Irreversible bond connected self-polymerized covalent organic framework material, composite electrocatalyst and preparation method and application thereof

Abstract

The present application relates to the field of covalent organic framework materials, and discloses an irreversible bond connected self-polymerization covalent organic framework material, a composite electrocatalyst and a preparation method and application thereof. The irreversible bond connected self-polymerization covalent organic framework material is prepared by suzuki coupling to form a monomer with equal reaction functional groups, and then self-polymerization of the monomer; the monomer has equal aldehyde groups and methyl groups, or equal o-phthalic groups and amides. The irreversible bond connected self-polymerization covalent organic framework material provided by the present application utilizes a "two-in-one" strategy and melt polymerization, simplifies the synthesis process, accelerates the reaction rate, and shortens the preparation time; the irreversible bond connected self-polymerization covalent organic framework material has high crystallinity, good stability, and large specific surface area; and the composite electrocatalyst prepared by taking the irreversible bond connected self-polymerization covalent organic framework material as a metal catalyst carrier realizes long cycle stability, and has higher electrocatalytic selectivity and higher yield.

Description

Technical Field

[0001] This invention relates to the field of covalent organic framework materials, specifically to an irreversible bond-linked self-polymerizing covalent organic framework material, a composite electrocatalyst, its preparation method, and its application. Background Technology

[0002] Covalent organic frameworks (COFs) are a class of crystalline porous organic polymers composed of organic monomers linked by covalent bonds. Due to their tunable structure, high specific surface area, low density, and chemical stability, COFs have wide applications in catalysis, gas adsorption and separation, sensing, energy storage, and optical devices. After years of development, COFs have evolved to utilize various linkage mechanisms, including boronic acid esters, imines, ethylene, amides, imides, and ester groups. Among these, COFs with irreversible bond linkages exhibit high crystallinity and high stability.

[0003] It has broad application prospects and advantages. However, the synthesis of irreversibly bonded COFs is very difficult, and the commonly used solvothermal method is basically not feasible for large-scale preparation, which affects its further application.

[0004] Melt polymerization is considered an essential method for preparing irreversibly bonded COFs, and kilogram-scale synthesis has already been achieved. However, during the synthesis process, the melt is prone to inhomogeneity during large-scale synthesis, inevitably leading to a decrease in crystallinity. In addition, existing synthesis methods are time-consuming (5-7 days) and require a strictly deoxygenated reaction environment, making the synthesis process complex and difficult to scale up.

[0005] Existing electrocatalysts are typically metal-based, especially noble metal-based catalysts such as platinum, palladium, ruthenium, and rhodium. Common noble metal elemental electrodes are usually too expensive and have extremely low atom utilization, making them unsuitable for industrial applications. Therefore, dispersing metals onto COF supports is considered an effective strategy. However, current noble metal-based catalysts supported on COFs with reversible bonds suffer from problems such as metal nanoparticle agglomeration and deactivation, and the support's inability to withstand prolonged current operation. This results in low catalytic performance and high catalyst cost, limiting their application.

[0006] Therefore, it is of great significance to develop an irreversibly bonded self-polymerizing covalent organic framework material and a high-performance electrocatalyst using it as a support. Summary of the Invention

[0007] This application provides an irreversibly bonded self-polymerizing covalent organic framework material, a composite electrocatalyst, its preparation method and application, aiming to solve the problems of complex preparation processes for existing irreversibly bonded COFs that are difficult to generate on a large scale, and the low catalytic performance of existing electrocatalysts.

[0008] To achieve the above objectives, the present application adopts the following technical solution.

[0009] In a first aspect, this application provides an irreversibly bonded self-polymerizing covalent organic framework material, which is prepared by suzuki coupling to form monomers with equal amounts of reactive functional groups, and then by self-polymerizing the monomers.

[0010] The monomer has equal amounts of aldehyde and methyl groups, or equal amounts of orthophthalic acid and amide groups.

[0011] Another aspect of this application provides a method for preparing the aforementioned irreversibly bonded self-polymerizing covalent organic framework material, comprising:

[0012] S1, Organic compound A, Organic compound B, potassium carbonate and catalyst A are reacted in a reaction vessel under a nitrogen atmosphere to obtain a monomer;

[0013] S2 involves a melt condensation reaction of monomer and catalyst B in a reactor. After washing and purification, the product yields an irreversibly bonded self-polymerized covalent organic framework material.

[0014] In some embodiments, the organic compound A is an aromatic compound having multiple bromine or iodine functional groups;

[0015] Organic compound B is an aromatic compound having a phenylacetylene group, a phenylboronic acid group, or a phenylboronic acid pinacol ester group;

[0016] The catalyst A is an organic complex of palladium;

[0017] The solvent includes any one or a combination of several of the following: water, tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, and toluene.

[0018] In some implementation schemes:

[0019] The organic compound A includes 4,8-dibromo-2,6-dimethyl[1,3]oxazacyclopentano[4',5':4,5]benzo[d][1,3]oxazacyclopentano, 1,3,5-tribromo-2,4,6-triiodobenzene, 6,7-dibromo-2,3-dimethylquinoxaline, 5,8-dibromo-2,3-dimethylquinoxaline, 1,2-dibromo-4,5-diiodobenzene, 1,3-dibromo-4,6-diiodobenzene, 1 Any one of the following: 4-dibromo-2,5-diiodobenzene, 4-bromo-2,6-dimethylpyridine, 4-bromo-6-methylpyridine-2-carboxaldehyde, 1,4-dibromobenzene, 1,3,5-tribromobenzene, 1,3,4,6-tetrabromo-2,5-dimethylbenzene, 2,7-dibromopyrene, 2,6-dibromonaphthalene, 2,6-dibromoanthracene, 3,6-dibromobenzene-1,2,4,5-tetracarboxylic acid, or 3,6-diiodobenzene-1,2,4-5-tetracarboxylic acid;

[0020] And / or:

