyst layer increases from the side close to the proton exchange membrane to the direction away from the proton exchange membrane; the content of the cathode catalyst in the cathode catalyst layer increases from the side close to the proton exchange membrane to the direction away from the proton exchange membrane; the anode modification layer is disposed between the anode catalyst layer and the proton exchange membrane, and the anode modification layer contains a molybdenum-based catalyst for catalyzing the oxidation reaction of hydrogen. By increasing the content of the catalyst in the direction away from the proton exchange membrane, the catalytic ability inside the catalyst layer is improved, and the catalytic performance of electrolytic water is improved; at the same time, the molybdenum-based catalyst capable of catalyzing the oxidation reaction of hydrogen is added to the anode catalyst side, which can reduce the hydrogen on the oxygen evolution side, improve the safety performance in the hydrogen production process of electrolytic water, and improve the catalytic efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 The structure diagram of the membrane electrode for electrolytic water hydrogen production provided in an embodiment of the present application is shown;

[0046] Figure 2 The structure diagram of the membrane electrode for electrolytic water hydrogen production provided in another embodiment of the present application is shown;

[0047] REFERENCE SIGNS:

[0048] Proton exchange membrane-1, cathode catalyst layer-2, first cathode catalyst layer-21, second cathode catalyst layer-22, anode modification layer-3, anode catalyst layer-4, first anode catalyst layer-41, second anode catalyst layer-42. DETAILED DESCRIPTION

[0049] The specific embodiments are only intended for explaining the present application, and are not intended to limit the present application. Those skilled in the art can make modifications to the embodiments according to the needs after reading the present specification, and the modifications without creative contribution are protected by the patent law as long as they are within the scope of the claims of the present application.

[0050] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the scope of the present application.

[0051] In addition, the term "and / or" in the present application only describes the association relationship of the associated objects, and indicates that there can be three relationships, for example, A and / or B can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects unless otherwise specified.

[0052] The terms "first", "second", and the like in the present application are used to distinguish the same items or similar items with basically the same function, and it should be understood that there is no logical or time sequence dependence between "first", "second", and "nth", and the quantity and execution order are not limited.

[0053] In these embodiments, the parts and percentages are by mass unless otherwise indicated.

[0054] "Mass parts" refers to a basic unit of measurement representing the mass ratio relationship of multiple components. One part can represent any unit mass, such as 1 g, 2.689 g, etc. If we say that the mass parts of component A is a parts and the mass parts of component B is b parts, it means that the mass ratio of component A to component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number representing a multiple factor). It should not be misunderstood that unlike the mass parts, the sum of the mass parts of all components is not limited to 100 parts.

[0055] The embodiments of the present application will be described in further detail below with reference to the drawings of the specification.

[0056] As Figure 1 shown, the membrane electrode includes:

[0057] a proton exchange membrane 1, a cathode catalytic layer 2, an anode modification layer 3 and an anode catalytic layer 4; wherein the anode catalytic layer 4 and the cathode catalytic layer 2 are oppositely arranged on both sides of the proton exchange membrane 1, the anode catalytic layer 4 is used to catalyze the generation of oxygen, and the cathode catalytic layer 2 is used to catalyze the generation of hydrogen. The proton exchange membrane 1 is selected from one of a perfluorosulfonic acid proton exchange membrane, an organic / inorganic nanocomposite proton exchange membrane, and a fluorine-free proton exchange membrane. The thickness of the proton exchange membrane is 30 μm to 60 μm.

[0058] The anode modification layer 3 is arranged between the anode catalytic layer 4 and the proton exchange membrane 1, and the anode modification layer 3 contains a molybdenum-based catalyst for catalyzing the oxidation reaction of hydrogen. Because the pressure on the cathode hydrogen evolution side in the electrolytic cell is greater than the pressure on the anode oxygen evolution side during the electrolysis of water, the hydrogen gas diffuses through the proton exchange membrane to the anode oxygen evolution side as the pressure difference increases. The anode modification layer in the present application can catalyze the reaction of hydrogen gas that has diffused through the proton exchange membrane from the cathode hydrogen evolution side before it is transmitted to the anode oxygen evolution side, which can effectively reduce the hydrogen concentration on the anode oxygen evolution side, reduce the safety hazards caused by the contact between hydrogen and oxygen, and improve the safety of the water electrolysis process. At the same time, the anode modification layer can also enhance the mechanical strength of the proton exchange membrane, improve the service life of the proton exchange membrane, improve the electrolysis performance, and thus improve the hydrogen production.

