Alkaline electrolytic water hydrogen production diaphragm based on flower-ball-shaped mesoporous titanium oxide and preparation method of alkaline electrolytic water hydrogen production diaphragm
An alkaline water electrolysis hydrogen production membrane was prepared by combining flower-shaped mesoporous titanium dioxide with polysulfone resin. This solved the problem of insufficient performance of existing membranes under high current density, high temperature and high pressure, and realized an efficient and stable water electrolysis hydrogen production process, reducing energy consumption and cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-30
- Publication Date
- 2026-04-14
AI Technical Summary
Existing alkaline electrolyzer membranes are insufficient in performance under high current density, high temperature and high pressure, making it difficult to simultaneously meet the requirements of high ion conduction efficiency, gas barrier properties, alkali thermal stability and dynamic response speed, and thus cannot meet the needs of renewable energy hydrogen production.
Mesoporous titanium dioxide with flower-like structure was used as the membrane material. The mesoporous titanium dioxide was combined with polysulfone resin by the sol-gel method to form a composite membrane supported by PPS mesh, which provides continuous OH- transport channels and efficient gas barrier, and enhances the stability and hydrophilicity of the membrane.
It achieves low surface resistivity, high-efficiency gas barrier, long-term stability, and adaptability to high current density operating conditions, thereby reducing the energy consumption and production cost of the electrolyzer, and improving the working efficiency of the electrolyzer and the service life of the diaphragm.
Smart Images
Figure CN121853048A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of alkaline water electrolysis hydrogen production membrane technology, and more specifically to an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide and its preparation method. Background Technology
[0002] Hydrogen energy, as a clean energy carrier with zero carbon emissions, occupies a core position in the global energy transition and "carbon neutrality" strategy. Electrolysis of water to produce hydrogen is a key technological path for achieving large-scale green hydrogen production. Among these technologies, alkaline electrolyzers (AWE) have become the mainstream industrial-grade green hydrogen production solution due to their high technological maturity, low equipment cost, and compatibility with non-precious metal catalysts. Their core performance and operational safety highly depend on the diaphragm component between the cathode and anode. As the core functional component of the alkaline electrolyzer, the diaphragm undertakes three key missions: first, it physically separates the hydrogen produced at the cathode from the oxygen produced at the anode, eliminating the risk of mixing and explosion caused by gas cross-penetration, ensuring the safety of the electrolysis process and improving product purity; second, it constructs a continuous ion transport channel, allowing hydroxide ions (OH-) in the electrolyte to pass through. - It enables efficient migration, maintaining the continuous electrochemical reaction; thirdly, it supports electrolyte wetting and distribution, reduces interfacial impedance and concentration polarization, and withstands long-term corrosion under high-temperature and concentrated alkali conditions, ensuring the long-term stable operation of the electrolyzer.
[0003] Therefore, an ideal alkaline electrolyzer diaphragm must simultaneously meet core technical requirements such as high ion conduction efficiency, excellent gas barrier properties, strong alkali-resistant thermal stability, reliable mechanical strength, and good electrolyte compatibility. Its performance directly determines the energy conversion efficiency, service life, and overall cost of the electrolyzer. With the green hydrogen industry's increasingly urgent need for high current density (>1A / cm²), high temperature and high pressure (>130℃, >25bar) operation and cost reduction and efficiency improvement in electrolyzers, existing diaphragm technologies are gradually revealing their performance shortcomings: on the one hand, the balance between ion conduction efficiency and gas barrier properties is difficult to optimize, and traditional diaphragms are less effective in improving OH- ion conduction efficiency. - High conduction rates can easily lead to increased gas permeability, while strengthening gas barrier properties sacrifices conduction efficiency. On the other hand, the long-term stability against 30-40wt% KOH concentrated alkaline electrolyte and operating temperatures of 60-90℃ is insufficient, and problems such as interlayer delamination and swelling deformation can lead to a gradual increase in electrolyzer energy consumption and a shortened lifespan. In addition, the dynamic response speed and structural stability of existing membranes need to be improved to meet the current fluctuations brought about by hydrogen production from renewable energy sources (wind power, photovoltaics), and they cannot fully adapt to the needs of new energy hydrogen production scenarios.
[0004] Therefore, the development of a novel alkaline electrolyzer diaphragm is urgently needed. This diaphragm must possess characteristics such as low ion conduction resistance, efficient gas barrier properties, strong interlayer bonding stability, resistance to alkaline thermal aging, and adaptability to high current density operating conditions. It will be key to breaking through existing technological bottlenecks and promoting the development of alkaline water electrolysis hydrogen production technology towards higher efficiency, longer lifespan, and lower cost, and has significant technological value and practical implications for promoting the large-scale application of green hydrogen industry.
