Biomass-based organic-inorganic composite proton exchange membrane and preparation method thereof

Abstract

The invention relates to the field of fuel cells, and particularly discloses a biomass-based organic-inorganic composite proton exchange membrane and a preparation method thereof. The biomass-based organic-inorganic composite proton exchange membrane comprises a chitosan matrix and a sulfonated metal organic framework anchored with CeO2, the sulfonated metal organic framework anchored with CeO2 is dispersed in the chitosan matrix, and the addition amount of the sulfonated metal organic framework anchored with CeO2 is 0.5 wt%-10 wt% of that of chitosan. The preparation method comprises the following steps: 1) synthesizing nano cerium dioxide (CeO2) through a hydrothermal method; (2) preparing an aminated metal organic framework for anchoring CeO2; (3) preparing a sulfonated metal organic framework anchored with CeO2; 4) dispersing the sulfonated metal organic framework anchored with CeO2 into a chitosan solution, and casting to form a membrane, and 5) cross-linking the dry membrane with sulfuric acid to obtain the biomass-based organic-inorganic composite proton exchange membrane.The prepared composite membrane has significantly increased proton conductivity and oxidation stability, and the mechanical strength is obviously higher than that of an unmodified pure membrane.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, and particularly to a biomass-based organic-inorganic composite proton exchange membrane and a preparation method thereof. Background Art

[0002] A fuel cell is an energy conversion device that can directly convert the chemical energy of a fuel (such as methanol, hydrogen, natural gas, etc.) into electrical energy. With its advantages of high energy conversion efficiency and low pollution, it meets the needs of the development of the times and thus becomes one of the most promising power generation technologies. Among various fuel cells, the proton exchange membrane fuel cell has been the most widely studied. The proton exchange membrane is the core component of the proton exchange membrane fuel cell. In the battery, it not only plays the role of transporting protons, isolating electrons, preventing the oxygen and fuel at the anode and cathode from permeating and contacting, but also has a high proton transport ability, and should maintain excellent proton conductivity and mechanical strength under high-temperature and low-humidity working conditions. Currently, the most widely used proton exchange membrane on the market is the Nafion series membrane produced by DuPont. This membrane has a high conductivity under saturated humidity, but at high temperatures (>100 °C), the membrane's conductivity drops sharply due to water loss, making it difficult to be used in medium- and high-temperature fuel cells. Moreover, the preparation process of this membrane is extremely complex, the price is very expensive, and the fuel permeation problem caused by methanol permeation is also very serious. Therefore, it is particularly important to find a proton exchange membrane with high proton conductivity, mechanical strength, relatively low price, and not serious fuel permeation.

[0003] Chitosan (CS) is a biomass polysaccharide that can be extracted from chitin. Chitin (also known as chitin) is widely present in the shells of marine arthropods such as crabs and shrimps, the exoskeletons of insects, the cell membranes of fungi and algae, the shells and bones of mollusks, and the cell walls of higher animals. It is inexpensive; chitosan has good film-forming properties, and the film-forming process is simple and environmentally friendly (without the use of organic solvents). The cyclic structure on the chitosan molecule ensures the thermochemical stability of the chitosan membrane. However, under the condition of unmodified chitosan dry film, there is only 10 -9The conductivity of S / cm is equivalent to that of an insulating material, and its mechanical strength also needs to be further improved. Although research shows that the proton conductivity of uncrosslinked and unmodified chitosan dry films at room temperature is not high, there are a large number of hydroxyl and amino groups in the chitosan molecular chain, providing the possibility for its modification. Generally, there are two common modification methods for using chitosan in proton exchange membranes, namely chemical modification and organic-inorganic composite. Compared with chemical modification, the method of organic-inorganic composite does not damage the structure of the chitosan molecule, so it will not bring the disadvantage of mechanical property loss. At the same time, the method of organic-inorganic composite can greatly improve the mechanical properties of the chitosan membrane by uniformly dispersing inorganic particles in the chitosan matrix; at the same time, functionalized inorganic particles can also improve other properties of the chitosan membrane. Summary of the Invention

[0004] Aiming at the deficiencies of the above-mentioned prior art, the purpose of the present invention is to propose a biomass-based organic-inorganic composite proton exchange membrane and its preparation method.

[0005] Metal organic framework (MOF) is a widely used super-porous nano material. Through design and synthesis, a series of MOFs with specific functional groups can be prepared. Chromium-based MOF (NH 2 -MIL-101-Cr) with amino groups was synthesized by chromium nitrate nonahydrate and 2-aminoterephthalic acid. Due to the good adsorption of chitosan for Cr 3+ , chitosan has good compatibility with such MOFs. In addition, through the ring-opening reaction of 1,3-propane sultone, such MOFs can be sulfonated, that is, a sulfonic acid group is grafted onto the amino group as a proton transfer site. Incorporating the sulfonated MOF into chitosan as a proton exchange membrane can not only improve the mechanical properties of the matrix, but also enhance its proton conduction ability. However, in the working environment of fuel cells, a large number of free radicals will be generated, and these free radicals will attack the chitosan molecule, resulting in the degradation and fragmentation of the chitosan membrane. Cerium dioxide (CeO 2 ) has a unique oxygen vacancy mechanism, enabling the conversion between Ce(III) and Ce(IV) and consuming free radicals among them. Therefore, cerium dioxide is also often used as a free radical scavenger in various fields. In this application, CeO 2 was coupled and anchored in situ on NH 2 -MIL-101-Cr generated during the hydrothermal reaction through hydrothermal reaction, and sulfonated, so as to prepare a sulfonated metal organic framework anchored with CeO 2 , and compounded with chitosan to improve the mechanical properties, proton conductivity and antioxidant properties of the chitosan membrane.

[0006] To achieve the above-mentioned invention objective, the present invention provides a biomass-based organic-inorganic composite proton exchange membrane. The biomass-based organic-inorganic composite proton exchange membrane includes a chitosan matrix and sulfonated metal-organic framework Ce-MNS anchored with CeO 2 The Ce-MNS is dispersed in the chitosan matrix, and its addition amount is 0.5 wt.% - 10 wt.% of chitosan;

[0007] The Ce-MNS is prepared by the following method: CeO 2 nanoparticles and an amino-functionalized MIL-101 type chromium-based MOF precursor are prepared into an amino-functionalized metal-organic framework anchored with CeO 2 through an in-situ hydrothermal method; then, sulfonic acid groups are grafted onto the amino-functionalized metal-organic framework anchored with CeO 2 through a ring-opening reaction to obtain Ce-MNS.

