A method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolyzing alkaline water

Abstract

The invention discloses a method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water, belongs to the technical field of producing hydrogen by electrolysis of alkaline water, and is used to solve the technical problems that a diaphragm prepared from a polysulfone material in the prior art has poor hydrophilicity, poor electrical conductivity, and the mechanical properties of the diaphragm need to be further improved. The invention comprises the following steps: zwitterion-modified polysulfone, NMP and a microporous additive are mixed to obtain a casting solution, the casting solution is subjected to a post-process treatment to obtain a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water, the polysulfone is subjected to chlorination treatment, an anionic monomer sodium methacrylic sulfonate and a cationic monomer 4-vinyl pyridine are grafted, thereby improving the electrical conductivity of the polysulfone, and aluminum oxide, zirconium dioxide and titanium dioxide ground to micrometer level are modified by a complex coupling agent, and the obtained microporous additive has the advantages of high mechanical strength and strong hydrophilicity.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen production by electrolysis of alkaline water, and in particular to a method for preparing a corrosion-resistant diaphragm for hydrogen production by electrolysis of alkaline water. Background Art

[0002] As a "zero-carbon" clean energy, hydrogen energy has the characteristics of abundant reserves, renewable, clean and efficient, and only emits water during use, without emitting other harmful gases or solid particles. Its development and utilization is an inevitable trend in future energy development. The ways to produce green hydrogen include biomass hydrogen production, solar photolysis of water to produce hydrogen, and renewable electricity electrolysis of water to produce hydrogen. Among them, the electrolysis of water to produce hydrogen technology has the advantages of stability and large-scale mass production, and is increasingly favored by the market.

[0003] The diaphragm occupies a very important position in the electrolyzer. In the process of hydrogen production by alkaline water electrolysis, oxygen and hydrogen are generated at the anode and cathode respectively. Therefore, on the one hand, the diaphragm must be able to prevent hydrogen and oxygen from mixing with each other to ensure the purity of the hydrogen, and on the other hand, it must allow ions in the solution to pass through to ensure the continuation of the electrolysis process.

[0004] Common diaphragms include asbestos diaphragms, polyphenylene sulfide diaphragms, polyetheretherketone diaphragms, polysulfone diaphragms, etc. Polysulfone diaphragms are high molecular weight compounds with phenylene sulfone as structural units. The polysulfone structural unit contains 4 benzene rings and has a symmetrical structure. The conjugation effect and rigid structure of the benzene rings make the polysulfone resin have strong thermal stability and mechanical strength; however, the hydrophilicity of polysulfone diaphragms is poor. During the water electrolysis process, tiny bubbles of hydrogen and oxygen are easily gathered on the surface of the diaphragm, affecting the flow of the electrolyte, reducing the current efficiency, and increasing energy consumption. If the hydrophilicity of the polysulfone diaphragm can be enhanced, the polysulfone diaphragm will have a more superior application prospect in the field of water electrolysis diaphragms. In addition, how to improve the ionic conductivity of the polysulfone diaphragm is still a technical problem that needs to be solved urgently.

[0005] Patent application CN117822048A discloses a temperature-resistant alkaline water electrolysis hydrogen production diaphragm and a preparation method thereof. The temperature-resistant alkaline water electrolysis hydrogen production diaphragm is made of a double-sided composite porous coating on a fiber mesh cloth, wherein the solid components of the porous coating include zirconium oxide particles and resin, and the resin includes at least one or two of polyphenylene sulfide, polyether sulfone or bisphenol A type polysulfone; however, the zirconium oxide particles and the organic resin themselves are not compatible, thereby reducing the hydrophilicity of the prepared diaphragm. In addition, the zirconium oxide particles are filled in the resin, which reduces the pore size of the prepared diaphragm, further reducing the conductive performance of the prepared diaphragm.

[0006] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0007] The object of the present invention is to provide a method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water, so as to solve the technical problems in the prior art that the mechanical properties of diaphragms prepared from polysulfone materials need to be further improved and the diaphragms have poor hydrophilicity and poor conductivity.

[0008] The purpose of the present invention can be achieved by the following technical scheme: A method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolyzing alkaline water, comprising the following steps:

[0009] S1, mixing zwitterion-modified polysulfone and NMP to obtain a uniformly dispersed mixed solution; adding a microporous additive to the mixed solution, stirring at 500 r / min at room temperature for 24 hours to obtain a casting solution;

[0010] S2. Pour the casting liquid onto a glass plate, and quickly scrape the film on the glass plate with a scraping rod until the thickness of the liquid film on the glass plate is 500-600 μm; use deionized water as a coagulation bath, put the glass plate into the deionized water, and let the liquid film gel fall off and be taken out to obtain a diaphragm; the diaphragm is post-processed to obtain a corrosion-resistant electrolysis alkaline water hydrogen production diaphragm.