[0059] The content of the anode catalyst in the anode catalytic layer 4 increases from the side far away from the proton exchange membrane 1 to the side close to the proton exchange membrane; the content of the cathode catalyst in the cathode catalytic layer 2 increases from the side far away from the proton exchange membrane to the side close to the proton exchange membrane. The present application improves the content of the anode catalyst and the content of the cathode catalyst in the anode catalytic layer 4 and the cathode catalytic layer 2 close to the proton exchange membrane 1 by designing a gradient catalyst content, to provide more catalytic active sites for the oxygen evolution reaction and the hydrogen evolution reaction, and to improve the catalytic effect inside the catalytic layer.

[0060] In some embodiments, as Figure 2 shown, the cathode catalytic layer 2 includes a first cathode catalytic layer 21 located on the side close to the proton exchange membrane 1 and a second cathode catalytic layer 22 located on the side far away from the proton exchange membrane 1; the loading amount of the cathode catalyst in the first cathode catalytic layer 21 is greater than the loading amount of the cathode catalyst in the second cathode catalytic layer 22. The loading amount of the cathode catalyst in the first cathode catalytic layer 21 is 1.5 mg / cm 2 ~ 2.0 mg / cm 2 , and the loading amount of the cathode catalyst in the second cathode catalytic layer 22 is 1.0 mg / cm 2 ~ 1.5 mg / cm 2The total thickness of the cathode catalytic layer 2 is 5.0-10.0 μm, which can be 2.0 μm, 2.5 μm, 3.0 μm, 4.0 μm, 4.5 μm, 5.0 μm, but is not limited to the above values. Controlling the thickness of the cathode catalytic layer in the above range can ensure better catalytic effect and better ion conduction rate; if the cathode catalytic layer is too thin, the content of the catalyst will be reduced, affecting the hydrogen evolution reaction on the cathode side and the efficiency of water electrolysis; if the cathode catalytic layer is too thick, the transmission rate of hydroxyl ions to the anode side will be affected, also affecting the efficiency of water electrolysis.

[0061] Specifically, the first cathode catalytic layer and the second cathode catalytic layer are both prepared from a cathode catalytic slurry; the cathode catalytic slurry comprises a cathode catalyst, an ionic polymer, a solvent, deionized water and a dispersing agent. The cathode catalyst is a Pt / CNT composite material; the ionic polymer comprises a Nafion solution; the solvent comprises at least one of isopropyl alcohol, n-propanol, tert-butyl alcohol, ethylene glycol and glycerol; and the dispersing agent is at least one of polyacrylamide, sodium dimethyl sulfonate and N-methyl pyrrolidone.

[0062] The content of Pt is 25%-35% based on the mass of the Pt / CNT composite material; and the average particle size of Pt is 5-20 nm. The Pt nanoparticles are loaded on the highly conductive carbon nanotubes and highly uniformly dispersed on the cathode catalytic layer, effectively improving the electrochemical catalytic activity of the catalyst and the utilization rate of the catalyst; the CNT has excellent specific surface area, which can reduce the agglomeration of Pt, expose more active sites and improve the electrochemical activity of the catalyst.

[0063] The anode catalytic layer 4 comprises a first anode catalytic layer 41 located on the side close to the proton exchange membrane 1 and a second anode catalytic layer 42 located on the side away from the proton exchange membrane 1; the loading amount of the anode catalyst in the first anode catalytic layer 41 is higher than that in the second anode catalytic layer 42. The loading amount of the anode catalyst in the first anode catalytic layer 41 is 2.5-3.5 mg / cm 2 ; and the loading amount of the second anode catalyst 42 is 2.0-2.5 mg / cm 2 . The total thickness of the anode catalytic layer is 10-20 μm, which can be 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, but is not limited to the above values.

