PEM electrolysis water hydrogen production anode slurry, catalyst coated membrane and preparation method thereof

Abstract

This invention belongs to the field of proton exchange membrane (PEM) water electrolysis for hydrogen production, and discloses a PEM anode slurry, a catalyst-coated membrane, and their preparation method. The anode catalyst is premixed with ultrapure water under ultrasonic and stirring conditions, then an alcohol solvent and an ionomer are added and stirred before high-speed shear dispersion. Following this, the anode slurry is prepared through nano-grinding and degassing processes. The catalyst coating effect is improved by adjusting the ratio of ionomer to catalyst, the solid content of the slurry, the slurry formulation, and the dispersion process. This invention yields a highly efficient dispersion slurry with high stability, low sedimentation, and a dense and uniform coating, thus improving coating efficiency and water electrolysis performance.

Description

Technical Field

[0001] This invention relates to the field of proton exchange membrane electrolysis for hydrogen production, and more particularly to an anode slurry. Background Technology

[0002] The overuse of traditional fossil fuels has caused a series of energy and environmental pollution problems. Hydrogen energy, with its advantages of high efficiency, zero pollution, and renewability, has become the most ideal clean energy source for the 21st century. The development of hydrogen energy is crucial for becoming a sustainable society. Among these technologies, proton exchange membrane electrolysis (PEMWE) can produce high-purity hydrogen at high current densities and is compatible with intermittent renewable power generation, making it a key research focus in various countries.

[0003] The membrane electrode assembly (MEA), a core component of the PEM electrolyzer, is prepared through steps including catalyst slurry preparation, catalyst layer coating, and encapsulation. It consists of a proton exchange membrane, anode and cathode catalyst layers, and a gas diffusion layer. During electrolysis, water produces oxygen under the action of the anode catalyst and hydrogen under the action of the cathode catalyst.

[0004] Existing anode catalyst slurry formulations typically consist of an anode catalyst, ionomer, ultrapure water, and alcohol solvents. The catalyst can be coated onto the proton exchange membrane using methods such as ultrasonic spraying and slot coating. However, problems arise during slurry preparation and catalyst layer coating, including low viscosity, large particle size, easy sedimentation, low coating efficiency, and poor coating results. For example, prior art (CN118685820A) proposes using a low-solids-content slurry for ultrasonic spraying to prepare the catalyst layer. While the low-solids-content slurry is stable and does not easily settle, the resulting catalyst layer has low efficiency. To achieve efficient catalyst layer preparation, slot coating technology is required. However, slot coating technology requires a high-solids-content slurry, which suffers from high particle size, easy catalyst particle agglomeration, and uneven dispersion. Patent (CN115011992A) proposes increasing the slurry viscosity by adding a thickener (metal nano-oxide), but this method reduces the active sites of the catalyst, further affecting performance. Therefore, improving the uniformity and dispersibility of high-solids slurry, and thus achieving high-efficiency and high-consistency catalyst coating, is of great significance for the large-scale application of PEM water electrolysis for hydrogen production. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a PEM electrolysis water-to-hydrogen anode slurry, a catalyst-coated membrane, and their preparation method. This improves the preparation of the anode catalyst slurry, optimizes the catalyst layer coating effect, and enhances the performance of the membrane electrode.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A method for preparing a PEM (Polymer Electrolysis) anode slurry for hydrogen production via water electrolysis is characterized by the following steps: premixing the anode catalyst with ultrapure water under ultrasonic and stirring conditions; then adding an alcohol solvent and an ionomer, stirring and mixing, followed by high-speed shear dispersion; and finally, performing nano-grinding and vacuum stirring degassing processes to obtain the anode slurry. By designing the formulation ratio and optimizing the dispersion process, the method ensures that the catalyst is evenly distributed, the particle size is reduced, agglomeration is minimized, the viscosity is suitable, and it is easy to coat.

[0007] The above ionomer is a perfluorosulfonic acid resin solution with a solid content of 5-20 wt% and an ion exchange equivalent (EW) of 770-1100 g / mol. The solid content of the above-mentioned anode slurry is 10-35%; the mass ratio of perfluorosulfonic acid resin to anode catalyst is 0.1-0.5; and the volume ratio of ultrapure water to alcohol solvent is 0.3-3.12.

