Anode of membrane electrode of proton exchange membrane electrolytic cell and preparation method of anode
By forming a slurry of hydrogen removal catalyst and anode catalytic layer on the proton exchange membrane and the gas diffusion layer, and being closely bonded, the problem of hydrogen removal layer occupying the catalytic position is solved, the catalytic efficiency is improved and the proton exchange membrane swelling is reduced, and the efficient preparation of the proton exchange membrane electrolytic cell membrane electrode electrode is achieved.
Patent Information
- Application Number
- CN202510863937.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-25
- Publication Date
- 2025-08-15
AI Technical Summary
The hydrogen-depleting layer of the proton exchange membrane electrolyte membrane electrode anode occupies the catalytic position of part of the catalytic layer, resulting in a reduced catalytic efficiency and multiple coatings increase the risk of swelling of the proton exchange membrane.
The hydrogen-elimination catalyst and the anode catalytic layer slurry are formed on the proton exchange membrane and the gas diffusion layer respectively, and the pressure is tightly bonded by pressing force, and the contact surface pressure is controlled to be 2-3MPa to ensure that the hydrogen-elimination layer and the catalytic layer are symmetrically bonded, reducing the number of coatings and contact time.
The high catalytic efficiency is maintained, the swelling of the proton exchange membrane is reduced, and the electrolytic efficiency and the reduction of hydrogen content in the oxygen electrolyte products are improved.
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Figure CN120485801A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of proton exchange membrane electrolyzers, and in particular relates to a membrane electrode anode of a proton exchange membrane electrolyzer and a preparation method thereof. Background Art
[0002] At present, in practical applications, proton exchange membrane electrolyzers need to add a dehydrogenation layer on the anode side of the membrane electrode to reduce the hydrogen content in the product oxygen and ensure the safety of the equipment. However, the dehydrogenation layer and the anode catalyst layer are coated on the proton exchange membrane successively. The dehydrogenation layer will occupy part of the catalytic position of the catalytic layer, reducing the electrolysis efficiency of the proton exchange membrane electrolyzer and increasing the problem of proton exchange membrane swelling.
[0003] While adding an electronically insulating layer between the dehydrogenation layer and the catalytic layer can address the problem of the dehydrogenation layer occupying some of the catalytic sites on the catalytic layer, which reduces catalytic efficiency, this method also involves multiple slurry coatings on the proton exchange membrane side, which increases the membrane's contact time with the organic solvent and makes it more susceptible to swelling. The additional electronically insulating layer also increases the overall coating thickness and internal resistance. Therefore, a new membrane electrode structure design and preparation method are needed to address these issues. Summary of the Invention
[0004] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is that the hydrogen-scavenging layer of the membrane electrode anode of the proton exchange membrane electrolyzer occupies part of the catalytic position of the catalytic layer, reducing the catalytic efficiency, and requires multiple coatings to cause the proton exchange membrane to swell. A proton exchange membrane electrolyzer membrane electrode anode and a preparation method thereof are proposed, which do not reduce the catalytic efficiency of the catalytic layer, reduce the number of coatings and reduce the swelling of the proton exchange membrane.
[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: a method for preparing a membrane electrode anode of a proton exchange membrane electrolyzer, comprising: a hydrogen removal layer forming step; a catalytic layer forming step; an anode bonding step after the hydrogen removal layer forming step and the catalytic layer forming step; the hydrogen removal layer forming step comprises: forming a hydrogen removal layer slurry on the anode side of the proton exchange membrane; the catalytic layer forming step comprises a catalytic layer slurry preparation step and a catalytic layer spraying step; the catalytic layer slurry preparation step comprises: adding pure water, isopropyl alcohol, and Nafion solution to an iridium-based oxygen evolution catalyst, and using a high-speed shearing machine at 10,000 rp The slurry is stirred at a rate of m, and the solid content of the slurry is controlled to be greater than 10% to obtain a catalytic layer slurry; the catalytic layer slurry spraying step includes: coating the catalytic layer slurry on the anode gas diffusion layer titanium felt; the anode laminating step includes: tightly laminating the anode gas diffusion layer titanium felt coated with the catalytic layer slurry to the anode side of the proton exchange membrane covered with the hydrogen removal layer slurry through a pressing force, controlling the contact surface pressure to be 2-3MPa, so that the hydrogen removal layer slurry and the catalytic layer slurry are tightly laminating, and the catalytic layer slurry covering area of the anode gas diffusion layer is symmetrical with the center of the hydrogen removal layer slurry covering area of the proton exchange membrane, thereby obtaining a membrane electrode anode.