[0021] The organic compound B includes 4-formylphenylboronic acid, 3-fluoro-4-aldehydephenylboronic acid, 3,5-difluoro-4-formylphenylboronic acid, 4-formyl-3,5-dimethoxyphenylboronic acid, 2-methoxy-4-(4,4,5,5-tetramethylethyl-1,3,2-dioxoboranol-2-yl)benzaldehyde, 4-boronic acid pinacol ester-2-hydroxybenzaldehyde, 2-nitro-4-(4,4,5,5-tetramethyl-1,3,2-dioxoboranol-2-yl)benzaldehyde, 4'- Pinacol ester of formylbiphenyl-4-boronic acid; 4-(4-formylphenyl)phenyl-2-boronic acid pinacol ester, 2-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborhexacyclopentan-2-yl)pyridine, 4-ethynylbenzene-1-carboxaldehyde, 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborhexacyclopentan-2-yl)benzene-1,3-dicarboxaldehyde, 1,4-phenyldiboronic acid pinacol ester, 4,4'-biphenyldiboronic acid dipinacol ester, N-(4-( 4,4,5,5-Tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(2-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(2,6-difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(2-hydroxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl) The following are all of the following: phenyl)benzamide, N-(2,6-dihydroxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(4'-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)-[1,1'-biphenyl]-4-yl)benzamide, or N-(4-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)ethynyl)phenylbenzamide;

[0022] And / or:

[0023] The catalyst A comprises any one of tetrakis(triphenylphosphine)palladium(O), bis(triphenylphosphine)palladium dichloride, 1,1-bis(diphenylphosphine)ferrocenepalladium dichloride, or palladium acetate.

[0024] In some embodiments, the monomer has equal amounts of aldehyde and methyl groups, or equal amounts of phthalic acid and amide groups;

[0025] Catalyst B is a compound containing an anhydride functional group, a compound containing an acyl chloride functional group, or a compound containing a carboxylic acid functional group.

[0026] In some embodiments, the molar ratio of organic compound A, organic compound B, potassium carbonate and catalyst A is 1:(3-4):(3-4):(0.1-0.2);

[0027] And / or:

[0028] The molar ratio of catalyst B to monomer is 1:1 to 10:1;

[0029] The solvent reaction temperature is 70-80℃;

[0030] The temperature of the melt condensation reaction is 160-250℃.

[0031] Another aspect of this application provides the application of the above-described irreversibly bonded self-polymerized covalent organic framework material or the irreversibly bonded self-polymerized covalent organic framework material prepared by the above preparation method in electrocatalysts.

[0032] Another aspect of this application provides a composite electrocatalyst, comprising an electrocatalyst and a support for supporting the electrocatalyst;

[0033] The carrier is the aforementioned irreversibly bonded self-polymerized covalent organic framework material or the irreversibly bonded self-polymerized covalent organic framework material prepared by the aforementioned preparation method.

[0034] Another aspect of this application provides a method for preparing the above-mentioned composite electrocatalyst, comprising:

[0035] The self-polymerized covalent organic framework material with irreversible bonds is dispersed in a solvent, a metal salt solution is added, and the reaction is carried out under a nitrogen atmosphere with the help of a reducing agent. The solid product is collected, washed, and dried to obtain the final product.

[0036] The metal salt includes at least one of sodium chloropalladium, chloroauric acid, sodium chloroplatinate, ruthenium chloride, rhodium chloride, silver nitrate, and copper chloride;

[0037] The solvent is at least one of water, acetonitrile, ethylene glycol, ethanol, methanol or N-methylpyrrolidone;

[0038] The reducing agent includes any one of sodium citrate, sodium borohydride, or potassium borohydride.

[0039] Another aspect of this application provides the application of the aforementioned composite electrocatalyst in the electrocatalytic synthesis of ammonia.

[0040] Compared with the prior art, the beneficial effects of this application are as follows:

[0041] The irreversibly bonded self-polymerizing covalent organic framework material provided in this application simplifies the synthesis process, accelerates the reaction rate, and shortens the preparation time by utilizing a "two-in-one" strategy and melt polymerization, and has the potential for further scale-up synthesis. The irreversibly bonded self-polymerizing covalent organic framework material of this application has high crystallinity, good stability, and large specific surface area, and the electrocatalyst prepared using it as a support has high catalytic performance.

[0042] This application successfully loaded and dispersed a noble metal-based catalyst by using an irreversibly bonded self-polymerized covalent organic framework material as a metal catalyst support, which achieved long-term cycling stability under catalytic conditions; compared with existing covalent organic framework material-based catalysts, it has higher electrocatalytic selectivity and higher yield. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 XRD pattern of a self-polymerized covalent organic framework material with irreversible bond linkage;

[0045] Figure 2 Infrared spectra of self-polymerized covalent organic framework materials with irreversible bond linkages;

[0046] Figure 3 Nitrogen isothermal adsorption-desorption curves at 77 K for self-polymerized covalent organic framework materials with irreversible bond linkages;

[0047] Figure 4 The graph shows the ammonia yield and Faraday efficiency of the composite electrocatalyst at different voltages.

[0048] Figure 5 The catalytic activity diagram of the composite electrocatalyst after 15 cycles of operation. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0050] In the following description of this embodiment, the terms "including", "comprising", "having", and "containing" are all open-ended terms, meaning that they include but are not limited to.

[0051] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0052] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0053] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0054] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0055] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood as each intermediate value between the upper and lower limits of the specifically disclosed range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0056] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0057] In one aspect, this application provides an irreversibly bonded self-polymerizing covalent organic framework material, which is prepared by suzuki coupling to form monomers with equal amounts of reactive functional groups, and then by self-polymerizing the monomers.

[0058] The monomer has equal amounts of aldehyde and methyl groups, or equal amounts of orthophthalic acid and amide groups.

[0059] The irreversibly bonded self-polymerizing covalent organic framework material provided in this application simplifies the synthesis process, accelerates the reaction rate, and shortens the preparation time by utilizing a "two-in-one" strategy and melt polymerization. It has the potential for further scale-up synthesis and is suitable for industrial production.

[0060] The irreversibly bonded self-polymerized covalent organic framework material of this application has high crystallinity, good stability, and large specific surface area, and the electrocatalyst prepared using it as a support has high catalytic performance.

[0061] The irreversibly bonded self-polymerizing covalent organic framework materials of this application include self-polymerizing covalent organic framework materials linked by polyimide, polyether, azo, ether bond, triazine, imidazole, oxazol, thiazole, or pyrazine groups.

[0062] Secondly, this application provides a method for preparing the aforementioned irreversibly bonded self-polymerizing covalent organic framework material, comprising:

[0063] S1, Organic compound A, Organic compound B, potassium carbonate and catalyst A are reacted in a reaction vessel under a nitrogen atmosphere to obtain a monomer;

[0064] In this application, organic compound A is an aromatic compound having multiple bromine or iodine functional groups; organic compound B is an aromatic compound having a phenylacetylene group, a phenylboronic acid group, or a pinacol ester group of phenylboronic acid. In this application, the reactants undergo a solvent reaction at 70-80°C, and organic compounds A and B undergo a Suzuki coupling reaction to obtain monomers having equal amounts of aldehyde and methyl groups, or equal amounts of o-phenyldicarboxyl and amide groups.