[0008] The present invention also provides a preparation method of the above-mentioned biomass-based organic-inorganic composite proton exchange membrane, including the following steps:

[0009] (1) Preparation of the amino-functionalized metal-organic framework anchored with CeO 2 Chromium(III) nitrate nonahydrate, 2-aminoterephthalic acid, and NaOH are added to deionized water. After sufficient stirring until chromium(III) nitrate nonahydrate is completely dissolved, CeO

[0010] nanoparticles are added. After uniform dispersion, a mixed solution is obtained. Hydrothermal reaction is carried out at 140 - 180 °C for 24 - 48 h. The obtained crude product is washed and dried (preferably dried in a vacuum oven at 100 °C for 10 - 24 h) to obtain the amino-functionalized metal-organic framework anchored with CeO 2 nanoparticles; 2 ;

[0011] (2) Preparation of the sulfonated metal-organic framework anchored with CeO 2 1,3-Propane sultone is added to the dispersion of the amino-functionalized metal-organic framework anchored with CeO

[0012] . Stirring reaction is carried out at 80 - 120 °C for 24 - 48 h. After the reaction is cooled to room temperature, the mixture is poured into a solvent (preferably acetone or absolute ethanol) to dissolve the unreacted 1,3-propane sultone. The precipitate is collected by centrifugation, and the precipitate is immersed in sulfuric acid (preferably 0.5 M sulfuric acid) for ice-water bath acidification treatment. Finally, the residual acid is removed by centrifugation and washing, and after drying (preferably dried at 80 °C for 24 h), the sulfonated metal-organic framework Ce-MNS anchored with CeO 2 is obtained; 2 ;

[0013] The anchored CeO 2The ratio of the aminated metal-organic framework to N,N-dimethylformamide is 1 g: 50 - 150 mL, and the 2 molar ratio of the aminated metal-organic framework to 1,3-propanesultone is 1:1 - 4;

[0014] (3) Disperse the Ce-MNS obtained in step (2) into a chitosan solution to obtain a uniform dispersion, and cast it into a film. The Ce-MNS accounts for 0.5% - 10% of the mass of chitosan;

[0015] (4) Crosslink the cast film obtained in step (3) with dilute sulfuric acid (preferably with a concentration of 0.5 - 2 M). After crosslinking, the film is washed and dried to obtain the biomass-based organic-inorganic composite proton exchange membrane.

[0016] Furthermore, the preparation method of the CeO 2 nanoparticles is as follows: Dissolve cerium nitrate hexahydrate in deionized water, and adjust the pH value to 8 - 10 with ammonia water. The solution starts to change from transparent to milky white. Add the obtained solution to a hydrothermal reaction kettle, seal it, and react at 120 - 180 °C for 12 - 24 h. After cooling to room temperature, centrifuge, wash, dry, grind, and then calcine in a muffle furnace (preferably calcine at 500 °C for 5 h) to obtain CeO 2 nanoparticles.

[0017] Furthermore, the washing operation in (1) is as follows: Disperse the crude product in N,N-dimethylformamide, reflux at 90 °C for 2 h, after centrifugation, disperse it again in absolute ethanol, and reflux at 80 °C for 2 h.

[0018] Furthermore, in the mixed solution of (1), the molar concentration of chromium nitrate is 0.01 - 0.05 M, the molar concentration of 2-aminoterephthalic acid is 0.01 - 0.05 M, and the molar concentration of NaOH is 0.02 - 0.10 M; the molar ratio of CeO 2 nanoparticles to chromium nitrate nonahydrate is 1:1.

[0019] Furthermore, in (2), under nitrogen protection, stir and disperse the aminated metal-organic framework anchored with CeO 2 prepared in step (1) in N,N-dimethylformamide to obtain a dispersion of the aminated metal-organic framework anchored with CeO 2 aminated metal-organic framework.

[0020] Furthermore, in (3), dissolve chitosan in a 1 - 3 vol.% aqueous acetic acid solution to prepare a chitosan solution with a concentration of 0.5 wt.% - 5 wt.%.

[0021] The present invention also provides the use of the above-mentioned biomass-based organic-inorganic composite proton exchange membrane or the biomass-based organic-inorganic composite proton exchange membrane prepared by the above method in the preparation of proton exchange membrane fuel cells.

[0022] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the following beneficial effects and advantages can be achieved:

[0023] 1. For the sulfonated metal-organic framework modified chitosan-based composite proton exchange membrane based on anchored CeO 2 , due to the good adsorption of chitosan for Cr 3+ , there is good compatibility between the chromium-based metal-organic framework and the chitosan matrix. And the introduced sulfonic acid groups can form acid-base pairs with the amino groups in the chitosan structure, further promoting the good dispersion of the sulfonated metal-organic framework anchored with CeO 2 in chitosan, which can increase the mechanical properties of the chitosan membrane (the tensile strength of the composite membrane is increased by 13.2% - 72.5% compared with the pure chitosan membrane; under the same addition amount, the tensile strength of the composite membrane is increased by 30.2% compared with the chitosan / metal-organic framework composite membrane).

[0024] 2. For the biomass-based organic-inorganic composite proton exchange membrane provided by the present invention, by introducing sulfonic acid groups on the amino-functionalized metal-organic framework anchored with CeO 2 , it can serve as new proton transport sites in the composite membrane to play the role of transferring protons, thereby improving the proton conductivity of the composite membrane (compared with the pure chitosan membrane, the conductivity of the composite membrane is increased by 52% - 185%; under the same addition amount, the proton conductivity of the composite membrane is increased by 71% compared with the chitosan / metal-organic framework composite membrane, and is increased by 63.3% compared with the chitosan / metal-organic framework composite membrane anchored with CeO 2 ).

[0025] 3. For the biomass-based organic-inorganic composite proton exchange membrane provided by the present invention, by anchoring cerium dioxide with free radical scavenging ability on the metal-organic framework, it can effectively scavenge various free radicals (such as ·OOH and ·OH) generated during the battery reaction, prevent the free radicals from attacking the chitosan molecules and causing membrane degradation, and effectively improve the oxidation stability of the composite membrane (the oxidation stability of the composite membrane is increased by 1 - 2.3 times compared with the pure chitosan membrane; under the same addition amount, the oxidation stability of the composite membrane is increased by 73.3% compared with the chitosan / metal-organic framework composite membrane, and is increased by 62.5% compared with the chitosan / sulfonated metal-organic framework composite membrane).

