Three functionalized three-dimensional covalent organic framework materials, preparation method and application of three functionalized three-dimensional covalent organic framework materials in gas adsorption and separation

Abstract

The invention discloses three functionalized three-dimensional covalent organic framework materials, a preparation method and application thereof in gas adsorption and separation, and belongs to the technical field of porous organic framework material preparation. According to the preparation method, 2, 5-diethoxy terephthalaldehyde, 2, 5-dimethyl terephthalaldehyde, 2, 5-bis (propyl-2-alkyne-1-yloxy) terephthalaldehyde and tetra (4-aminophenyl) methane are used as raw materials through a Schiff base reaction, and 2, 5-diethoxy terephthalaldehyde, 2, 5-dimethyl terephthalaldehyde, 2, 5-bis (propyl-2-alkyne-1-yloxy) terephthalaldehyde and tetra (4-aminophenyl) Three functionalized three-dimensional covalent organic framework materials TAM-DETP, TAM-DMTA and TAM-BPTA are prepared under the catalysis of acetic acid, wherein the frameworks of the three functionalized three-dimensional covalent organic framework materials contain ethyoxyl, methyl and prop-2-alkyn-1-yloxy, and the three functionalized three-dimensional covalent organic framework materials are long-range ordered crystalline porous materials. The carbon dioxide / methane separation ratio of the TAM-BPTA is 23 at the temperature of 273 K and the pressure of 100 kPa; the TAM-BPTA has a carbon dioxide / methane separation ratio of 44 at a temperature of 298 K and a pressure of 100 kPa.

Description

Technical Field

[0001] The present invention belongs to the technical field of porous organic framework material preparation, and specifically discloses three functionalized three-dimensional covalent organic framework materials (TAM-DETP, TAM-DMTA and TAM-BPTA), preparation methods and applications thereof in gas adsorption and separation. Background Art

[0002] Covalent organic frameworks (COFs) are a class of porous materials connected by covalent bonds, which are formed by different types of polymerization reactions of organic molecular building blocks composed of light elements such as carbon, hydrogen, oxygen, nitrogen, and boron. As an emerging class of porous materials, COFs have the characteristics of rich structure, strong modifiability, and high specific surface area. Their structure can be predetermined by molecular building blocks of network chemistry. At present, COFs have good application potential in applications such as gas adsorption, optoelectronics, catalysis, separation, and proton conduction.

[0003] At present, there are more monomers suitable for constructing 2D COFs than 3D monomers. Therefore, the number of 2D COFs is relatively large, while the number of 3D COFs is relatively small. The monomers for constructing COFs are organic molecules, which have good modifiability. In addition to the groups used for polymerization reactions, different functional groups can also be introduced into the monomers to modify the pore structure and pore surface. The present invention constructs a three-dimensional functionalized covalent organic framework material with tetrahedral amines and functionally modified linear aldehyde groups. The introduction of functionalized groups can change the interaction between the host adsorbent and the guest gas. Summary of the invention

[0004] The purpose of the present invention is to provide three functionalized three-dimensional covalent organic framework materials (TAM-DETP, TAM-DMTA and TAM-BPTA), preparation methods and applications thereof in gas adsorption and separation. The present invention uses 2,5-diethoxyterephthalaldehyde, 2,5-dimethylterephthalaldehyde, 2,5-bis(prop-2-yn-1-yloxy)terephthalaldehyde and tetrakis(4-aminophenyl)methane as raw materials through Schiff base reaction, and prepares three functionalized three-dimensional covalent organic framework materials TAM-DETP, TAM-DMTA and TAM-BPTA with ethoxy, methyl and prop-2-yn-1-yloxy groups in the framework under acetic acid catalysis. The adsorption and separation properties of carbon dioxide, methane, ethane and ethylene of these materials are studied in detail at 273K and 298K.

