Covalent organic framework material with multi-level pore structure and preparation method

Abstract

The present invention discloses a covalent organic framework material with a multi-level pore structure. The covalent organic framework material is prepared by constructing a dynamic combinatorial library. This covalent organic framework material has a multi-level pore structure composed of pores of three scales: micropores, mesopores, and macropores. It can serve as a carrier for metal-based catalysts such as zirconium or palladium, and can also function as a nanoreactor in the catalytic synthesis of polymer materials such as polyketones.

Description

Technical Field

[0001] The present invention relates to the field of covalent organic framework materials, and in particular to a covalent organic framework material with a multi-level pore structure and a preparation method thereof. Background Art

[0002] Covalent organic frameworks (COFs) are an emerging class of porous organic polymers characterized by periodic structures, well-defined micropore sizes, and ease of chemical modification. They hold enormous potential for applications in gas storage, separation, catalysis, sensors, and energy storage. As a polymeric material, COFs exhibit multiscale structures, encompassing molecular, nanocrystalline, mesoscopic aggregates, and macroscopic ensembles. Significant progress has been made in the design of COF molecular backbones and the customization of nanopores. Furthermore, breakthroughs have been made in the fabrication of advanced structures (such as nanospheres, hollow fibers, films, and foams) through self-assembly or physical processing. Pore structure, as a component of COF multiscale architecture, has also garnered significant attention. However, reported COF hierarchical porosity often relies on the design of the molecular backbone, limiting its applicability. Furthermore, the insolubility and infusibility of COFs restrict the fabrication of these structures through secondary processing. A more broadly applicable, one-pot, one-step synthesis strategy that allows for the control of the product aggregate structure is lacking. The construction of hierarchical porosity can enhance the material's mass transfer capacity and improve its catalytic and adsorption properties. Summary of the Invention

[0003] In view of this, the present invention provides a covalent organic framework material with multi-level pores and a preparation method to solve the problems of complex synthesis steps, high monomer requirements and difficulty in simple preparation of existing COF materials with multi-level pores.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] The first aspect of an embodiment of the present invention provides a method for preparing a covalent organic framework material having a multi-level pore structure, the preparation method comprising: dissolving a trifunctional amine A3, a trifunctional aldehyde B3, a difunctional monomer C2, and aniline and benzaldehyde in an organic solvent to construct a dynamic combination library, adding a catalyst to start the reaction, stirring at a temperature of 10 to 40°C, filtering after sufficient reaction, and generally continuing the reaction for 24 to 96 hours to obtain a covalent organic framework product.

[0006] Furthermore, the trifunctional amine A3 is composed of one or more of tris(4-aminophenyl)amine, 1,3,5-tris(4-aminophenyl)benzene, and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine mixed in any proportion.

[0007] Furthermore, the trifunctional aldehyde B3 is composed of one or more of tris(4-formaldehydephenyl)amine, 1,3,5-tris(4-formaldehydephenyl)benzene, 2,4,6-tris(4-formaldehydephenyl)-1,3,5-triazine, and trimesaldehyde mixed in any proportion.

[0008] Furthermore, the difunctional monomer C2 is composed of one or more of terephthalaldehyde, 2,5-dimethoxyterephthalaldehyde, 4,4'-biphenyldialdehyde, p-phenylenediamine, 2,5-dimethoxyp-phenylenediamine, and 4,4'-biphenylenediamine mixed in any proportion.

[0009] Furthermore, the concentration of the trifunctional amine A3 is 1 to 50 mmol / L; the concentration of the trifunctional amine B3 is 1 to 50 mmol / L; the concentration of the difunctional amine C2 is 0.1 to 200 mmol / L; and the concentrations of the aniline and benzaldehyde are 12 to 600 mmol / L.

[0010] Furthermore, the organic solvent is a mixed solvent prepared by mixing acetonitrile, benzonitrile, mesitylene, dioxane, DMF and DMAC in any proportion.

[0011] Furthermore, the catalyst is scandium trifluoromethanesulfonate solution or acetic acid; wherein the concentration of scandium trifluoromethanesulfonate solution is 1-40 mg / mL, and its usage accounts for 1%-10% of the volume of the reaction solution; the concentration of acetic acid in the reaction solution is 0.01-10 mol / mL.