[0026] In summary, using chitosan and anchored CeO 2The biomass-based organic-inorganic composite proton exchange membrane prepared from sulfonated metal-organic frameworks is expected to have broad application prospects in proton exchange membrane fuel cells. Description of the Drawings

[0027] Figure 1 Infrared spectra of the amino-functionalized metal-organic framework anchored with CeO 2 prepared in Example 1 and the sulfonated metal-organic framework anchored with CeO 2 ;

[0028] Figure 2 Infrared spectra of the amino-functionalized metal-organic framework anchored with CeO 2 prepared in Example 1 and the sulfonated metal-organic framework anchored with CeO 2 ; (a, b are the amino-functionalized metal-organic framework anchored with CeO 2 ; c, d are the sulfonated metal-organic framework anchored with CeO 2 ) Detailed Description of the Invention

[0029] Hereinafter, the applicant will further elaborate on the technical solutions of the present invention in combination with specific examples and drawings, aiming to enable those skilled in the art to have a clearer understanding and recognition of this application.

[0030] None of the following specific examples should be construed or interpreted in any way as limiting the scope of protection claimed in the claims of this application.

[0031] In the following examples, the molecular weight of the chitosan used is 500,000.

[0032] Example 1: A method for preparing a biomass-based organic-inorganic composite proton exchange membrane, comprising the following steps:

[0033] (1) Dissolve 1.0 g of Ce(NO 3 ) 3 ·6H 2 O in 45 mL of deionized water, and adjust the pH value to 9 with ammonia water. The solution starts to turn milky white from transparent. Add the obtained solution to a 100 mL hydrothermal reaction kettle, seal it, and react at 160 °C for 18 h. After cooling to room temperature (25 °C, the same below), centrifuge it with a centrifuge, wash it repeatedly with deionized water 3 times, dry, grind it, and then calcine it in a muffle furnace at 500 °C for 5 h (the heating rate of the muffle furnace is 10 °C / min, the same below) to obtain CeO 2 nano-particles.

[0034] (2) Dissolve Cr(NO 3 ) 3 ·9H 2O, 2-aminoterephthalic acid, and NaOH were added to 10 mL of deionized water. After stirring well until chromium(III) nitrate nonahydrate was completely dissolved, the CeO 2 nanoparticles obtained in step (1) were added. After uniform dispersion, the mixture was transferred to a hydrothermal reaction kettle and reacted at 160 °C for 24 h. After cooling to room temperature, the crude product was obtained by centrifugation, rinsed with refluxing N,N-dimethylformamide and absolute ethanol, the solid product was collected and dried in a vacuum oven at 100 °C for 10 h to obtain the amino-functionalized metal-organic framework anchored with CeO 2 , wherein the amino-functionalized metal-organic framework is a chromium-based MIL-101 type MOF with amino groups.

[0035] In the mixture, the molar concentration of chromium(III) nitrate is 0.015 M, the molar concentration of 2-aminoterephthalic acid is 0.015 M, and the molar concentration of NaOH is 0.03 M; the addition amount of CeO 2 nanoparticles is: CeO 2 :chromium(III) nitrate nonahydrate = 1:1 (molar ratio); the reflux rinsing with N,N-dimethylformamide and absolute ethanol specifically means that the crude product is dispersed in N,N-dimethylformamide and refluxed at 90 °C for 2 h. After centrifugation, it is then dispersed in ethanol (both refer to absolute ethanol) and refluxed at 80 °C for 2 h, and the centrifuged product is collected.

[0036] (3) The amino-functionalized metal-organic framework anchored with CeO 2 was stirred and dispersed in N,N-dimethylformamide under nitrogen protection at room temperature (25 °C, the same below) to obtain a dispersion. Then, 1,3-propanesultone was added to the dispersion, and the mixture was stirred and reacted at 90 °C for 24 h. After cooling to room temperature, the mixture was poured into acetone to dissolve the unreacted 1,3-propanesultone. The precipitate was collected by centrifugation, and the precipitate was immersed in 0.5 M sulfuric acid for ice-water bath acidification treatment. Finally, the residual acid was removed by centrifugation and washing, and dried at 80 °C for 24 h to obtain the sulfonated metal-organic framework Ce-MNS anchored with CeO 2 .

[0037] The ratio of the amino-functionalized metal-organic framework anchored with CeO 2 to N,N-dimethylformamide is 1 g:150 mL, and the molar ratio of the amino-functionalized metal-organic framework anchored with CeO 2 to 1,3-propanesultone is 1:2.

[0038] (4) Chitosan was dissolved in a 2 vol.% aqueous acetic acid solution to prepare a 2 wt.% chitosan solution. The Ce-MNS obtained in step (3) was dispersed into the chitosan solution (where the mass of Ce-MNS is 4.5% of the mass of chitosan) to obtain a uniform dispersion, and cast into a film.

[0039] (5) Crosslink the casting film obtained in step (4) with 0.5 M dilute sulfuric acid (specifically: immerse the casting film in dilute sulfuric acid for 2 hours, the same hereinafter), and after repeatedly rinsing the crosslinked film with deionized water, dry it (dry it in an oven at 60 °C for 24 hours, the same hereinafter) to obtain a biomass-based organic-inorganic composite proton exchange membrane. Comparative Example 1: Preparation of a pure chitosan membrane, the steps are as follows:

[0040] Dissolve chitosan in a 2 vol.% acetic acid aqueous solution to prepare a chitosan solution with a concentration of 2 wt.%, and cast it into a film; crosslink the casting film with 0.5 M dilute sulfuric acid, and after repeatedly rinsing the crosslinked film with deionized water, dry it to obtain a pure chitosan membrane.

[0041] Comparative Example 2: Preparation of a chitosan / metal-organic framework composite membrane, the process is as follows:

[0042] (1) Add Cr(NO 3 ) 3 ·9H 2 O, 2-aminoterephthalic acid, and NaOH to 10 mL of deionized water, stir well until chromium(III) nitrate nonahydrate is completely dissolved, then transfer the mixture to a 100 mL hydrothermal reaction kettle, seal it, and react at 160 °C for 24 h. After cooling to room temperature, obtain the crude product by centrifugation, reflux and rinse it with N,N-dimethylformamide and absolute ethanol, collect the solid product and dry it in a vacuum oven at 100 °C for 10 h to obtain the metal-organic framework.

