-PO3H2 / -NH2 acid-base interaction functionalized metal-organic framework modified polymer hybrid proton exchange membrane

Abstract

This invention belongs to the field of membrane technology and discloses a polymer hybrid proton exchange membrane modified with a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework. The preparation method includes the following steps: (1) adding a metal salt and an amino-functionalized ligand to an organic solvent to form a precursor solution and performing a solvothermal reaction to obtain MOF-NH2; (2) placing MOF-NH2 in a phytic acid aqueous solution and stirring to obtain P-MOF-NH2; (3) adding P-MOF-NH2 to a sulfonated polymer solution to obtain a casting solution; using this casting solution, a polymer hybrid proton exchange membrane modified with a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework is finally obtained. This invention improves the structure and composition of key functional components in the proton exchange membrane by introducing a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-MOF-NH2) to modify the polymer hybrid proton exchange membrane, effectively enhancing the proton conductivity of the prepared proton exchange membrane.

Description

Technical Field

[0001] This invention belongs to the field of membrane technology, and more specifically, relates to a polymer hybrid proton exchange membrane modified with a metal-organic framework and functionalized with -PO3H2 / -NH2 acid-base pair. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs) have become one of the most promising energy conversion devices, enjoying widespread popularity across various sectors of society. They possess advantages such as being environmentally friendly, having rapid start-up, and high efficiency, directly converting the chemical energy of fuel into electrical energy without combustion. The proton exchange membrane (PEM) is one of the core components of a PEMFC, transferring protons while preventing fuel leakage between the anode and cathode. Proton conductivity is a key factor determining the performance of a PEMFC, and improving proton conductivity is an effective means of obtaining high-performance PEMFCs.

[0003] Metal-organic frameworks (MOFs) possess high porosity, easily tunable structure, and large specific surface area. Therefore, they show promising application prospects in separation, sensing, adsorption, and drug loading. Recently, the application of MOFs in proton conduction has attracted considerable attention. Studies have shown that the hydrogen bond network or functional sites in MOF pores can effectively transfer protons. Consequently, an increasing number of MOF-modified proton exchange membranes have been developed. For example, *Chemical Communications* (2013, 49, 143-145) reported the preparation of a Fe-MIL-101-NH2 / SPPO hybrid membrane by adding Fe-MIL-101-NH2 to sulfonated 2,6-dimethyl-p-polyphenyloxy (SPPO). This membrane exhibited a proton conductivity of 0.25 S / cm at 90 °C and 80% RH (relative humidity), a significant improvement over the unmodified SPPO membrane. The journal *Membrane Science* (458(2014)86-95) reported the preparation of a (NAPI-Fe-MIL-101-NH2)-SPPO hybrid membrane by adding Fe-MIL-101-NH2 encapsulated with 1-(3-aminopropyl)imidazolium (NAPI) to SPPO. This membrane exhibited a proton conductivity of 0.04 S / cm at 160 °C and 0.15% RH, a significant improvement over the unmodified SPPO membrane. The journal *Chemistry A* (2015,3,15838-15842) reported the preparation of a ZIF-8@GO / Nafion hybrid membrane by doping the GO and ZIF-8 composite ZIF-8@GO into the perfluorosulfonic acid resin Nafion. This membrane achieved a proton conductivity of 0.28 S / cm at 120 °C and 40% RH, a substantial improvement over the unmodified Nafion membrane. The American Chemical Society Applied Materials & Interfaces (ACS Applied Materials & Interfaces 2017, 9, 35075-35085) reported the preparation of a ZCN / SPEEK hybrid film by doping 2DZIF-8 / carbon nanotube composite (ZCN) into sulfonated polyether ether ketone (SPEEK). The ZCN / SPEEK hybrid film exhibited a proton conductivity of 50.24 mS / cm at 120 °C and 30% RH, which was significantly improved compared to the unmodified SPEEK film.The journal *Membrane Science* (565(2018) 281-292) reported the preparation of SPES-Cr-MIL-101-NH2 composite membranes by bonding Cr-MIL-101-NH2 to the aromatic backbone of sulfonated polyether sulfone (SPES) via the Hinsberg reaction. These membranes exhibited a proton conductivity of 0.041 S / cm at 160 °C and 0% RH, a significant improvement over unmodified SPES membranes. The journal *ACS Applied Materials & Interfaces* (2019, 11, 39979-39990) reported the preparation of MIL-53(Al)-NH2 / SPES hybrid membranes by doping flower-like MIL-53(Al)-NH2 into SPES. These membranes exhibited a proton conductivity of 0.248 S / cm at 80 °C and 100% RH, nearly 1.6 times higher than unmodified SPES membranes. The journal *Membrane Science* (601(2020)117914) reported the fabrication of a 3DNWS / Nafion hybrid film by doping a 3D network ZIF-8 composite (3DNWS) modified on polyisophthalamide nanofibers with ZIF-8 into Nafion. This 3DNWS / Nafion hybrid film exhibited a proton conductivity of 0.258 S / cm at 80°C and 100% RH, which is approximately 2.1 times that of the unmodified Nafion film. The journal *Materials Research and Technology* (22(2023)2660-2672) reported the fabrication of a ZSC / SPEEK hybrid film by doping ZSC composite particles (ZIF-8 modified on silica-coated carbon nanotubes) into SPEEK. This ZSC / SPEEK hybrid film exhibited a proton conductivity of 38.10 mS / cm at 80°C and 100% RH, which is approximately 1.8 times that of the unmodified SPEEK film. Although the proton conductivity of these MOF-modified membranes has been improved, the improved proton conductivity is not high enough and there is still considerable room for improvement. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, the present invention aims to provide a polymer hybrid proton exchange membrane modified with a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework. This is achieved by improving the structure and composition of key functional components in the proton exchange membrane, introducing a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-MOF-NH2) to modify the polymer hybrid proton exchange membrane, effectively enhancing the proton conductivity of the prepared membrane. Furthermore, the present invention controls the overall process flow design of the preparation method, enabling the production of a proton exchange membrane with significantly improved proton conductivity and excellent stability through a simple process.