[0005] The preparation method of the three functionalized three-dimensional covalent organic framework materials (TAM-DETP, TAM-DMTA and TAM-BPTA) described in the present invention comprises the following steps: dissolving an organic aldehyde monomer and an organic amine monomer in an organic solution, and dispersing them into a homogeneous solution by ultrasonication; then adding an acid catalyst to the obtained homogeneous solution and dispersing them uniformly; and then performing a "freeze-vacuum-thaw" cycle operation 2 to 4 times in a liquid nitrogen and argon atmosphere, with the freezing temperature being 77K and thawing to room temperature; and then reacting at 110 to 130°C for 60 to 80 hours under vacuum sealing conditions; and after the reaction is completed, The reaction solution is filtered, washed and vacuum dried to obtain TAM-DETP, TAM-DMTA or TAM-BPTA; wherein the organic aldehyde monomer is one of 2,5-diethoxyterephthalaldehyde, 2,5-dimethylterephthalaldehyde and 2,5-bis(prop-2-yn-1-yloxy)terephthalaldehyde, and the organic amine monomer is tetrakis(4-aminophenyl)methane; the molar ratio of the aldehyde group in the organic aldehyde to the amino group in the organic amine is 2:1; the acid catalyst is acetic acid, and its concentration is 3M to 9M; the organic solution is one of mesitylene, toluene and 1-4-dioxane or a mixed solution. The prepared TAM-DETP, TAM-DMTA and TAM-BPTA can be used in the field of gas adsorption and separation, and the gas is methane, carbon dioxide, ethylene and ethane.

[0006] The reaction formula of the present invention is as follows:

[0007]

[0008] The structural formula of the obtained functionalized three-dimensional covalent organic framework material is shown below:

[0009]

[0010] Where R = OC 2 H 5 , CH 3 、OCH 2 C≡CH, corresponding to TAM-DETP, TAM-DMTA and TAM-BPTA respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 : SEM image of TAM-DETP;

[0012] Figure 2 : SEM image of TAM-DMTA;

[0013] Figure 3 : SEM image of TAM-BPTA;

[0014] Figure 4 : X-ray powder diffraction pattern of TAM-DETP;

[0015] Figure 5 : X-ray powder diffraction pattern of TAM-DMTA;

[0016] Figure 6 : X-ray powder diffraction pattern of TAM-BPTA;

[0017] Figure 7 : Infrared spectrum of TAM-DETP;

[0018] Figure 8 : Infrared spectrum of TAM-DMTA;

[0019] Fig. 9 : Infrared spectrum of TAM-BPTA;

[0020] Fig.10 : Nitrogen adsorption and desorption curves of TAM-DETP;

[0021] Fig.11 : Nitrogen adsorption and desorption curves of TAM-DMTA;

[0022] Fig.12 : Ethylene and ethane adsorption isotherms of TAM-DETP at 298K.

[0023] Fig.13 : Ethylene / ethane separation ratio curve of TAM-DETP at 298K;

[0024] Fig.14 : CO2 and CH4 adsorption isotherms of TAM-BPTA at 273K;

[0025] Fig.15 : CO2 and CH4 adsorption isotherms of TAM-BPTA at 298K;

[0026] Fig.16 : CO2 / CH4 separation ratio curve of TAM-BPTA at 273K;

[0027] Fig.17 : CO2 / CH4 separation ratio curve of TAM-BPTA at 298K.