[0011] NMP is used as a solvent to dissolve zwitterion-modified polysulfone, and then a microporous additive is added to prepare a corresponding casting solution. The casting solution is subjected to a series of post-process treatments to prepare a corrosion-resistant alkaline water electrolysis hydrogen production diaphragm.

[0012] Furthermore, in step S1, the method for preparing the zwitterion-modified polysulfone comprises the following steps:

[0013] A1. Add polysulfone and chloroform into a three-necked flask, mix and stir until the polysulfone is completely dissolved in the chloroform to obtain a solution; introduce chlorine gas into the three-necked flask at a flow rate of 15 mL / min;

[0014] A2. At 50-60° C., a three-necked flask is subjected to ultraviolet irradiation using an ultrahigh pressure spherical mercury lamp to obtain a product; the temperature is then raised to 65° C. to evaporate all the chloroform solvent to obtain a solid; the solid is washed with deionized water and vacuum dried to constant weight to obtain chlorinated polysulfone;

[0015] Due to the unique molecular structure of polysulfone, electrophilic substitution reaction is easy to occur on its main chain. Polysulfone itself contains electron-donating ether bonds, so that chlorination of polysulfone can be achieved. Chloroform is used as a solvent to dissolve the polysulfone solid to obtain a corresponding solution. Chlorine gas is introduced into the solution. Under the action of ultraviolet radiation, the polysulfone in the solution undergoes a nucleophilic substitution reaction with the chlorine gas to prepare chlorinated polysulfone.

[0016] The reaction formula for preparing chlorinated polysulfone by reacting polysulfone with chlorine is as follows:

[0017]

[0018] A3, chlorinated polysulfone, 4-vinylpyridine, sodium methyl propylene sulfonate and DMSO are mixed to obtain a mixed solid-liquid; under a nitrogen atmosphere, cuprous bromide is added to the mixed solid-liquid, accompanied by mechanical stirring at 100-200 r / min, and reacted at 100-120° C. for 12 hours to obtain a product;

[0019] A4. The product is transferred into methanol to precipitate, which is repeatedly filtered and washed with methanol to obtain a solid from which cuprous bromide is removed; the solid is vacuum dried at 80° C. to a constant weight to obtain a solid zwitterion-modified polysulfone.

[0020] Functional groups with negative charges are attached to the polymer chains of chlorinated polysulfone; using DMSO as solvent, cuprous bromide as catalyst, and organic halide chlorinated polysulfone as initiator, an atom transfer free polymerization reaction occurs, and then anionic monomer sodium methyl methacrylate sulfonate and cationic monomer 4-vinyl pyridine are grafted to prepare solid zwitterionic modified polysulfone.

[0021] The reaction formula of chlorinated polysulfone, 4-vinylpyridine and sodium methyl methacrylate sulfonate is as follows:

[0022]

[0023] Furthermore, in step A1, the usage ratio of polysulfone and chloroform is 50g:100mL; in step A2, the frequency of ultraviolet irradiation is 10-20KHz, and the duration of ultraviolet irradiation is 30-60min.

[0024] Furthermore, in step A3, the amount ratio of chlorinated polysulfone, 4-vinylpyridine, sodium methyl propylene sulfonate, DMSO and cuprous bromide is 30g:5-10g:15-20g:100mL; in step A4, the amount of methanol is 300mL.

[0025] Furthermore, in step S1, the method for preparing the microporous additive comprises the following steps:

[0026] B1. Evenly mix trimethoxysilane and platinum catalyst S-201, and then add the remaining trimethoxysilane, methyl methacrylate and polymerization inhibitor phenothiazine to obtain a mixture; react the mixture at 100-110° C. for 2 h, and then distill and filter under reduced pressure to obtain a coupling agent liquid;

[0027] With platinum as a catalyst, trimethoxysilane having a SiH group and methyl methacrylate containing a double bond undergo an addition reaction to obtain a coupling agent liquid.