[0012] A second aspect of the embodiments of the present invention provides a covalent organic framework material having a multi-level pore structure, which is prepared by the above-mentioned method for preparing a covalent organic framework material having a multi-level pore structure.

[0013] Furthermore, the covalent organic framework material has a multi-level pore structure consisting of three scales of pores: micropores, mesopores, and macropores; the pore size distribution of the multi-level pore structure changes with the change of monomer combination and monomer molar ratio; the micropore size distribution is 0.8-1.9 nm, the mesopore size distribution is 2.1-40 nm, and the macropore size distribution is 200-1000 nm; the BET specific surface area of ​​the covalent organic framework material is 50-3000 m 2 / g, and the crystallinity is 30%-100%.

[0014] A third aspect of the embodiments of the present invention provides an application of a covalent organic framework material having a multi-level pore structure as a carrier for loading a metal-based catalyst or as a nanoreactor.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) the mesopores and macropores in the multi-level pore structure originate from the aggregated structure of the covalent organic framework material, so the synthetic monomers of the material do not need to be specially designed, and only conventional synthetic monomers need to be used; (2) the multi-level pore structure obtained by the synthesis method can be adjusted by the ratio of synthetic monomers, which has the advantage of dynamic adjustability; (3) the synthesis method only depends on the initial monomer ratio, and the target product can be obtained in one pot and one step, which has higher efficiency; (4) the obtained covalent organic framework material with multi-level pores can be loaded with metal-based catalysts such as zirconium or palladium and used in the catalytic synthesis process of polymer materials such as polyketone, and has the function of regulating the growth of product molecular chains and inducing crystallization. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 This is the SEM image of TAPB-PDA-BTCA COF in Example 1 of the present invention;

[0018] Figure 2 This is the PXRD characterization diagram of TAPB-PDA-BTCA COF in Example 1 of the present invention;

[0019] Figure 3 The nitrogen adsorption isotherm and pore size distribution diagram of TAPB-PDA-BTCA COF@1-2 in Example 1 of the present invention;

[0020] Figure 4 The TAPB-PDA-BTCA COF@1-2 in Example 1 of the present invention supports the palladium acetate catalyst. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. Unless there is any conflict, the features of the following embodiments and implementations may be combined with each other.

[0022] The present invention provides a preparation method of a covalent organic framework material with a multi-level pore structure. The preparation method comprises: dissolving a trifunctional amine A3, a trifunctional aldehyde B3, a difunctional monomer C2, aniline, and benzaldehyde in an organic solvent to construct a dynamic combinatorial library, wherein the concentration of the trifunctional amine A3 is 1 to 50 mmol / L; the concentration of the trifunctional amine B3 is 1 to 50 mmol / L; the concentration of the difunctional amine C2 is 0.1 to 200 mmol / L; and the concentrations of the aniline and benzaldehyde are 12 to 600 mmol / L; adding a catalyst to start a reaction, stirring at a temperature of 10 to 40° C., continuing the reaction for 24 to 96 hours, and then filtering to obtain a covalent organic framework product.

[0023] The covalent organic framework material has a multi-level pore structure; the pore size distribution of the multi-level pore structure changes with the change of the monomer combination and the monomer molar ratio; wherein the covalent organic framework material has a multi-level pore structure composed of three scale pores: micropores, mesopores, and macropores; the micropore size distribution is 0.8-1.9nm, the mesopore size distribution is 2.1-40nm, and the macropore size distribution is 200-1000nm; the BET specific surface area of ​​the covalent organic framework material is 50-3000m 2 / g, and the crystallinity is 30%-100%.

[0024] The trifunctional amine A3 is composed of one or more of tris(4-aminophenyl)amine, 1,3,5-tris(4-aminophenyl)benzene, and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine in any proportion. The trifunctional aldehyde B3 is composed of one or more of tris(4-formaldehydephenyl)amine, 1,3,5-tris(4-formaldehydephenyl)benzene, 2,4,6-tris(4-formaldehydephenyl)-1,3,5-triazine, and trimesic acid in any proportion. The difunctional monomer C2 is composed of one or more of terephthalaldehyde, 2,5-dimethoxyterephthalaldehyde, 4,4'-biphenyldicarboxaldehyde, p-phenylenediamine, 2,5-dimethoxy-p-phenylenediamine, and 4,4'-biphenyldiamine in any proportion.