[0005] To achieve the above objectives, according to one aspect of the present invention, a method for preparing a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework modified polymer hybrid proton exchange membrane is provided, characterized by comprising the following steps:

[0006] (1) Add the metal salt and amino-functionalized ligand to an organic solvent and sonicate them to dissolve them completely to form a precursor solution; then, subject the precursor solution to a solvothermal reaction at 100-280°C for 8-74 h, and then separate and wash the product to obtain the corresponding amino-functionalized metal-organic framework, denoted as MOF-NH2.

[0007] Wherein, the metal salt is one or a mixture of several transition metal salts and lanthanide metal salts; the ligand is one or a mixture of several amino aromatic carboxylic acid compounds and amino nitrogen-containing heterocyclic compounds;

[0008] (2) The MOF-NH2 obtained in step (1) is placed in phytic acid aqueous solution and stirred for 5 to 24 hours. Then the product is separated and washed to obtain the corresponding -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework, which is denoted as P-MOF-NH2.

[0009] (3) The P-MOF-NH2 obtained in step (2) is added to the sulfonated polymer solution and ultrasonically treated to obtain a uniformly dispersed casting solution. Then, the casting solution is used to form a membrane material. After drying, the membrane is then subjected to hydrogen peroxide solution, acid and deionized water soaking treatment in sequence to obtain a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework modified polymer hybrid proton exchange membrane.

[0010] As a further preferred embodiment of the present invention, in step (2), before the stirring reaction begins, the phytic acid concentration of the reaction system is 25.3 to 151.8 mg / mL.

[0011] As a further preferred embodiment of the present invention, in step (3), the mass of P-MOF-NH2 accounts for 0.6 to 1.8 wt% of the mass of the polymer matrix contained in the sulfonated polymer solution;

[0012] Preferably, the mass of P-MOF-NH2 accounts for 1.2 wt% of the mass of the polymer matrix contained in the sulfonated polymer solution.

[0013] As a further preferred embodiment of the present invention, in step (1), the molar ratio of the metal salt and the amino-functionalized ligand is 1:4 to 4:1;

[0014] The organic solvent is one or a mixture of several of N,N-dimethylformamide, N,N-diethylformamide, tetrahydrofuran, pyrrolidone, and dimethyl sulfoxide.

[0015] As a further preferred embodiment of the present invention, in steps (1) and (2), the solvent used for cleaning is independently selected from one or a mixture of several of CH3OH, C2H5OH, CHCl3, CH2Cl2, CH3Cl, acetone, and butanone.

[0016] As a further preferred embodiment of the present invention, in step (3), the sulfonated polymer solution is one of a homogeneous solution of perfluorosulfonic acid resin, sulfonated polyether ether ketone, sulfonated polybenzimidazole, sulfonated polyether sulfone, or sulfonated polyimide; the concentration of the sulfonated polymer solution is 1 to 40 wt%.