[0028] The reaction mechanism of the addition reaction between trimethoxysilane and methyl methacrylate is as follows:

[0029]

[0030] The mass spectrometry and elemental analysis data of the synthesis product of trimethoxysilane and methyl methacrylate are as follows: m / z: 208.08 (100.0%), 209.08 (13.0%), 210.07 (3.4%), 210.08 (1.7%)

[0031] B2, mixing γ-mercaptopropyltrimethoxysilane and coupling agent liquid evenly to obtain a complex coupling agent liquid;

[0032] B3. Mix alumina, zirconium dioxide and titanium dioxide to obtain an inorganic mixture; add the inorganic mixture to 1 mol / L NaOH solution, stir at 100 r / min for 5-10 min at room temperature, and then filter to obtain an alkali-treated inorganic mixture; add the alkali-treated inorganic mixture to a ball mill and mill until the particle size is 300-400 μm to obtain an inorganic powder mixture; mix the inorganic powder mixture and a complex coupling agent liquid and stir at high speed to obtain a microporous additive.

[0033] An inorganic powder mixture is modified using a mixture of coupling agent liquid and γ-mercaptopropyltrimethoxysilane as a complex coupling agent. Alumina, zirconium dioxide and titanium dioxide are used as components of the inorganic powder mixture. The inorganic powder mixture is treated with alkali solution in advance to increase the content of hydroxyl groups on the surface of the inorganic powder mixture, thereby increasing the degree of modification of the inorganic powder mixture by the complex coupling agent.

[0034] Furthermore, in step B1, the usage ratio of trimethoxysilane and platinum catalyst S-201 is 12g:5g; the usage ratio of the remaining trimethoxysilane, methyl methacrylate and inhibitor phenothiazine is 110g:100-126g:2-3g.

[0035] Furthermore, in step B2, the usage ratio of γ-mercaptopropyltrimethoxysilane and coupling agent liquid is 20g:10-20g.

[0036] Furthermore, in step B2, the usage ratio of alumina, zirconium dioxide and titanium dioxide is 100g:100g:100g; and the usage ratio of the inorganic powder mixture and the coupling agent liquid is 300g:10-20g.

[0037] Furthermore, the dosage ratio of zwitterion-modified polysulfone, NMP and microporous additive is 30-50 g:200 mL:5-10 g.

[0038] Furthermore, the post-process steps include: pre-pressing the diaphragm into shape, then adding it into deionized water for washing three times to obtain a washed diaphragm; placing the diaphragm in a vacuum drying oven at 70°C and drying it for 10-20 minutes to obtain a corrosion-resistant electrolysis alkaline water hydrogen production diaphragm.

[0039] The present invention has the following beneficial effects:

[0040] 1. The present invention pre-chlorinates polysulfone to prepare chlorinated polysulfone containing chloride ions; then grafts anionic monomer sodium methacrylic sulfonate and cationic monomer 4-vinylpyridine through atom transfer radical polymerization to prepare solid zwitterion-modified polysulfone. Polysulfone is modified by various functional groups such as sulfonic acid group, pyridine group, chloride ion, etc., so as to improve the conductive property of polysulfone itself.

[0041] 2. When the present invention adopts the precipitation phase transformation method to prepare a corrosion-resistant electrolysis alkaline water hydrogen production diaphragm, a microporous additive is added, and the microporous additive is used as a supporting layer to prepare an organic-inorganic composite diaphragm, thereby improving the mechanical properties and corrosion resistance of the prepared diaphragm. The microporous additive is specifically a modified inorganic powder mixture, and the inorganic powder mixture includes a mixture. The present invention uses a complex coupling agent to pre-modify the inorganic mixed powder, thereby improving the compatibility of the inorganic mixed powder and the polysulfone material; in addition, the functional groups of the zwitterionic modified polysulfone can be electrostatically adsorbed with the thiol and ester functional groups of the complex coupling agent, thereby improving the compositeness of the microporous additive and the polysulfone material. In order to avoid a large amount of inorganic particles blocking the lithium ion channel and increasing the impedance of the diaphragm, the amount of the microporous additive is further adjusted. DETAILED DESCRIPTION

[0042] The technical scheme of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Example 1

[0044] This embodiment provides a method for preparing a corrosion-resistant microporous additive for an alkaline water electrolysis hydrogen production diaphragm, comprising the following steps:

[0045] B1. Add 12 g of trimethoxysilane and 5 g of platinum catalyst S-201 into a 500 mL three-necked flask and mix well; then add 110 g of trimethoxysilane, 100 g of methyl methacrylate and 2 g of inhibitor phenothiazine into the three-necked flask to obtain a mixture; then transfer the three-necked flask to an oil bath, set the temperature of the oil bath to 100 ° C, react for 2 h, and then perform reduced pressure distillation and filter the solid to obtain a coupling agent liquid.