[0065] Specifically, organic compound A can be selected from 4,8-dibromo-2,6-dimethyl[1,3]oxazacyclopentano[4',5':4,5]benzo[d][1,3]oxazacyclopentano, 1,3,5-tribromo-2,4,6-triiodobenzene, 6,7-dibromo-2,3-dimethylquinoxaline, 5,8-dibromo-2,3-dimethylquinoxaline, 1,2-dibromo-4,5-diiodobenzene, 1,3-dibromo-4,6-diiodobenzene, etc. Any one of 1,4-dibromo-2,5-diiodobenzene, 4-bromo-2,6-dimethylpyridine, 4-bromo-6-methylpyridine-2-carboxaldehyde, 1,4-dibromobenzene, 1,3,5-tribromobenzene, 1,3,4,6-tetrabromo-2,5-dimethylbenzene, 2,7-dibromopyrene, 2,6-dibromonaphthalene, 2,6-dibromoanthracene, 3,6-dibromobenzene-1,2,4,5-tetracarboxylic acid, or 3,6-diiodobenzene-1,2,4-5-tetracarboxylic acid.

[0066] Organic compound B can be selected from 4-formylphenylboronic acid, 3-fluoro-4-aldehyde phenylboronic acid, 3,5-difluoro-4-formylphenylboronic acid, 4-formyl-3,5-dimethoxyphenylboronic acid, 2-methoxy-4-(4,4,5,5-tetramethylethyl-1,3,2-dioxoboranol-2-yl)benzaldehyde, 4-boronic acid pinacol ester-2-hydroxybenzaldehyde, 2-nitro-4-(4,4,5,5-tetramethyl-1,3,2-dioxoborane-2-yl)benzaldehyde, 4'-methyl Acylbiphenyl-4-boronic acid pinacol ester; 4-(4-formylphenyl)phenyl-2-boronic acid pinacol ester, 2-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborhexacyclopentan-2-yl)pyridine, 4-ethynylbenzene-1-carboxaldehyde, 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborhexacyclopentan-2-yl)benzene-1,3-dicarboxaldehyde, 1,4-phenyldiboronic acid pinacol ester, 4,4'-biphenyldiboronic acid dipinacol ester, N-(4-( 4,4,5,5-Tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(2-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(2,6-difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(2-hydroxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide Any one of the following: N-(2,6-dihydroxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(4'-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)-[1,1'-biphenyl]-4-yl)benzamide, or N-(4-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)ethynyl)phenylbenzamide

[0067] Catalyst A is used to catalyze the Suzuki coupling reaction between organic compound A and organic compound B. It is an organic complex of palladium, including any one of tetra(triphenylphosphine)palladium(O), bis(triphenylphosphine)palladium dichloride, 1,1-bis(diphenylphosphine)ferrocene palladium dichloride, or palladium acetate.

[0068] Solvents include any one or a combination of several of the following: water, tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, and toluene.

[0069] In this application, in order to achieve better results, the preferred molar ratio of organic compound A, organic compound B, potassium carbonate and catalyst A is 1:(3-4):(3-4):(0.1-0.2); the preferred solvent reaction temperature is 70-80℃.

[0070] In this application, the monomer has equal amounts of aldehyde and methyl groups, or equal amounts of phthalic acid and amide groups. The monomer having equal amounts of aldehyde and methyl groups includes compounds having any of the following structures:

[0071]

[0072] Monomers having equal amounts of o-phenylenedicarboxyl groups and amides, including compounds having any of the following structures:

[0073]

[0074] S2 involves a melt condensation reaction of monomer and catalyst B in a reactor. After washing and purification, the product yields an irreversibly bonded self-polymerized covalent organic framework material.

[0075] In this application, catalyst B is a compound containing an anhydride functional group, a compound containing an acyl chloride functional group, or a compound containing a carboxylic acid functional group, such as benzoic anhydride, sodium benzoate, benzoyl chloride, 4-trifluoromethylbenzoic anhydride, 4-methoxybenzoic anhydride, acetic anhydride, trifluoroacetic anhydride, benzoic acid, 4-fluorobenzoic acid, acetic acid, formic acid, and propionic acid, or one or more of these.

[0076] In this application, monomer and catalyst B are added to a reactor, the reactor is sealed, and the mixture is heated to 160-250℃ to carry out a melt condensation reaction. The reactor can be an oxygen-free environment or an aerobic environment; when an oxygen-free environment is selected, the reactor is evacuated until the pressure inside the reactor is ≤0.15mmHg.

[0077] The molar ratio of catalyst B to monomer is preferably 1:1-10:1, more preferably 6:1-8:1.

[0078] The reactor can be made of high-temperature and high-pressure resistant Pyrex tubing, flame-sealed ampoules, or high-pressure reactors lined with polytetrafluoroethylene.

[0079] In this application, the product of the melt condensation reaction is immersed in DMF to remove unreacted monomers, then washed with methanol to remove excess catalyst, and then dried at 60-150°C to obtain an irreversibly bonded self-polymerized covalent organic framework material.

[0080] The irreversibly bonded self-polymerizing covalent organic framework material prepared in this application has a chemical structure including any one of the following general formulas:

[0081]

[0082] Among them, hexagons and quadrilaterals represent the aromatic rings and aromatic heterocyclic functional groups in the monomers other than the functional groups that participate in the synthesis reaction.

[0083] The irreversibly bonded self-polymerized covalent organic framework material prepared in this application has high crystallinity and high stability. Electrocatalysts prepared using it as a support can withstand long-term current operating environments, exhibit high electrocatalytic performance, and have broad application prospects.

[0084] This application also provides a composite electrocatalyst, which uses the aforementioned irreversibly bonded self-polymerizing covalent organic framework material as a support to support a metal electrocatalyst. This composite electrocatalyst exhibits high support stability, can withstand prolonged current operating conditions, and the metal nanoparticles are not prone to aggregation and deactivation, resulting in high electrocatalytic performance.

[0085] This application also provides a method for preparing the above-mentioned composite electrocatalyst, including:

[0086] The self-polymerized covalent organic framework material with irreversible bonds is dispersed in a solvent, a metal salt solution is added, and the reaction is carried out under a nitrogen atmosphere with the help of a reducing agent. The solid product is collected, washed, and dried to obtain the final product.