[0025] The organic solvent is a mixed solvent prepared by mixing acetonitrile, benzonitrile, mesitylene, dioxane, DMF and DMAC in any proportion.

[0026] The catalyst is a scandium trifluoromethanesulfonate solution with a concentration of 1-40 mg / mL and a dosage of 1%-10% of the volume of the reaction solution or acetic acid with a concentration of 0.01-10 mol / mL in the reaction system.

[0027] The preparation method of the covalent organic framework material with a multi-level pore structure is described below in conjunction with Examples 1-7.

[0028] Example 1

[0029] A dynamic combinatorial library was constructed using 1,3,5-tris(4-aminophenyl)benzene, trimesic acid, and terephthalaldehyde. 70.2 mg of 1,3,5-tris(4-aminophenyl)benzene (TAPB, 0.2 mmol), 20.1 mg of terephthalaldehyde (PDA, 0.15 mmol), and 16.2 mg of trimesic acid (BTCA, 0.1 mmol) were dissolved in 20 mL of acetonitrile. 244 μL of benzaldehyde (2.4 mmol) and 219 μL of aniline (2.4 mmol) were then added to the monomer solution. The reaction was then initiated by the addition of scandium trifluoromethanesulfonate solution (11.7 mg dissolved in 1.6 mL of acetonitrile, 24 μmol). The system was maintained at 25°C with slow stirring. After 72 hours, the powder was collected by filtration and washed with n-hexane. The product was dried in a fume hood for 12 hours and then in a vacuum oven at 40°C for 24 hours to obtain TAPB-PDA-BTCA COF@3-2. The amino and aldehyde group concentrations in the reaction solution were fixed at 30 mmol / L, and the initial ratios of PDA and BTCA were changed to 1 / 2 and 3 / 1. TAPB-PDA-BTCA COF@1-2 and TAPB-PDA-BTCA COF@3-1 were synthesized according to the same procedure, hereinafter referred to as COF@3-1, COF@3-2, and COF@1-2.

[0030] The SEM images of the three products are shown in the attached Figure 1 As shown, COF@3-1 is a sea urchin-shaped solid particle with thin rods (about 106 nanometers) growing on the shell and an average particle size of 718 nanometers. In contrast, COF@3-2 and COF@1-2 are hollow spheres with average diameters of 608 nanometers and 713 nanometers, respectively. The shell thicknesses of the two products are similar, about 89 nanometers and 99 nanometers. In addition, it can be found from the SEM image that the COF@3-2 shell is composed of very tiny particles, which are connected together to form a large number of grooves. COF@1-2 has a similar structure, but the particle units are more fused, making the shell smoother. The product was further characterized using X-ray powder diffraction spectroscopy (PXRD) and Fourier transform infrared spectroscopy (FT-IR). As shown in the attached figure Figure 2 As shown, the PXRD spectrum of COF@3-1 shows only a "bump", which can be attributed to its amorphous structure. Correspondingly, COF@3-2 and COF@1-2 exhibit diffraction peaks at 5.8° (100), 9.7° (110), and 11.2° (200), which are consistent with the theoretical diffraction peaks of TAPB-BTCA COF crystals. The relative intensity of these diffraction peaks increases with the increase of the initial BTCA content, and COF@1-2 shows the sharpest diffraction peaks.

[0031] The nitrogen isothermal adsorption characterization of the samples was carried out. Among them, COF@1-2 with the highest crystallinity has a nitrogen adsorption isotherm similar to the type II curve. It has sharp absorption at both low relative pressure (P / P0 < 0.01) and high relative pressure (P / P0 > 0.95). The former is due to the absorption of micropores, while the latter corresponds to the condensation of nitrogen on the macropores of COF particles caused by capillary effect. At the same time, the desorption and adsorption curves show a type H4 hysteresis at 0.05 < P / P0 < 0.95, which is usually related to the adsorption of nitrogen in narrow slit pores. These results indicate that there should be a large number of slits in the COF@1-2 shell, which is consistent with the SEM and TEM images. According to the Brunauer-Emmett-Teller (BET) model, the total specific surface area of COF@1-2 was calculated to be 735 m 2 g -1 ( Figure 3 ) while the TAPB-BTCA COF synthesized under the same conditions is 962 m 2 g -1 . Based on the calculation of the t-plot method (de Boer model), the micropores account for 71.6% of the total specific surface area of COF@1-2.