[0064] The first anode catalytic layer 41 and the second anode catalytic layer 42 are both prepared from an anode catalytic slurry; the anode catalytic slurry comprises an anode catalyst, an ionic polymer, a solvent, deionized water and a dispersing agent.

[0065] The anode catalyst comprises one or more of Ir, IrO2, Ru, RuO2, and IrRuOx; the ionomer is a Nafion solution; the solvent comprises at least one of isopropyl alcohol, n-propyl alcohol, t-butyl alcohol, ethylene glycol, and glycerol; and the dispersant comprises at least one of polyacrylamide, sodium dimethyl sulfonate, and N-methyl pyrrolidone. The dispersant is added during preparation of the cathode catalytic slurry and the anode catalytic slurry, which can effectively reduce the agglomeration loss of the catalyst particles and improve the durability of the catalyst particles.

[0066] In some embodiments, the molybdenum-based catalyst in the anode modification layer comprises at least one of a MoS2 / C composite material and a MoO2 / C composite material. The MoS2 / C composite material or the MoO2 / C composite material is mixed with a porous carbon material and a binder to form a slurry, and the slurry is coated on the surface of the proton exchange membrane. The thickness of the anode modification layer is 0.5 μm to 1.0 μm, and preferably 0.8 μm. The MoS2 / C composite material and / or the MoO2 / C composite material in the anode modification layer can catalyze the hydrogen reaction, and at the same time, the MoS2 / C composite material and / or the MoO2 / C composite material have good electrical conductivity and oxygen evolution catalytic activity, which can eliminate hydrogen and promote the oxygen evolution reaction. The porous carbon material and the binder can form a three-dimensional network structure, which can act as a deformation inhibition layer of the proton exchange membrane, effectively reducing the swelling deformation of the proton exchange membrane, improving the stability of the structure, and further improving the catalytic performance.

[0067] In some embodiments, the membrane electrode further comprises a cathode modification layer arranged on the outer side of the cathode catalytic layer in a detachable manner, for adsorbing scale-forming ions in the electrolytic water. The cathode modification layer can be installed on the outer side of the cathode catalytic layer in the form of a buckle when assembling the electrolytic water device. A potential lower than that of the cathode catalytic layer is applied to the cathode modification layer before the electrolytic water reaction, so that the cathode modification layer adsorbs most of the calcium, magnesium, and other scale-forming ions in the cathode-side water, avoids the formation of scale on the cathode catalytic layer, and improves the stability and service life of the catalytic layer. The cathode modification layer is a stainless steel plate.

[0068] The preparation method of the membrane electrode comprises:

[0069] Preparation of anode catalytic slurry: mixing anode catalyst with ionomer, solvent, deionized water and dispersant, ultrasonic dispersion to obtain uniform first anode catalytic slurry and second anode catalytic slurry; wherein the mass ratio of anode catalyst to ionomer, solvent, deionized water and dispersant in the first anode catalytic slurry is (20%-30%):(3%-8%):(30%-50%):(20%-45%):(1%-2%); the mass ratio of anode catalyst to ionomer, solvent, deionized water and dispersant in the second anode catalytic slurry is (15%-20%):(3%-8%):(30%-45%):(25%-45%):(1%-2%).

[0070] Preparation of cathode catalytic slurry: mixing cathode catalyst with ionomer, solvent, deionized water and dispersant according to the mass ratio, stirring and dispersing in a planetary ball mill to obtain first cathode catalytic slurry and second cathode catalytic slurry; wherein the mass ratio of cathode catalyst to ionomer, solvent, deionized water and dispersant in the first cathode catalytic slurry is (15%-20%):(3%-8%):(30%-50%):(25%-45%):(1%-2%); the mass ratio of cathode catalyst to ionomer, solvent, deionized water and dispersant in the second cathode catalytic slurry is (10%-15%):(3%-8%):(30%-50%):(25%-45%):(1%-2%).