[0087] Specifically, the irreversibly bonded self-polymerized covalent organic framework material is ground into a fine powder and dispersed in a solvent, then sonicated for 30 minutes; then a metal salt solution is added dropwise, stirred overnight, a reducing agent is added, the temperature is controlled at 50-120℃, and stirred in a nitrogen atmosphere for 1-8 hours, so that the metal nanoparticles are loaded onto the irreversibly bonded self-polymerized covalent organic framework material through an in-situ solvothermal reaction.

[0088] The metal salt includes at least one of sodium chloropalladium, chloroauric acid, sodium chloroplatinate, ruthenium chloride, rhodium chloride, silver nitrate, and copper chloride; the solvent is at least one of water, acetonitrile, ethylene glycol, ethanol, methanol, or N-methylpyrrolidone; and the reducing agent includes any one of sodium citrate, sodium borohydride, or potassium borohydride.

[0089] The composite electrocatalyst prepared in this application can be used for catalytic oxygen reaction, hydrogen evolution reaction, nitrogen reduction reaction, oxygen reduction reaction or electrocatalytic synthesis of organic molecules, and is especially suitable for electrocatalytic synthesis of ammonia. It has high selectivity and high yield and has high economic value.

[0090] The present application will be specifically described below through examples.

[0091] Example 1

[0092] This embodiment provides a method for preparing a monomer, including:

[0093] Weigh 1 mmol of 4,8-dibromo-2,6-dimethyl[1,3]oxazacyclopentano[4',5':4,5]benzo[d][1,3]oxazacyclopentano, 3 mmol of 4-formylphenylboronic acid, 4 mmol of potassium carbonate, and 0.1 mmol of tetra(triphenylphosphine)palladium into a 100 mL Shrek flask. Then add 4 mL of water and 20 mL of tetrahydrofuran to the Shrek flask. React at 75 °C for 24 hours under a nitrogen atmosphere. The reaction equation is as follows:

[0094]

[0095] After the reaction was completed, the residue was collected by filtration, washed with water and tetrahydrofuran respectively, and then dried in a vacuum oven at 75°C for 12 hours to obtain the monomer 4-{2-[(1-aza-ethyleneethyl)oxy]-1-[(4E)-2-methyl-5H,4H-1,3-oxazacyclopentanyl-4-ethylene]ethyl}benzene-1-carboxaldehyde benzaldehyde, denoted as DMOD.

[0096] The results of its NMR test are as follows:

[0097] 1 H NMR (400MHz, CDCl3): δ2.77(6H,s),8.10(4H,d),8.41(4H,d),10.13(2H,s).

[0098] Example 2

[0099] This embodiment provides a method for preparing a monomer, including:

[0100] Weigh 1 mmol of 4,8-dibromo-2,6-dimethyl[1,3]oxazacyclopentano[4',5':4,5]benzo[d][1,3]oxazacyclopentano, 3 mmol of 3-fluoro-4-aldehyde phenylboronic acid, 4 mmol of potassium carbonate, and 0.1 mmol of tetra(triphenylphosphine)palladium into a 100 mL Shrek flask. Then add 4 mL of water and 20 mL of tetrahydrofuran to the Shrek flask. React at 75 °C for 24 hours under a nitrogen atmosphere. The reaction equation is as follows:

[0101]

[0102] After the reaction was completed, the residue was collected by filtration, washed with water and tetrahydrofuran respectively, and then dried in a vacuum oven at 75°C for 12 hours to obtain the monomer 2-fluoro-4-[8-(3-fluoro-4-formylphenyl)-2,6-dimethyl[1,3]oxazacyclopentano[4',5':4,5]benzo[d][1,3]oxazacyclopentano-4-yl]phenyl-1-carboxaldehyde, denoted as DMOD-2F.

[0103] The results of its NMR test are as follows:

[0104] 1 H NMR (400MHz, CDCl3): δ2.81(6H,s),8.10(2H,t),8.24(4H,m),10.48(2H,s).

[0105] Example 3

[0106] This embodiment provides a method for preparing a monomer, including:

[0107] Weigh 1 mmol of 4,8-dibromo-2,6-dimethyl[1,3]oxazacyclopentano[4',5':4,5]benzo[d][1,3]oxazacyclopentano, 3 mmol of 3,5-difluoro-4-aldehyde phenylboronic acid, 4 mmol of potassium carbonate, and 0.1 mmol of tetra(triphenylphosphine)palladium into a 100 mL Shrek flask. Then add 4 mL of water and 20 mL of tetrahydrofuran to the Shrek flask. React at 75 °C for 24 hours under a nitrogen atmosphere. The reaction equation is as follows:

[0108]

[0109] After the reaction was completed, the residue was collected by filtration, washed with water and tetrahydrofuran respectively, and then dried in a vacuum oven at 75°C for 12 hours to obtain the monomer 4-[8-(3,5-difluoro-4-formylphenyl)-2,6-dimethyl[1,3]oxazacyclopentano[4',5':4,5]benzo[d][1,3]oxazacyclopentano-4-yl]-2,6-difluorophenyl-1-carboxaldehyde, denoted as DMOD-4F.

[0110] The results of its NMR test are as follows:

[0111] 1 H NMR (400MHz, CDCl3): δ2.82(6H,s),8.11(4H,d),10.44(2H,s).

[0112] Example 4

[0113] This embodiment provides a method for preparing a monomer, including:

[0114] Weigh 1 mmol of 6,7-dibromo-2,3-dimethylquinoxaline, 3 mmol of 4-formylphenylboronic acid, 4 mmol of potassium carbonate, and 0.1 mmol of tetra(triphenylphosphine)palladium into a 100 mL Shrek flask. Then add 4 mL of water and 20 mL of tetrahydrofuran to the Shrek flask. React at 75 °C for 24 hours under a nitrogen atmosphere. The reaction equation is as follows:

[0115]

[0116] After the reaction was completed, the residue was collected by filtration, washed with water and tetrahydrofuran respectively, and then dried in a vacuum oven at 75°C for 12 hours to obtain the monomer 4-[7-(4-formylphenyl)-2,3-dimethylquinoxalin-6-yl]benzene-1-carboxaldehyde.

[0117] The results of its NMR test are as follows:

[0118] 1 H NMR (400MHz, CDCl3): δ2.83(6H,s),7.42(4H,d),7.85(4H,d),8.41(2H,s),10.18(2H,s).