[0032] According to the fitting of the QSDFT adsorption branch model, the total pore volume of the sample is about 0.51 cm 3 g -1 , and the concentrated distribution of micropores is at 1.67 nm ( Figure 3 ), close to the theoretical lattice parameter of 1.87 nm. In addition, the sample has a wide pore size distribution in the mesopore range of 2.5 - 32.0 nm, corresponding to the above-mentioned slit pores. And there are hollow macropores of 515 nm. Therefore, COF particles with hierarchical pores ranging from a few nanometers to hundreds of nanometers have been successfully synthesized by the preparation method of this example.

[0033] Example 2

[0034] A dynamic combinatorial library was constructed using tris(4-aminophenyl)amine, tris(4-formylphenyl)amine, and 2,5-dimethoxyterephthalaldehyde. A certain amount of the three monomers was dissolved in benzonitrile to a concentration of 30 mmol / L of tris(4-aminophenyl)amine, 20 mmol / L of tris(4-formylphenyl)amine, and 60 mmol / L of 2,5-dimethoxyterephthalaldehyde. Benzaldehyde and aniline were then added to the monomer solution to a combined concentration of 360 mmol / L. The reaction was then initiated by the addition of scandium trifluoromethanesulfonate solution (25 mg / mL, 4% of the reaction volume) or acetic acid (to a 3 mol / mL acetic acid concentration in the reaction solution). The reaction was maintained at 30°C with slow stirring. After 24 hours, the powder was collected by filtration and washed with n-hexane. The product was dried in a fume hood for 12 hours and then in a vacuum oven at 40°C for 24 hours to obtain COF-2. The obtained COF-2 has micropores distributed in the range of 1.8 nm, mesopores in the range of 2.1 to 10 nm, and hollow macropores in the range of 200 to 510 nm. The product has a crystallinity of 30% and a BET specific surface area of ​​50 m 2 g -1 .

[0035] Example 3

[0036] A dynamic combinatorial library was constructed using 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, 1,3,5-tris(4-formylphenyl)benzene, and 4,4'-biphenyldicarboxaldehyde. A certain amount of the three monomers was dissolved in a mesitylene / dioxane mixture (v / v = 1 / 2) to achieve a concentration of 1 mmol / L for 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, 1 mmol / L for 1,3,5-tris(4-formylphenyl)benzene, and 0.1 mmol / L for 4,4'-biphenyldicarboxaldehyde. Benzaldehyde and aniline were then added to the monomer solution to achieve a combined concentration of 12 mmol / L. The reaction was then initiated by the addition of scandium trifluoromethanesulfonate solution (1 mg / mL, 10% of the reaction volume) or acetic acid (to achieve an acetic acid concentration of 0.01 mol / mL). The system was maintained at 40°C with slow stirring. After 24 hours, the powder was collected by filtration and washed with n-hexane. The product was dried in a fume hood for 12 hours and in a vacuum oven at 40°C for 24 hours to obtain the product COF-3. The obtained COF-3 has micropores distributed in the range of 1.9 nm, mesopores in the range of 23 to 40 nm, and hollow macropores in the range of 400 to 710 nm; the crystallinity of the product is 85%, and the BET specific surface area is 1000 m 2 g -1 .

[0037] Example 4

[0038] A dynamic combinatorial library was constructed using 1,3,5-tris(4-aminophenyl)benzene, 2,4,6-tris(4-formylphenyl)-1,3,5-triazine, and p-phenylenediamine. A certain amount of the three monomers was dissolved in a mesitylene / dioxane mixture (v / v = 1 / 4) to achieve a concentration of 40 mmol / L for 1,3,5-tris(4-aminophenyl)benzene, 50 mmol / L for 2,4,6-tris(4-formylphenyl)-1,3,5-triazine, and 10 mmol / L for p-phenylenediamine. Benzaldehyde and aniline were then added to the monomer solution to achieve a combined concentration of 400 mmol / L. The reaction was then initiated by the addition of scandium trifluoromethanesulfonate solution (40 mg / mL, 1% of the reaction volume) or acetic acid (to achieve an acetic acid concentration of 10 mol / mL). The reaction was maintained at 15°C with gentle stirring. After 96 hours, the powder was collected by filtration and washed with n-hexane. The product was dried in a fume hood for 12 hours and then in a vacuum oven at 40°C for 24 hours to obtain the product COF-4. The obtained COF-4 has micropores distributed in the range of 1.9 nm, mesopores in the range of 11 to 32 nm, and hollow macropores in the range of 640 to 1000 nm. The crystallinity of the product is 100%, and the BET specific surface area is 3000 m 2 g -1 .