[0071] Preparation of anode modification layer slurry: mixing molybdenum-based catalyst, porous carbon material and binder to form anode modification layer slurry;

[0072] Coating the anode modification layer slurry on one surface of the proton exchange membrane and drying to obtain an anode modification layer attached to the proton exchange membrane; the thickness of the anode modification layer is 0.5-1.0 μm.

[0073] Coating the first anode catalytic slurry on the surface of the anode modification layer by transfer printing method and placing it on a vacuum adsorption heating plate for heating to form a first anode catalytic layer; coating the second anode catalytic slurry on the surface of the first anode catalytic layer by transfer printing method and placing it on a vacuum adsorption heating plate for heating to form a second anode catalytic layer;

[0074] Coating the first cathode catalyst slurry on the other surface of the proton exchange membrane by transfer printing method and placing it on a vacuum adsorption heating plate for heating to form a first cathode catalytic layer; coating the second cathode catalyst slurry on the other surface of the proton exchange membrane by transfer printing method and placing it on a vacuum adsorption heating plate for heating to form a second cathode catalytic layer.

[0075] An electrolytic water device is assembled, which includes an electrolytic cell comprising the membrane electrode for electrolysis of water to produce hydrogen as described above. A cathode diffusion layer is further included outside the cathode catalytic layer of the membrane electrode, and an anode diffusion layer is included outside the anode catalytic layer. The anode diffusion layer and the cathode diffusion layer are one of a nickel foam, a nickel fiber felt, a nickel woven mesh, and a nickel expanded mesh.

[0076] Example 1

[0077] An anode catalytic slurry is prepared: IrO2, Nafion solution, isopropyl alcohol, deionized water and N-methyl pyrrolidone are mixed in a mass ratio of 20%:8%:25%:45%:2% and ultrasonic dispersion is performed for 2.0 h to obtain a uniform first anode catalytic slurry; IrO2, Nafion solution, isopropyl alcohol, deionized water and N-methyl pyrrolidone are mixed in a mass ratio of 15%:8%:30%:45%:2% and ultrasonic dispersion is performed for 2.0 h to obtain a uniform second anode catalytic slurry;

[0078] A cathode catalytic slurry is prepared: the cathode catalyst, the ionic polymer, the solvent, the deionized water and the dispersant are mixed in a mass ratio of 15%:8%:30%:45%:2%, and placed in a planetary ball mill for stirring at a speed of 2500 rpm for 1.0 h; the cathode catalyst, the ionic polymer, the solvent, the deionized water and the dispersant are mixed in a mass ratio of 10%:8%:35%:45%:2%, and placed in a planetary ball mill for stirring at a speed of 2500 rpm for 1.0 h to obtain a second cathode catalytic slurry.

[0079] An anode modification layer slurry is prepared: the MoS2 / C composite material, the carbon nanotube and the epoxy resin are mixed in a mass ratio of 10%:60%:30% to form an anode modification layer slurry;

[0080] The anode modification layer slurry is coated on one surface of a perfluorosulfonic acid proton exchange membrane, and dried to obtain an anode modification layer attached to the perfluorosulfonic acid proton exchange membrane; the thickness of the anode modification layer is 0.5 μm;

[0081] The first anode catalytic slurry is coated on the surface of the anode modification layer by a transfer printing method, and placed on a vacuum adsorption heating plate at 80°C for heating for 2.0 h to form a first anode catalytic layer; the second anode catalytic slurry is coated on the surface of the first anode catalytic layer by a transfer printing method, and placed on a vacuum adsorption heating plate at 80°C for heating for 2.0 h to form a second anode catalytic layer, and the total thickness of the anode catalytic layer is 10 μm;

[0082] The first cathode catalyst slurry is coated on the other surface of the 2.0 h Nafion membrane by the transfer printing method, and is placed on a vacuum adsorption heating plate at 75°C for heating for 2.0 h to form a first cathode catalyst layer; the second cathode catalyst slurry is coated on the other surface of the Nafion membrane by the transfer printing method, and is placed on a vacuum adsorption heating plate at 75°C for heating for 2.0 h to form a second cathode catalyst layer; the total thickness of the cathode catalyst layer is 5 μm.