[0005] Titanium oxide, as a rare earth metal oxide, offers new possibilities for overcoming the aforementioned bottlenecks due to its unique properties. Titanium oxide exhibits outstanding chemical inertness, remaining undissolved, unswelled, and undegraded even after prolonged immersion in a 30–40 wt% KOH concentrated alkaline electrolyte at an operating temperature of 60–90℃, far superior to easily aging polymer membranes. It can withstand temperatures exceeding 500℃, enduring the thermal cycling and thermal shock of the electrolytic cell, significantly extending the membrane's service life. The porous structure of mesoporous titanium oxide provides continuously interconnected OH groups. - The high surface area of the transport channel enhances mass transfer between ions, reduces concentration polarization, and is suitable for high current density conditions (>1 A / cm²). Titanium oxide is non-toxic and harmless, avoiding the carcinogenic risks of asbestos membranes and the environmental hazards of some organic membranes; the raw material is abundant, and the preparation process is mature (sol-gel method, hydrothermal method, etc.), possessing the potential for large-scale production and cost reduction.
[0006] Therefore, providing an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide with good stability and high-density slurry preparation, and its preparation method, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0007] In view of this, the present invention provides a composite membrane for alkaline water electrolysis hydrogen production based on flower-shaped mesoporous titanium dioxide, which is easy to prepare, has a uniform and flat surface, high hydrophilicity in a strongly alkaline electrolysis environment, ensures efficient ion migration channels, is low in cost, and has low surface resistivity, as well as a method for its preparation.
[0008] To achieve the above objectives, the present invention adopts the following technical solution:
[0009] A method for preparing an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide includes the following steps: S1, flower-shaped mesoporous titanium dioxide was prepared by mixing sodium dodecyl sulfate and tetrabutyl titanate; S2, mix and stir the polysulfone resin with N-methylpyrrolidone to uniformly disperse the polysulfone resin in the N-methylpyrrolidone; then add polyvinylpyrrolidone and continue stirring until it is completely dissolved to obtain a mixed solution; S3. Add flower-shaped mesoporous titanium dioxide to the mixed solution, stir at 400 r / min until the sample is completely dispersed, and then stir at low speed of 200 r / min to perform degassing treatment to obtain casting solution; S4. Immerse the polyphenylene sulfide mesh in the casting solution to ensure that the casting solution fully penetrates the interior of the polyphenylene sulfide mesh support. Then, use a doctor blade to coat the membrane to determine the thickness. Let the coated membrane stand in the air for pre-evaporation. Then, repeatedly soak and wash the supported composite membrane with deionized water until the water is clear and not turbid, to obtain a polyphenylene sulfide mesh supported polysulfone-mesoporous flower ball titanium dioxide composite membrane.
[0010] Preferably, in step S1, the mass ratio of sodium dodecyl sulfate to tetrabutyl titanate is 1.5g:3.4ml. Preferably, step S1 specifically includes: Dissolve 1-3g of sodium dodecyl sulfate in 30mL of tetrahydrofuran solution until the sodium dodecyl sulfate is completely dissolved. Then add 2-4mL of concentrated HCl and 2-4mL of acetic acid, stir for 15-30min, and then add 2-4mL of tetrabutyl titanate dropwise. Stir for 15-30min, and then keep warm at 60℃ for 48-96h. Cool to room temperature to obtain a yellow precipitate. Wash the precipitate three times with anhydrous ethanol by centrifugation, and then dry it in a 60℃ oven to obtain flower-shaped mesoporous titanium dioxide.
[0011] Preferably, in step S2, the mass ratio of the polysulfone resin, N-methylpyrrolidone, and polyvinylpyrrolidone is 7.5:27.5:5; and the stirring speed is 300 r / min for all of them.
[0012] Preferably, in step S3, the ratio of the mixed solution to the flower-shaped mesoporous titanium dioxide is 4:6 (mass ratio of flower-shaped titanium dioxide to polysulfone resin in step S3). After adding the flower-shaped titanium dioxide to the mixed solution, the stirring speed is 300 r / min for 24 h. After complete dispersion, the degassing treatment is carried out at a low stirring speed of 150 r / min for 24 h. Preferably, in step S4, the wetting time is 15-20 min; the thickness is 400 μm; and the pre-evaporation time is 10-15 min.
[0013] As can be seen from the above technical solution, compared with the prior art, the present invention has the following technical effects: (1) The mesoporous structure (2–50 nm) provides continuous ion channels with a specific surface area of 100–300 m². 2 / g, far exceeding commercially available titanium dioxide (typically <50 m). 2 / g), can significantly reduce OH -Transmission resistance is reduced, concentration polarization is decreased, and it is suitable for high current density conditions; however, the random pores or dense structure of commercial titanium dioxide can easily cause tortuous ion transport paths and low conduction efficiency.