[0017] The casting solution is used to form a film material, specifically by coating the casting solution into a film, thereby forming a film material.

[0018] The drying process involves placing the membrane material in an oven at 50–80°C, raising the temperature to 110–150°C, and then maintaining the temperature for 12–36 hours. Preferably, the heating rate is less than 0.5°C / min, and more preferably 0.1–0.5°C / min.

[0019] As a further preferred embodiment of the present invention, in step (3), the concentration of the hydrogen peroxide aqueous solution is 1 to 10 wt%.

[0020] The acid solution is specifically a mixture of one or more of hydrochloric acid, sulfuric acid, and phosphoric acid, and the concentration of the acid solution is 0.1 to 4 mol / L.

[0021] According to another aspect of the present invention, the present invention provides a polymer hybrid proton exchange membrane with -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework prepared by the above preparation method.

[0022] According to another aspect of the present invention, the present invention provides the application of the above-mentioned -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework modified polymer hybrid proton exchange membrane in proton exchange membrane fuel cells.

[0023] Compared with existing technologies and traditional MOF-modified polymer hybrid proton exchange membrane processes, the technical solutions conceived in this invention introduce a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-MOF-NH2) into the proton exchange membrane. Due to the modification of these hydrophilic groups, the porous P-MOF-NH2 exhibits high hydrophilicity, which greatly improves the water retention capacity of the polymer hybrid proton exchange membrane, thereby significantly promoting proton conduction. Furthermore, the -PO3H2 / -NH2 acid-base pair effectively reduces the steric hindrance of proton transfer through P-MOF-NH2. In addition, compared with basic groups (such as imidazole groups, -NH2) and acidic groups (such as -SO3H), the -PO3H2 in P-MOF-NH2 is an amphoteric transfer group, containing two proton donor sites and one proton acceptor site; therefore, -PO3H2 possesses superior proton transfer capability. Furthermore, the -NH2 group of P-MOF-NH2 can form an acid-base pair with the -SO3H group of the sulfonated polymer to promote proton conduction, and the -PO3H2 group of P-MOF-NH2 can form a hydrogen bond network with the -SO3H group of the sulfonated polymer, thereby constructing a proton transport network at the interface between P-MOF-NH2 and the sulfonated polymer. These features can significantly improve the proton conductivity of the resulting proton exchange membrane (as described below). Figure 1 and 2 (As shown).

[0024] The preparation method of this invention involves first preparing a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-MOF-NH2), and then doping it into a polymer to obtain a polymer hybrid proton exchange membrane modified with the -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-MOF-NH2). Specifically, for P-MOF-NH2, an amino-functionalized metal-organic framework (i.e., MOF-NH2) is first prepared, and then the MOF-NH2 is modified with phytic acid to obtain the -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-MOF-NH2). The operation process is extremely simple, the production cost is low, the preparation conditions are mild, and it is easy to mass-produce and scale up, possessing a good industrial production foundation and broad application prospects.

[0025] Compared to the inventor's previous research, this invention has the following characteristics:

[0026] The proton exchange membrane obtained in the previous study by the inventors of this invention, entitled "Surface-modified -SO3H / -NH2 acid-base pair nanosheets modified polymer hybrid proton exchange membrane and its preparation" (see Chinese patent document with application number 202310291628.0), although it also involved -SO3H / -NH2 acid-base pair modified nanoparticles modified polymer proton exchange membrane and its preparation, the nanoparticles used in the previous study were -SO3H / -NH2 acid-base pair modified nanosheets BAGO, while the nanoparticles used in this invention are -PO3H2 / -NH2 acid-base pair functionalized MOFs. The types of nanoparticles used in the two are different. More importantly, the acid-base pair involved in the previous study was only -SO3H / -NH2, while the acid-base pair involved in this invention includes both -SO3H / -NH2 and -PO3H2 / -NH2. Accordingly, in terms of the performance of the final product, the proton exchange membrane prepared in the embodiments of this invention has a maximum proton conductivity of 0.317 S / cm at 90°C and 95% RH, which is significantly greater than the maximum proton conductivity of 0.279 S / cm of the proton exchange membrane prepared in the previous study at 90°C and 95% RH.