[0119] Example 5

[0120] This embodiment provides a method for preparing a monomer, including:

[0121] Weigh 1 mmol of 3,6-dibromophenyl-1,2,4,5-tetracarboxylic acid, 3 mmol of N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, 4 mmol of potassium carbonate, and 0.1 mmol of tetra(triphenylphosphine)palladium into a 100 mL Shrek flask. Then add 4 mL of water and 20 mL of tetrahydrofuran to the Shrek flask. React at 75 °C for 24 hours under a nitrogen atmosphere. The reaction equation is as follows:

[0122]

[0123] After the reaction was completed, the residue was collected by filtration, washed with water and tetrahydrofuran respectively, and then dried in a vacuum oven at 75°C for 12 hours to obtain the monomer 4,4'-bis(benzoamide)-[1,1':4',1'-triphenyl]-2',3',5',6'-tetracarboxylic acid, denoted as BZTTA.

[0124] The results of its NMR test are as follows:

[0125] 1 H NMR (400MHz, DMSO): δ7.43-7.96(18H,m),10.2(2H,s),11.7(4H,s).

[0126] Example 6

[0127] This embodiment provides a method for preparing a monomer, including:

[0128] Weigh 1 mmol of 3,6-dibromophenyl-1,2,4,5-tetracarboxylic acid, 3 mmol of N-(2-fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, 4 mmol of potassium carbonate, and 0.1 mmol of tetra(triphenylphosphine)palladium into a 100 mL Shrek flask. Then add 4 mL of water and 20 mL of tetrahydrofuran to the Shrek flask. React at 75 °C for 24 hours under a nitrogen atmosphere. The reaction equation is as follows:

[0129]

[0130] After the reaction was completed, the residue was collected by filtration, washed with water and tetrahydrofuran respectively, and then dried in a vacuum oven at 75°C for 12 hours to obtain the monomer 4,4'-bis(benzoamide)-3,3'-difluoro-[1,1':4',1'-triphenyl]-2',3',5',6'-tetracarboxylic acid, denoted as BZTTA-2F.

[0131] The results of its NMR test are as follows:

[0132] 1 H NMR (400MHz, DMSO): δ7.54-7.96(16H,m),10.3(2H,s),12.7(4H,s).

[0133] Example 7

[0134] This embodiment provides a method for preparing a monomer, including:

[0135] Weigh 1 mmol of 3,6-dibromophenyl-1,2,4,5-tetracarboxylic acid, 3 mmol of N-(2,6-difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, 4 mmol of potassium carbonate, and 0.1 mmol of tetra(triphenylphosphine)palladium into a 100 mL Shrek flask. Then add 4 mL of water and 20 mL of tetrahydrofuran to the Shrek flask. React at 75 °C for 24 hours under a nitrogen atmosphere. The reaction equation is as follows:

[0136]

[0137] After the reaction was completed, the residue was collected by filtration, washed with water and tetrahydrofuran respectively, and then dried in a vacuum oven at 75°C for 12 hours to obtain the monomer 4,4”-bis(benzoamide)-3,3”,5,5”-tetrafluoro-[1,1’:4’,1”-triphenyl]-2’,3’,5’,6’-tetracarboxylic acid, denoted as BZTTA-4F.

[0138] The results of its NMR test are as follows:

[0139] 1 H NMR (400MHz, DMSO): δ7.39-7.96(14H,m),10.4(2H,s),12.8(4H,s).

[0140] Example 8

[0141] This embodiment provides a method for preparing a monomer, including:

[0142] Weigh 1 mmol of 3,6-dibromophenyl-1,2,4,5-tetracarboxylic acid, 3 mmol of N-(4'-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)-[1,1'-biphenyl]-4-yl)benzamide, 4 mmol of potassium carbonate, and 0.1 mmol of tetra(triphenylphosphine)palladium into a 100 mL Shrek flask. Then add 4 mL of water and 20 mL of tetrahydrofuran to the Shrek flask. React at 75 °C for 24 hours under a nitrogen atmosphere. The reaction equation is as follows:

[0143]

[0144] After the reaction was completed, the filter residue was collected by vacuum filtration, washed with water and tetrahydrofuran respectively, and then dried in a vacuum oven at 75°C for 12 hours to obtain the monomer 4,4”-bis(benzamide)-[1,1”,1”:4”,1””-quinolinyl]-2”,3”,5’,6”-tetracarboxylic acid, denoted as BZTTA-2Ph.

[0145] The results of its NMR test are as follows:

[0146] 1 H NMR (400MHz, DMSO): δ7.25(8H,m)7.44-7.96(18H,m),10.2(2H,s),12.5(4H,s).

[0147] Example 9

[0148] This embodiment provides a method for preparing irreversibly bonded self-polymerizing covalent organic framework materials under aerobic conditions, including:

[0149] 0.1 mmol of the monomer DMOD prepared in Example 1 and 0.6 mmol of benzoic acid were placed in a high-temperature and high-pressure resistant thick-walled glass tube, which was then sealed using a hydrogen-oxygen generator to form a sealed system. The sealed glass tube was placed in a 250°C oven and reacted for 24 hours to obtain an orange blocky solid. After soaking in DMF, it was extracted in methanol by Soxhlet extraction for 4 hours to obtain an irreversibly bonded self-polymerized covalent organic framework material, denoted as DMOD-COF, with a yield of 96%.

[0150] The reaction formula is as follows:

[0151]

[0152] Example 10

[0153] This embodiment provides a method for preparing irreversibly bonded self-polymerizing covalent organic framework materials under anaerobic conditions. The difference between Example 10 and Example 9 is that after adding the raw materials to a thick-walled glass tube, a vacuum is drawn until the pressure inside the glass tube is ≤0.15 mmHg, and then the glass tube is sealed using a hydrogen-oxygen generator to form a sealed system. All other aspects are the same as in Example 9.

[0154] The yield of Example 10 was 98%.

[0155] Example 11

[0156] This embodiment provides a method for preparing irreversibly bonded self-polymerizing covalent organic framework materials under anaerobic conditions. The difference between Example 11 and Example 10 is that the amounts of both raw materials are increased by 30 times; otherwise, they are the same as in Example 10.

[0157] The yield of Example 11 was 98%.

