Preparation method of anode catalyst coating film for hydrogen production by electrolysis of water
By using a mixed solution of ammonium oxalate and gluconic acid in the coating film of the water electrolysis hydrogen production catalyst, a porous structure is formed, which solves the problems of high cost and insufficient mass transfer performance of noble metal oxide catalysts and realizes a highly efficient water electrolysis hydrogen production process.
Patent Information
- Application Number
- CN202511105468.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-07
- Publication Date
- 2025-11-21
AI Technical Summary
In existing water electrolysis hydrogen production technologies, precious metal oxide catalysts are expensive, and the mass transfer performance of catalyst coating membranes is insufficient.
A mixed aqueous solution of ammonium oxalate and gluconic acid was used as the third solvent. A porous catalyst coating film was formed through ball milling, spraying, leveling and cooking processes to improve the dispersion uniformity and mass transfer performance of the catalyst.
A porous structure for catalyst coating membrane was achieved, which improved the catalytic performance of hydrogen production by water electrolysis, reduced the amount of precious metals used, and enhanced mass transfer performance and electrolysis efficiency.
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Figure CN120989651A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of preparation methods for coated films of anode catalysts in water electrolysis for hydrogen production. Background Technology
[0002] Hydrogen (H2) possesses advantages such as high energy density, small molecular weight, and combustion products consisting solely of water, making it an ideal carrier for future energy storage and supply. Currently, the main technologies for producing elemental hydrogen include fossil fuel reforming, industrial by-product gas production, and water electrolysis. Water electrolysis offers advantages such as simple raw materials, no greenhouse gas emissions, high efficiency, and high product purity, and is considered a future direction for the energy industry.
[0003] Hydrogen production technologies via water electrolysis mainly include alkaline electrolyte (AWE) hydrogen production, proton exchange membrane (PEM) water electrolysis, solid polymer anion exchange membrane (AEM) water electrolysis, and solid oxide (SOE) water electrolysis.
[0004] In membrane electrode assemblies (MEAs) for hydrogen production via water electrolysis, the anode catalyst is a key material, primarily used to accelerate the oxygen evolution reaction (OER). Common anode catalyst materials include iron oxide (IrO2), ruthenium oxide (RuO2), iridium-ruthenium composite catalysts, and transition metal-based catalysts. However, iron oxide (IrO2), ruthenium oxide (RuO2), and iridium-ruthenium composite catalysts are relatively expensive. Therefore, cutting-edge research focuses on preparing anode catalysts by supporting noble metal oxides on porous supports. This approach leverages the porous support to improve catalytic electrolysis performance while reducing production costs by lowering the iridium-ruthenium metal loading.
[0005] A novel method for preparing an anode catalyst coating membrane for hydrogen production by water electrolysis is provided. By adjusting the preparation process of the anode catalyst coating membrane, a porous anode catalyst layer structure is obtained, which has excellent electrolytic catalytic performance. Summary of the Invention
[0006] Objective of the invention: The technical problem to be solved by the present invention is to provide a novel method for preparing an anode catalyst coating membrane for hydrogen production by water electrolysis. This method can achieve uniform dispersion of the catalyst slurry and form a porous catalyst coating membrane structure, thereby improving the mass transfer performance of the prepared catalyst coating membrane.
[0007] Technical solution: The present invention provides a method for preparing a coated membrane of an anode catalyst for hydrogen production via water electrolysis, comprising the following steps:
[0008] (1) After the catalyst is added to water and dispersed by ball milling, a second solvent is added and dispersed by ball milling again to obtain the material;
[0009] (2) Add the material to the perfluorosulfonic acid proton exchange membrane solution and disperse it by ultrasonication to obtain a mixed solution;
[0010] (3) Add a third solvent to the mixed solution and ultrasonically mix for 3-5 minutes to obtain a slurry; the third solvent is a mixed aqueous solution of gluconic acid and ammonium oxalate, and the amount added is 5-10% of the mass of the mixed solution;
[0011] (4) The slurry is sprayed to form a catalyst coating film, which is then leveled and boiled.
[0012] The anode catalyst coating of the present invention is prepared by preparing the catalyst into a slurry mixture solution, adding a mixed aqueous solution of gluconic acid and ammonium oxalate as a third solvent for ultrasonic dispersion, and then spraying, leveling and boiling to obtain an anode catalyst layer with excellent electrolytic performance.