[0027] The proton exchange membrane obtained in the inventors' previous research, "Polydopamine-Modified Hollow Metal-Organic Framework Modified Polymer Hybrid Proton Exchange Membrane and Its Preparation" (see Chinese Patent Application No. 202110550492.1), although also involving MOF-modified polymer proton exchange membranes and their preparation, involved a three-step process: first preparing the MOF, then etching it into a hollow structure using a phenolic acid aqueous solution, followed by polydopamine modification. In contrast, the MOF material used in this invention is prepared by first preparing the MOF and then stirring it in a phytic acid aqueous solution (two steps in total). Therefore, the MOF material preparation process in this invention is simpler. Furthermore, the proton exchange membrane obtained in the previous research examples had a maximum proton conductivity of 0.311 S / cm at 80°C and 95% RH, which is lower than the maximum proton conductivity of 0.317 S / cm obtained in the embodiments of this invention at 90°C and 95% RH.

[0028] The inventors of this invention previously studied a proton exchange membrane entitled "Polymer Hybrid Proton Exchange Membrane Modified with Metal-Organic Framework and its Preparation Method" (see Chinese Patent Application No. 201610552499.6). Although this study also involved MOF-modified polymer proton exchange membranes and their preparation, it focused on using two-dimensional (2D) nanosheets as nanotemplates to prepare interconnected MOF materials. In preparing the MOF materials, an amino-functionalized MOF (MOF-NH2) was first prepared, followed by the preparation of polydopamine-modified 2D nanosheets, and then MOF-NH2 was modified onto the polydopamine-modified 2D nanosheets (a total of three steps). This invention, however, focuses on using phytic acid to modify an amino-functionalized MOF (MOF-NH2) to prepare a -PO3H2 / -NH2 acid-base pair functionalized MOF. In preparing the MOF materials, MOF-NH2 was first prepared, and then MOF-NH2 was placed in an aqueous phytic acid solution and stirred (a total of two steps) to modify the phytic acid. It is evident that the present invention simplifies the preparation of MOF materials. Furthermore, the proton exchange membrane prepared in the previous research embodiment exhibited a maximum proton conductivity of 0.303 S / cm at 90°C and 95% RH, which is lower than the maximum proton conductivity of 0.317 S / cm of the proton exchange membrane prepared in the embodiments of the present invention at 90°C and 95% RH.

[0029] The inventors of this invention previously studied a proton exchange membrane entitled "Amino-functionalized rod-shaped metal-organic framework modified polymer hybrid proton exchange membrane and its preparation method" (see Chinese patent document application number 202110550492.1). Although this also involved amino-functionalized MOF (MOF-NH2) modified polymer proton exchange membranes and their preparation, the morphology of the MOF-NH2 in the previous study was rod-shaped. However, this invention does not limit the morphology of MOF-NH2, but mainly focuses on the fact that MOF-NH2 reacts with phytic acid to become a -PO3H2 / -NH2 acid-base pair functionalized MOF. In addition, the mechanisms by which the two methods improve the proton conductivity of polymer hybrid proton exchange membranes are significantly different. Previous studies primarily relied on the high hydrophilicity and high continuity of the amino-functionalized rod-shaped metal-organic framework (R-MOF-NH2) to enhance the water retention capacity of the hybrid proton exchange membrane. Furthermore, the highly continuous acid-base pair channels formed by the -NH2 group of R-MOF-NH2 and the -SO3H group in the polymer effectively improved the proton conductivity of the hybrid proton exchange membrane. This invention, however, primarily utilizes the modification of P-MOF-NH2 with hydrophilic groups -PO3H2 and -NH2, along with its porous structure, to impart high hydrophilicity to P-MOF-NH2, thereby significantly improving the water retention capacity of the polymer hybrid proton exchange membrane and thus substantially promoting proton conduction. Furthermore, the additional proton transfer site -PO3H2 introduced into the polymer hybrid membrane in this invention has better proton transfer capability compared with basic groups (such as imidazole groups, -NH2) and acidic groups (such as -SO3H). (-PO3H2 has more proton conduction sites; it is an amphoteric transfer group, with one -PO3H2 containing two proton donor sites and one proton acceptor site.) In addition, the -PO3H2 / -NH2 acid-base pair can effectively reduce the steric hindrance of proton transfer through P-MOF-NH2, and the -NH2 of P-MOF-NH2 can form a -SO3H / -NH2 acid-base pair with the -SO3H of the sulfonated polymer. Thus, two different types of acid-base pair proton conduction pathways, -PO3H2 / -NH2 and -SO3H / -NH2, are formed in the polymer hybrid membrane. It is evident that although both methods utilize the -NH2 group of MOF-NH2 to form a -SO3H / -NH2 acid-base pair with the -SO3H group of the sulfonated polymer to enhance membrane proton conduction, the acid-base pair utilized in this invention to enhance proton conduction includes not only the -SO3H / -NH2 acid-base pair but also the -PO3H2 / -NH2 acid-base pair. Furthermore, the proton exchange membrane prepared in the embodiments of this invention exhibits a maximum proton conductivity of 0.317 S / cm at 90°C and 95% RH, which is significantly higher than the maximum proton conductivity of 0.258 S / cm of the proton exchange membrane prepared in the previous research embodiment at 90°C and 95% RH.