[0008] The anode catalyst is at least one of iridium oxide, ruthenium oxide, iridium black, iridium-based mixed oxides, and ruthenium-based mixed oxides; the alcohol solvent includes at least one of ethanol, n-propanol, and isopropanol.

[0009] Furthermore, the iridium-based mixed oxide is IrFeO. X IrCoO X or IrMnO X The ruthenium-based mixed oxides are Mn-RuO2 or RuFeO2.

[0010] The high-speed shear dispersion was carried out at a speed of 5000-15000 rpm for 30-120 min; the nano-grinding was carried out at a speed of 200-3000 rpm for 2-24 h; and the vacuum stirring degassing was carried out at a speed of 300-2500 rpm for 3-20 min.

[0011] The viscosity of the above-mentioned anode slurry is 16-52 mPa·s.

[0012] A catalyst-coated membrane is prepared by means of: the above-mentioned anode slurry is coated onto a PTFE substrate through a slit, dried, and then the catalyst layer is tightly attached to the proton exchange membrane. Under the protection of expanded PTFE material, hot pressing is performed to realize the transfer of the catalyst layer to the surface of the proton exchange membrane, thereby obtaining the catalyst-coated membrane.

[0013] The adsorption platform temperature for the above-mentioned slit coating is 40-70 ℃, the wet film thickness is 50-100 μm; the hot pressing temperature is 130-150 ℃, the time is 10-30 min, and the pressure is 3-10 t.

[0014] The thickness of the PTFE substrate is 12-100 μm, and the thickness of the expanded PTFE is 1-10 mm.

[0015] The application of the above-mentioned catalyst-coated membrane in hydrogen production by water electrolysis.

[0016] The beneficial effects of this invention are: (1) The technical method of this invention, through adjusting the ratio of ionomer to catalyst, solid content, and dispersion process, produces a slurry that is uniformly dispersed, not prone to agglomeration, has moderate viscosity, and is easy to coat. The viscosity of the catalyst slurry was increased to 52 mPa·s, and the particle size distribution D90 was reduced to 0.6 μm. After standing for 24 h, no significant sedimentation was observed in the slurry. This optimized the catalyst layer coating effect, resulting in a uniform and dense catalyst layer, while also improving coating efficiency and water electrolysis performance.

[0017] (2) This invention reduces catalyst particle size and agglomeration by regulating the dispersion process, thereby increasing the number of active sites for catalytic reaction, reducing proton transport impedance, and further improving the water electrolysis performance of the membrane electrode assembly prepared by this invention. Specifically, when the slurry viscosity is 34 mPa·s and the electrolyzer is 2 A / cm³, the electrolysis performance is improved. 2 At the given current, the electrolysis voltage in the examples was as low as 1.912 V, significantly lower than the 2.4 V of Comparative Example 1. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 These are particle size distribution diagrams of Examples 1-4, Comparative Example 1, and Comparative Example 2 of the present invention.

[0020] Figure 2 This is a viscosity comparison chart of Examples 1-4, Comparative Example 1, and Comparative Example 2 of the present invention.

[0021] Figure 3 These are comparative graphs showing the sedimentation effects of slurry in Examples 1-4, Comparative Example 1, and Comparative Example 2 of the present invention.

[0022] Figure 4 The images shown are (A) and (B) of the catalyst coating film prepared in Example 1 of this invention.

[0023] Figure 5 This is a microscopic image of the coated film prepared in Comparative Example 2 of the present invention.

[0024] Figure 6 These are test graphs of the electrolysis performance of comparative examples 1, 3, and 4 of this invention. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1 The preparation method of PEM electrolysis water-to-hydrogen anode slurry in this embodiment includes the following steps: Based on the following formula: the mass ratio of perfluorosulfonic acid resin to catalyst is 0.23, the mass ratio of ultrapure water to n-propanol is 3.12, and the solid content of the slurry is 13%. The following materials were weighed: 21.56 g of iridium dioxide catalyst, 117.81 g of ultrapure water, 24.81 g of a 20% solids perfluorosulfonic acid resin solution (model D2020, ion exchange equivalent of 770 g / mol), and 37.76 g of n-propanol. The weighed ultrapure water was added to the catalyst, and the container was placed in a constant temperature water bath for ultrasonication while being manually stirred. Then, the ionomer and n-propanol were added, and after stirring for 10 min, high-speed shearing was performed for 30 min at 10000 rpm, followed by nano-milling for 2 h at 1500 rpm, and vacuum stirring and degassing for 10 min at 800 rpm to obtain the anode slurry. After uniform dispersion, the slurry viscosity was tested to be 16 mPa·s (e.g., ...). Figure 2 The particle size distribution D90 is 5.1 μm (e.g., Figure 1 After 24 hours of storage, the slurry showed no obvious settling (e.g. Figure 3 ).