[0013] The addition of a mixed aqueous solution of ammonium oxalate and gluconic acid, and its brief dispersion in the slurry solution, serves two purposes. First, the brief dispersion ensures that ammonium oxalate and gluconic acid maintain their original structures within the slurry system. This allows for thorough decomposition at high temperatures during spray drying and leveling, resulting in the release of gases and the construction of a porous catalyst coating. Second, the water-soluble gluconic acid allows its hydroxyl groups to form hydrogen bonds with the hydroxyl groups on the surface of the iridium oxide catalyst. Furthermore, the steric hindrance effect of the gluconic acid molecular chains prevents particles from approaching each other, further improving the dispersion of the iridium oxide catalyst in the solution. This effectively prevents slurry agglomeration and sedimentation, thereby enhancing the mass transfer performance of the prepared catalyst coating.
[0014] Furthermore, the water vapor and ammonia generated by the thermal decomposition of ammonium oxalate during spray drying and leveling can further promote the thermal decomposition of gluconic acid, increasing the pore structure of the prepared catalyst coating film; and at the same time, the gas generated by the thermal decomposition of gluconic acid can reduce the residual gluconic acid.
[0015] Furthermore, the smoothed catalyst coating membrane undergoes further steaming, which not only effectively removes residual and undecomposed ammonium oxalate and gluconic acid from the catalyst coating membrane system, ensuring the stability of the catalyst coating membrane, but also allows the steam flow during steaming to further assist in constructing the porous structure of the catalyst coating membrane, expanding the contact area between the catalyst coating membrane and the water to be electrolyzed, improving the utilization rate of the catalyst, and enhancing the electrolytic catalytic performance.
[0016] Furthermore, in step (4) of the preparation method, the cooking involves treating the smoothed catalyst coating film in water at 40-80°C for 5-20 minutes, followed by multiple rinsing and drying.
[0017] Furthermore, in step (3) of the preparation method, the mass ratio of gluconic acid and ammonium oxalate in the third solvent is 1:(3-7).
[0018] Furthermore, in step (3) of this preparation method, the mass fraction of the mixed aqueous solution of gluconic acid and ammonium oxalate is 5-15 wt%.
[0019] Furthermore, in step (4) of the preparation method, the smoothing is to hot-press the catalyst coating film at 100-120℃ and 1200-1500kg for 45-90s.
[0020] Furthermore, in step (1) of the preparation method, the catalyst is an iridium-containing water electrolysis hydrogen production catalyst, including iridium oxide, ruthenium-iridium alloy or supported iridium oxide.
[0021] Furthermore, in step (1) of the preparation method, the mass ratio of water to catalyst is (10-25):1; the mass ratio of the second solvent to catalyst is (60-120):1. Preferably, the second solvent is a low-boiling-point alcohol, including methanol, ethanol, isopropanol, or n-propanol.
[0022] Furthermore, in step (2) of the preparation method, the mass ratio of the amount of the perfluorosulfonic acid proton exchange membrane added to the catalyst is (0.5-1.2):1.
[0023] Furthermore, in step (1) of the preparation method, the mass ratio of the ball milling beads to the catalyst used in the ball milling dispersion is (30-100):1, and the diameter of the ball milling beads is 1-8 mm.
[0024] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are: the preparation method, by adding a compound of ammonium oxalate and gluconic acid, and by using ball milling, cooking and leveling processes, finally obtains a uniformly dispersed and porous electrolytic water hydrogen production anode catalyst coating film, and there is no ammonium oxalate or gluconic acid residue, which has excellent mass transfer performance.
[0025] Instruction manual illustrations
[0026] Figure 1 The polarization curve of the catalyst coating film prepared in this invention. Figure 1 ;
[0027] Figure 2 The polarization curve of the catalyst coating film prepared in this invention. Figure 2 ;
[0028] Figure 3 The polarization curve of the catalyst coating film prepared in this invention. Figure 3 . Detailed Implementation
[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.
[0030] It should be noted that the spraying process used in the following embodiments and comparative examples of the present invention is as follows: substrate temperature 100℃, spraying spacing 3mm, nozzle height 40mm, spraying speed 100mm / s, spraying flow rate 3.5mL / min, 10 layers sprayed, effective spraying area 20mm×20mm, and room temperature environment for spraying 20℃.
[0031] In the following embodiments and comparative examples of the present invention, the flattening process used is as follows: the sprayed catalyst coating film (CCM) is sandwiched in a polytetrafluoroethylene film, and then an aluminum foil is placed on each side. The hot press is set at 120°C and 1500 kg pressure for 60 seconds.
[0032] In the following embodiments and comparative examples of the present invention, the perfluorosulfonic acid proton exchange membrane solution used is Nafion solution, i.e., perfluorosulfonic acid proton exchange membrane solution, which is a perfluorosulfonic acid proton exchange membrane solution known in the art. Its concentration has little impact on the technical efficacy of the present invention, so it will not be described in detail. It can be directly purchased from DuPont D2020 (mass fraction of 20w%).