[0043] The molar concentration of chromium(III) nitrate in the mixture is 0.015 M, the molar concentration of 2-aminoterephthalic acid is 0.015 M, and the molar concentration of NaOH is 0.03 M; the reflux rinsing of the crude product with N,N-dimethylformamide and absolute ethanol specifically means dispersing the crude product in N,N-dimethylformamide, refluxing at 90 °C for 2 h, centrifuging, then dispersing it in ethanol, refluxing at 80 °C for 2 h, and collecting the centrifuged product.

[0044] (2) Dissolve chitosan in a 2 vol.% acetic acid aqueous solution to prepare a chitosan solution with a concentration of 2 wt.%, disperse the metal-organic framework obtained in step (1) into the chitosan solution (where the mass of the metal-organic framework is 4.5% of the mass of chitosan) to obtain a uniform dispersion, and cast it into a film.

[0045] (3) Crosslink the casting film obtained in step (2) with 0.5 M dilute sulfuric acid, and after repeatedly rinsing the crosslinked film with deionized water, dry it to obtain a chitosan / metal-organic framework composite proton exchange membrane.

[0046] Comparative Example 3: Preparation of a chitosan / sulfonated metal-organic framework composite membrane, the process is as follows:

[0047] (1) Cr(NO 3 ) 3 ·9H 2 O, 2-aminoterephthalic acid, and NaOH were added to 10 mL of deionized water. After sufficient stirring until the chromium(III) nitrate nonahydrate was completely dissolved, the mixture was transferred to a 100 mL hydrothermal reactor, sealed, and reacted at 160 °C for 24 h. After cooling to room temperature, the crude product was obtained by centrifugation, refluxed and rinsed with N,N-dimethylformamide and absolute ethanol, the solid product was collected and dried in a vacuum oven at 100 °C for 10 h to obtain the aminated metal-organic framework.

[0048] The molar concentration of chromium(III) nitrate in the mixture was 0.015 M, the molar concentration of 2-aminoterephthalic acid was 0.015 M, and the molar concentration of NaOH was 0.03 M; the reflux rinsing of the crude product with N,N-dimethylformamide and absolute ethanol specifically involved dispersing the crude product in N,N-dimethylformamide, refluxing at 90 °C for 2 h, after centrifugation, dispersing it in ethanol, refluxing at 80 °C for 2 h, and collecting the centrifuged product.

[0049] (2) The aminated metal-organic framework prepared in step (1) was stirred and dispersed in N,N-dimethylformamide at room temperature under nitrogen protection to obtain a dispersion. Then, 1,3-propanesultone was added to the dispersion, and the mixture was stirred and reacted at 90 °C for 24 h. After the reaction cooled to room temperature, the mixture was poured into a large amount of acetone, the precipitate was collected by centrifugation, and the precipitate was immersed in 0.5 M sulfuric acid for ice-water bath acidification treatment. Finally, after centrifugation and washing to remove the residual acid, it was dried at 80 °C for 24 h to obtain the sulfonated metal-organic framework.

[0050] The ratio of the aminated metal-organic framework to N,N-dimethylformamide was 1 g:150 mL, and the molar ratio of the aminated metal-organic framework to 1,3-propanesultone was 1:2.

[0051] (3) Chitosan was dissolved in a 2 vol.% aqueous acetic acid solution to prepare a 2 wt.% chitosan solution. The sulfonated metal-organic framework obtained in step (2) was dispersed into the chitosan solution (where the mass of the sulfonated metal-organic framework was 4.5% of the mass of chitosan) to obtain a uniform dispersion, and then cast into a film.

[0052] (3) The film cast in step (2) was crosslinked with 0.5 M dilute sulfuric acid. After the crosslinked film was repeatedly rinsed with deionized water and dried, a chitosan / sulfonated metal-organic framework composite proton exchange membrane was obtained. Comparative Example 4: Preparation of a chitosan / anchored CeO 2 metal-organic framework composite membrane, the process was as follows:

[0053] (1) Dissolve 1.0 g of Ce(NO 3 ) 3 ·6H 2 O in 45 mL of deionized water, and adjust the pH value to 9 with ammonia water. The solution starts to change from transparent to milky white. Add the obtained solution into a 100 mL hydrothermal reactor, seal it, and react at 160 °C for 18 h. After cooling to room temperature, centrifuge it, wash it repeatedly with deionized water 3 times, dry and grind it, and then calcine it in a muffle furnace at 500 °C for 5 h to obtain CeO 2 nanoparticles.

[0054] (2) Add Cr(NO 3 ) 3 ·9H 2 O, 2-aminoterephthalic acid, and NaOH into 10 mL of deionized water. After stirring well until chromium(III) nitrate nonahydrate is completely dissolved, add the CeO 2 nanoparticles obtained in step (1). After uniform dispersion, transfer the mixed solution to a hydrothermal reactor and react at 160 °C for 24 h. After cooling to room temperature, obtain the crude product by centrifugation, reflux and rinse it with N,N-dimethylformamide and absolute ethanol, collect the solid product and dry it in a vacuum oven at 100 °C for 10 h to obtain the amino-functionalized metal-organic framework anchored with CeO 2 .

[0055] In the mixed solution, the molar concentration of chromium(III) nitrate is 0.015 M, the molar concentration of 2-aminoterephthalic acid is 0.015 M, and the molar concentration of NaOH is 0.03 M; the addition amount of CeO 2 nanoparticles is: CeO 2 :chromium(III) nitrate nonahydrate = 1:1 (molar ratio); the reflux rinsing of the crude product with N,N-dimethylformamide and absolute ethanol specifically means dispersing the crude product in N,N-dimethylformamide, refluxing at 90 °C for 2 h, centrifuging, then dispersing in ethanol, refluxing at 80 °C for 2 h, and collecting the centrifuged product.

[0056] (3) Dissolve chitosan in a 2 vol.% acetic acid aqueous solution to prepare a chitosan solution with a concentration of 2 wt.%. Disperse the amino-functionalized metal-organic framework anchored with CeO 2 obtained in step (2) into the chitosan solution (where the mass of the amino-functionalized metal-organic framework anchored with CeO 2 is 4.5% of the mass of chitosan) to obtain a uniform dispersion liquid, and cast it into a film.