[0030] Compared to the previous study published in *ACS Applied Materials & Interfaces* (2014, 6, 9799-9807), although it also involved the use of phytic acid-modified MOFs for modifying polymer proton exchange membranes and their preparation, the MOF used in that previous study was MIL101(Cr), which was not amino-functionalized. In contrast, the MOF used in this invention is an amino-functionalized MOF (MOF-NH2), making the two MOFs significantly different. Furthermore, the previous study primarily focused on immobilizing phytic acid molecules within the framework of MIL101(Cr) through coordination bonds and the cage effect, thereby effectively optimizing the proton transport channel. This invention, however, utilizes the competitive coordination and acid-base interaction between phytic acid molecules and the metal moiety of MOF-NH2 to modify MOF-NH2, resulting in a -PO3H2 / -NH2 acid-base pair functionalized MOF (P-MOF-NH2). The hydrophilic groups -PO3H2 and -NH2 of P-MOF-NH2, along with its porous structure, significantly enhance the membrane's water retention capacity, thereby greatly improving its proton conductivity. Simultaneously, the -PO3H2 / -NH2 acid-base pair of P-MOF-NH2 effectively reduces the proton transport resistance through P-MOF-NH2. Furthermore, the -SO3H / -NH2 acid-base pair formed by the -NH2 group of P-MOF-NH2 and the -SO3H group of the polymer can also serve as an efficient proton transport pathway within the membrane. Therefore, the mechanisms by which these two methods improve the proton conductivity of the membrane are clearly different. On the other hand, the previous study showed an optimal proton conductivity of 0.228 S / cm at 100% RH and 80°C, which is significantly lower than the optimal proton conductivity of 0.317 S / cm of the present invention at 95% RH and 90°C.

[0031] In summary, this invention utilizes a metal-organic framework (P-MOF-NH2) functionalized with a single key functional component—the -PO3H2 / -NH2 acid-base pair—to construct multiple acid-base pair proton transport channels on the P-MOF-NH2 matrix and at the P-MOF-NH2 / polymer interface, consisting of the -PO3H2 / -NH2 acid-base pair. Furthermore, the porous structure of P-MOF-NH2 and the modification with hydrophilic groups -PO3H2 and -NH2 endow P-MOF-NH2 with high water affinity, significantly enhancing the membrane's water retention capacity and thus greatly promoting proton conduction. This invention modifies polymer hybrid proton exchange membranes using a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-MOF-NH2), resulting in modified proton exchange membranes that exhibit excellent performance in both proton transport and operational stability. Taking the following examples as examples, the modified hybrid proton exchange membranes obtained in each example, when kept constant at 90°C and 95%RH for about 1700 min, showed almost no decrease in proton conductivity, demonstrating excellent stability. Attached Figure Description

[0032] Figure 1 The image shows a comparison of the temperature-dependent proton conductivity of the -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-UiO-66-NH2) hybrid proton exchange membranes (doped at 0.6, 1.2, and 1.8 wt% of the Nafion matrix, respectively) and the unhybridized proton exchange membranes obtained in Examples 1, 2, and 3 of this invention (95% RH, RH: relative humidity). In the figures, “RN” represents an unhybridized proton exchange membrane; “P-UiO-66-NH2 / RN-0.6” represents a P-UiO-66-NH2 hybrid proton exchange membrane with a P-UiO-66-NH2 doping amount of 0.6 wt% of the Nafion matrix mass (i.e., the sample obtained in Example 1); “P-UiO-66-NH2 / RN-1.2” represents a P-UiO-66-NH2 hybrid proton exchange membrane with a P-UiO-66-NH2 doping amount of 1.2 wt% of the Nafion matrix mass (i.e., the sample obtained in Example 2); and “P-UiO-66-NH2 / RN-1.8” represents a P-UiO-66-NH2 hybrid proton exchange membrane with a P-UiO-66-NH2 doping amount of 1.8 wt% of the Nafion matrix mass (i.e., the sample obtained in Example 3).