[0027] A method for preparing a catalyst-coated film, comprising the following steps: Catalyst slurry was uniformly coated onto a 50 μm thick PTFE membrane using a flat-plate slot coater (adsorption platform temperature 50℃). The wet thickness was 80 μm, and the dry thickness was 8.5 μm. The coating was uniform during the coating process, and there was no obvious flow of the slurry. After drying, the PTFE membrane with the catalyst layer was tightly adhered to a proton exchange membrane and hot-pressed under the protection of expanded PTFE material (1.5 mm thick) to transfer the catalyst layer to the surface of the proton exchange membrane. The hot-pressing temperature was 150℃, the time was 10 min, and the pressure was 3.5t, thus obtaining the catalyst-coated membrane (CCM).

[0028] Figure 4 The figures (A) and (B) show the physical image of the catalyst-coated film prepared in this embodiment. As can be seen from the figures, the present invention, according to the method described herein, has prepared a large-area (30*30 cm) catalyst-coated film. 2The CCM exhibits high consistency, uniformity, and density. Microscopic images show that the CCM is free of defects such as cracks and pinholes.

[0029] Example 2 The preparation method of PEM electrolysis water-to-hydrogen anode slurry in this embodiment includes the following steps: Based on the following formula: the mass ratio of perfluorosulfonic acid resin to catalyst is 0.3, the mass ratio of ultrapure water to n-propanol is 2.98, and the solid content of the slurry is 13%. The following materials were weighed: 19.71 g of iridium dioxide catalyst, 111.48 g of ultrapure water, 29.57 g of a 20% solids perfluorosulfonic acid resin solution (model D2020, ion exchange equivalent of 770 g / mol), and 37.41 g of n-propanol. The weighed ultrapure water was added to the catalyst, and the container was placed in a constant-temperature water bath for ultrasonication while being manually stirred. Then, the ionomer and n-propanol were added, and after stirring for 10 min, high-speed shearing was performed for 30 min at 10000 rpm, followed by nano-milling for 2 h at 1500 rpm, and vacuum stirring and degassing for 10 min at 800 rpm to obtain the anode slurry. After uniform dispersion, the slurry viscosity was tested and found to be 20 mPa·s (e.g., ...). Figure 2 The particle size distribution D90 is 4.9 μm (e.g., Figure 1 After 24 hours of storage, the slurry showed no obvious settling (e.g. Figure 3 ).

[0030] A method for preparing a catalyst-coated film, comprising the following steps: Catalyst slurry was uniformly coated onto a 50 μm thick PTFE membrane using a flat-plate slit coater (adsorption platform temperature 50 ℃). The wet thickness was 80 μm and the dry thickness was 8.7 μm. The coating consistency was high during the coating process, and there was no flow of the slurry. After drying, the PTFE membrane with the catalyst layer was tightly adhered to the proton exchange membrane and hot-pressed under the protection of expanded PTFE material (thickness 1.5 mm) to achieve the transfer of the catalyst layer to the surface of the proton exchange membrane. The hot-pressing temperature was 150℃, the time was 10 min, and the pressure was 3.5t, thus obtaining the catalyst-coated membrane (CCM).

[0031] Example 3 The preparation method of PEM electrolysis water-to-hydrogen anode slurry in this embodiment includes the following steps: Based on the following formula: the mass ratio of perfluorosulfonic acid resin to catalyst is 0.3, the mass ratio of ultrapure water to n-propanol is 2.3, and the solid content of the slurry is 20%. The following materials were weighed: 22.96 g of iridium dioxide catalyst, 64.0 g of ultrapure water, 34.44 g of a 20% solid content perfluorosulfonic acid resin solution (model D2020, ion exchange equivalent of 770 g / mol), and 27.83 g of n-propanol. The weighed ultrapure water was added to the catalyst, and the container was placed in a constant temperature water bath for ultrasonication while being manually stirred. Then, the ionomer and n-propanol were added, and after stirring for 10 min, high-speed shearing was performed for 30 min at 10000 rpm, followed by nano-milling for 2 h at 1500 rpm, and vacuum stirring and degassing for 10 min at 800 rpm to obtain the anode slurry. After uniform dispersion, the slurry viscosity was tested to be 25 mPa·s (e.g., ...). Figure 2 The particle size distribution D90 is 1.05 μm (e.g., Figure 1 After 24 hours of storage, the slurry showed no obvious settling (e.g. Figure 3 ).