[0014] (2) The uniform pore size of mesoporous titanium dioxide can accurately sieve H2 / O2 molecules, inhibit gas cross-permeation, and reduce the risk of mixed explosion; the large pores (>50 nm) or defect structure of commercial titanium dioxide are difficult to effectively block gas, which can easily lead to a decrease in product purity.
[0015] (3) The high specific surface area of mesoporous titanium dioxide enhances its wettability with alkaline electrolytes and has a lower interfacial impedance. Moreover, its mesoporous framework is not prone to swelling or collapse in concentrated KOH, and its long-term operational stability is better than some commercially available titanium dioxide powders that are prone to agglomeration.
[0016] (4) The technical method of the present invention has a short reaction time, low cost, and is easy to promote. Attached Figure Description
[0017] 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the nitrogen adsorption-desorption curve of the flower-shaped titanium dioxide of the present invention.
[0019] Figure 2 This is a schematic diagram of the nitrogen adsorption-desorption curve of commercial titanium dioxide according to the present invention.
[0020] Figure 3 This is the result of the indoor voltage test in this invention.
[0021] Figure 4 TEM image of flower-shaped titanium dioxide.
[0022] Figure 5 Contact angle diagram of commercial titanium dioxide and flower-shaped titanium dioxide composite film.
[0023] Figure 6 SEM image of a polysulfone-titanium oxide composite film supported by a PPS mesh. Detailed Implementation
[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.
[0025] Example 1 This embodiment provides a method for preparing an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide, including the following steps: (1) Dissolve 1.5g sodium dodecyl sulfate in 30mL tetrahydrofuran solution until sodium dodecyl sulfate is completely dissolved. Then add 2.4mL concentrated HCl (strong acid catalyst to accelerate the hydrolysis of titanium source) and 3.2mL acetic acid (chelating agent, the carboxyl group in acetic acid forms a stable chelate with Ti4+). After stirring for 30min, add 3.4mL TBOT dropwise. After stirring for half an hour, keep warm at 60℃ for 96h. Cool to room temperature to obtain a yellow precipitate. Wash three times with anhydrous ethanol by centrifugation and dry in a 60℃ oven to obtain a mesoporous titanium oxide sample.
[0026] The microstructure of the flower head prepared in step (1) was observed using a transmission electron microscope (TEM), and the results are as follows: Figure 4 As shown, from Figure 4 As can be seen, the size of the mesoporous spherical titanium dioxide sample obtained in step (1) is approximately 300~350 nm. The specific surface area of the macroporous-mesoporous titanium dioxide from step (1) was measured using a fully automated gas adsorption analyzer, as shown in the figure. Figure 1 The specific surface area of its macroporous-mesoporous titanium dioxide was found to be 148 m². 2 / g.
[0027] (2) Mix 4g of polysulfone resin with 20g of N-methylpyrrolidone and stir at 400r / min to make the polysulfone uniformly dispersed in N-methylpyrrolidone; then add 6g of polyvinylpyrrolidone and continue stirring at 300r / min to completely dissolve it and obtain a mixed solution.
[0028] (3) Add 4g of flower-shaped mesoporous titanium dioxide to the mixed solution, stir at 300r / min for 24h until the mesoporous flower-shaped titanium dioxide is completely and evenly dispersed, and then stir at 100r / min for degassing treatment to obtain casting solution.
[0029] (4) Immerse the PPS (polyphenylene sulfide) mesh in the casting solution for 20 minutes to allow the casting solution to fully penetrate the interior of the PPS mesh support. Then, use a scraper to coat the membrane to a thickness of 200 μm. Let the membrane stand in the air for 10 minutes to allow for pre-evaporation. Then, use deionized water to repeatedly soak and clean the supported composite membrane to obtain a PPS mesh supported polysulfone-flower-shaped titanium dioxide composite membrane.