[0033] Furthermore, in this embodiment of the invention, after the third solvent is added to the mixed solution and ultrasonically mixed for a specified time, the spraying process is immediately carried out without interruption. After spraying, leveling is immediately performed without interruption. The spraying time is only 2-4 minutes, thus ensuring that the thermal decomposition of the third solvent mainly occurs during the leveling process.
[0034] The catalyst used in this invention is an iridium-containing water electrolysis hydrogen production catalyst raw material, including iridium oxide, ruthenium-iridium alloy or supported iridium oxide, with iridium contents of 85wt%, 45wt% and 40wt%, respectively.
[0035] Example 1
[0036] The preparation method of the coated film of the anode catalyst for hydrogen production by water electrolysis in Example 1 includes the following steps:
[0037] (1) Weigh 0.15g of iridium oxide catalyst, 7.5g of milling beads (bead diameter of 3mm) and 2.25g of ultrapure water and add them to the milling cup. Mill and disperse the mixture for 3min at a maximum milling speed of 500rpm / min. Then add 13.8g of isopropanol and mill for 3min to obtain the material.
[0038] (2) Add 0.75g of perfluorosulfonic acid proton exchange membrane solution to the mixed solution in the above steps, and sonicate for 20min to obtain 16.95g of mixed solution;
[0039] (3) Add 1.356g (8% of the mass of the mixed solution) of a third solvent with a mass fraction of 10wt% to the mixed solution, and ultrasonically disperse for 4min to obtain 18.036g of slurry; the third solvent is a mixed aqueous solution of gluconic acid and ammonium oxalate, and the mass ratio of gluconic acid and ammonium oxalate in the third solvent is 1:3.
[0040] (4) After the slurry is sprayed to obtain a catalyst coating film and smoothed, it is treated in water at 60°C for 10 minutes, and then rinsed (3 times) and dried to obtain the anode catalyst coating film.
[0041] Comparative Example 1
[0042] The first set of experiments in Comparative Example 1 is basically the same as that in Example 1, except that a third solvent is not added. Specifically, it includes the following steps:
[0043] (1) Weigh 0.15g of iridium oxide catalyst, 7.5g of milling beads (bead diameter of 3mm) and 3.606g of ultrapure water and add them to the milling cup. Mill and disperse the mixture for 3min at a maximum milling speed of 500rpm / min. Then add 13.8g of isopropanol and mill for 3min to obtain the material.
[0044] (2) Add 0.75g of perfluorosulfonic acid proton exchange membrane solution to the mixed solution in the above steps, and ultrasonically disperse for 20min to obtain 18.306g of slurry;
[0045] (3) After the slurry is sprayed to obtain a catalyst coating film and smoothed, it is treated in water at 60°C for 10 minutes, and then rinsed and dried several times to obtain the anode catalyst coating film.
[0046] Examples 1-2 (Adjustment of the Amount of Third Solvent Added)
[0047] The method for preparing the anode catalyst coating film of the water electrolysis hydrogen production membrane electrode in Examples 1-2 includes the following steps:
[0048] (1) Weigh 0.15g of iridium oxide catalyst, 7.5g of ball milling beads (bead diameter of 3mm) and 2.7585g of ultrapure water and add them to the ball milling cup. Disperse the mixture by ball milling for 3min at a maximum ball milling speed of 500rpm / min. Then add 13.8g of isopropanol and ball mill for 3min to obtain the material.
[0049] (2) Add 0.75g of perfluorosulfonic acid proton exchange membrane solution to the mixed solution in the above steps, and disperse by ultrasonication for 20min to obtain 17.4585g of mixed solution;
[0050] (3) Add 0.8729g (5% of the mass of the mixed solution) of a third solvent with a mass fraction of 10wt% to the mixed solution and ultrasonically disperse for 4min to obtain 18.306g of slurry; the third solvent is a mixed aqueous solution of gluconic acid and ammonium oxalate, and the mass ratio of gluconic acid and ammonium oxalate in the third solvent is 1:3.
[0051] (4) After the slurry is sprayed to obtain a catalyst coating film and smoothed, it is treated in water at 60°C for 10 minutes, and then rinsed and dried several times to obtain the anode catalyst coating film.
[0052] Examples 1-3 (Adjustment of the Amount of Third Solvent Added)
[0053] The method for preparing the anode catalyst coating film of the water electrolysis hydrogen production membrane electrode in Examples 1-3 includes the following steps:
[0054] (1) Weigh 0.15g of iridium oxide catalyst, 7.5g of ball milling beads (bead diameter of 3mm) and 1.911g of ultrapure water and add them to the ball milling cup. Disperse the mixture by ball milling for 3min at a maximum ball milling speed of 500rpm / min. Then add 13.8g of isopropanol and ball mill for 3min to obtain the material.