[0057] (4) Crosslink the cast film obtained in step (3) with 0.5 M dilute sulfuric acid. After repeatedly rinsing the crosslinked film with deionized water and drying, a chitosan / anchored CeO2 Metal-organic framework composite proton exchange membrane.

[0058] The performance test results of the membranes prepared in Example 1 and Comparative Examples 1-4 are shown in Table 1 (the thickness of each membrane is 60-80 microns).

[0059] Table 1

[0060]

[0061] From Figure 1 it can be seen that, compared with the infrared spectrum of the amino-functionalized metal-organic framework anchored with CeO 2 , in the infrared spectrum of the sulfonated metal-organic framework anchored with CeO 2 , the characteristic peaks attributed to the sulfonic acid groups appear at 1049 and 1209 cm -1 , confirming that the sulfonic acid groups are successfully grafted onto the metal-organic framework anchored with CeO 2 . The micro-morphologies of the metal-organic framework and the sulfonated metal-organic framework anchored with CeO 2 are characterized by SEM. As Figure 2 shown, it can be clearly observed that the metal-organic framework exhibits a typical octahedral structure, which is consistent with the structure reported in the literature; the sulfonated metal-organic framework anchored with CeO 2 also exhibits an octahedral structure, indicating that the addition of CeO 2 does not destroy the original structure of the metal-organic framework, and there are many nanoparticles on the surface of the octahedron, which are the CeO 2 nanoparticles uniformly distributed on the surface of the metal-organic framework.

[0062] Example 2: A preparation method of a biomass-based organic-inorganic composite proton exchange membrane, comprising the following steps:

[0063] (1) Dissolve 1.0 g of Ce(NO 3 ) 3 ·6H 2 O in 30 mL of deionized water, and adjust the pH value to 8 with ammonia water. The solution starts to turn milky white from transparent. Add the obtained solution into a 100 mL hydrothermal reaction kettle, seal it and react at 180 °C for 12 h. After cooling to room temperature, centrifuge it with a centrifuge, and wash it repeatedly with deionized water 3 times. After drying and grinding, calcine it in a muffle furnace at 500 °C for 5 h to obtain CeO 2 nanoparticles.

[0064] (2) Dissolve Cr(NO 3 ) 3 ·9H 2O, 2-aminoterephthalic acid and NaOH were added to 50 mL of deionized water. After stirring well until chromium(III) nitrate nonahydrate was completely dissolved, the CeO 2 nanoparticles obtained in step (1) were added. After uniform dispersion, the mixture was transferred to a hydrothermal reactor and reacted at 160 °C for 36 h. After cooling to room temperature, the crude product was obtained by centrifugation, refluxed and rinsed with N,N-dimethylformamide and absolute ethanol. The solid product was collected and dried in a vacuum oven at 100 °C for 10 h to obtain the amino-functionalized metal-organic framework anchored with CeO 2 .

[0065] In the mixture, the molar concentration of chromium(III) nitrate was 0.01 M, the molar concentration of 2-aminoterephthalic acid was 0.01 M, and the molar concentration of NaOH was 0.02 M; the addition amount of CeO 2 nanoparticles was: CeO 2 :chromium(III) nitrate nonahydrate = 1:1 (molar ratio); the reflux rinsing of the crude product with N,N-dimethylformamide and absolute ethanol specifically means that the crude product was dispersed in N,N-dimethylformamide and refluxed at 90 °C for 2 h. After centrifugation, it was dispersed in ethanol and refluxed at 80 °C for 2 h, and the centrifuged product was collected.

[0066] (3) The amino-functionalized metal-organic framework anchored with CeO 2 was stirred and dispersed in N,N-dimethylformamide at room temperature under nitrogen protection to obtain a dispersion. Then, 1,3-propanesultone was added to the dispersion and stirred at 90 °C for 48 h. After the reaction cooled to room temperature, the mixture was poured into a large amount of acetone, and the precipitate was collected by centrifugation. The precipitate was immersed in 0.5 M sulfuric acid for ice-water bath acidification treatment. Finally, it was centrifuged and washed to remove the residual acid and dried at 80 °C for 24 h to obtain the sulfonated metal-organic framework Ce-MNS anchored with CeO 2 .

[0067] The ratio of the amino-functionalized metal-organic framework anchored with CeO 2 to N,N-dimethylformamide was 1 g:50 mL, and the molar ratio of the amino-functionalized metal-organic framework anchored with CeO 2 to 1,3-propanesultone was 1:1.

[0068] (4) Chitosan was dissolved in 1 vol.% aqueous acetic acid solution to prepare a chitosan solution with a concentration of 0.5 wt.%. The Ce-MNS obtained in step (3) was dispersed into the chitosan solution (where the mass of Ce-MNS was 10% of the mass of chitosan) to obtain a uniform dispersion, and it was cast into a film.

[0069] (5) Crosslink the casting film obtained in step (4) with 1.0 M dilute sulfuric acid, and after repeatedly rinsing the crosslinked film with deionized water and drying, a biomass-based organic-inorganic composite proton exchange membrane is obtained.

[0070] Example 3: A preparation method of a biomass-based organic-inorganic composite proton exchange membrane, comprising the following steps:

[0071] (1) Dissolve 1.0 g of Ce(NO 3 ) 3 ·6H 2 O in 60 mL of deionized water, and adjust the pH value to 10 with ammonia water. The solution starts to change from transparent to milky white. Add the obtained solution to a 100 mL hydrothermal reaction kettle, seal it, and react at 120 °C for 24 h. After cooling to room temperature, centrifuge it with a centrifuge, and repeatedly wash it 3 times with deionized water. After drying and grinding, calcine it in a muffle furnace at 500 °C for 5 h to obtain CeO 2 nanoparticles.

[0072] (2) Add Cr(NO 3 ) 3 ·9H 2 O, 2-aminoterephthalic acid, and NaOH to 25 mL of deionized water. After fully stirring until chromium(III) nitrate nonahydrate is completely dissolved, add the CeO 2 nanoparticles obtained in step (1). After dispersing evenly, transfer the mixed solution to a hydrothermal reaction kettle and react at 160 °C for 48 h. After cooling to room temperature, obtain the crude product by centrifugation, reflux and rinse it with N,N-dimethylformamide and absolute ethanol, collect the solid product and dry it in a vacuum oven at 100 °C for 10 h to obtain the amino-functionalized metal-organic framework anchored with CeO 2 .