[0046] B2. Evenly mix 20 g of γ-mercaptopropyltrimethoxysilane and 10 g of coupling agent liquid to obtain a complex coupling agent liquid.

[0047] B3. Mix 100 g of aluminum oxide, 100 g of zirconium dioxide and 100 g of titanium dioxide to obtain an inorganic mixture; mix the inorganic mixture and 1000 mL of 1 mol / L NaOH solution at room temperature at 100 r / min for 5 min, and then filter to obtain an alkali-treated inorganic mixture; add the alkali-treated inorganic mixture to a ball mill and mill until the particle size is ground to 300 μm to obtain an inorganic powder mixture; add the above-mentioned inorganic powder mixture and 10 g of a complex cross-linking agent liquid to a high-speed mixer, mix and stir at 500 r / min for 30 min, the rotation speed of the rotor of the high-speed mixer is 4000 r / min, and the stirring temperature is 100°C to obtain a microporous additive.

[0048] Example 2

[0049] This embodiment provides a method for preparing a corrosion-resistant microporous additive for an alkaline water electrolysis hydrogen production diaphragm, comprising the following steps:

[0050] B1. Add 12 g of trimethoxysilane and 5 g of platinum catalyst S-201 into a 500 mL three-necked flask and mix well; then add 110 g of trimethoxysilane, 115 g of methyl methacrylate and 3 g of inhibitor phenothiazine into the three-necked flask to obtain a mixture; then transfer the three-necked flask to an oil bath, set the temperature of the oil bath to 105° C., react for 2 h, and then perform vacuum distillation and filter the solid to obtain a coupling agent liquid.

[0051] B2. Evenly mix 20 g of γ-mercaptopropyltrimethoxysilane and 15 g of coupling agent liquid to obtain a complex coupling agent liquid.

[0052] B3. Mix 100 g of aluminum oxide, 100 g of zirconium dioxide and 100 g of titanium dioxide to obtain an inorganic mixture; mix the inorganic mixture and 1000 mL of 1 mol / L NaOH solution at room temperature at 100 r / min for 6 min, and then filter to obtain an alkali-treated inorganic mixture; add the alkali-treated inorganic mixture to a ball mill and mill until the particle size is ground to 350 μm to obtain an inorganic powder mixture; add the above-mentioned inorganic powder mixture and 15 g of a complex cross-linking agent liquid to a high-speed mixer, mix and stir at 500 r / min for 40 min, the rotation speed of the rotor of the high-speed mixer is 4500 r / min, and the stirring temperature is 102°C to obtain a microporous additive.

[0053] Example 3

[0054] This embodiment provides a method for preparing a corrosion-resistant microporous additive for an alkaline water electrolysis hydrogen production diaphragm, comprising the following steps:

[0055] B1. Add 12 g of trimethoxysilane and 5 g of platinum catalyst S-201 into a 500 mL three-necked flask and mix well; then add 110 g of trimethoxysilane, 126 g of methyl methacrylate and 3 g of inhibitor phenothiazine into the three-necked flask to obtain a mixture; then transfer the three-necked flask to an oil bath, set the temperature of the oil bath to 110° C., react for 2 h, and then perform vacuum distillation and filter the solid to obtain a coupling agent liquid.

[0056] B2. Evenly mix 20 g of γ-mercaptopropyltrimethoxysilane and 20 g of coupling agent liquid to obtain a complex coupling agent liquid.

[0057] B3. Mix 100 g of aluminum oxide, 100 g of zirconium dioxide and 100 g of titanium dioxide to obtain an inorganic mixture; mix the inorganic mixture and 1000 mL of 1 mol / L NaOH solution at room temperature at 100 r / min for 10 min, and then filter to obtain an alkali-treated inorganic mixture; add the alkali-treated inorganic mixture to a ball mill and mill until the particle size is ground to 400 μm to obtain an inorganic powder mixture; add the above-mentioned inorganic powder mixture and 20 g of a complex cross-linking agent liquid to a high-speed mixer, mix and stir at 500 r / min for 60 min, the rotation speed of the rotor of the high-speed mixer is 5000 r / min, and the stirring temperature is 105°C to obtain a microporous additive.