[0006] Preferably, the anode bonding step includes cutting a 4.5*4.5 cm hollow hole from a polyethylene naphthalate frame with a thickness of 40-280 μm, hot pressing the polyethylene naphthalate frame and the proton exchange membrane symmetrically at 100-120°C and a pressure of 2-3 MPa for 1-3 minutes using a hot press, and then gluing the anode gas diffusion layer to the polyethylene naphthalate frame with glue. The anode gas diffusion layer is symmetrical with the polyethylene naphthalate frame and the proton exchange membrane to obtain the membrane electrode anode.
[0007] Preferably, in the step of preparing the dehydrogenation layer slurry, the weight of the dehydrogenation catalyst is 8-10 mg, the volume of pure water is 5-8 ml, the volume of the organic solvent is 8-10 ml, the concentration of the Nafion solution is 5%, and the volume of the Nafion solution is 8-10 ml.
[0008] Preferably, in the step of preparing the catalytic layer slurry, the weight of the anode catalyst is 20-25 mg, the volume of pure water is 2-4 ml, the volume of the organic solvent is 4-5 ml, the concentration of the Nafion solution is 20%, and the volume of the Nafion solution is 8-10 ml.
[0009] Preferably, in the hydrogen removal layer forming step, the hydrogen removal layer slurry is coated on the center of a 9*9cm proton exchange membrane at a flow rate of 1.5-3ml / min by an ultrasonic sprayer, with a coating area of 5*5cm, and dried at 80-100°C to obtain the hydrogen removal layer.
[0010] Preferably, in the hydrogen removal layer forming step, the hydrogen removal layer slurry is slit coated to form a slurry layer with an area of 5*5cm and a thickness of 20-50μm in the center of a 9*9cm polytetrafluoroethylene membrane, and then dried at 80-100°C. After that, the slurry on the polytetrafluoroethylene membrane is transferred to the center of the proton exchange membrane by a hot press at 100-120°C and a pressure of 2-3MPa for 1-3min to obtain the hydrogen removal layer.
[0011] Preferably, in the catalyst layer forming step, the anode catalyst layer slurry is coated on a 5*5cm anode gas diffusion layer titanium felt by an ultrasonic sprayer at a flow rate of 1.5-3ml / min, with a coating area of 5*5cm, and dried at 80-100°C to obtain a catalyst layer.
[0012] Preferably, the dehydrogenation catalyst is a platinum black catalyst or a Pt-Co alloy catalyst.
[0013] Preferably, the iridium-based oxygen evolution catalyst is one of IrO2 or iridium black catalyst.
[0014] The present invention also discloses a membrane electrode anode of a proton exchange membrane electrolyzer, which is obtained according to any of the above-mentioned preparation methods; the anode catalyst layer slurry region of the anode gas diffusion layer is tightly fitted with the hydrogen removal layer slurry region of the proton exchange membrane; the anode catalyst layer slurry region of the anode gas diffusion layer is centrally symmetrical with the hydrogen removal layer slurry region of the proton exchange membrane.
[0015] Compared with the prior art, the present invention has the following beneficial effects:
[0016] (1) In a method for preparing a membrane electrode anode of a proton exchange membrane electrolyzer disclosed in the present invention, a dehydrogenation catalyst slurry and an anode catalyst layer slurry are formed into films on a proton exchange membrane and a gas diffusion layer respectively and then tightly bonded. This can prevent the problems in the prior art in that the dehydrogenation layer and the anode catalyst layer overlap during the successive coating process, the dehydrogenation layer occupies part of the catalytic position of the catalytic layer, hinders the transmission of ions, electrons and water to the active sites of the catalyst, reduces the active area of the catalytic layer, and thus reduces the catalytic efficiency of the catalyst. The technical solution of the present invention maintains a high catalytic efficiency while increasing the dehydrogenation layer and reducing the hydrogen content in the oxygen electrolysis product.