[0032] A method for preparing a catalyst-coated film, comprising the following steps: Catalyst slurry was uniformly coated onto a 50 μm thick PTFE membrane using a flat-plate slot coater (adsorption platform temperature 50 ℃). The wet thickness was 80 μm, and the dry thickness was 9.5 μm. The coating exhibited high consistency during the coating process, with no slurry flow. After drying, the PTFE membrane with the catalyst layer was tightly adhered to a proton exchange membrane and then hot-pressed under the protection of expanded PTFE material (1.5 mm thick) to transfer the catalyst layer onto the proton exchange membrane surface. The hot-pressing temperature was 150℃, the time was 10 min, and the pressure was 5.5 t, thus obtaining the catalyst-coated membrane (CCM).

[0033] Example 4 The preparation method of PEM electrolysis water-to-hydrogen anode slurry in this embodiment includes the following steps: Based on the following formula: the mass ratio of perfluorosulfonic acid resin to catalyst is 0.3, the mass ratio of ultrapure water to n-propanol is 2.3, and the solid content of the slurry is 20%. The following materials were weighed: 22.96 g of iridium dioxide catalyst, 64.0 g of ultrapure water, 34.44 g of a 20% solid content perfluorosulfonic acid resin solution (model D2020, ion exchange equivalent of 770 g / mol), and 27.83 g of n-propanol. The weighed ultrapure water was added to the catalyst, and the container was placed in a constant temperature water bath for ultrasonication while being manually stirred. Then, the ionomer and n-propanol were added, and after stirring for 10 min, high-speed shearing was performed for 60 min at 10000 rpm, followed by nano-milling for 2 h at 2000 rpm, and vacuum stirring and degassing for 10 min at 800 rpm to obtain the anode slurry. After uniform dispersion, the slurry viscosity was tested to be 34 mPa·s (e.g., ...). Figure 2 The particle size distribution D90 is 0.8 μm (e.g., Figure 1 After 24 hours of storage, the slurry showed no obvious settling (e.g. Figure 3 ).

[0034] A method for preparing a catalyst-coated film, comprising the following steps: Catalyst slurry was uniformly coated onto a 50 μm thick PTFE membrane using a flat-plate slot coater (adsorption platform temperature 60 ℃). The wet thickness was 80 μm, and the dry thickness was 9.3 μm. The slurry was uniformly distributed, the coating was dense, and there was no flow. After drying, the PTFE membrane with the catalyst layer was tightly adhered to a proton exchange membrane and hot-pressed under the protection of expanded PTFE material (3 mm thick) to transfer the catalyst layer to the surface of the proton exchange membrane. The hot-pressing temperature was 150 ℃, the time was 10 min, and the pressure was 5.5 t, thus obtaining the catalyst-coated membrane (CCM).

[0035] Example 5 The preparation method of PEM electrolysis water-to-hydrogen anode slurry in this embodiment includes the following steps: Based on the following formula: the mass ratio of perfluorosulfonic acid resin to catalyst is 0.5, the mass ratio of ultrapure water to n-propanol is 0.3, and the solid content of the slurry is 10%. The following materials were weighed: 15 g of iridium dioxide catalyst, 13.85 g of ultrapure water, 150 g of a 5% solids perfluorosulfonic acid resin solution (model D520, ion exchange equivalent of 1100 g / mol), and 46.14 g of n-propanol. The weighed ultrapure water was added to the catalyst, and the container was placed in a constant-temperature water bath for ultrasonication while being manually stirred. Then, the ionomer and n-propanol were added, and after stirring for 10 min, high-speed shearing was performed for 120 min at 5000 rpm, followed by nano-milling for 2 h at 3000 rpm, and vacuum stirring for degassing for 3 min at 2500 rpm to obtain the anode slurry. After uniform dispersion, the slurry viscosity was tested to be 36 mPa·s, the particle size distribution D90 was 0.93 μm, and no significant sedimentation was observed after 24 hours of standing.