[0083] Example 2

[0084] The anode catalyst slurry is prepared: IrO2, Nafion solution, isopropyl alcohol, deionized water and N-methyl pyrrolidone are mixed in a mass ratio of 30%:5%:35%:28%:2%, and ultrasonic dispersion is performed for 2.0 h to obtain a uniform first anode catalyst slurry; IrO2, Nafion solution, isopropyl alcohol, deionized water and N-methyl pyrrolidone are mixed in a mass ratio of 20%:5%:35%:38%:2%, and ultrasonic dispersion is performed for 2.0 h to obtain a uniform second anode catalyst slurry;

[0085] The cathode catalyst slurry is prepared: the cathode catalyst, the ionic polymer, the solvent, the deionized water and the dispersant are mixed in a mass ratio of 20%:5%:40%:33%:2%, and are placed in a planetary ball mill for stirring at a speed of 2500 rpm for 1.0 h; the cathode catalyst, the ionic polymer, the solvent, the deionized water and the dispersant are mixed in a mass ratio of 15%:5%:40%:38%:2%, and are placed in a planetary ball mill for stirring at a speed of 2500 rpm for 1.0 h to obtain a second cathode catalyst slurry.

[0086] The anode modification layer slurry is prepared: the MoS2 / C composite material, the carbon nanotube and the epoxy resin are mixed in a mass ratio of 10%:60%:30% to form an anode modification layer slurry;

[0087] The anode modification layer slurry is coated on one surface of the Nafion membrane, and is dried to obtain an anode modification layer attached to the Nafion membrane; the thickness of the anode modification layer is 0.8 μm;

[0088] The first anode catalyst slurry is coated on the surface of the anode modification layer by the transfer printing method, and is placed on a vacuum adsorption heating plate at 80°C for heating for 2.0 h to form a first anode catalyst layer; the second anode catalyst slurry is coated on the surface of the first anode catalyst layer by the transfer printing method, and is placed on a vacuum adsorption heating plate at 80°C for heating for 2.0 h to form a second anode catalyst layer, and the total thickness of the anode catalyst layer is 15 μm;

[0089] The first cathode catalyst slurry was coated on the other surface of the Nafion 2125 membrane by the transfer printing method and heated on a vacuum adsorption heating plate at 75°C for 2.0 h to form a first cathode catalyst layer; the second cathode catalyst slurry was coated on the other surface of the Nafion 2125 membrane by the transfer printing method and heated on a vacuum adsorption heating plate at 75°C for 2.0 h to form a second cathode catalyst layer; the total thickness of the cathode catalyst layer was 10 μm.

[0090] Comparative Example 1

[0091] Preparation of anode catalyst slurry: IrO2, Nafion solution, isopropyl alcohol, and deionized water were mixed in a mass ratio of 30%:5%:35%:30% and ultrasonically dispersed for 2.0 h to obtain a uniform anode catalyst slurry.

[0092] Preparation of cathode catalyst slurry: the cathode catalyst, ionomer, solvent, and deionized water were mixed in a mass ratio of 20%:5%:40%:35%, stirred in a planetary ball mill at a speed of 2500 rpm for 1.0 h to obtain a second cathode catalyst slurry.

[0093] The anode catalyst slurry was coated on the surface of the Nafion 2125 membrane by the transfer printing method and heated on a vacuum adsorption heating plate at 80°C for 2.0 h to form an anode catalyst layer, and the thickness of the anode catalyst layer was 15 μm;

[0094] The cathode catalyst slurry was coated on the other surface of the Nafion 2125 membrane by the transfer printing method and heated on a vacuum adsorption heating plate at 75°C for 2.0 h to form a cathode catalyst layer, and the total thickness of the cathode catalyst layer was 10 μm.