[0017] (2) In the method for preparing the membrane electrode anode of a proton exchange membrane electrolyzer disclosed in the present invention, the dehydrogenation catalyst slurry and the anode catalyst layer slurry are formed into films on the proton exchange membrane and the gas diffusion layer respectively and then tightly bonded, thereby reducing the number of times and contact time between the proton exchange membrane and the organic solvent, and preventing the problem of swelling of the proton exchange membrane caused by the proton exchange membrane being in contact with the organic solvent in the slurry for a long time in the prior art, in which the dehydrogenation layer and the anode catalyst layer are coated on the proton exchange membrane one after another. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 A schematic diagram of the membrane electrode anode structure provided by an embodiment of the present invention;
[0019] Figure 2 A partial side view of the proton exchange membrane and hydrogen removal layer of the membrane electrode anode structure provided in an embodiment of the present invention;
[0020] Figure 3 A schematic diagram of the structure of the anode gas diffusion layer and the anode catalyst layer of the membrane electrode anode structure provided by an embodiment of the present invention;
[0021] Figure 4 This is a line graph showing the test results of hydrogen content in oxygen provided by an embodiment of the present invention.
[0022] In the above figures, 1, proton exchange membrane; 2, hydrogen removal layer; 3, anode catalyst layer; 4, anode gas diffusion layer; DETAILED DESCRIPTION
[0023] The following is a detailed and complete description of the technical solutions in the specific embodiments of the present invention. Obviously, the described embodiments are only some specific implementation methods of the overall technical solution of the present invention, and are not all implementation methods. Based on the overall concept of the present invention, all other embodiments obtained by ordinary skill in the art are within the scope of protection of the present invention.
[0024] The present invention provides a method for preparing a proton exchange membrane electrolyzer membrane electrode anode, comprising: Figure 2 The hydrogen removal layer formation step shown; Figure 3 After the hydrogen removal layer forming step and the catalytic layer forming step, Figure 1The anode lamination step is shown; the hydrogen removal layer formation step includes forming a hydrogen removal layer slurry on the anode side of the proton exchange membrane 1; the catalytic layer formation step includes preparing a catalytic layer slurry and spraying the catalytic layer. The catalytic layer slurry preparation step includes adding pure water, isopropyl alcohol, and Nafion solution to an iridium-based oxygen evolution catalyst and stirring the slurry at a high-speed shearing speed of 10,000 rpm, controlling the solid content of the slurry to greater than 10%, to obtain a catalytic layer slurry. The catalytic layer slurry spraying step includes coating the catalytic layer slurry on the titanium felt of the anode gas diffusion layer 4. The anode lamination step includes tightly laminating the titanium felt of the anode gas diffusion layer 4 coated with the catalytic layer slurry to the anode side of the proton exchange membrane 1 covered with the hydrogen removal layer slurry by pressing force, controlling the contact surface pressure to 2-3 MPa, so that the hydrogen removal layer 2 and the anode catalyst layer 3 are tightly laminating and symmetrical with each other, thereby obtaining a membrane electrode anode. The cleanliness level of the environment exceeds 10,000 to ensure a smooth and free of foreign matter lamination interface. Forming the dehydrogenation catalyst slurry and the anode catalyst layer slurry into separate films and then closely laminating them together can prevent the problems encountered in the prior art where the dehydrogenation layer and the anode catalyst layer overlap during their subsequent coating, where the dehydrogenation layer occupies part of the catalytic sites of the catalyst layer, hindering the transmission of ions, electrons, and water to the catalyst active sites, reducing the active area of the catalyst layer, and thus reducing the catalytic efficiency of the catalyst. The technical solution of the present invention maintains a high catalytic efficiency while increasing the dehydrogenation layer and reducing the hydrogen content in the oxygen electrolysis product. In addition, forming the dehydrogenation catalyst slurry and the anode catalyst layer slurry into separate films and then closely laminating them together reduces the number of times and duration of contact between the proton exchange membrane and the organic solvent, thereby preventing the problem of swelling of the proton exchange membrane caused by multiple and prolonged contact between the proton exchange membrane and the organic solvent in the slurry, which occurs when the dehydrogenation layer and the anode catalyst layer are coated on the proton exchange membrane in the prior art.