[0036] A method for preparing a catalyst-coated film, comprising the following steps: Catalyst slurry was uniformly coated onto a 100 μm thick PTFE membrane using a flat-plate slot coater (adsorption platform temperature 40 ℃). The wet thickness was 100 μm, and the dry thickness was 10.2 μm. The coating exhibited high consistency during coating, with no slurry flow and a dense coating. After drying, the PTFE membrane with the catalyst layer was tightly adhered to a proton exchange membrane and hot-pressed under the protection of expanded PTFE material (1 mm thick) to transfer the catalyst layer onto the proton exchange membrane surface. The hot-pressing temperature was 130 ℃, the time was 30 min, and the pressure was 3 t, thus obtaining the catalyst-coated membrane (CCM).

[0037] Example 6 The preparation method of PEM electrolysis water-to-hydrogen anode slurry in this embodiment includes the following steps: Based on the following formula: the mass ratio of perfluorosulfonic acid resin to catalyst is 0.1, the mass ratio of ultrapure water to n-propanol is 2.8, and the solid content of the slurry is 35%. The following materials were weighed: 10 g of iridium dioxide catalyst, 8.5 g of ultrapure water, 9.99 g of a 10% solids perfluorosulfonic acid resin solution (model D2179, ion exchange equivalent of 790 g / mol), and 3.0 g of n-propanol. The weighed ultrapure water was added to the catalyst, and the container was placed in a constant-temperature water bath for ultrasonication while being manually stirred. Then, the ionomer and n-propanol were added, and after stirring for 10 min, high-speed shearing was performed for 60 min at 15000 rpm, followed by nano-milling for 24 h at 200 rpm, and vacuum stirring and degassing for 20 min at 300 rpm to obtain the anode slurry. After uniform dispersion, the slurry viscosity was tested to be 52 mPa·s, the particle size distribution D90 was 0.6 μm, and no significant sedimentation was observed after 24 hours of standing.

[0038] A method for preparing a catalyst-coated film, comprising the following steps: Catalyst slurry was uniformly coated onto a 12 μm thick PTFE membrane using a flat-plate slot coater (adsorption platform temperature 70 ℃). The wet thickness was 50 μm, and the dry thickness was 7 μm. The coating exhibited high consistency during the coating process, with no slurry flow. After drying, the PTFE membrane with the catalyst layer was tightly adhered to a proton exchange membrane and then hot-pressed under the protection of expanded PTFE material (10 mm thick) to transfer the catalyst layer onto the proton exchange membrane surface. The hot-pressing temperature was 140 ℃, the time was 20 min, and the pressure was 6 t, thus obtaining the catalyst-coated membrane (CCM).

[0039] Example 7 The preparation method of PEM electrolysis water-to-hydrogen anode slurry in this embodiment includes the following steps: Based on the following formula: the mass ratio of perfluorosulfonic acid resin to catalyst is 0.4, the mass ratio of ultrapure water to n-propanol is 1.5, and the solid content of the slurry is 30%. The following materials were weighed: 38.79 g of iridium dioxide catalyst, 22.50 g of ultrapure water, 103.44 g of a 15% solids perfluorosulfonic acid resin solution (model D2179, ion exchange equivalent of 790 g / mol), and 15.0 g of n-propanol. The weighed ultrapure water was added to the catalyst, and the container was placed in a constant-temperature water bath for ultrasonication while being manually stirred. Then, the ionomer and n-propanol were added, and the mixture was stirred for 10 min. Following this, high-speed shearing was performed for 90 min at 8000 rpm, followed by nano-milling for 12 h at 1000 rpm, and vacuum stirring and degassing for 20 min at 1500 rpm to obtain the anode slurry. After being evenly dispersed, the viscosity of the slurry was tested to be 46 mPa·s, the particle size distribution D90 was 0.95 μm, and there was no obvious sedimentation after the slurry was left to stand for 24 hours.

[0040] A method for preparing a catalyst-coated film, comprising the following steps: Catalyst slurry was uniformly coated onto a 50 μm thick PTFE membrane using a flat-plate slot coater (adsorption platform temperature 55 ℃). The wet thickness was 80 μm, and the dry thickness was 9.6 μm. The coating exhibited high consistency during the coating process, with no slurry flow. After drying, the PTFE membrane with the catalyst layer was tightly adhered to a proton exchange membrane and then hot-pressed under the protection of expanded PTFE material (5 mm thick) to transfer the catalyst layer onto the proton exchange membrane surface. The hot-pressing temperature was 150℃, the time was 10 min, and the pressure was 10t, thus obtaining the catalyst-coated membrane (CCM).