[0055] (2) Add 0.75g of perfluorosulfonic acid proton exchange membrane solution to the mixed solution in the above steps, and disperse by ultrasonication for 20min to obtain 16.611g of mixed solution;
[0056] (3) Add 1.6611g (accounting for 10% of the mass of the mixed solution) of a third solvent with a mass fraction of 10wt% to the mixed solution and ultrasonically disperse for 4min to obtain 18.306g of slurry; the third solvent is a mixed aqueous solution of gluconic acid and ammonium oxalate, and the mass ratio of gluconic acid and ammonium oxalate in the third solvent is 1:3;
[0057] (4) After the slurry is sprayed to obtain a catalyst coating film and smoothed, it is treated in water at 60°C for 10 minutes, and then rinsed and dried several times to obtain the anode catalyst coating film.
[0058] Example 2
[0059] The preparation method of the coated film of the anode catalyst for hydrogen production by water electrolysis in Example 2 is the same as that in Example 1 in terms of process steps and parameters. The second batch of experiments in Example 1 specifically includes the following steps:
[0060] (1) Weigh 0.15g of iridium oxide catalyst, 7.5g of milling beads (bead diameter of 3mm) and 2.25g of ultrapure water and add them to the milling cup. Mill and disperse the mixture for 3min at a maximum milling speed of 500rpm / min. Then add 13.8g of isopropanol and mill for 3min to obtain the material.
[0061] (2) Add 0.75g of perfluorosulfonic acid proton exchange membrane solution to the mixed solution in the above steps, and sonicate for 20min to obtain 16.95g of mixed solution;
[0062] (3) Add 1.356g (8% of the mass of the mixed solution) of a third solvent with a mass fraction of 10wt% to the mixed solution, and ultrasonically disperse for 4min to obtain 18.036g of slurry; the third solvent is a mixed aqueous solution of gluconic acid and ammonium oxalate, and the mass ratio of gluconic acid and ammonium oxalate in the third solvent is 1:3.
[0063] (4) After the slurry is sprayed to obtain a catalyst coating film and smoothed, it is treated in water at 60°C for 10 minutes, and then rinsed (3 times) and dried to obtain the anode catalyst coating film.
[0064] Comparative Example 2 - Group No. 1
[0065] Comparative Example 2 is basically the same as Comparative Example 1, except that the third solvent is ammonium oxalate solution throughout, and the specific steps include the following:
[0066] (1) Weigh 0.15g of iridium oxide catalyst, 7.5g of milling beads (bead diameter of 3mm) and 2.25g of ultrapure water and add them to the milling cup. Mill and disperse the mixture for 3min at a maximum milling speed of 500rpm / min. Then add 13.8g of isopropanol and mill for 3min to obtain the material.
[0067] (2) Add 0.75g of perfluorosulfonic acid proton exchange membrane solution to the mixed solution in the above steps, and sonicate for 20min to obtain 16.95g of mixed solution;
[0068] (3) Add 1.356g (8% of the mass of the mixed solution) of ammonium oxalate solution with a mass fraction of 10wt% to the mixed solution, and ultrasonically disperse for 4min to obtain 18.036g of slurry;
[0069] (4) After the slurry is sprayed to obtain a catalyst coating film and smoothed, it is treated in water at 60°C for 10 minutes, and then rinsed (3 times) and dried to obtain the anode catalyst coating film.
[0070] Comparative Example 2 - Group No. 2
[0071] Comparative Example 2 is the second batch of experiments in Group 1 of Comparative Example 1, meaning that the process steps and parameters are the same as those in Group 1 of Comparative Example 2, as detailed below:
[0072] (1) Weigh 0.15g of iridium oxide catalyst, 7.5g of milling beads (bead diameter of 3mm) and 2.25g of ultrapure water and add them to the milling cup. Mill and disperse the mixture for 3min at a maximum milling speed of 500rpm / min. Then add 13.8g of isopropanol and mill for 3min to obtain the material.
[0073] (2) Add 0.75g of perfluorosulfonic acid proton exchange membrane solution to the mixed solution in the above steps, and sonicate for 20min to obtain 16.95g of mixed solution;
[0074] (3) Add 1.356g (8% of the mass of the mixed solution) of ammonium oxalate solution with a mass fraction of 10wt% to the mixed solution, and ultrasonically disperse for 4min to obtain 18.036g of slurry;
[0075] (4) After the slurry is sprayed to obtain a catalyst coating film and smoothed, it is treated in water at 60°C for 10 minutes, and then rinsed (3 times) and dried to obtain the anode catalyst coating film.