[0025] In the above technical solution, the solid content of the anode catalyst layer slurry is also improved to ensure that the anode catalyst layer 3 and the anode gas diffusion layer 4 can fit tightly together to prevent loose fitting, which affects the interface conductivity between the anode catalyst layer 3 and the anode gas diffusion layer 4. The role of increasing the solid content is to improve the coating effect of the anode catalyst layer on the metal substrate gas diffusion layer, because metal materials are more likely to fall off than membrane materials, and a slurry with a higher solid content (thicker) is required; on the other hand, controlling the contact surface pressure to 2-3MPa can make the catalyst layer and the dehydrogenation layer fit tightly together. If the pressure is too low, the fit will not be tight enough. If the pressure is too high, the dehydrogenation layer, catalyst layer and gas diffusion layer will have the risk of cracking and falling off, shortening the service life. In addition, because the solid content in the slurry is increased, it is necessary to use a high-speed shearing machine to stir the slurry at a rate of 10,000 rpm to prevent the slurry from being unevenly stirred, which affects the film-forming effect and the anode catalytic effect.
[0026] In a preferred embodiment, the anode lamination step includes cutting a 4.5*4.5 cm hollow hole from a polyethylene naphthalate frame having a thickness of 40-280 μm, hot pressing the polyethylene naphthalate frame with a pressure of 2-3 MPa for 1-3 minutes, and symmetrically laminating the polyethylene naphthalate frame to the proton exchange membrane 1. The anode gas diffusion layer 4 is then glued to the polyethylene naphthalate frame, with the anode gas diffusion layer 4 being symmetrical with the polyethylene naphthalate frame and the proton exchange membrane 1, thereby obtaining the membrane electrode anode. This anode lamination method with a frame has the following advantages: the polyethylene naphthalate frame can provide physical support for the anode gas diffusion layer, preventing excessive compression of the gas diffusion layer from causing damage to the proton exchange membrane or the gas diffusion layer itself.
[0027] In a preferred embodiment, in the step of preparing the dehydrogenation layer slurry, the weight of the dehydrogenation catalyst is 8-10 mg, the volume of pure water is 5-8 ml, the volume of the organic solvent is 8-10 ml, the concentration of the Nafion solution is 5%, and the volume of the Nafion solution is 8-10 ml.
[0028] In a preferred embodiment, in the catalyst layer slurry preparation step, the weight of the anode catalyst is 20-25 mg, the volume of pure water is 2-4 ml, the volume of the organic solvent is 4-5 ml, the concentration of the Nafion solution is 20%, and the volume of the Nafion solution is 8-10 ml.
[0029] In a preferred embodiment, in the hydrogen removal layer forming step, the hydrogen removal layer slurry is applied to the center of a 9*9 cm proton exchange membrane using an ultrasonic sprayer at a flow rate of 1.5-3 ml / min, covering an area of 5*5 cm. The membrane is then dried at 80-100°C to form the hydrogen removal layer 2. The hydrogen removal layer is sprayed to a thickness of 20-50 μm. This thickness ensures an appropriate hydrogen removal catalyst loading and internal resistance. If the thickness is less than this, the hydrogen removal catalyst loading is too low, weakening the hydrogen removal effect. If the thickness is greater than this, the internal resistance of the hydrogen removal layer is too high, resulting in increased energy consumption for hydrogen production.