[0041] Comparative Example 1 The preparation method of the PEM electrolysis water-to-hydrogen anode slurry in this comparative example differs from that in Example 1 in that it does not involve nano-grinding. The steps are as follows: Based on the following formula: the mass ratio of perfluorosulfonic acid resin to catalyst is 0.23, the mass ratio of ultrapure water to n-propanol is 3.12, and the solid content of the slurry is 13%. The following materials were weighed: 21.56 g of iridium dioxide catalyst, 117.81 g of ultrapure water, 24.81 g of a 20% solids perfluorosulfonic acid resin solution (model D2020, ion exchange equivalent of 770 g / mol), and 37.76 g of n-propanol. The weighed ultrapure water was added to the catalyst, and the container was placed in a constant-temperature water bath for ultrasonication while being manually stirred. Then, the ionomer and n-propanol were added, and after stirring for 10 min, high-speed shearing was performed for 30 min at 10000 rpm, followed by vacuum stirring and degassing for 10 min at 800 rpm to obtain the anode slurry. The viscosity of the slurry after dispersion was tested to be 8.5 mPa·s (e.g., ...). Figure 2The particle size distribution D90 is 5.6 μm (e.g., Figure 1 After 24 hours of standing, the slurry showed obvious settling and stratification (e.g.) Figure 3 ).

[0042] A method for preparing a catalyst-coated film, comprising the following steps: Catalyst slurry was uniformly coated onto a 50 μm thick PTFE membrane using a flat-plate slot coater (adsorption platform temperature 50 ℃). The wet thickness was 80 μm, and the dry thickness was 8 μm. During the coating process, the coating was incomplete, and the slurry was prone to sedimentation. After drying, the PTFE membrane with the catalyst layer was tightly adhered to a proton exchange membrane and hot-pressed under the protection of expanded PTFE material (1.5 mm thick) to achieve the transfer of the catalyst layer to the surface of the proton exchange membrane. The hot-pressing temperature was 150 ℃, the time was 10 min, and the pressure was 3.5 t, thus obtaining the catalyst-coated membrane (CCM).

[0043] Comparative Example 2 The preparation method of the PEM electrolysis anode slurry for hydrogen production in this comparative example differs from that in Example 1 in that it does not involve subsequent high-speed shearing, nano-dispersion, and vacuum stirring degassing treatments. The steps are as follows: Based on the following formula: the mass ratio of perfluorosulfonic acid resin to catalyst is 0.23, the mass ratio of ultrapure water to n-propanol is 3.12, and the solid content of the slurry is 13%. The following materials were weighed: 21.56 g of iridium dioxide catalyst, 117.81 g of ultrapure water, 24.81 g of a 20% solids perfluorosulfonic acid resin solution (model D2020, ion exchange equivalent of 770 g / mol), and 37.76 g of n-propanol. The weighed ultrapure water was added to the catalyst, the container was placed in a constant temperature water bath for ultrasonication while being manually stirred, and then the ionomer and n-propanol were added. Ultrasonic dispersion was performed for 2 hours to obtain the anode slurry. The viscosity of the slurry after dispersion was measured to be 10.92 mPa·s (e.g., ...). Figure 2 The particle size distribution D90 is 7.2 μm (e.g., Figure 1 After 24 hours of standing, the slurry showed obvious settling and stratification (e.g.) Figure 3 ).

[0044] A method for preparing a catalyst-coated film, comprising the following steps: Catalyst slurry was uniformly coated onto a 50 μm thick PTFE membrane using a flat-plate slit coater (adsorption platform temperature 50 ℃). The wet thickness was 80 μm, and the dry thickness was 6.7 μm. The coating uniformity of the catalyst layer was poor. After drying, the PTFE membrane with the catalyst layer was tightly adhered to a proton exchange membrane and hot-pressed under the protection of expanded PTFE material (1.5 mm thick) to transfer the catalyst layer to the surface of the proton exchange membrane. The hot-pressing temperature was 150 ℃, the time was 10 min, and the pressure was 3.5 t, thus obtaining the catalyst-coated membrane (CCM).