[0030] The surface resistivity of the diaphragm in the flower-shaped titanium dioxide and Comparative Example 1 was tested, and the results are shown below. Table 1. Diaphragm surface resistance test
[0031] The data comparison in the table shows that the average sheet resistivity of Example 1 (flower-shaped titanium dioxide) is 0.18 Ω·cm², which is relatively low. In contrast, the average sheet resistivity of Comparative Example 1 (commercial titanium dioxide) is 0.48 Ω·cm², significantly higher than that of Example 1. Therefore, compared to commercial titanium dioxide, flower-shaped titanium dioxide exhibits a significantly lower sheet resistivity. This directly verifies the effectiveness of introducing mesoporous channels to increase mass transfer and reduce the sheet resistivity of the composite membrane. This allows the membrane with low sheet resistivity to support higher operating current densities, thereby greatly improving the efficiency of the electrolyzer. The adsorption-desorption curves of flower-shaped titanium dioxide and commercial titanium dioxide were tested, and the results are shown below. Table 2 Nitrogen adsorption-desorption test:
[0032] Flower-shaped titanium dioxide has a significantly higher specific surface area than commercial titanium dioxide. This is attributed to the introduction of mesoporous channels, which results in more hydroxyl groups on the surface, meaning more surface active sites, stronger hydrophilicity, and a better ion-conducting interface.
[0033] The cell voltages of commercially available ZIRFON-UTP-500 diaphragms and diaphragms prepared from flower-shaped titanium dioxide were tested, and the results are as follows: Figure 3 .
[0034] Compared to commercial membranes, its operating voltage is reduced by about 0.10V, which is of great practical significance for reducing the production cost of green hydrogen.
[0035] Table 3
[0036] The flower-shaped titanium dioxide diaphragm is significantly superior to commercial diaphragms in terms of bubble point pressure, hydrophilicity (small contact angle), alkali absorption rate, and mechanical strength. These properties are crucial for diaphragms in alkaline electrolyzers: high bubble point pressure improves airtightness, small contact angle improves wettability, high alkali absorption rate improves ion conduction and stability, and high tensile strength improves mechanical durability. Overall, it has significant performance advantages.
[0037] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0038] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide, characterized in that, Includes the following steps: S1, flower-shaped mesoporous titanium dioxide was prepared by mixing sodium dodecyl sulfate and tetrabutyl titanate; S2, mix and stir the polysulfone resin with N-methylpyrrolidone to uniformly disperse the polysulfone resin in the N-methylpyrrolidone; then add polyvinylpyrrolidone and continue stirring until it is completely dissolved to obtain a mixed solution; S3. Add flower-shaped mesoporous titanium dioxide to the mixed solution, stir until the sample is completely dispersed, then stir at low speed to degas and obtain the casting solution. S4. Immerse the polyphenylene sulfide mesh in the casting solution to ensure that the casting solution fully penetrates the interior of the polyphenylene sulfide mesh support. Then, use a doctor blade to coat the membrane to determine the thickness. Let the coated membrane stand in the air for pre-evaporation. Then, repeatedly soak and wash the supported composite membrane with deionized water until the water is clear and not turbid, thus obtaining a polyphenylene sulfide mesh supported polysulfone-mesoporous flower ball titanium dioxide composite membrane.
2. The method for preparing an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide according to claim 1, characterized in that, In step S1, the mass ratio of sodium dodecane sulfate to tetrabutyl titanate is 1g:2ml-3g:12ml.
3. The method for preparing an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide according to claim 1, characterized in that, The average particle size of the flower-shaped mesoporous titanium dioxide in step S1 is 300 nm.
4. The method for preparing an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide according to claim 2, characterized in that, Step S1 specifically includes: Dissolve 1-3g of sodium dodecyl sulfate in 30mL of tetrahydrofuran solution until the sodium dodecyl sulfate is completely dissolved. Then add 2-4mL of concentrated HCl and 2-4mL of acetic acid, stir for 15-30min, and then add 4-6mL of tetrabutyl titanate dropwise. Stir for 15-30min, and then keep warm at 60℃ for 48-96h. Cool to room temperature to obtain a yellow precipitate. Wash the precipitate three times with anhydrous ethanol by centrifugation, and then dry it in a 60℃ oven to obtain flower-shaped mesoporous titanium dioxide.
5. The method for preparing an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide according to claim 1, characterized in that, In step S2, the mass ratio of polysulfone resin, N-methylpyrrolidone, and polyvinylpyrrolidone is 7.5:27.5:5; the stirring speed is 300 r / min.
6. The method for preparing an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide according to claim 1, characterized in that, In step S3, the mass ratio of the flower-shaped titanium dioxide to the polysulfone resin is 4:
6. After adding the flower-shaped titanium dioxide to the mixed solution, the stirring speed is 300 r / min for 24 h. After complete dispersion, the degassing treatment is carried out by low-speed stirring at a stirring speed of 150 r / min for 24 h.
7. The method for preparing an alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide according to claim 1, characterized in that, The immersion time in step S4 is 15-20 min; the thickness is 400 μm; and the pre-evaporation time is 10-15 min.
8. An alkaline water electrolysis hydrogen production membrane based on flower-shaped mesoporous titanium dioxide, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.