[0076] Mass transfer performance testing
[0077] The catalyst coating films prepared in Examples 1, 1-2, 1-3, and Comparative Example 1 were subjected to water electrolysis performance tests, and the results are as follows: Figure 1 As shown. (Through) Figure 1 As can be seen, the polarization curves of Comparative Example 1 are all above those of Example 1, thus verifying that the catalyst coating film prepared by the present invention has excellent mass transfer performance based on the addition of a third solvent.
[0078] Furthermore, the mass transfer performance of the coated films prepared in different batches under the same process parameters in Examples 1 and 2 was compared, and the results obtained are as follows: Figure 2 As shown. Combined with Figure 2 It can be seen that the polarization curves of Examples 1 and 2 basically overlap. The mass transfer performance of the coating films prepared in different batches under the same process parameters (Group 1 of Comparative Example 2 and Group 2 of Comparative Example 2) was compared, and the results are as follows: Figure 3 As shown. Combined with Figure 3 It can be seen that the polarization curves of Group 1 in Comparative Example 2 and Group 2 in Comparative Example 2 differ. Therefore, it can be concluded that the present invention, by compounding gluconic acid in the third solvent, can effectively and significantly improve the dispersion stability of the slurry system, ensuring the quality stability between different batches while maintaining the same spraying process. Furthermore, combined with… Figure 2Furthermore, the stability of the two mass transfer properties also indirectly reflects that the third solvent added in this invention ultimately leaves no residue.
[0079] In addition to the above embodiments, it should be noted that the technical effects claimed above can be obtained by using the preparation process and the specific substances and contents used in this invention. Therefore, no further experimental verification is required, as all of them can be verified through theoretical analysis.
Claims
1. A method for preparing a coated membrane of an anode catalyst for hydrogen production via water electrolysis, characterized in that, Includes the following steps: (1) After the catalyst is added to water and dispersed by ball milling, a second solvent is added and dispersed by ball milling again to obtain the material; (2) Add the material to the perfluorosulfonic acid proton exchange membrane solution and disperse it by ultrasonication to obtain a mixed solution; (3) Add a third solvent to the mixed solution and ultrasonically mix for 3-5 minutes to obtain a slurry; the third solvent is a mixed aqueous solution of gluconic acid and ammonium oxalate, and the amount added is 5-10% of the mass of the mixed solution; (4) The slurry is sprayed to form a catalyst coating film, which is then leveled and boiled.
2. The method for preparing the anolyte catalyst coating film according to claim 1, characterized in that, In step (4), the cooking process involves treating the smoothed catalyst coating film in water at 40-80°C for 5-20 minutes, followed by multiple rinsing and drying.
3. The method for preparing the anolyte catalyst coating film according to claim 1, characterized in that, In step (3), the mass ratio of gluconic acid and ammonium oxalate in the third solvent is 1:(3-7).
4. The method for preparing the anolyte catalyst coating film according to claim 1, characterized in that, In step (3), the mass fraction of the mixed aqueous solution of gluconic acid and ammonium oxalate is 5-15 wt%.
5. The method for preparing the anolyte catalyst coating film according to claim 1, characterized in that, In step (4), the smoothing is to hot press the catalyst coating film at 100-120℃ and 1200-1500kg for 45-90s.
6. The method for preparing the anolyte catalyst coating film according to claim 1, characterized in that, In step (1), the catalyst is an iridium-containing water electrolysis hydrogen production catalyst, including iridium oxide, ruthenium-iridium alloy or supported iridium oxide.
7. The method for preparing the anolyte catalyst coating film according to claim 1, characterized in that, In step (1), the mass ratio of water to catalyst is (10-25):1; the mass ratio of the amount of second solvent added to catalyst is (60-120):
1.
8. The method for preparing the anolyte catalyst coating film according to claim 1 or 7, characterized in that, The second solvent is a low-boiling-point alcohol, including methanol, ethanol, isopropanol, or n-propanol.
9. The method for preparing the anolyte catalyst coating film according to claim 1, characterized in that, In step (2), the mass ratio of the amount of perfluorosulfonic acid proton exchange membrane added to the catalyst is (0.5-1.2):
1.
10. The method for preparing the anolyte catalyst coating film according to claim 1, characterized in that, In step (1), the mass ratio of the ball milling beads to the catalyst used in the ball milling dispersion is (30-100):1, and the diameter of the ball milling beads is 1-8 mm.