Claims

1. A membrane electrode for hydrogen production by electrolysis of water, characterized by, The membrane electrode comprises: a proton exchange membrane, an anode catalytic layer and a cathode catalytic layer arranged on both sides of the proton exchange membrane, an anode modification layer and a cathode modification layer; The content of the anode catalyst in the anode catalytic layer increases from the side far away from the proton exchange membrane to the side close to the proton exchange membrane, and the content of the cathode catalyst in the cathode catalytic layer increases from the side far away from the proton exchange membrane to the side close to the proton exchange membrane; the total thickness of the cathode catalytic layer is 5.0 ~10.0 ; the total thickness of the anode catalytic layer is 10 ~20 ; The anode catalytic layer comprises a first anode catalytic layer located close to the proton exchange membrane and a second anode catalytic layer located away from the proton exchange membrane, the loading amount of anode catalyst in the first anode catalytic layer is 2.5-3.5 mg / cm 2 ; the loading amount of anode catalyst in the second anode catalytic layer is 2.0-2.5 mg / cm 2 ; wherein the first anode catalytic layer is formed by coating the first anode catalytic slurry on the surface of the anode modification layer through the transfer printing method, and placing on a vacuum adsorption heating plate for heating; and the second anode catalytic layer is formed by coating the second anode catalytic slurry on the surface of the first anode catalytic layer through the transfer printing method, and placing on a vacuum adsorption heating plate for heating. The cathode catalytic layer comprises a first cathode catalytic layer located close to the proton exchange membrane side and a second cathode catalytic layer located away from the proton exchange membrane side, the loading amount of the cathode catalyst in the first cathode catalytic layer is 1.5 mg / cm 2 ~2.0 mg / cm 2 , and the loading amount of the cathode catalyst in the second cathode catalytic layer is 1.0 mg / cm 2 ~1.5 mg / cm 2 ; wherein the first cathode catalytic layer is formed by coating the first cathode catalyst slurry on the other surface of the proton exchange membrane through the transfer printing method, and placing it on a vacuum adsorption heating plate for heating; and the second cathode catalytic layer is formed by coating the second cathode catalyst slurry on the other surface of the proton exchange membrane through the transfer printing method, and placing it on a vacuum adsorption heating plate for heating. An anode modification layer is disposed between the anode catalyst layer and the proton exchange membrane, the anode modification layer containing a molybdenum-based catalyst for catalyzing the oxidation reaction of hydrogen gas, the molybdenum-based catalyst including at least one of a MoS2 / C composite material, a MoO2 / C composite material, and the thickness of the anode modification layer is 0.5 ~1.0 ; the cathode modification layer is arranged outside the cathode catalytic layer and is used for adsorbing scale-forming ions in electrolytic water.

2. The membrane electrode for hydrogen production by electrolysis of water according to claim 1, wherein The first cathode catalytic layer and the second cathode catalytic layer are both prepared from a cathode catalytic slurry; the cathode catalytic slurry comprises a cathode catalyst, an ionic polymer, a solvent, deionized water and a dispersing agent; the cathode catalyst is a Pt / CNT composite material.

3. The membrane electrode for hydrogen production by water electrolysis according to claim 2, characterized by, The content of Pt is 25% to 35% based on the mass of the Pt / CNT composite material; the average particle size of Pt is 5 nm to 20 nm.

4. The membrane electrode for hydrogen production by water electrolysis according to claim 1, wherein The first anode catalytic layer and the second anode catalytic layer are both prepared from an anode catalytic slurry; the anode catalytic slurry comprises an anode catalyst, an ionic polymer, a solvent, deionized water and a dispersing agent; the anode catalyst comprises one or more of Ir, IrO2, Ru, RuO2 and IrRuOx.

5. The membrane electrode for hydrogen production by water electrolysis according to claim 1, wherein The proton exchange membrane is selected from one of a perfluorosulfonic acid proton exchange membrane, an organic / inorganic nanocomposite proton exchange membrane and a fluorine-free proton exchange membrane.