[0073] In the mixed solution, the molar concentration of chromium(III) nitrate is 0.05 M, the molar concentration of 2-aminoterephthalic acid is 0.05 M, and the molar concentration of NaOH is 0.10 M; the addition amount of CeO 2 nanoparticles is: CeO 2 : chromium(III) nitrate nonahydrate = 1:1 (molar ratio); the specific operation of refluxing and rinsing the crude product with N,N-dimethylformamide and absolute ethanol is to disperse the crude product in N,N-dimethylformamide and reflux at 90 °C for 2 h. After centrifugation, disperse it in ethanol and reflux at 80 °C for 2 h, and collect the centrifuged product.

[0074] (3) The anchored CeO 2The amino-functionalized metal-organic framework is stirred and dispersed in N,N-dimethylformamide at room temperature under nitrogen protection to obtain a dispersion. Then, 1,3-propanesultone is added to the dispersion, and the mixture is stirred and reacted at 90 °C for 36 h. After the reaction is cooled to room temperature, the mixture is poured into a large amount of acetone, and the precipitate is collected by centrifugation. The precipitate is immersed in 0.5 M sulfuric acid for acidification treatment in an ice-water bath. Finally, the precipitate is centrifuged and washed to remove the residual acid, and dried at 80 °C for 24 h to obtain the sulfonated metal-organic framework Ce-MNS anchored with CeO 2 The sulfonated metal-organic framework Ce-MNS anchored with CeO

[0075] The amino-functionalized metal-organic framework anchored with CeO 2 The ratio of the amino-functionalized metal-organic framework anchored with CeO 2 to N,N-dimethylformamide is 1 g: 100 mL, and the molar ratio of the amino-functionalized metal-organic framework anchored with CeO

[0076] (4) Dissolve chitosan in an aqueous acetic acid solution of 3 vol.%, and prepare a chitosan solution with a concentration of 5 wt.%. Disperse the Ce-MNS obtained in step (3) into the chitosan solution (where the mass of Ce-MNS is 0.5% of the mass of chitosan) to obtain a uniform dispersion, and cast it into a film.

[0077] (5) Crosslink the cast film obtained in step (4) with 2 M dilute sulfuric acid. After the crosslinked film is repeatedly rinsed with deionized water, it is dried to obtain a biomass-based organic-inorganic composite proton exchange membrane.

[0078] Example 4: A method for preparing a biomass-based organic-inorganic composite proton exchange membrane, comprising the following steps:

[0079] (1) Dissolve 1.0 g of Ce(NO 3 ) 3 ·6H 2 O in 50 mL of deionized water, and adjust the pH value to 9 with ammonia water. The solution starts to change from transparent to milky white. Add the obtained solution to a 100 mL hydrothermal reaction kettle, seal it, and react at 150 °C for 20 h. After cooling to room temperature, centrifuge it with a centrifuge, and wash it repeatedly with deionized water 3 times. After drying and grinding, calcine it in a muffle furnace at 500 °C for 5 h to obtain CeO 2 nanoparticles.

[0080] (2) Add Cr(NO 3 ) 3 ·9H 2 O, 2-aminoterephthalic acid, and NaOH to 40 mL of deionized water. After stirring well until chromium(III) nitrate nonahydrate is completely dissolved, add the CeO 2After the nanoparticles were evenly dispersed, the mixed solution was transferred to a hydrothermal reactor and reacted at 160 °C for 40 h. After cooling to room temperature, the crude product was obtained by centrifugation, refluxed and rinsed with N,N-dimethylformamide and absolute ethanol, the solid product was collected and dried in a vacuum oven at 100 °C for 10 h to obtain the amino-functionalized metal-organic framework anchored with CeO 2 .

[0081] In the mixed solution, the molar concentration of chromium nitrate was 0.03 M, the molar concentration of 2-aminoterephthalic acid was 0.03 M, and the molar concentration of NaOH was 0.06 M; the addition amount of CeO 2 nanoparticles was: CeO 2 : chromium nitrate nonahydrate = 1:1 (molar ratio); the reflux rinsing of the crude product with N,N-dimethylformamide and absolute ethanol specifically means that the crude product was dispersed in N,N-dimethylformamide and refluxed at 90 °C for 2 h. After centrifugation, it was dispersed in ethanol and refluxed at 80 °C for 2 h, and the centrifuged product was collected.

[0082] (3) The amino-functionalized metal-organic framework anchored with CeO 2 was stirred and dispersed in N,N-dimethylformamide at room temperature under nitrogen protection to obtain a dispersion liquid. Then, 1,3-propanesultone was added to the dispersion liquid and stirred at 90 °C for 40 h. After the reaction cooled to room temperature, the mixture was poured into a large amount of acetone, the precipitate was collected by centrifugation, and the precipitate was immersed in 0.5 M sulfuric acid for ice-water bath acidification treatment. Finally, through centrifugation and washing, the residual acid was removed and dried at 80 °C for 24 h to obtain the sulfonated metal-organic framework Ce-MNS anchored with CeO 2 .

[0083] The ratio of the amino-functionalized metal-organic framework anchored with CeO 2 to N,N-dimethylformamide was 1 g:80 mL, and the molar ratio of the amino-functionalized metal-organic framework anchored with CeO 2 to 1,3-propanesultone was 1:3.

[0084] (4) Chitosan was dissolved in 1.5 vol.% acetic acid aqueous solution to prepare a chitosan solution with a concentration of 1 wt.%. The Ce-MNS obtained in step (3) was dispersed into the chitosan solution (where the mass of Ce-MNS was 2% of the mass of chitosan) to obtain a uniform dispersion liquid, and it was cast into a film.

[0085] (5) The film obtained in step (4) was crosslinked with 1.5 M dilute sulfuric acid, and the crosslinked film was repeatedly rinsed with deionized water and then dried to obtain a biomass-based organic-inorganic composite proton exchange membrane.

[0086] Example 5: A preparation method of a biomass-based organic-inorganic composite proton exchange membrane, comprising the following steps:

[0087] (1) Dissolve 1.0 g of Ce(NO 3 ) 3 ·6H 2 O in 40 mL of deionized water, and adjust the pH value to 9 with ammonia water. The solution starts to change from transparent to milky white. Add the obtained solution to a 100 mL hydrothermal reaction kettle, seal it, and react at 160 °C for 12 h. After cooling to room temperature, centrifuge it with a centrifuge, wash it repeatedly with deionized water, dry, grind it, and then calcine it in a muffle furnace at 500 °C for 5 h to obtain CeO 2 nano-particles.