[0030] In a preferred embodiment, in the hydrogen removal layer formation step, the hydrogen removal layer slurry is slit-coated to form a slurry layer with an area of 5*5cm and a thickness of 20-50μm on the center of a 9*9cm polytetrafluoroethylene membrane. The slurry is then dried at 80-100°C. The slurry on the polytetrafluoroethylene membrane is then transferred to the center of the proton exchange membrane using a hot press at 100-120°C and a pressure of 2-3MPa for 1-3 minutes to obtain the hydrogen removal layer 2. Compared with the method of preparing the hydrogen removal layer by spraying, the transfer method omits the slit coating step and has higher production efficiency in small-format, small-batch scenarios. In contrast, the transfer method has a higher production speed than the spray coating method in large-format, multi-batch membrane electrode preparation scenarios, making it more suitable for large-scale production scenarios.
[0031] In a preferred embodiment, in the catalyst layer forming step, the anode catalyst layer slurry is applied to a 5*5 cm anode gas diffusion layer titanium felt by an ultrasonic sprayer at a flow rate of 1.5-3 ml / min, with a coating area of 5*5 cm, and then dried at 80-100°C to obtain the catalyst layer 3. The spraying thickness of the anode catalyst layer is 20-50 μm. At this thickness, an appropriate oxygen evolution catalyst loading and catalyst layer internal resistance can be guaranteed. If the thickness is less than this, the oxygen evolution catalyst loading will be too low, resulting in an increase in the overpotential of hydrogen production by water electrolysis, resulting in an increase in hydrogen production energy consumption. If the thickness is greater than this, the catalyst layer internal resistance is too high, which also increases hydrogen production energy consumption.
[0032] In a preferred embodiment, the hydrogen removal catalyst is a platinum black catalyst or a Pt-Co alloy catalyst. In this embodiment, the platinum black catalyst or the Pt-Co alloy catalyst catalyzes hydrogen that permeates the proton exchange membrane and enters the anode into water, thereby reducing the hydrogen content in the oxygen at the anode.
[0033] In a preferred embodiment, the iridium-based oxygen evolution catalyst is one of IrO2 or iridium black catalyst. In this solution, IrO2 or iridium black catalyst catalyzes water to produce oxygen and hydrogen ions, reducing the reaction energy barrier of the reaction and significantly reducing the energy consumption of hydrogen production by water electrolysis.
[0034] like Figure 1 As shown, the present invention also discloses a membrane electrode anode for a proton exchange membrane electrolyzer, which is obtained according to any of the above-mentioned preparation methods; the anode catalyst layer 3 on the anode gas diffusion layer 4 is tightly bonded to the hydrogen removal layer 2 on the proton exchange membrane 1; the anode catalyst layer slurry region of the anode gas diffusion layer and the hydrogen removal layer slurry region of the proton exchange membrane are centrally symmetrical, and are considered centrally symmetrical if the distance between the edges of the two slurry regions is less than 1 mm as measured by a three-dimensional dimension detection station. This arrangement ensures that the hydrogen removal layer and the anode catalyst layer participate in the reaction at all reaction interfaces for hydrogen production by water electrolysis, maximizing the catalytic effects of hydrogen removal and oxygen evolution.
[0035] In order to more clearly and in detail introduce a proton exchange membrane electrolyzer membrane electrode anode and a preparation method thereof provided by an embodiment of the present invention, a description will be given below in conjunction with specific embodiments.
[0036] Example 1
[0037] Weigh 8mg of platinum black catalyst and put it in a beaker, add 5ml of pure water to soak it, then add 8ml of isopropanol and 8ml of 5% Nafion solution to prepare a hydrogen removal layer slurry; weigh 20mg of IrO2 catalyst and put it in a beaker, add 2ml of pure water, 4ml of isopropanol, 8ml An anode catalyst layer is prepared with a 20% Nafion solution, and the slurry is stirred at a rate of 10,000 rpm using a high-speed shearing machine to control the slurry solid content to be greater than 10%. The hydrogen removal layer slurry is applied to the center of a 9*9 cm proton exchange membrane at a flow rate of 1.5 ml / min using an ultrasonic sprayer, with a coating area of 5*5 cm, and then dried at 80°C. The anode catalyst layer slurry is applied to a 5*5 cm anode gas diffusion layer titanium felt at a flow rate of 1.5 ml / min using an ultrasonic sprayer, with a coating area of 5*5 cm, and then dried at 80°C. The anode gas diffusion layer is tightly attached to the proton exchange membrane by a pressing force, and the coating areas of the anode gas diffusion layer and the proton exchange membrane are symmetrical.