[0158] Example 12

[0159] This embodiment provides a method for preparing irreversibly bonded self-polymerizing covalent organic framework materials under aerobic conditions, including:

[0160] 0.1 mmol of the monomer DMOD-2F prepared in Example 2 and 0.4 mmol of benzoic anhydride were placed in a high-temperature and high-pressure resistant thick-walled glass tube, which was then sealed using a hydrogen-oxygen generator to form a sealed system. The sealed glass tube was placed in a 250°C oven and reacted for 24 hours to obtain a red, blocky solid. After soaking in DMF, it was extracted in methanol by Soxhlet extraction for 4 hours to obtain a red, irreversibly bonded, self-polymerized covalent organic framework material, denoted as DMOD-2F-COF, with a yield of 97%.

[0161] The reaction formula is as follows:

[0162]

[0163] Example 13

[0164] This embodiment provides a method for preparing irreversibly bonded self-polymerizing covalent organic framework materials under aerobic conditions, including:

[0165] 0.1 mmol of the monomer DMOD-4F prepared in Example 3 and 0.4 mmol of benzoic anhydride were placed in a high-temperature and high-pressure resistant thick-walled glass tube, which was then sealed using a hydrogen-oxygen generator to form a sealed system. The sealed glass tube was placed in a 250°C oven and reacted for 24 hours to obtain a reddish-brown blocky solid. After soaking in DMF, it was extracted in methanol by Soxhlet extraction for 4 hours to obtain an orange blocky, irreversibly bonded, self-polymerized covalent organic framework material, denoted as DMOD-4F-COF, with a yield of 98%.

[0166] The reaction formula is as follows:

[0167]

[0168] Example 14

[0169] This embodiment provides a method for preparing irreversibly bonded self-polymerizing covalent organic framework materials under aerobic conditions, including:

[0170] 0.1 mmol of 4-(4-{8-[4-(4-formylphenyl)phenyl]-2,6-dimethyl[1,3]oxazacyclopentano[4',5':4,5]benzo[d][1,3]oxazacyclopentano-4-yl}phenyl)benzene-1-carboxaldehyde and 0.4 mmol of benzoic anhydride were placed in a high-temperature and high-pressure resistant thick-walled glass tube, which was then sealed using a hydrogen-oxygen generator to form a sealed system. The sealed glass tube was placed in a 250°C oven and reacted for 24 hours to obtain a yellow blocky solid. After soaking in DMF, it was extracted in methanol by Soxhlet extraction for 4 hours to obtain an orange blocky, irreversibly bonded, self-polymerized covalent organic framework material with a yield of 97%.

[0171] The reaction formula is as follows:

[0172]

[0173] Example 15

[0174] This embodiment provides a method for preparing irreversibly bonded self-polymerizing covalent organic framework materials under anaerobic conditions, including:

[0175] 0.1 mmol of the monomer BZTTA prepared in Example 5 and 0.4 mmol of benzoic anhydride were placed in a high-temperature and high-pressure resistant thick-walled glass tube. The tube was evacuated until the internal pressure was ≤0.15 mmHg, and then sealed using a hydrogen-oxygen generator to form a sealed system. The sealed glass tube was placed in a 250°C oven and reacted for 24 hours to obtain a light yellow blocky solid. After soaking in DMF, it was extracted in methanol by Soxhlet extraction for 4 hours to obtain a yellow, irreversibly bonded, self-polymerized covalent organic framework material, denoted as BZTTA-COF, with a yield of 92%.

[0176] The reaction formula is as follows:

[0177]

[0178] Example 16

[0179] This embodiment provides a method for preparing irreversibly bonded self-polymerizing covalent organic framework materials under anaerobic conditions.

[0180] 0.1 mmol of the monomer BZTTA-2F prepared in Example 6 and 0.4 mmol of benzoic anhydride were placed in a high-temperature and high-pressure resistant thick-walled glass tube. The tube was evacuated until the internal pressure was ≤0.15 mmHg, and then sealed using a hydrogen-oxygen generator to form a sealed system. The sealed glass tube was placed in a 250°C oven and reacted for 24 hours to obtain a brown, blocky solid. After soaking in DMF, it was extracted in methanol by Soxhlet extraction for 4 hours to obtain an irreversibly bonded, self-polymerized covalent organic framework material, denoted as BZTTA-2F-COF, with a yield of 95%.

[0181] The reaction formula is as follows:

[0182]

[0183] Example 17

[0184] This embodiment provides a method for preparing irreversibly bonded self-polymerizing covalent organic framework materials under anaerobic conditions.

[0185] 0.1 mmol of the monomer BZTTA-4F prepared in Example 7 and 0.4 mmol of benzoic anhydride were placed in a high-temperature and high-pressure resistant thick-walled glass tube. The tube was evacuated until the internal pressure was ≤0.15 mmHg, and then sealed using a hydrogen-oxygen generator to form a sealed system. The sealed glass tube was placed in a 250°C oven and reacted for 24 hours to obtain an orange blocky solid. After soaking in DMF, it was extracted in methanol by Soxhlet extraction for 4 hours to obtain an irreversibly bonded self-polymerized covalent organic framework material, denoted as BZTTA-4F-COF, with a yield of 96%.

[0186] The reaction formula is as follows:

[0187]

[0188] Example 18

[0189] This embodiment provides a method for preparing irreversibly bonded self-polymerizing covalent organic framework materials under anaerobic conditions.

[0190] 0.1 mmol of the monomer BZTTA-2Ph prepared in Example 8 and 0.4 mmol of benzoic anhydride were placed in a high-temperature and high-pressure resistant thick-walled glass tube. The tube was evacuated until the internal pressure was ≤0.15 mmHg, and then sealed using a hydrogen-oxygen generator to form a sealed system. The sealed glass tube was placed in a 250°C oven and reacted for 24 hours to obtain a deep yellow blocky solid. After soaking in DMF, it was extracted in methanol by Soxhlet extraction for 4 hours to obtain a deep yellow blocky, irreversibly bonded, self-polymerized covalent organic framework material, denoted as BZTTA-2Ph-COF, with a yield of 91%.

[0191] The reaction formula is as follows:

[0192]

[0193] Example 19

[0194] This embodiment provides a method for preparing a composite electrocatalyst, including:

[0195] Weigh 20 mg of the DMOD-COF powder prepared in Example 9 and disperse it in 20 mL of ethylene glycol solution. Sonicate for 30 minutes. Then, add 0.6 mL of a 3.0 mg / mL sodium chloropalladium solution to the solution. After stirring for 2 hours, add 1 mL of a 0.28 mg / mL sodium citrate solution dropwise. Heat to 120 °C under a nitrogen atmosphere and react for 1 hour to obtain an orange suspension. Centrifuge the suspension to separate the solid phase. Wash with water and ethanol sequentially, then dry in a vacuum oven at 50 °C to obtain an orange powdery composite electrocatalyst, denoted as Pd / DMOD-COF.