[0058] Example 4

[0059] This embodiment provides a method for preparing a zwitterion-modified polysulfone for a corrosion-resistant diaphragm for hydrogen production by electrolysis of alkaline water, comprising the following steps:

[0060] A1. Add 50 g of polysulfone and 100 mL of chloroform into a 250 mL three-necked flask, mix and stir until the polysulfone is completely dissolved in the chloroform to obtain a solution; connect the condenser and the three-way valve to the three-necked flask, connect chlorine gas to one side of the three-necked flask at a flow rate of 15 mL / min, and connect a vacuum pump to one side of the three-necked flask.

[0061] A2. Transfer the three-necked flask to a water bath, set the temperature of the water bath to 50° C.; use an ultra-high pressure spherical mercury lamp as an ultraviolet light source to irradiate the three-necked flask with ultraviolet light; the frequency of the ultraviolet irradiation is 10 kHz, and the duration of the ultraviolet irradiation is 30 min to obtain a product; then heat the three-necked flask to 65° C., react until all the chloroform solvent is evaporated to obtain a solid; wash the solid with deionized water, and then dry it in a vacuum drying oven at 80° C. until constant weight, to obtain chlorinated polysulfone.

[0062] A3. Weigh 30 g of chlorinated polysulfone, 5 g of 4-vinylpyridine, 15 g of sodium methyl propylene sulfonate and 100 mL of DMSO into a 250 mL three-necked flask, stir at 100 r / min for 10 min to obtain a mixed solid-liquid mixture; then pass high-purity N into the three-necked flask for 15 min. 2 To remove oxygen, 0.2 g of catalyst cuprous bromide was added to the three-necked flask, and the port of the three-necked flask was sealed; the three-necked flask was transferred to a water bath, accompanied by mechanical stirring at 100 r / min, and reacted at 100° C. for 12 h to obtain the product.

[0063] A4. Stop the reaction, cool the three-necked flask to room temperature, transfer the product into 300 mL of methanol, precipitate, filter repeatedly and wash with methanol to obtain a solid with cuprous bromide removed; vacuum dry the solid at 80° C. to constant weight to obtain zwitterion-modified polysulfone.

[0064] Example 5

[0065] This embodiment provides a method for preparing a zwitterion-modified polysulfone for a corrosion-resistant diaphragm for hydrogen production by electrolysis of alkaline water, comprising the following steps:

[0066] A1. Add 50 g of polysulfone and 100 mL of chloroform into a 250 mL three-necked flask, mix and stir until the polysulfone is completely dissolved in the chloroform to obtain a solution; connect the condenser and the three-way valve to the three-necked flask, connect chlorine gas to one side of the three-necked flask at a flow rate of 15 mL / min, and connect a vacuum pump to one side of the three-necked flask.

[0067] A2. Transfer the three-necked flask to a water bath, set the temperature of the water bath to 55° C.; use an ultra-high pressure spherical mercury lamp as an ultraviolet light source to irradiate the three-necked flask with ultraviolet light; the frequency of the ultraviolet irradiation is 15 KHz, and the duration of the ultraviolet irradiation is 40 min to obtain a product; then heat the three-necked flask to 65° C., react until all the chloroform solvent is evaporated to obtain a solid; wash the solid with deionized water, and then dry it in a vacuum drying oven at 80° C. until constant weight, to obtain chlorinated polysulfone.

[0068] A3, weigh 30g of chlorinated polysulfone, 8g of 4-vinylpyridine, 18g of sodium methyl propylene sulfonate and 100mL of DMSO, add them into a 250mL three-necked flask, mix and stir at 140r / min for 16min to obtain a mixed solid-liquid; then, pass high-purity N into the three-necked flask for 15min 2 To remove oxygen, 0.2 g of catalyst cuprous bromide was added to the three-necked flask, and the port of the three-necked flask was sealed; the three-necked flask was transferred to a water bath, accompanied by mechanical stirring at 160 r / min, and reacted at 110° C. for 12 h to obtain the product.

[0069] A4. Stop the reaction, cool the three-necked flask to room temperature, transfer the product into 300 mL of methanol, precipitate, filter repeatedly and wash with methanol to obtain a solid with cuprous bromide removed; vacuum dry the solid at 80° C. to constant weight to obtain zwitterion-modified polysulfone.