[0028] Figure 1 As shown, the scanning electron microscope image of TAM-DETP of the present invention corresponds to Example 1; it can be seen from the figure that TAM-DETP is peach-pit shaped and has a size of about 3 μm;

[0029] Figure 2 As shown, the scanning electron microscope image of TAM-DMTA of the present invention corresponds to Example 2; it can be seen from the figure that TAM-DMTA is wedge-shaped and has a size of about 0.5 μm;

[0030] Figure 3 As shown, the scanning electron microscope image of TAM-BPTA of the present invention corresponds to Example 3; it can be seen from the figure that TAM-BPTA is wedge-shaped and has a size of about 1 μm;

[0031] Figure 4 As shown, the X-ray powder diffraction pattern of TAM-DETP of the present invention corresponds to Example 1; it can be seen from the figure that TAM-DETP has good crystallinity and is a long-range ordered crystalline porous material;

[0032] Figure 5 As shown, the X-ray powder diffraction pattern of TAM-DMTA of the present invention corresponds to Example 2; it can be seen from the figure that TAM-DMTA has good crystallinity and is a long-range ordered crystalline porous material;

[0033] Figure 6 As shown, the X-ray powder diffraction pattern of TAM-BPTA of the present invention corresponds to Example 3; it can be seen from the figure that TAM-BPTA has good crystallinity and is a long-range ordered crystalline porous material;

[0034] Figure 7 As shown, the infrared spectra of TAM-DETP and the corresponding monomers of the present invention correspond to Example 1; it can be seen from the figure that the NH of tetrakis(4-aminophenyl)methane after the reaction corresponds to 3343cm -1 The stretching vibration peak at 1681 cm corresponding to C=O of 2,5-diethoxyterephthalaldehyde -1 The absorption peak at 1614cm -1 The characteristic absorption peak of C=N double bond appears at , indicating that tetrakis(4-aminophenyl)methane and aldehyde monomer react to form a high-purity imine-linked polymer;

[0035] Figure 8 As shown, the infrared spectra of TAM-DMTA and the corresponding monomers of the present invention correspond to Example 2; it can be seen from the figure that the NH of tetrakis(4-aminophenyl)methane after the reaction corresponds to 3343cm -1 The stretching vibration peak at 1682 cm corresponding to C=O of 2,5-dimethylterephthalaldehyde -1 The absorption peak at 1600cm -1 The characteristic absorption peak of C=N double bond appears at , indicating that tetrakis(4-aminophenyl)methane and aldehyde monomer react to form a high-purity imine-linked polymer;

[0036] Fig. 9As shown, the infrared spectra of TAM-BPTA and the corresponding monomers of the present invention correspond to Example 3; it can be seen from the figure that the NH of tetrakis(4-aminophenyl)methane after the reaction corresponds to 3343 cm -1 The stretching vibration peak at 1681 cm corresponding to the C=O of 2,5-bis(prop-2-yn-1-yloxy)terephthalaldehyde -1 The absorption peak at 1616cm -1 The characteristic absorption peak of C=N double bond appears at , indicating that tetrakis(4-aminophenyl)methane and aldehyde monomer react to form a high-purity imine-linked polymer;

[0037] Fig.10 As shown in FIG. 1 , the nitrogen adsorption and degassing isotherms of TAM-DETP of the present invention correspond to those of Example 1; the BET specific surface area of ​​TAM-DETP is 1356 m 2 g1;

[0038] Fig.11 As shown, the nitrogen adsorption and desorption isotherms of TAM-DMTA of the present invention correspond to Example 2; the BET specific surface area of ​​TAM-DMTA is 191m 2 g1;

[0039] Fig.12 As shown in the figure, at 298K, the ethylene and ethane adsorption isotherms of TAM-DETP correspond to Example 1; at 1 bar, the ethylene and ethane adsorption capacities are 30.09 cm -3 g -1 and 18.31cm -3 g -1 ;

[0040] Fig.13 As shown, at 298K, the ethylene / ethane separation ratio curve of TAM-DETP corresponds to Example 1; at 100 kPa, its ethylene / ethane separation ratio is 3;

[0041] Fig.14 As shown in the figure, at 273K, the carbon dioxide and methane adsorption isotherms of TAM-BPTA correspond to Example 3; at 1 bar, the carbon dioxide and methane adsorption capacities of TAM-BPTA are 61.92 cm -3 g -1 and 12.40cm -3 g -1 ;