[0039] Example 5

[0040] A dynamic combinatorial library was constructed using 1,3,5-tris(4-aminophenyl)benzene, tris(4-formylphenyl)amine, and 2,5-dimethoxy-p-phenylenediamine. A certain amount of the three monomers was dissolved in DMF solvent to a concentration of 50 mmol / L for 1,3,5-tris(4-aminophenyl)benzene, 50 mmol / L for tris(4-formylphenyl)amine, and 200 mmol / L for 2,5-dimethoxy-p-phenylenediamine. Benzaldehyde and aniline were then added to the monomer solution to a concentration of 600 mmol / L. The reaction was then initiated by the addition of scandium trifluoromethanesulfonate solution (10 mg / mL, 8% of the reaction volume) or acetic acid (to a 1 mol / mL acetic acid concentration in the reaction solution). The reaction was maintained at 15°C with slow stirring. After 48 hours, the powder was collected by filtration and washed with n-hexane. The product was dried in a fume hood for 12 hours and then in a vacuum oven at 40°C for 24 hours to obtain COF-5. The obtained COF-5 has micropores distributed in the range of 1.1nm, mesopores in the range of 2.5-15nm, and hollow macropores in the range of 400-500nm. The crystallinity of the product is 40%, and the BET specific surface area is 100m 2 g -1 .

[0041] Example 6

[0042] A dynamic combinatorial library was constructed using 1,3,5-tris(4-aminophenyl)benzene, trimesic acid, and 4,4'-biphenylenediamine. A certain amount of the three monomers was dissolved in DMAc solvent to a concentration of 5 mmol / L for 1,3,5-tris(4-aminophenyl)benzene, 35 mmol / L for trimesic acid, and 150 mmol / L for 4,4'-biphenylenediamine. Benzaldehyde and aniline were then added to the monomer solution to a concentration of 240 mmol / L. The reaction was then initiated by the addition of scandium trifluoromethanesulfonate solution (15 mg / mL, 8% of the reaction volume) or acetic acid (to a concentration of 0.5 mol / mL in the reaction solution). The reaction was maintained at 10°C with slow stirring. After 72 hours, the powder was collected by filtration and washed with n-hexane. The product was dried in a fume hood for 12 hours and then in a vacuum oven at 40°C for 24 hours to obtain COF-6. The obtained COF-6 has micropores distributed in the range of 0.8nm, mesopores in the range of 2.1-30nm, and hollow macropores in the range of 200-340nm. The product has a crystallinity of 60% and a BET specific surface area of ​​300m 2 g -1 .

[0043] Example 7

[0044] A dynamic combinatorial library was constructed using 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, trimesic acid, and terephthalaldehyde. A certain amount of the three monomers was dissolved in an acetonitrile / dioxane mixture (v / v = 1 / 4) to a concentration of 25 mmol / L for 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, 15 mmol / L for trimesic acid, and 30 mmol / L for terephthalaldehyde. Benzaldehyde and aniline were then added to the monomer solution to a concentration of 60 mmol / L. The reaction was then initiated by the addition of scandium trifluoromethanesulfonate solution (15 mg / mL, 8% of the reaction volume) or acetic acid (to a concentration of 0.5 mol / mL in the reaction solution). The system was maintained at 25°C with gentle stirring. After 72 hours, the powder was collected by filtration and washed with n-hexane. The product was dried in a fume hood for 12 hours and then in a vacuum oven at 40°C for 24 hours to obtain the product COF-6. The obtained COF-6 has micropores distributed in the range of 1.3 nm, mesopores in the range of 2.5 to 27 nm, and hollow macropores in the range of 400 to 510 nm. The product has a crystallinity of 80% and a BET specific surface area of ​​600 m 2 g -1 .