[0070] Example 6

[0071] This embodiment provides a method for preparing a zwitterion-modified polysulfone for a corrosion-resistant diaphragm for hydrogen production by electrolysis of alkaline water, comprising the following steps:

[0072] A1. Add 50 g of polysulfone and 100 mL of chloroform into a 250 mL three-necked flask, mix and stir until the polysulfone is completely dissolved in the chloroform to obtain a solution; connect the condenser and the three-way valve to the three-necked flask, connect chlorine gas to one side of the three-necked flask at a flow rate of 15 mL / min, and connect a vacuum pump to one side of the three-necked flask.

[0073] A2. Transfer the three-necked flask to a water bath, set the temperature of the water bath to 60° C.; use an ultra-high pressure spherical mercury lamp as an ultraviolet light source to irradiate the three-necked flask with ultraviolet light; the frequency of the ultraviolet irradiation is 20 kHz, and the duration of the ultraviolet irradiation is 60 min to obtain a product; then heat the three-necked flask to 65° C., react until all the chloroform solvent is evaporated to obtain a solid; wash the solid with deionized water, and then dry it in a vacuum drying oven at 80° C. until constant weight, to obtain chlorinated polysulfone.

[0074] A3. Weigh 30 g of chlorinated polysulfone, 10 g of 4-vinylpyridine, 20 g of sodium methyl propylene sulfonate and 100 mL of DMSO into a 250 mL three-necked flask, stir at 200 r / min for 20 min to obtain a mixed solid-liquid mixture; then pass high-purity N into the three-necked flask for 15 min. 2 To remove oxygen, 0.2 g of catalyst cuprous bromide was added to the three-necked flask, and the port of the three-necked flask was sealed; the three-necked flask was transferred to a water bath, accompanied by mechanical stirring at 100-200 r / min, and reacted at 120° C. for 12 hours to obtain the product.

[0075] A4. Stop the reaction, cool the three-necked flask to room temperature, transfer the product into 300 mL of methanol, precipitate, filter repeatedly and wash with methanol to obtain a solid with cuprous bromide removed; vacuum dry the solid at 80° C. to constant weight to obtain zwitterion-modified polysulfone.

[0076] Example 7

[0077] This embodiment provides a method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolyzing alkaline water, comprising the following steps:

[0078] S1. Add 30 g of the zwitterionic modified polysulfone prepared in Example 4 and 200 mL of NMP into a 500 mL beaker, and stir mechanically until a uniformly dispersed mixed solution is obtained; weigh 5 g of the microporous additive prepared in Example 1 and add it to the above mixed solution, transfer the beaker to a constant temperature magnetic stirrer, seal the beaker, and stir at 500 r / min at room temperature for 24 h to obtain a casting solution.

[0079] S2. Pour the casting liquid onto a glass plate, and then quickly scrape the film on the glass plate with a scraping rod until the thickness of the liquid film on the glass plate is 500 μm; use deionized water as a coagulation bath, put the glass plate into the deionized water, the liquid film gel falls off, and the liquid film is taken out from the deionized water to obtain a diaphragm; pre-press the diaphragm into shape, and then add it to deionized water for washing three times to obtain a washed diaphragm; put the diaphragm into a vacuum drying oven at 70°C and dry it for 10 minutes to obtain a corrosion-resistant electrolysis of alkaline water for hydrogen production diaphragm.

[0080] Example 8

[0081] This embodiment provides a method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolyzing alkaline water, comprising the following steps:

[0082] S1. Add 40 g of the zwitterionic modified polysulfone prepared in Example 5 and 200 mL of NMP into a 500 mL beaker, and stir mechanically until a uniformly dispersed mixed solution is obtained; weigh 6 g of the microporous additive prepared in Example 2 and add it to the above mixed solution, transfer the beaker to a constant temperature magnetic stirrer, seal the beaker, and stir at 500 r / min at room temperature for 24 h to obtain a casting solution.

[0083] S2. Pour the casting liquid onto a glass plate, and then quickly scrape the film on the glass plate with a scraping rod until the thickness of the liquid film on the glass plate is 5800 μm; use deionized water as a coagulation bath, put the glass plate into the deionized water, the liquid film gel falls off, and the liquid film is taken out from the deionized water to obtain a diaphragm; pre-press the diaphragm into shape, and then add it to deionized water for washing three times to obtain a washed diaphragm; put the diaphragm into a vacuum drying oven at 70°C and dry it for 10 minutes to obtain a corrosion-resistant electrolysis of alkaline water for hydrogen production diaphragm.