[0088] (2) Add Cr(NO 3 ) 3 ·9H 2 O, 2-aminoterephthalic acid and NaOH to 50 mL of deionized water. After stirring well until chromium(III) nitrate nonahydrate is completely dissolved, add the CeO 2 nano-particles obtained in step (1). After dispersing evenly, transfer the mixed solution to a hydrothermal reaction kettle and react at 160 °C for 30 h. After cooling to room temperature, obtain the crude product by centrifugation, reflux and rinse it with N,N-dimethylformamide and absolute ethanol, collect the solid product and dry it in a vacuum oven at 100 °C for 10 h to obtain the amino-functionalized metal-organic framework anchored with CeO 2 .

[0089] In the mixed solution, the molar concentration of chromium(III) nitrate is 0.04 M, the molar concentration of 2-aminoterephthalic acid is 0.04 M, and the molar concentration of NaOH is 0.08 M; the addition amount of CeO 2 nano-particles is: CeO 2 :chromium(III) nitrate nonahydrate = 1:1 (molar ratio); the reflux and rinsing of the crude product with N,N-dimethylformamide and absolute ethanol specifically means dispersing the crude product in N,N-dimethylformamide, refluxing at 90 °C for 2 h, centrifuging, then dispersing in ethanol, refluxing at 80 °C for 2 h, and collecting the centrifuged product.

[0090] (3) The anchored CeO 2The aminated metal organic framework was dispersed in N,N-dimethylformamide under nitrogen protection at room temperature to obtain a dispersion, and then 1,3-propane sultone was added to the dispersion, and the reaction was stirred at 90°C for 24 hours. After the reaction was cooled to room temperature, the mixture was poured into a large amount of acetone, and the precipitate was collected by centrifugation. The precipitate was immersed in 0.5M sulfuric acid for ice water bath acidification. Finally, the residual acid was removed by centrifugation and washing, and the mixture was dried at 80°C for 24 hours to obtain the anchored CeO 2 Sulfonated metal-organic framework Ce-MNS.

[0091] The anchored CeO 2 The ratio of the aminated metal organic framework to N,N-dimethylformamide is 1 g:120 mL. 2 The molar ratio of the aminated metal organic framework to 1,3-propane sultone is 1:2.

[0092] (4) Dissolving chitosan in a 2 vol.% acetic acid aqueous solution to prepare a chitosan solution with a concentration of 3 wt.%, dispersing the Ce-MNS obtained in step (3) into the chitosan solution (wherein the mass of Ce-MNS is 6% of the mass of chitosan) to obtain a uniform dispersion, and casting it into a membrane.

[0093] (5) The cast membrane obtained in step (4) is cross-linked with 1.0 M dilute sulfuric acid, and the cross-linked membrane is repeatedly rinsed with deionized water and then dried to obtain a biomass-based organic-inorganic composite proton exchange membrane.

[0094] Example 6: A method for preparing a biomass-based organic-inorganic composite proton exchange membrane, comprising the following steps:

[0095] (1) 1.0 g Ce(NO 3 ) 3 6H 2 O was dissolved in 50 mL of deionized water, and the pH value was adjusted to 9 by ammonia water. The solution changed from transparent to milky white. The obtained solution was added to a 100 mL hydrothermal reactor, sealed and reacted at 160 ° C for 20 h. After cooling to room temperature, it was centrifuged by a centrifuge and repeatedly washed with deionized water. After drying and grinding, it was calcined at 500 ° C for 5 h in a muffle furnace to obtain CeO 2 Nanoparticles.

[0096] (2) Cr(NO 3 ) 3 9H 2 O, 2-aminoterephthalic acid and NaOH were added to 25 mL of deionized water, stirred thoroughly until chromium nitrate nonahydrate was completely dissolved, and then CeO 2After the nanoparticles were evenly dispersed, the mixed solution was transferred to a hydrothermal reactor and reacted at 160 °C for 40 h. After cooling to room temperature, the crude product was obtained by centrifugation, refluxed and rinsed with N,N-dimethylformamide and absolute ethanol. The solid product was collected and dried in a vacuum oven at 100 °C for 10 h to obtain the amino-functionalized metal-organic framework anchored with CeO 2 .

[0097] In the mixed solution, the molar concentration of chromium nitrate was 0.02 M, the molar concentration of 2-aminoterephthalic acid was 0.02 M, and the molar concentration of NaOH was 0.04 M; the addition amount of CeO 2 nanoparticles was: CeO 2 : chromium nitrate nonahydrate = 1:1 (molar ratio); the reflux rinsing of the crude product with N,N-dimethylformamide and absolute ethanol specifically means that the crude product was dispersed in N,N-dimethylformamide and refluxed at 90 °C for 2 h. After centrifugation, it was dispersed in ethanol and refluxed at 80 °C for 2 h, and the centrifuged product was collected.

[0098] (3) The amino-functionalized metal-organic framework anchored with CeO 2 was stirred and dispersed in N,N-dimethylformamide at room temperature under nitrogen protection to obtain a dispersion. Then, 1,3-propanesultone was added to the dispersion and stirred at 90 °C for 24 h. After the reaction cooled to room temperature, the mixture was poured into a large amount of acetone, and the precipitate was collected by centrifugation. The precipitate was immersed in 0.5 M sulfuric acid for ice-water bath acidification treatment. Finally, it was centrifuged and washed to remove the residual acid and dried at 80 °C for 24 h to obtain the sulfonated metal-organic framework Ce-MNS anchored with CeO 2 .

[0099] The ratio of the amino-functionalized metal-organic framework anchored with CeO 2 to N,N-dimethylformamide was 1 g:60 mL, and the molar ratio of the amino-functionalized metal-organic framework anchored with CeO 2 to 1,3-propanesultone was 1:2.

[0100] (4) Chitosan was dissolved in a 2 vol.% acetic acid aqueous solution to prepare a chitosan solution with a concentration of 1 wt.%. The Ce-MNS obtained in step (3) was dispersed in the chitosan solution (where the mass of Ce-MNS was 8% of the mass of chitosan) to obtain a uniform dispersion, and it was cast into a film.