[0196] Example 20

[0197] This embodiment provides a method for preparing a composite electrocatalyst, including:

[0198] Weigh 20 mg of the DMOD-4F-COF powder prepared in Example 9 and disperse it in 20 mL of ethylene glycol solution. Sonicate for 30 minutes. Then, add 0.6 mL of a 3.0 mg / mL sodium chloropalladium solution to the solution. After stirring for 2 hours, add 1 mL of a 0.28 mg / mL sodium citrate solution dropwise. Heat to 120 °C under a nitrogen atmosphere and react for 1 hour to obtain an orange suspension. Centrifuge the suspension to separate the solid phase. Wash with water and ethanol sequentially, then dry in a vacuum oven at 50 °C to obtain an orange powdery composite electrocatalyst, denoted as Pd / DMOD-4F-COF.

[0199] Example 21

[0200] This embodiment provides a method for preparing a composite electrocatalyst, including:

[0201] Weigh 20 mg of the DMOD-COF powder prepared in Example 9 and disperse it in 20 mL of ethylene glycol solution. Sonicate for 30 minutes. Then, add 0.6 mL of chloroauric acid solution (2.4 mg / mL) dropwise to the solution. After stirring for 2 hours, add 1 mL of sodium citrate solution (0.35 mg / mL) dropwise. Heat to 120 °C under a nitrogen atmosphere and react for 1 hour to obtain an orange suspension. Centrifuge the suspension to separate the solid phase. Wash with water and ethanol sequentially, then dry in a vacuum oven at 50 °C to obtain an orange powdery composite electrocatalyst, denoted as Au / DMOD-COF.

[0202] Example 22

[0203] This embodiment provides a method for preparing a composite electrocatalyst, including:

[0204] Weigh 20 mg of the DMOD-COF powder prepared in Example 9 and disperse it in 20 mL of ethylene glycol solution. Sonicate for 30 minutes. Then, add 0.04 mL of ruthenium trichloride solution (4.8 mg / mL) dropwise to the solution. After stirring for 2 hours, add 1 mL of sodium borohydride solution (5 mg / mL) dropwise. Heat to 50°C under a nitrogen atmosphere and react for 4 hours to obtain an orange suspension. Centrifuge the suspension to separate the solid phase. Wash with water and ethanol sequentially, then dry in a vacuum oven at 50°C to obtain an orange powdery composite electrocatalyst, denoted as Ru / DMOD-COF.

[0205] The performance of the irreversibly bonded self-polymerized covalent organic framework material (DMOD-COF) prepared in Example 9, the irreversibly bonded self-polymerized covalent organic framework materials prepared in Examples 10-11, and the irreversibly bonded self-polymerized covalent organic framework material (BZTTA-COF) prepared in Example 15 was evaluated, as follows:

[0206] 1. XRD test, its spectrum is as follows Figure 1 As shown.

[0207] Figure 1 In the image, (a), (b), (c), and (d) are the XRD spectra of the irreversibly bonded self-polymerized covalent organic framework materials prepared in Examples 9, 10, 11, and 15, respectively. Figure 1 It can be seen that the aforementioned self-polymerizing covalent organic framework materials with irreversible bond linkages all have high crystallinity.

[0208] 2. Infrared spectroscopy was performed on the DMOD-COF prepared in Example 9 and the BZTTA-COF prepared in Example 15, and their spectra are shown below. Figure 2 As shown.

[0209] in, Figure 2 (a) shows the infrared spectrum of DMOD-COF, indicating that DMOD-COF is a vinyl-linked COF material, with a 1631.5 cm⁻¹. -1 The peak corresponds to the stretching vibration of a carbon-carbon double bond.

[0210] Figure 2 (b) shows the infrared spectrum of BZTTA-COF, indicating that BZTTA-COF is a polyimide-linked COF material, in which 1375 cm⁻¹... -1 The peak corresponds to the stretching vibration of the imide CNC.

[0211] 3. BET Surface Area Test

[0212] The nitrogen isotherm adsorption-desorption curves of DMOD-COF and BZTTA-COF at 77 K were tested respectively, and if... Figure 3 As shown, (a) is the nitrogen isotherm adsorption-desorption curve of DMOD-COF, and (b) is the nitrogen isotherm adsorption-desorption curve of BZTTA-COF. From... Figure 3 The BET surface area of ​​DMOD-COF can be calculated from the isothermal adsorption curve to be 929 m². 2 / g, the BET surface area of ​​BZTTA-COF is 628m². 2 / g, all have a large specific surface area.

[0213] The composite catalyst Pd / DMOD-4F-COF prepared in Example 20 was used for the electrocatalytic synthesis of ammonia, and its electrocatalytic performance was evaluated. Electrocatalytic tests were performed on an electrochemical workstation using a three-electrode system, and the specific methods are as follows:

[0214] Take 10 mg of powdered Pd / DMOD-4F-COF and place it in a mortar. Add 3 mL of ethanol and 20 μL of Nafion ethanol solution. Grind evenly and then drop the slurry onto hydrophobic carbon paper. After drying, use it as the working electrode in the three-electrode system. A platinum electrode is used as the counter electrode, a silver chloride electrode is used as the reference electrode, and a 0.1 M sodium sulfate aqueous solution is used as the electrolyte.

[0215] Before the test, nitrogen gas was introduced into the three-electrode system for at least one hour, followed by two hours of electrostatic potential testing at different operating voltages. Ammonia in the solution was detected using a UV-Vis spectrophotometer with various colorimetric reagents.

[0216] Ammonia yield and Faraday efficiency at different voltages, such as Figure 4 As shown. From Figure 4 It can be seen that Pd / DMOD-4F-COF exhibits high ammonia yield and Faradaic efficiency under different voltages. Among them, Pd / DMOD-4F-COF reaches the maximum ammonia yield of 90±2.6 μg h⁻¹ at -0.2V vs. RHE. -1 mg cat. -1 The maximum Faraday efficiency of 44% demonstrates that the composite electrocatalyst of this application possesses high catalytic efficiency. The results obtained by standardizing the catalytic products using different colorimetric agents are essentially consistent, further confirming the high catalytic efficiency of the composite electrocatalyst of this application.