[0038] Example 2
[0039] Weigh 9 mg of platinum black catalyst and put it in a beaker, add 6 ml of pure water to soak, then add 9 ml of isopropanol and 9 ml of 5% Nafion solution to prepare a hydrogen removal layer slurry; weigh 22 mg of iridium black catalyst and put it in a beaker, add 3 ml of pure water, 4 ml of isopropanol, 9 ml An anode catalyst layer is prepared with a 20% Nafion solution, and the slurry is stirred at a rate of 10,000 rpm using a high-speed shearing machine to control the slurry solid content to be greater than 10%. The hydrogen removal layer slurry is applied to the center of a 9*9 cm proton exchange membrane at a flow rate of 2 ml / min using an ultrasonic sprayer, with a coating area of 5*5 cm, and then dried at 90°C. The anode catalyst layer slurry is applied to a 5*5 cm anode gas diffusion layer titanium felt at a flow rate of 2 ml / min using an ultrasonic sprayer, with a coating area of 5*5 cm, and then dried at 80°C. The anode gas diffusion layer is tightly attached to the proton exchange membrane by a pressing force, and the coating areas of the anode gas diffusion layer and the proton exchange membrane are symmetrical.
[0040] Example 3
[0041] Weigh 10mg of platinum black catalyst and put it in a beaker, add 7ml of pure water to soak, then add 10ml of isopropanol and 10ml of 5% Nafion solution to prepare a hydrogen removal layer slurry; weigh 25mg of IrO2 catalyst and put it in a beaker, add 4ml of pure water, 5ml of isopropanol, 10ml An anode catalyst layer is prepared with a 20% Nafion solution, and the slurry is stirred at a rate of 10,000 rpm using a high-speed shearing machine to control the slurry solid content to be greater than 10%. The hydrogen removal layer slurry is slit coated to coat a slurry layer with an area of 5*5 cm and a thickness of 50 μm on the center of a 9*9 cm polytetrafluoroethylene membrane, and then dried at 90°C. Thereafter, the slurry on the polytetrafluoroethylene membrane is transferred to the center of a proton exchange membrane using a hot press at 120°C and a pressure of 3 MPa for 3 minutes to obtain a hydrogen removal layer. The anode catalyst layer slurry is coated on a 5*5 cm anode gas diffusion layer titanium felt using an ultrasonic sprayer at a flow rate of 2.5 ml / min, with a coating area of 5*5 cm, and then dried at 90°C. The anode gas diffusion layer is tightly attached to the proton exchange membrane by a pressing force, and the coating areas of the anode gas diffusion layer and the proton exchange membrane are symmetrical.
[0042] Example 4
[0043] 10 mg of Pt-Co alloy catalyst was weighed and placed in a beaker, 8 ml of pure water was added to soak it, and then 10 ml of isopropanol and 8 ml of 5% Nafion solution were added to prepare a dehydrogenation layer slurry; 25 mg of IrO2 catalyst was weighed and placed in a beaker, 2 ml of pure water, 5 ml of isopropanol, and 10 ml of 20% Nafion solution were added to prepare an anode catalyst layer, and a high-speed shearing machine was used to stir the slurry at a rate of 10,000 rpm to control the slurry solid content to be greater than 10%; the dehydrogenation layer slurry was applied to the center of a 9*9 cm proton exchange membrane at a flow rate of 3 ml / min using an ultrasonic sprayer, with a coating area of 5*5 cm, and then dried at 100°C; the anode catalyst layer slurry was applied to a 5*5 cm anode gas diffusion membrane at a flow rate of 3 ml / min using an ultrasonic sprayer. A layer of titanium felt with a coating area of 5*5cm was prepared and dried at 100°C. A 40μm thick PEN (polyethylene naphthalate) frame was cut to form a 4.5*4.5cm hollow hole. The frame was hot-pressed at 120°C and a pressure of 2MPa for 2min using a hot press to symmetrically fit the PEN frame and the proton exchange membrane. The anode gas diffusion layer was then glued to the PEN frame with glue. The anode gas diffusion layer was symmetrical to the PEN frame and the proton exchange membrane.