6. A method for preparing a membrane electrode for hydrogen production by electrolysis of water, the method for preparing a membrane electrode according to any one of claims 1 to 5, characterized in that, The preparation method comprises: preparing an anode catalytic slurry: mixing an anode catalyst with an ionic polymer, a solvent, deionized water and a dispersing agent, and performing ultrasonic dispersion to obtain uniform first and second anode catalytic slurries; preparing a cathode catalytic slurry: mixing a cathode catalyst with an ionic polymer, a solvent, deionized water and a dispersing agent, and placing the mixture in a planetary ball mill for stirring and dispersion to obtain first and second cathode catalytic slurries; preparing an anode modification layer slurry: mixing a molybdenum-based catalyst, a porous carbon material and a binder to form an anode modification layer slurry; coating the anode modification layer slurry on one surface of the proton exchange membrane, and drying to obtain an anode modification layer attached to the proton exchange membrane; The first anode catalytic slurry is coated on the surface of the anode modification layer by a transfer printing method and placed on a vacuum adsorption heating plate for heating to form a first anode catalytic layer; the second anode catalytic slurry is coated on the surface of the first anode catalytic layer by a transfer printing method and placed on a vacuum adsorption heating plate for heating to form a second anode catalytic layer, the loading amount of the anode catalyst in the first anode catalytic layer is 2.5-3.5 mg / cm 2 , and the loading amount of the second anode catalyst is 2.0-2.5 mg / cm 2 . The first cathode catalyst slurry is coated on the other surface of the proton exchange membrane by a transfer printing method and placed on a vacuum adsorption heating plate for heating to form a first cathode catalyst layer; the second cathode catalyst slurry is coated on the other surface of the proton exchange membrane by a transfer printing method and placed on a vacuum adsorption heating plate for heating to form a second cathode catalyst layer, wherein the loading amount of the cathode catalyst in the first cathode catalyst layer is 1.5 mg / cm 2 ~2.0 mg / cm 2 , and the loading amount of the cathode catalyst in the second cathode catalyst layer is 1.0 mg / cm 2 ~1.5 mg / cm 2 ; the surface of the second cathode catalytic layer is provided with a detachable cathode modification layer.

7. The method for preparing a membrane electrode for hydrogen production by water electrolysis according to claim 6, characterized in that, The step of preparing the anode catalytic slurry comprises: mixing the anode catalyst, the ionic polymer, the solvent, the deionized water and the dispersing agent in a mass ratio of (20% to 30%):(3% to 8%):(30% to 50%):(20% to 45%):(1% to 2%), and performing ultrasonic dispersion to obtain the uniform first anode catalytic slurry.

8. The method for preparing a membrane electrode for hydrogen production by water electrolysis according to claim 6, characterized by, The step of preparing the anode catalytic slurry comprises: mixing the anode catalyst, the ionic polymer, the solvent, the deionized water and the dispersing agent in a mass ratio of (15% to 20%):(3% to 8%):(30% to 45%):(25% to 45%):(1% to 2%), and performing ultrasonic dispersion to obtain the uniform second anode catalytic slurry.

9. The method for preparing a membrane electrode for hydrogen production by water electrolysis according to claim 6, characterized in that, The step of preparing the cathode catalytic slurry comprises: mixing the cathode catalyst, the ionic polymer, the solvent, the deionized water and the dispersing agent in a mass ratio of (15% to 20%):(3% to 8%):(30% to 50%):(25% to 45%):(1% to 2%), and placing the mixture in a planetary ball mill for stirring and dispersion to obtain the first cathode catalytic slurry.

10. The method for preparing a membrane electrode for hydrogen production by water electrolysis according to claim 6, characterized by, The mass ratio of the cathode catalyst, ionomer, solvent, deionized water and dispersant is (10%-15%):(3%-8%):(30%-50%):(25%-45%):(1%-2%), which is mixed and stirred and dispersed in a planetary ball mill to obtain a second cathode catalyst slurry.

11. The method for preparing a membrane electrode for hydrogen production by water electrolysis according to claim 6, characterized in that, The thickness of the anode modification layer is 0.5 1.0 .

12. An apparatus for electrolyzing water comprising an electrolytic cell, characterized by, The electrolyzer comprises the membrane electrode for electrolysis of water to produce hydrogen according to any one of claims 1 to 5.

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