[0217] The composite electrocatalyst of this application was subjected to cyclic operation to test its catalytic activity, and the results are as follows: Figure 5 As shown. By Figure 5 It can be seen that the composite electrocatalyst still maintains good catalytic activity after 15 cycles of operation.

[0218] Although this application has been described in detail in this specification with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of this application are all within the scope of protection claimed in this application.

Claims

1. A self-polymerizing covalent organic framework material with irreversible bond linkages, characterized in that, pass Suzuki coupling synthesizes monomers with equal amounts of reactive functional groups, and then the monomers are self-polymerized to prepare the product. The monomer has equal amounts of aldehyde and methyl groups, or equal amounts of orthophthalic acid and amide groups; The monomer includes any one of the following compounds: ； ； 。 2. The method for preparing the irreversibly bonded self-polymerizing covalent organic framework material according to claim 1, characterized in that, include: S1, Organic compound A, Organic compound B, potassium carbonate and catalyst A are reacted in a reaction vessel under a nitrogen atmosphere to obtain a monomer; S2 involves a melt condensation reaction of monomer and catalyst B in a reactor. After washing and purification, the product yields an irreversibly bonded self-polymerized covalent organic framework material.

3. The preparation method according to claim 2, characterized in that, The organic compound A is an aromatic compound having multiple bromine or iodine functional groups; Organic compound B is an aromatic compound having a phenylacetylene group, a phenylboronic acid group, or a phenylboronic acid pinacol ester group; The catalyst A is an organic complex of palladium; The solvent includes any one or a combination of several of the following: water, tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, and toluene.

4. The preparation method according to claim 3, characterized in that: The organic compound A includes 4,8-dibromo-2,6-dimethyl[1,3]oxazacyclopentano[4',5':4,5]benzo[d][1,3]oxazacyclopentano, 1,3,5-tribromo-2,4,6-triiodobenzene, 6,7-dibromo-2,3-dimethylquinoxaline, 5,8-dibromo-2,3-dimethylquinoxaline, 1,2-dibromo-4,5-diiodobenzene, 1,3-dibromo-4,6-diiodobenzene, 1 Any one of the following: 4-dibromo-2,5-diiodobenzene, 4-bromo-2,6-dimethylpyridine, 4-bromo-6-methylpyridine-2-carboxaldehyde, 1,4-dibromobenzene, 1,3,5-tribromobenzene, 1,3,4,6-tetrabromo-2,5-dimethylbenzene, 2,7-dibromopyrene, 2,6-dibromonaphthalene, 2,6-dibromoanthracene, 3,6-dibromobenzene-1,2,4,5-tetracarboxylic acid, or 3,6-diiodobenzene-1,2,4-5-tetracarboxylic acid; And / or: Organic compound B includes 4-formylphenylboronic acid, 3-fluoro-4-aldehyde phenylboronic acid, 3,5-difluoro-4-formylphenylboronic acid, 4-formyl-3,5-dimethoxyphenylboronic acid, 2-methoxy-4-(4,4,5,5-tetramethylethyl-1,3,2-dioxoboranol-2-yl)benzaldehyde, 4-boronic acid pinacol ester-2-hydroxybenzaldehyde, 2-nitro-4-(4,4,5,5-tetramethyl-1,3,2-dioxoborane-2-yl)benzaldehyde, 4'-formylbiphenyl-4-boronic acid pinacol ester; 4-(4-formylphenyl)phenyl-2-boronic acid pinacol ester, 2-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxoborane-2-yl)pyridine 4-Ethynylbenzene-1-carboxaldehyde, 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)benzene-1,3-dicarboxaldehyde, 1,4-phenyldiboronic acid pinacol ester, 4,4'-biphenyldiboronic acid pinacol ester, N-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)phenyl)benzamide, N-(2-fluoro-4-(4,4,5, 5-Tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(2,6-difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(2-hydroxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide, N-(2,6-dihydroxy-4-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl)benzamide Any one of 5,5-tetramethyl-1,3,2-dioxaborane-2-yl)phenyl)benzamide, N-(4'-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)-[1,1'-biphenyl]-4-yl)benzamide, or N-(4-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)phenyl)ethynyl)phenylbenzamide; And / or: The catalyst A comprises any one of tetra(triphenylphosphine)palladium(O), bis(triphenylphosphine)palladium dichloride, 1,1-bis(diphenylphosphine)ferrocenepalladium dichloride, or palladium acetate.

5. The preparation method according to claim 2, characterized in that, The monomer has equal amounts of aldehyde and methyl groups, or equal amounts of orthophthalic acid and amide groups; Catalyst B is a compound containing an anhydride functional group, a compound containing an acyl chloride functional group, or a compound containing a carboxylic acid functional group.

6. The preparation method according to claim 2, characterized in that, The molar ratio of organic compound A, organic compound B, potassium carbonate and catalyst A is 1:(3-4):(3-4):(0.1-0.2); And / or: The molar ratio of catalyst B to monomer is 1:1 to 10:1; The solvent reaction temperature is 70-80℃; The temperature of the melt condensation reaction is 160-250℃.

7. The application of the irreversibly bonded self-polymerized covalent organic framework material according to claim 1 or the irreversibly bonded self-polymerized covalent organic framework material prepared by the preparation method according to any one of claims 2-6 in electrocatalysts.

8. A composite electrocatalyst, characterized in that, Includes an electrocatalyst and a support on which the electrocatalyst is supported; The carrier is the irreversibly bonded self-polymerized covalent organic framework material according to claim 1 or the irreversibly bonded self-polymerized covalent organic framework material prepared by the preparation method according to any one of claims 2-6.

9. The method for preparing the composite electrocatalyst according to claim 8, characterized in that, include: The self-polymerized covalent organic framework material with irreversible bonds is dispersed in a solvent, a metal salt solution is added, and the reaction is carried out under a nitrogen atmosphere with the help of a reducing agent. The solid product is collected, washed, and dried to obtain the final product. The metal salt includes at least one of sodium chloropalladium, chloroauric acid, sodium chloroplatinate, ruthenium chloride, rhodium chloride, silver nitrate, and copper chloride; The solvent is at least one of water, acetonitrile, ethylene glycol, ethanol, methanol or N-methylpyrrolidone; The reducing agent includes any one of sodium citrate, sodium borohydride, or potassium borohydride.

10. The application of the composite electrocatalyst according to claim 8 in the electrocatalytic synthesis of ammonia.

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