[0042] Fig.15 As shown in the figure, at 298K, the carbon dioxide and methane adsorption isotherms of TAM-BPTA correspond to Example 3; at 1 bar, the carbon dioxide and methane adsorption capacities of TAM-BPTA are 50.30 cm-3 g -1 and 6.73cm -3 g -1 ;

[0043] Fig.16 As shown, at 273K, the separation ratio curve of carbon dioxide / methane of TAM-BPTA corresponds to Example 3; at 100 kPa, the separation ratio of carbon dioxide / methane of TAM-BPTA is 23;

[0044] Fig.17 As shown, at 298K, the carbon dioxide / methane separation ratio curve of TAM-BPTA corresponds to Example 3; at 100kPa, the carbon dioxide / methane separation ratio of TAM-BPTA is 44. DETAILED DESCRIPTION

[0045] Embodiment 1:

[0046] Preparation of TAM-DETP: Weigh tetrakis(4-aminophenyl)methane (1mmol) and 2,5-diethoxyterephthalaldehyde (2mmol) into an ampoule, then add 2mL of mesitylene, and ultrasonicate for 30 minutes to ensure that the solution is evenly mixed; add 0.2mL of 3M acetic acid solution to the above solution, and then perform a "freeze-vacuum-thaw" cycle twice under liquid nitrogen and argon atmosphere, with the freezing temperature at 77K and thawing to room temperature; then seal the ampoule under vacuum and react at 120°C for 72 hours. After the temperature of the ampoule drops to room temperature, slowly open the ampoule; vacuum filter the reaction solution to obtain a sample, then wash it with anhydrous tetrahydrofuran and soak it for 1 day, during which the anhydrous tetrahydrofuran solvent is replaced every 8 hours; dry it in a vacuum drying oven (temperature at 100°C, drying for 12 hours) to obtain TAM-DETP (19 mg).

[0047] Embodiment 2:

[0048] Preparation of TAM-DMTA: Weigh tetrakis(4-aminophenyl)methane (1mmol) and 2,5-dimethylterephthalaldehyde (2mmol) and add them to an ampoule, then add 2mL of mesitylene, and ultrasonicate for 30 minutes to ensure that the solution is evenly mixed; add 0.2 ml of 3M acetic acid solution to the above solution, and then perform a "freeze-vacuum-thaw" cycle twice in a liquid nitrogen and argon atmosphere, with a freezing temperature of 77K and thawing to room temperature; then seal the ampoule under vacuum and react at 120°C for 72 hours. After the temperature of the ampoule drops to room temperature, slowly open the ampoule; vacuum filter the reaction solution to obtain a sample, then wash it with anhydrous tetrahydrofuran and soak it for 1 day, during which the anhydrous tetrahydrofuran solvent is replaced every 8 hours; dry the product in a vacuum drying oven (temperature 100°C, drying for 12 hours) to obtain TAM-DMTA (21 mg).

[0049] Embodiment 3:

[0050] Preparation of TAM-BPTA: Weigh tetrakis(4-aminophenyl)methane (1mmol) and 2,5-bis(prop-2-yn-1-yloxy)terephthalaldehyde (2mmol) and add them to the reaction vessel, then add 2mL of mesitylene, and ultrasonicate for 30 minutes to ensure that the solution is evenly mixed; add 0.2mL of 3M acetic acid solution to the above solution, and then perform a "freeze-vacuum-thaw" cycle twice under liquid nitrogen and argon atmosphere, with the freezing temperature at 77K and thawing to room temperature; then seal the reaction vessel under vacuum and react at 120℃ for 72 hours. After the temperature of the ampoule drops to room temperature, slowly open the ampoule; vacuum filter the reaction solution to obtain a sample, then wash it with anhydrous tetrahydrofuran and soak it for 1 day, during which the anhydrous tetrahydrofuran solvent is replaced every 8 hours; dry it in a vacuum drying oven (temperature at 100℃, drying for 12 hours) to obtain TAM-BPTA (23 mg).