[0033] Figure 2 The graph shows a comparison of the temperature-dependent proton conductivity (95% RH) of proton exchange membranes hybridized with UiO-66-NH2 and P-UiO-66-NH2 (both doped at 1.2 wt% of the Nafion matrix mass) and unhybridized proton exchange membranes. In the graph, "RN" represents the unhybridized proton exchange membrane; "UiO-66-NH2 / RN-1.2" represents the UiO-66-NH2 hybridized proton exchange membrane with a UiO-66-NH2 doping amount of 1.2 wt% of the Nafion matrix mass (i.e., the sample obtained in the comparative example); and "P-UiO-66-NH2 / RN-1.2" represents the P-UiO-66-NH2 hybridized proton exchange membrane with a P-UiO-66-NH2 doping amount of 1.2 wt% of the Nafion matrix mass (i.e., the sample obtained in Example 2). Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0035] The polymer hybrid proton exchange membrane modified with a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-MOF-NH2) in this invention is prepared by first obtaining a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-MOF-NH2), and then doping it into a polymer to obtain the polymer hybrid proton exchange membrane modified with the -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework (P-MOF-NH2). The preparation method can be carried out, for example, according to the following steps:

[0036] (1) Prepare amino (-NH2) functionalized metal-organic frameworks, denoted as MOF-NH2;

[0037] (2) MOF-NH2 was placed in phytic acid aqueous solution and stirred to obtain a metal-organic framework with -PO3H2 / -NH2 acid-base pair functionalization, denoted as P-MOF-NH2;

[0038] (3) P-MOF-NH2 is added to the sulfonated polymer solution to form a casting solution and a membrane material. After soaking in hydrogen peroxide, acid and deionized water, a polymer hybrid proton exchange membrane with -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework is obtained.

[0039] The following are specific examples:

[0040] Example 1

[0041] 1. Weigh 95 mg ZrCl4 and 73 mg 2-aminoterephthalic acid (BDC-NH2) (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of N,N-dimethylformamide (DMF) solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF, then wash it thoroughly with methanol, and finally dry it under vacuum to obtain UiO-66-NH2.

[0042] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0043] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 0.6 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0044] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of 0.181 S / cm at 90°C and 95% RH, which is approximately 0.38 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). Figure 1 As shown, at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0045] Example 2

[0046] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0047] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0048] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0049] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of 0.253 S / cm at 90°C and 95% RH, which is approximately 0.93 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). Figure 1 As shown, at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0050] Example 3

[0051] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0052] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0053] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.8 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0054] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of 0.242 S / cm at 90°C and 95% RH, which is approximately 0.85 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). Figure 1 As shown, at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0055] Example 4

[0056] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0057] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 5 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain P-UiO-66-NH2.

[0058] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0059] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of up to 0.209 S / cm at 90°C and 95% RH, which is approximately 0.60 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0060] Example 5

[0061] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0062] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 24 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain P-UiO-66-NH2.

[0063] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0064] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of up to 0.258 S / cm at 90°C and 95% RH, which is approximately 0.97 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0065] Example 6

[0066] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0067] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (15 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions (the concentration of phytic acid in the mixed solution system is ~25.3 mg / mL) and stir at 25 °C for 12 h. Centrifuge to separate the product, wash it with pure water first, then wash it thoroughly with methanol, and then vacuum dry it to obtain P-UiO-66-NH2.

[0068] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0069] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of up to 0.195 S / cm at 90°C and 95% RH, which is approximately 0.49 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0070] Example 7

[0071] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0072] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (90 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions (the concentration of phytic acid in the mixed solution system is ~151.8 mg / mL) and stir at 25 °C for 12 h. Centrifuge to separate the product, wash it with pure water first, then wash it thoroughly with methanol, and then vacuum dry it to obtain P-UiO-66-NH2.