[0044] Comparative Example 1
[0045] 10 mg of platinum black catalyst was weighed and placed in a beaker, and 5 ml of pure water was added for soaking. 10 ml of isopropyl alcohol and 8 ml of 5% Nafion solution were then added to prepare a hydrogen removal layer slurry. 25 mg of IrO2 catalyst was weighed and placed in a beaker, and 5 ml of pure water, 20 ml of isopropyl alcohol, and 8 ml of 5% Nafion solution were added to prepare an anode catalyst layer slurry. The hydrogen removal layer slurry was applied to the center of a 9*9 cm proton exchange membrane at a flow rate of 2 ml / min using an ultrasonic sprayer, with a coating area of 5*5 cm, and then dried at 80°C. The anode catalyst layer slurry was then applied to the hydrogen removal layer prepared in the previous step using an ultrasonic sprayer at a flow rate of 2 ml / min, with a coating area of 5*5 cm overlapping the hydrogen removal layer, and then dried at 80°C. An anode gas diffusion layer was placed on the proton exchange membrane coating area, with the anode gas diffusion layer and the proton exchange membrane coating area being symmetrical.
[0046] Effect test
[0047] Figure 2 The results of hydrogen content testing on a PEM water electrolysis hydrogen production fixture were compared for Example 1 and Comparative Example 1. Compared to the original structure of the membrane electrode anode side proton exchange membrane in Comparative Example 1, which had a continuous coating of hydrogen removal layer and catalytic layer, Example 1 maintained essentially the same hydrogen content in oxygen, demonstrating that the membrane electrode anode structure and preparation method in this example still maintained effective hydrogen removal.
[0048] Example 1 and Comparative Example 1 were tested at 2A / cm 2 The hydrogen production performance test was carried out under a current density of 1000 nm, normal pressure and an operating temperature of 60°C. The voltage of Example 1 was 1.83 V, which was lower than 1.88 V of Comparative Example 1, proving the reduction of the hydrogen production overpotential, that is, the improvement of the hydrogen production efficiency per unit hydrogen production amount.
[0049] The test results of Examples 2, 3, and 4 are all similar to the test results of Example 1.
Claims
1. A method for preparing a membrane electrode anode of a proton exchange membrane electrolyzer, characterized in that: include: a hydrogen removal layer forming step; a catalytic layer forming step; an anode laminating step after the hydrogen removal layer forming step and the catalytic layer forming step; The hydrogen removal layer forming step comprises: forming the hydrogen removal layer slurry into a film on the anode side of the proton exchange membrane; The catalytic layer forming step includes a catalytic layer slurry preparation step and a catalytic layer spraying step; The catalyst layer slurry preparation step comprises: adding pure water, isopropyl alcohol, and Nafion solution to an iridium-based oxygen evolution catalyst, stirring the slurry at a rate of 10,000 rpm using a high-speed shearing machine, and controlling the slurry solid content to be greater than 10% to obtain a catalyst layer slurry; The catalyst layer slurry spraying step includes: coating the catalyst layer slurry on the anode gas diffusion layer titanium felt; The anode laminating step includes: tightly laminating the anode gas diffusion layer titanium felt coated with the catalytic layer slurry to the anode side of the proton exchange membrane covered with the hydrogen removal layer slurry through a pressing force, controlling the contact surface pressure to 2-3 MPa, so that the hydrogen removal layer slurry and the catalytic layer slurry are tightly laminating, and the catalytic layer slurry-covered area of the anode gas diffusion layer is centrally symmetrical with the hydrogen removal layer slurry-covered area of the proton exchange membrane, thereby obtaining a membrane electrode anode.