[0084] Example 9

[0085] This embodiment provides a method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolyzing alkaline water, comprising the following steps:

[0086] S1. Add 50 g of the zwitterionic modified polysulfone prepared in Example 6 and 200 mL of NMP into a 500 mL beaker, and stir mechanically until a uniformly dispersed mixed solution is obtained; weigh 10 g of the microporous additive prepared in Example 3 and add it to the above mixed solution, transfer the beaker to a constant temperature magnetic stirrer, seal the beaker, and stir at 500 r / min at room temperature for 24 h to obtain a casting solution.

[0087] S2. Pour the casting liquid onto a glass plate, and then quickly scrape the film on the glass plate with a scraping rod until the thickness of the liquid film on the glass plate is 600 μm; use deionized water as a coagulation bath, put the glass plate into the deionized water, the liquid film gel falls off, and the liquid film is taken out from the deionized water to obtain a diaphragm; pre-press the diaphragm into shape, and then add it into deionized water for washing three times to obtain a washed diaphragm; put the diaphragm into a vacuum drying oven at 70°C and dry it for 10 minutes to obtain a corrosion-resistant electrolysis of alkaline water for hydrogen production diaphragm.

[0088] Comparative Example 1

[0089] The difference between this comparative example and Example 9 is that when preparing the zwitterion-modified polysulfone, the polysulfone is not subjected to chlorination treatment.

[0090] Comparative Example 2

[0091] The difference between this comparative example and Example 9 is that chlorinated polysulfone is used instead of zwitterion-modified polysulfone.

[0092] Comparative Example 3

[0093] The difference between this comparative example and Example 9 is that when preparing the microporous additive, the coupling agent liquid is used to replace γ-mercaptopropyltrimethoxysilane.

[0094] Performance Testing:

[0095] 1. The corrosion-resistant alkaline water electrolysis hydrogen production diaphragm prepared in Examples 7-9 was cut into samples with a length of 50 mm and a width of 15 mm. The cut samples were washed and soaked in deionized water for 3 times, and then placed in a vacuum drying oven at 50°C to be fully dried, and the tensile strength of the samples was measured.

[0096] 2. According to SJ-J10171.7-91 "Determination of alkali absorption rate of diaphragm", the alkali absorption rate of the corrosion-resistant electrolysis alkaline water hydrogen production diaphragm prepared in Examples 7-9 was determined.

[0097] 3. The porosity of the corrosion-resistant alkaline water electrolysis hydrogen production diaphragm prepared in Examples 7-9 was measured.

[0098] 4. The pure water contact angle of the corrosion-resistant alkaline water electrolysis hydrogen production diaphragm prepared in Examples 7-9 was measured using a contact angle measuring instrument. The specific test results are shown in the following table:

[0099] Table 1 - Performance test data table

[0100]

[0101] Data Analysis:

[0102] The corrosion-resistant hydrogen production membranes prepared by electrolysis of alkaline water in Examples 7-9 of the present invention all have excellent mechanical properties by incorporating microporous additives, which are manifested in an increase in the tensile strength value. The corrosion-resistant hydrogen production membranes prepared by electrolysis of alkaline water in Examples 7-9 of the present invention all have excellent electrical conductivity, which is manifested in a large alkali absorption rate of the membrane; however, in Comparative Example 1, the polysulfone was not chlorinated, and in Comparative Example 2, the chlorinated polysulfone was not grafted with anionic monomers and cationic monomers, thereby reducing the conductivity of the prepared membrane, which is manifested in a decrease in the alkali absorption rate of the membrane.

[0103] In the corrosion-resistant hydrogen production membranes prepared by electrolysis of alkaline water in Examples 7-9 of the present invention, polysulfone is modified multiple times, and the microporous additive is modified by a complex coupling agent, thereby increasing the hydrophilic groups of the prepared membranes and improving the hydrophilicity of the prepared membranes, which is manifested as a decrease in the water contact angle. However, Comparative Examples 1, 2, and 3 reduce the types and quantities of the hydrophilic groups of the prepared membranes to varying degrees, which is manifested as a decrease in the hydrophilicity of the membranes and an increase in the water contact angle.