[0073] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0074] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of 0.257 S / cm at 90°C and 95% RH, which is approximately 0.96 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0075] Example 8

[0076] 1. Weigh 95 mg ZrCl4 and 292 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:4) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0077] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0078] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0079] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of 0.317 S / cm at 90°C and 95% RH, which is approximately 1.42 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0080] Example 9

[0081] 1. Weigh 380 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 4:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0082] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0083] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0084] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of 0.313 S / cm at 90°C and 95% RH, which is approximately 1.39 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0085] Example 10

[0086] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 100 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0087] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0088] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0089] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of 0.243 S / cm at 90°C and 95% RH, which is approximately 0.85 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0090] Example 11

[0091] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 280 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0092] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0093] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0094] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of up to 0.256 S / cm at 90°C and 95% RH, which is approximately 0.95 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0095] Example 12

[0096] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0097] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0098] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.1 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0099] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of up to 0.250 S / cm at 90°C and 95% RH, which is approximately 0.91 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0100] Example 13

[0101] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0102] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0103] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80°C oven. Start at 80°C for 1.5 h, then slowly increase the temperature to 120°C and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40°C for 1 h, then acidify it with 4 M H2SO4 at 40°C for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0104] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of 0.257 S / cm at 90°C and 95% RH, which is approximately 0.96 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0105] Example 14

[0106] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 8 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0107] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0108] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0109] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of 0.193 S / cm at 90°C and 95% RH, which is approximately 0.47 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0110] Example 15

[0111] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 74 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0112] 2. Weigh 105 mg UiO-66-NH2 and disperse it in 6.3 mL of pure water. Measure 1.121 mL of phytic acid aqueous solution (50 wt%) and dilute it in 2.1 mL of pure water. Mix the two solutions and stir at 25 °C for 12 h. Centrifuge to separate the product. Wash it with pure water first, then wash it thoroughly with methanol and dry it under vacuum to obtain P-UiO-66-NH2.

[0113] 3. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% P-UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the P-UiO-66-NH2 hybrid proton exchange membrane.

[0114] The proton exchange membrane prepared in this embodiment exhibits a proton conductivity of up to 0.256 S / cm at 90°C and 95% RH, which is approximately 0.95 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm). After being kept constant at 90°C and 95% RH for approximately 1700 min, the proton conductivity showed almost no decrease.

[0115] Comparative Example

[0116] 1. Weigh 95 mg ZrCl4 and 73 mg BDC-NH2 (the molar ratio of ZrCl4 to BDC-NH2 is approximately 1:1) and dissolve them in 40.84 mL of DMF solvent. Then, add 9.15 mL of CH3COOH to the solution and transfer it to 120 °C for a solvothermal reaction for 16 h. Centrifuge to separate the product, wash it with DMF first, then wash it thoroughly with methanol, and then dry it under vacuum to obtain UiO-66-NH2.

[0117] 2. Take 4 mL of commercially available Nafion solution (5 wt%), evaporate it into a gel, add 4 mL of DMF, and continue evaporating for 10 min. Add 1.2 wt% UiO-66-NH2 to the above Nafion solution and sonicate for 1 h to disperse it evenly. Carefully pour the dispersion into a mold and quickly place it in an 80℃ oven. Start at 80℃ for 1.5 h, then slowly increase the temperature to 120℃ and maintain it for 24 h. Finally, soak the membrane in 3 wt% H2O2 solution at 40℃ for 1 h, then acidify it with 0.2 M H2SO4 at 40℃ for 1 h to convert the membrane to H2O. + The membrane is then soaked in deionized water to obtain the UiO-66-NH2 hybrid proton exchange membrane.

[0118] The proton exchange membrane prepared in this embodiment has a proton conductivity of up to 0.179 S / cm at 90°C and 95% RH, which is about 0.37 times higher than that of the unmodified Nafion proton exchange membrane (0.131 S / cm).

[0119] The proton exchange membrane prepared in the comparative example showed significantly lower proton conductivity at 90°C and 95% RH compared to that of Example 2 with the same doping ratio. This was also similar to that of Examples 4-9, demonstrating the significant advantage of P-UiO-66-NH2 in improving the proton conductivity of proton exchange membranes.

[0120] The above embodiments are merely examples. In addition to UiO-66 materials, the method of the present invention is also applicable to other MOF materials. Accordingly, it is only necessary to replace the reaction raw materials of the solvothermal reaction in step (1) with the metal salts of the corresponding metal elements. In addition to BDC-NH2, the ligands can also be amino aromatic carboxylic acid compounds (e.g., 2-aminopyromellitic acid) or amino nitrogen-containing heterocyclic compounds (e.g., 2-amino-4,5-imidazolium dicarboxylate).

[0121] In addition to the above embodiments, the sulfonated polymer solution (the sulfonated polymer is the matrix material constituting the proton exchange membrane) can be any of the following besides the commercially available Nafion solution: other perfluorosulfonic acid resins, sulfonated polyether ether ketones, sulfonated polybenzimidazoles, sulfonated polyether sulfones, or sulfonated polyimides. The solvent in the sulfonated polymer solution is a solvent that can enable the sulfonated polymer to form a homogeneous solution.