[0051] In summary, the present invention uses tetrakis(4-aminophenyl)methane to react with 2,5-diethoxyterephthalaldehyde, 2,5-dimethylterephthalaldehyde and 2,5-bis(prop-2-yn-1-yloxy)terephthalaldehyde under acetic acid catalysis to carry out Schiff base reaction to synthesize TAM-DETP, TAM-DMTA and TAM-BPTA. X-ray powder diffraction proves that they have good crystallinity and are long-range ordered crystalline porous materials. The BET specific surface area of ​​TAM-DETP obtained by nitrogen adsorption-desorption isotherm is 1356m 2 g -1 The BET specific surface area of ​​TAM-DMTA is 191 m 2 g -1 At 298K and 1 bar, the adsorption capacities of ethylene and ethane for TAM-DETP were 30.09 cm -3 g -1 and 18.31cm -3 g -1 At 298K and 100kPa, the ethylene / ethane separation ratio of TAM-DETP is 3. At 273K and 1bar, the carbon dioxide and methane adsorption capacities of TAM-BPTA are 61.92cm -3 g -1 and 12.40cm -3 g -1 At 298K and 1 bar, the adsorption capacities of carbon dioxide and methane by TAM-BPTA were 50.30 cm -3 g -1 and 6.73cm -3 g -1At 273K and 100kPa, the separation ratio of carbon dioxide / methane of TAM-BPTA is 23; at 298K and 100kPa, the separation ratio of carbon dioxide / methane of TAM-BPTA is 44.

[0052] As described above, for those skilled in the art, various other corresponding changes and modifications can be made based on the technical solutions and technical concepts of the present invention, and all these changes and modifications belong to the protection scope required by the present invention.

Claims

1. Functionalized three-dimensional covalent organic framework material, characterized by: Its structural formula is shown below: Among them, R=OC2H5, CH3, OCH2C≡CH, corresponding to TAM-DETP, TAM-DMTA and TAM-BPTA respectively.

2. The method for preparing the functionalized three-dimensional covalent organic framework material according to claim 1, characterized in that: An organic aldehyde monomer and an organic amine monomer are dissolved in an organic solution and dispersed into a homogeneous solution by ultrasound; an acid catalyst is then added to the obtained homogeneous solution to disperse it evenly, and then a "freeze-vacuum-thaw" cycle operation is performed 2 to 4 times in a liquid nitrogen and argon atmosphere, the freezing temperature is 77K, and the thawing is performed to room temperature; then the reaction is carried out at 110 to 130°C for 60 to 80 hours under vacuum sealing conditions; after the reaction is completed, the reaction solution is filtered, washed and vacuum dried to obtain TAM-DETP, TAM-DMTA and TAM-BPTA; wherein the organic aldehyde monomer is one of 2,5-diethoxyterephthalaldehyde, 2,5-dimethylterephthalaldehyde, and 2,5-bis(prop-2-yn-1-yloxy)terephthalaldehyde, and the organic amine monomer is tetrakis(4-aminophenyl)methane; the molar ratio of the aldehyde group in the organic aldehyde to the amino group in the organic amine is 2:

1.

3. The method for preparing a functionalized three-dimensional covalent organic framework material according to claim 2, characterized in that: The acid catalyst is acetic acid, and its concentration is 3-9M.

4. The method for preparing a functionalized three-dimensional covalent organic framework material according to claim 2, characterized in that: The organic solvent is one of mesitylene, toluene and 1-4-dioxane or a mixture of several of them.

5. Use of the functionalized three-dimensional covalent organic framework material according to claim 1 in gas adsorption and separation.

6. The method for using the functionalized three-dimensional covalent organic framework material in gas adsorption and separation as claimed in claim 5, characterized in that: The gas is ethylene, ethane, methane or carbon dioxide.

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