[0045] Comparing Example 1 and Comparative Example 1, it was found that the slurry without nano-grinding treatment had a higher particle size, was prone to sedimentation, and resulted in poor coating consistency. Comparing Example 1 and Comparative Example 2, it was found that without subsequent high-speed shearing, nano-grinding, and vacuum stirring degassing treatments, the slurry had a high particle size, and the coating was prone to defects such as pinholes and cracks (e.g., Figure 5 (As shown).

[0046] Application examples Using the technical method provided by this invention, a slurry prepared by the methods mentioned in Examples 3, 4 and Comparative Example 1 is coated onto a PTFE membrane using a slot coater to form an anodic catalyst layer (loading 1 mgIr / cm²). 2 After the catalyst layer dries, it is coated onto a PTFE membrane with a loading of 0.2 mg Pt / cm³. 2 The cathode catalyst layer and the 117 proton exchange membrane were fabricated into a CCM by hot pressing transfer. The CCM was then assembled with the gas diffusion layer (GDL) on the cathode and the porous titanium felt transport layer (PTL) on the anode to form a membrane electrode assembly (MEA) in an electrolyzer. Electrolysis performance tests were then conducted, and the results are as follows: Figure 6 As shown in the figure. It can be seen that in an electrolytic cell with a current of 2 A / cm 2 Under the given current, the electrolysis voltages of Examples 4, 3, and Comparative Example 1 were 1.912 V, 1.955 V, and 2.4 V, respectively, indicating that the electrolysis performance of the examples was significantly improved. This further verifies that the technical solution of the present invention can increase the active sites of the catalytic reaction and reduce the proton transport impedance.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a PEM electrolytic water hydrogen generation anode slurry, characterized in that, The steps are as follows: the anode catalyst is premixed with ultrapure water under ultrasonic and stirring conditions, then an alcohol solvent and ionomer are added and stirred and mixed, followed by high-speed shear dispersion, and then nano-grinding and vacuum stirring to degas the anode slurry. The high-speed shear dispersion speed is 5000-15000 rpm and the time is 30-120 min; the nano-grinding speed is 200-3000 rpm and the time is 2-24 h; the vacuum stirring degassing speed is 300-2500 rpm and the time is 3-20 min.

2. The method for preparing PEM electrolysis water-to-hydrogen anode slurry according to claim 1, characterized in that, The ionomer is a perfluorosulfonic acid resin solution with a content of 5-20 wt% and an ion exchange equivalent of 770-1100 g / mol.

3. The method for preparing PEM electrolysis water-to-hydrogen anode slurry according to claim 2, characterized in that, The solid content of the anode slurry is 10-35%; the mass ratio of perfluorosulfonic acid resin to anode catalyst is 0.1-0.5; and the mass ratio of ultrapure water to alcohol solvent is 0.3-3.

12.

4. The method for preparing PEM electrolysis water-to-hydrogen anode slurry according to any one of claims 1-3, characterized in that, The anode catalyst is at least one of iridium oxide, ruthenium oxide, iridium black, iridium-based mixed oxides, and ruthenium-based mixed oxides.

5. The method for preparing PEM electrolysis water-to-hydrogen anode slurry according to claim 4, characterized in that, The alcohol solvent includes at least one of ethanol, n-propanol, and isopropanol.

6. The PEM anode slurry for hydrogen production via water electrolysis prepared by the method described in claim 1, characterized in that, The viscosity of the anode slurry is 16-52 mPa·s.

7. A catalyst-coated film, characterized in that, The preparation method is as follows: the anode slurry described in claim 6 is coated onto a PTFE substrate using slit coating technology, and after drying, the catalyst layer is tightly attached to the proton exchange membrane. Under the protection of expanded PTFE material, hot pressing is performed to achieve the transfer of the catalyst layer to the surface of the proton exchange membrane, thereby obtaining a catalyst-coated film.

8. The catalyst coating film according to claim 7, characterized in that, The adsorption platform temperature for the slit coating is 40-70 ℃, and the wet film thickness is 50-100 μm; the hot pressing temperature is 130-150 ℃, the time is 10-30 min, and the pressure is 3-10 t.

9. The catalyst coating film according to claim 8, characterized in that, The thickness of the PTFE substrate is 12-100 μm, and the thickness of the expanded PTFE is 1-10 mm.

10. The application of the catalyst coating membrane according to claim 7 in hydrogen production by water electrolysis.

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