[0104] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0105] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0106] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water, characterized in that: The following steps are involved: S1, mixing zwitterion-modified polysulfone and NMP to obtain a uniformly dispersed mixed solution; Add the microporous additive to the mixed solution, stir at 500 r / min for 24 h at room temperature to obtain a casting solution; S2, pour the casting liquid onto the glass plate, and quickly scrape the film on the glass plate with a film scraping rod until the thickness of the liquid film on the glass plate is 500-600 μm; use deionized water as a coagulation bath, put the glass plate into the deionized water, and the liquid film gel falls off and is taken out to obtain a diaphragm; The diaphragm is post-processed to obtain a corrosion-resistant diaphragm for electrolyzing alkaline water to produce hydrogen; the preparation method of the zwitterion-modified polysulfone comprises the following steps: A1. Add polysulfone and chloroform into a three-necked flask, mix and stir until the polysulfone is completely dissolved in the chloroform to obtain a solution; introduce chlorine gas into the three-necked flask at a flow rate of 15 mL / min; A2. At 50-60° C., a three-necked flask is subjected to ultraviolet irradiation using an ultrahigh pressure spherical mercury lamp to obtain a product; the temperature is then raised to 65° C. to evaporate all the chloroform solvent to obtain a solid; the solid is washed with deionized water and vacuum dried to constant weight to obtain chlorinated polysulfone; A3, chlorinated polysulfone, 4-vinylpyridine, sodium methyl propylene sulfonate and DMSO are mixed to obtain a mixed solid-liquid; under a nitrogen atmosphere, cuprous bromide is added to the mixed solid-liquid, accompanied by mechanical stirring at 100-200 r / min, and reacted at 100-120° C. for 12 hours to obtain a product; A4. The product is transferred into methanol to precipitate, and the precipitate is repeatedly filtered and washed with methanol to obtain a solid from which cuprous bromide is removed; the solid is vacuum dried at 80° C. to a constant weight to obtain a solid zwitterion-modified polysulfone; The preparation method of the microporous additive comprises the following steps: B1. Evenly mix trimethoxysilane and platinum catalyst S-201, and then add the remaining trimethoxysilane, methyl methacrylate and polymerization inhibitor phenothiazine to obtain a mixture; react the mixture at 100-110° C. for 2 h, and then distill and filter under reduced pressure to obtain a coupling agent liquid; B2, mixing γ-mercaptopropyltrimethoxysilane and coupling agent liquid evenly to obtain a complex coupling agent liquid; B3. Mix alumina, zirconium dioxide and titanium dioxide to obtain an inorganic mixture; mix the inorganic mixture with 1 mol / L NaOH solution and stir for 5-10 minutes, then filter to obtain an alkali-treated inorganic mixture; ball-mill the alkali-treated inorganic mixture to obtain an inorganic powder mixture with a particle size of 300-400 μm; mix the above inorganic powder mixture and a complex cross-linking agent liquid and stir at high speed to obtain a microporous additive.

2. The method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water according to claim 1, characterized in that: In step A1, the usage ratio of polysulfone and chloroform is 50g:100mL; in step A2, the frequency of ultraviolet irradiation is 10-20KHz, and the duration of ultraviolet irradiation is 30-60min.

3. The method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water according to claim 1, characterized in that: In step A3, the amount ratio of chlorinated polysulfone, 4-vinylpyridine, sodium methyl propylene sulfonate, DMSO and cuprous bromide is 30g:5-10g:15-20g:100mL; in step A4, the amount of methanol is 300mL.

4. The method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water according to claim 1, characterized in that: In step B1, the usage ratio of trimethoxysilane and platinum catalyst S-201 is 12g:5g; the usage ratio of the remaining trimethoxysilane, methyl methacrylate and inhibitor phenothiazine is 110g:100-126g:2-3g.

5. The method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water according to claim 1, characterized in that: In step B2, the usage ratio of γ-mercaptopropyltrimethoxysilane and coupling agent liquid is 20g:10-20g.

6. The method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water according to claim 1, characterized in that: In step B2, the usage ratio of alumina, zirconium dioxide and titanium dioxide is 100g:100g:100g; the usage ratio of the inorganic powder mixture and the coupling agent liquid is 300g:5-10g.

7. The method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water according to claim 1, characterized in that: The dosage ratio of zwitterion modified polysulfone, NMP and microporous additive is 30-50g:200mL:5-10g.

8. The method for preparing a corrosion-resistant diaphragm for producing hydrogen by electrolysis of alkaline water according to claim 1, characterized in that: The post-processing steps include: pre-pressing the diaphragm into shape, then adding it into deionized water for washing three times to obtain a washed diaphragm; placing the diaphragm in a vacuum drying oven at 70° C. and drying it for 10-20 minutes to obtain a corrosion-resistant diaphragm for producing hydrogen by electrolyzing alkaline water.

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