[0045] Example 8

[0046] Another aspect of the present invention also proposes the use of covalent organic framework materials with a multi-level pore structure as supports for metal-based catalysts. Specifically, the COF samples synthesized in Examples 1-7 can all be used as supports for metal-based catalysts. Taking a palladium catalyst as an example, the following method is used to prepare a dispersion: 7 mg of COF is dispersed in 3 mL of methanol under ultrasound assistance to prepare a dispersion. The dispersion is maintained at 0°C, and 1.1 mg of palladium acetate is added to the dispersion. The mixture is stirred for 24 hours, filtered, and dried to obtain a COF product loaded with a palladium catalyst.

[0047] Another aspect of the present invention also proposes the use of a covalent organic framework material with a multi-level pore structure as a nanoreactor after in-situ loading. Specifically, as shown in the attached Figure 4 As shown, 2 mL of a dispersion of a bisphosphine ligand (DP) is added to the dispersion that has been stirred for 24 h in the above process to prepare an in situ catalytic solution. The mixture is used in the catalytic synthesis of polymers such as polyketone. The COF then acts as a nanoreactor. Its multi-level pore structure has confinement and extrusion effects, and products with high molecular weight, high crystallinity, and adjustable micromorphology can be obtained.

[0048] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the contents disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only.

[0049] It will be understood that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A method for preparing a covalent organic framework material having a multi-level pore structure, characterized in that: The preparation method comprises: dissolving a trifunctional amine A3, a trifunctional aldehyde B3, a difunctional monomer C2, aniline, and benzaldehyde in an organic solvent to construct a dynamic combinatorial library, adding a catalyst to start a reaction, stirring at a temperature of 10-40° C., and filtering after sufficient reaction to obtain a covalent organic framework product; the covalent organic framework product has a multi-level pore structure composed of three different pore sizes: micropores of 0.8-1.9 nm, mesopores of 2.1-40 nm, and macropores of 200-1000 nm, and a specific surface area of ​​50-3000 m 2 / g, crystallinity is 30%~100%, and the shell is composed of several particles fused together; The trifunctional amine A3, trifunctional aldehyde B3 and difunctional monomer C2 are one of the following combinations: (1) 1,3,5-tris(4-aminophenyl)benzene, trimesic acid, terephthalaldehyde; (2) tris(4-aminophenyl)amine, tris(4-formylphenyl)amine, 2,5-dimethoxyterephthalaldehyde; (3) 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, 1,3,5-tris(4-formylphenyl)benzene, 4,4'-biphenyldicarboxaldehyde; (4) 1,3,5-tris(4-aminophenyl)benzene, 2,4 ,6-tris(4-formylphenyl)-1,3,5-triazine, p-phenylenediamine; (5) 1,3,5-tris(4-aminophenyl)benzene, tris(4-formylphenyl)amine, 2,5-dimethoxy-p-phenylenediamine; (6) 1,3,5-tris(4-aminophenyl)benzene, trimesic acid, 4,4'-biphenylenediamine; (7) 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, trimesic acid, terephthalaldehyde.

2. The method for preparing a covalent organic framework material having a multi-level pore structure according to claim 1, wherein: The concentration of the trifunctional amine A3 is 1-50 mmol / L; the concentration of the trifunctional aldehyde B3 is 1-50 mmol / L; the concentration of the difunctional monomer C2 is 0.1-200 mmol / L; and the concentrations of the aniline and benzaldehyde are 12-600 mmol / L.

3. The method for preparing a covalent organic framework material having a multi-level pore structure according to claim 1, characterized in that: The organic solvent is a mixed solvent prepared by mixing acetonitrile, benzonitrile, mesitylene, dioxane, DMF and DMAC in any proportion.

4. The method for preparing a covalent organic framework material having a multi-level pore structure according to claim 1, wherein: The catalyst is a scandium trifluoromethanesulfonate solution or acetic acid; wherein the concentration of the scandium trifluoromethanesulfonate solution is 1-40 mg / mL, and its usage accounts for 1%-10% of the volume of the reaction solution; the concentration of acetic acid in the reaction solution is 0.01-10 mol / mL.

5. Use of the covalent organic framework product with a multi-level pore structure according to claim 1 as a carrier for loading a metal-based catalyst or as a nanoreactor.

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