[0101] (5) The film obtained in step (4) was crosslinked with 2 M dilute sulfuric acid. After the crosslinked film was repeatedly rinsed with deionized water and dried, a biomass-based organic-inorganic composite proton exchange membrane was obtained.

[0102] The performance test results of the membranes prepared in the above Examples 1-6 are shown in Table 2 (the thickness of each membrane is 60-80 microns).

[0103] Table 2

[0104]

[0105] As can be seen from Table 2, the proton conductivity and tensile strength of the composite membranes prepared in Examples 1-6 are both superior to those of the pure chitosan membrane. Among them, the proton conductivity increases by 52%-185% compared with the pure chitosan membrane, the tensile strength increases by 13.7%-72.5% compared with the pure chitosan membrane, and the oxidation stability increases by 1-2.3 times compared with the pure chitosan membrane.

[0106] Test methods for membrane performance:

[0107] (1) Tensile strength: Cut the membrane sample into rectangular strips with a length×width = 40×10 mm, and carry out tensile tests on a universal material testing machine at a tensile rate of 2 mm / min under room temperature conditions. The maximum tensile stress suffered by the membrane sample until fracture is recorded as the tensile strength.

[0108] (2) Proton conductivity: The resistance of the membrane is tested on a frequency response analyzer, and the frequency scanning range is 1-10 6 Hz, and the amplitude of the AC signal is 50 mV. The cut membrane (length×width = 3 cm×2 cm) is tested by the two-electrode AC impedance method. Before testing, the membrane sample is placed in room temperature deionized water until saturated. The proton conductivity σ (S / cm) of the membrane is calculated by the following formula:

[0109]

[0110] In the formula, L and A are the distance between the two electrodes and the effective cross-sectional area of the membrane to be measured between the two electrodes respectively, and R is the resistance of the membrane, which is obtained by the Nyquist diagram obtained from the AC impedance test.

[0111] (3) Oxidation stability: The oxidation stability is characterized by Fenton's reagent (a 3 wt.% H 4 solution of 2 ppm FeSO 2 O 2 ) to simulate the working environment of the fuel cell. Cut the composite membrane into the same size (1.5 cm×4 cm). Subsequently, soak the sample strip in the Fenton solution at 80°C and record the time required for it to break. Measure it more than three times repeatedly and calculate the average value.

[0112] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be regarded as equivalent substitution methods and included within the protection scope of the present invention.

Claims

1. A biomass-based organic-inorganic composite proton exchange membrane, comprising a chitosan matrix and a sulfonated metal organic framework Ce-MNS anchoring CeO2, wherein the Ce-MNS is dispersed in the chitosan matrix and the addition amount thereof is 0.5 wt.% -10 wt.% of the chitosan; The Ce-MNS is prepared by the following method: CeO2 nanoparticles and MIL-101 chromium-based MOF precursors with amino groups are used to prepare an amino metal organic framework anchoring CeO2 through an in-situ hydrothermal method; and then sulfonic acid groups are grafted onto the amino metal organic framework anchoring CeO2 through a ring-opening reaction to prepare Ce-MNS.

2. The method for preparing the biomass-based organic-inorganic composite proton exchange membrane according to claim 1, comprising the following steps: (1) Preparation of CeO2-anchored amino metal organic framework Chromium nitrate nonahydrate, 2-aminoterephthalic acid and NaOH are added to deionized water, and after the chromium nitrate nonahydrate is fully dissolved by stirring, CeO2 nanoparticles are added, and the mixture is uniformly dispersed to obtain a mixed solution, and a hydrothermal reaction is performed at 140-180°C for 24-48h. The obtained crude product is washed and dried to obtain an amino metal organic framework anchoring CeO2; (2) Preparation of sulfonated metal organic framework anchored with CeO2 Then, 1,3-propane sultone is added to the dispersion of the CeO2-anchored amino metal organic framework, and the mixture is stirred at 80-120°C for 24-48 hours. After the reaction is cooled to room temperature, the mixture is poured into a solvent to dissolve the unreacted 1,3-propane sultone, and the precipitate is collected and immersed in sulfuric acid for ice-water bath acidification. After removing the residual acid, the precipitate is dried to obtain the CeO2-anchored sulfonated metal organic framework Ce-MNS. The ratio of the CeO2-anchored aminated metal organic framework to N,N-dimethylformamide is 1 g: 50-150 mL, and the molar ratio of the CeO2-anchored aminated metal organic framework to 1,3-propane sultone is 1: 1-4; (3) dispersing the Ce-MNS obtained in step (2) into a chitosan solution to obtain a uniform dispersion, and casting the dispersion into a film, wherein the Ce-MNS accounts for 0.5% to 10% of the mass of the chitosan; (4) cross-linking the cast membrane obtained in step (3) with dilute sulfuric acid, and washing and drying the cross-linked membrane to obtain the biomass-based organic-inorganic composite proton exchange membrane.

3. The preparation method according to claim 2, characterized in that: The solvent is acetone or anhydrous ethanol.

4. The preparation method according to claim 2, characterized in that: The washing operation in (1) is as follows: the crude product is dispersed in N,N-dimethylformamide, refluxed at 90°C for 2 h, centrifuged, and then dispersed in anhydrous ethanol, and refluxed at 80°C for 2 h.

5. The preparation method according to claim 2, characterized in that: The molar concentration of chromium nitrate in the mixed solution (1) is 0.01-0.05 M, the molar concentration of 2-aminoterephthalic acid is 0.01-0.05 M, and the molar concentration of NaOH is 0.02-0.10 M; the molar ratio of CeO2 nanoparticles to chromium nitrate nonahydrate is 1:

1.

6. The preparation method according to claim 2, characterized in that: In the above (2), under nitrogen protection, the CeO2-anchored aminated metal organic framework prepared in step (1) is stirred and dispersed in N,N-dimethylformamide to obtain a dispersion of the CeO2-anchored aminated metal organic framework.

7. The preparation method according to claim 2, characterized in that: In the above (3), chitosan is dissolved in a 1-3 vol.% acetic acid aqueous solution to prepare a chitosan solution with a concentration of 0.5 wt.%-5 wt.%.

8. Use of the biomass-based organic-inorganic composite proton exchange membrane according to claim 1 or the biomass-based organic-inorganic composite proton exchange membrane obtained by the preparation method according to any one of claims 2 to 7 in the preparation of proton exchange membrane fuel cells.

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