[0122] Furthermore, all raw materials used in the above embodiments, unless otherwise specified, were commercially available. Additionally, the proton conductivity testing conditions (temperature and humidity) in the above embodiments are merely examples; testing can be performed under other temperature and / or humidity conditions depending on the actual situation. Generally, at higher humidity (greater than or equal to 90% RH), proton conductivity increases with increasing temperature.

[0123] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework modified polymer hybrid proton exchange membrane, characterized in that, Includes the following steps: (1) Add the metal salt and amino-functionalized ligand to an organic solvent and sonicate them to dissolve them completely to form a precursor solution; then, subject the precursor solution to a solvothermal reaction at 100 ~ 280 °C for 8 ~ 74 h, and then separate and wash the product to obtain the corresponding amino-functionalized metal-organic framework, denoted as MOF-NH2. Wherein, the metal salt is one or a mixture of several transition metal salts and lanthanide metal salts; the ligand is one or a mixture of several amino aromatic carboxylic acid compounds and amino nitrogen-containing heterocyclic compounds; (2) The MOF-NH2 obtained in step (1) is placed in phytic acid aqueous solution and stirred for 5 to 24 h. Then the product is separated and washed to obtain the corresponding -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework, which is denoted as P-MOF-NH2. (3) Add the P-MOF-NH2 obtained in step (2) to the sulfonated polymer solution and sonicate to obtain a uniformly dispersed casting solution; then, use the casting solution to form a membrane material, and after drying, it is then subjected to hydrogen peroxide solution, acid and deionized water soaking treatment in sequence to obtain a -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework modified polymer hybrid proton exchange membrane.

2. The preparation method according to claim 1, characterized in that, In step (2), before the stirring reaction begins, the phytic acid concentration in the reaction system is 25.3 ~ 151.8 mg / mL.

3. The preparation method according to claim 1, characterized in that, In step (3), the mass of P-MOF-NH2 accounts for 0.6 to 1.8 wt% of the mass of the polymer matrix contained in the sulfonated polymer solution.

4. The preparation method according to claim 3, characterized in that, In step (3), the mass of P-MOF-NH2 accounts for 1.2 wt% of the mass of the polymer matrix contained in the sulfonated polymer solution.

5. The preparation method according to claim 1, characterized in that, In step (1), the molar ratio of the metal salt to the amino-functionalized ligand is 1:4 to 4:1; The organic solvent is one or a mixture of several of N,N-dimethylformamide, N,N-diethylformamide, tetrahydrofuran, pyrrolidone, and dimethyl sulfoxide.

6. The preparation method according to claim 1, characterized in that, In steps (1) and (2), the solvent used for cleaning is independently selected from one or a mixture of several of CH3OH, C2H5OH, CHCl3, CH2Cl2, CH3Cl, acetone, and butanone.

7. The preparation method according to claim 1, characterized in that, In step (3), the sulfonated polymer solution is one of a homogeneous solution of perfluorosulfonic acid resin, sulfonated polyether ether ketone, sulfonated polybenzimidazole, sulfonated polyether sulfone, or sulfonated polyimide; the concentration of the sulfonated polymer solution is 1 to 40 wt%. The casting solution is used to form a film material, specifically by coating the casting solution into a film, thereby forming a film material. The drying is placing the film material in a 50 ~ 80 o C oven, heating to 110 ~ 150 o C, and then holding for 12 ~ 36 h.

8. The preparation method according to claim 7, characterized in that, The temperature increase rate of the temperature increase is less than 0.5 o C / min.

9. The preparation method according to claim 7, characterized in that, The temperature increasing rate of the temperature increase is 0.1 ~ 0.5 o C / min.

10. The preparation method according to claim 1, characterized in that, In step (3), the concentration of the hydrogen peroxide solution is 1 ~ 10 wt%; The acid solution is specifically a mixture of one or more of hydrochloric acid, sulfuric acid, and phosphoric acid, and the concentration of the acid solution is 0.1 ~ 4 mol / L.

11. A -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework modified polymer hybrid proton exchange membrane prepared by the preparation method according to any one of claims 1-10.

12. The application of the -PO3H2 / -NH2 acid-base pair functionalized metal-organic framework modified polymer hybrid proton exchange membrane as described in claim 11 in a proton exchange membrane fuel cell.

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