2. The method for preparing a proton exchange membrane electrolyzer membrane electrode anode according to claim 1, characterized in that: The anode lamination step includes cutting a 4.5*4.5 cm hollow hole from a polyethylene naphthalate frame with a thickness of 40-280 μm, hot pressing the polyethylene naphthalate frame and the proton exchange membrane symmetrically at the center of the frame by a hot press at 100-120° C. and a pressure of 2-3 MPa for 1-3 minutes, and then gluing the anode gas diffusion layer to the polyethylene naphthalate frame with glue. The anode gas diffusion layer is symmetrical with the polyethylene naphthalate frame and the proton exchange membrane to obtain the membrane electrode anode.
3. The method for preparing a proton exchange membrane electrolyzer membrane electrode anode according to claim 1, characterized in that: In the hydrogen removal layer slurry preparation step, the weight of the hydrogen removal catalyst is 8-10 mg, the volume of the pure water is 5-8 ml, the volume of the organic solvent is 8-10 ml, the concentration of the Nafion solution is 5%, and the volume of the Nafion solution is 8-10 ml.
4. The method for preparing a membrane electrode anode of a proton exchange membrane electrolyzer according to claim 1, characterized in that: In the step of preparing the catalytic layer slurry, the weight of the anode catalyst is 20-25 mg, the volume of pure water is 2-4 ml, the volume of the organic solvent is 4-5 ml, the concentration of the Nafion solution is 20%, and the volume of the Nafion solution is 8-10 ml.
5. The method for preparing a membrane electrode anode of a proton exchange membrane electrolyzer according to claim 1, characterized in that: In the hydrogen removal layer forming step, the hydrogen removal layer slurry is coated on the center of a 9*9cm proton exchange membrane at a flow rate of 1.5-3ml / min by an ultrasonic sprayer, with a coating area of 5*5cm, and dried at 80-100°C to obtain the hydrogen removal layer.
6. The method for preparing a membrane electrode anode of a proton exchange membrane electrolyzer according to claim 1, characterized in that: In the hydrogen removal layer forming step, the hydrogen removal layer slurry is slit coated to form a slurry layer with an area of 5*5 cm and a thickness of 20-50 μm in the center of a 9*9 cm polytetrafluoroethylene membrane. The slurry layer is then dried at 80-100° C., and then the slurry on the polytetrafluoroethylene membrane is transferred to the center of the proton exchange membrane using a hot press at 100-120° C. and a pressure of 2-3 MPa for 1-3 minutes to obtain the hydrogen removal layer.
7. The method for preparing a membrane electrode anode of a proton exchange membrane electrolyzer according to claim 1, characterized in that: In the catalytic layer forming step, the anode catalytic layer slurry is coated on the 5*5cm anode gas diffusion layer titanium felt by an ultrasonic sprayer at a flow rate of 1.5-3ml / min, with a coating area of 5*5cm, and dried at 80-100℃ to obtain the catalytic layer.
8. The method for preparing a membrane electrode anode of a proton exchange membrane electrolyzer according to claim 1, characterized in that: The hydrogen removal catalyst is a platinum black catalyst or a Pt-Co alloy catalyst.
9. The method for preparing a membrane electrode anode of a proton exchange membrane electrolyzer according to claim 1, characterized in that: The iridium-based oxygen evolution catalyst is one of IrO2 and iridium black catalyst.
10. A membrane electrode anode for a proton exchange membrane electrolyzer, characterized in that: Obtained according to the preparation method according to any one of claims 1 to 9; The anode catalyst layer slurry region of the anode gas diffusion layer is closely attached to the hydrogen removal layer slurry region of the proton exchange membrane; The anode catalyst layer slurry region of the anode gas diffusion layer is centrally symmetrical with the hydrogen removal layer slurry region of the proton exchange membrane.