Three functionalized three-dimensional covalent organic framework materials, methods of preparation and applications thereof in gas adsorption and separation

Abstract

Three kinds of functionalized three-dimensional covalent organic framework materials, preparation method and application thereof in gas adsorption and separation belong to the technical field of porous organic framework material preparation.The three kinds of functionalized three-dimensional covalent organic framework materials TAM-DETP, TAM-DMTA and TAM-BPTA with ethoxyl, methyl and prop-2-yn-1-yloxy in the skeleton are prepared by Schiff base reaction with 2,5-diethoxyl terephthaldehyde, 2,5-dimethyl terephthaldehyde, 2,5-bis(prop-2-yn-1-yloxy) terephthaldehyde and tetra(4-aminophenyl) methane as raw materials under the catalysis of acetic acid, which are long-range ordered crystalline porous materials.The separation ratio of carbon dioxide / methane of TAM-BPTA is 23 at 273K and 100kPa; the separation ratio of carbon dioxide / methane of TAM-BPTA is 44 at 298K and 100kPa.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of porous organic framework material, and specifically to three kinds of functionalized three-dimensional covalent organic framework materials (TAM-DETP, TAM-DMTA and TAM-BPTA), a preparation method thereof and application thereof in gas adsorption and separation. BACKGROUND

[0002] Covalent organic frameworks (COFs) are a kind of porous materials composed of carbon, hydrogen, oxygen, nitrogen, boron and other light elements, which are connected by different types of polymerization reactions. As a kind of emerging porous material, COFs have the characteristics of rich structure, strong modifiability and high specific surface area. Their structure can be determined in advance by using the molecular building blocks of reticular chemistry. At present, COFs have good application potential in gas adsorption, photoelectricity, 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 reaction, different functional groups can be introduced into the monomers to modify the pore structure and pore surface. The present application constructs three-dimensional functionalized covalent organic framework materials by using tetrahedral amines and functionally modified linear aldehyde groups. The introduction of functional groups can change the interaction between the host adsorbent and the guest gas. SUMMARY

[0004] The present application aims to provide three kinds of functionalized three-dimensional covalent organic framework materials (TAM-DETP, TAM-DMTA and TAM-BPTA), a preparation method thereof and application thereof in gas adsorption and separation. The present application uses 2,5-diethoxyterephthaldehyde, 2,5-dimethylterephthaldehyde, 2,5-bis(prop-2-yn-1-yloxy)terephthaldehyde and tetrakis(4-aminophenyl)methane as raw materials to prepare three kinds of functionalized three-dimensional covalent organic framework materials TAM-DETP, TAM-DMTA and TAM-BPTA containing ethoxy, methyl and prop-2-yn-1-yloxy in the framework under the catalysis of acetic acid. The adsorption and separation properties of the materials for carbon dioxide, methane, ethane and ethylene are studied in detail at 273K and 298K.

[0005] The preparation method of the three kinds of functionalized three-dimensional covalent organic framework materials (TAM-DETP, TAM-DMTA and TAM-BPTA) comprises the following steps: dissolving organic aldehyde monomers and organic amine monomers in an organic solution and dispersing into a homogeneous solution by ultrasonic; then uniformly adding an acid catalyst into the obtained homogeneous solution, and then performing a "freezing-vacuumizing-thawing" cycle operation 2-4 times under liquid nitrogen and argon atmosphere, wherein the freezing temperature is 77K, and the thawing is to room temperature; then reacting at 110-130 DEG C under vacuum sealing condition for 60-80 hours; after the reaction is completed, filtering, washing and vacuum drying the reaction solution to obtain TAM-DETP, TAM-DMTA or TAM-BPTA; wherein the organic aldehyde monomer is one of 2,5-diethoxyterephthaldehyde, 2,5-dimethylterephthaldehyde and 2,5-bis(prop-2-yn-1-yloxy)terephthaldehyde, the organic amine monomer is tetra(4-aminophenyl)methane, the molar ratio of aldehyde groups in the organic aldehyde to amino groups in the organic amine is 2:1, the acid catalyst is acetic acid, the concentration of the acid catalyst is 3M-9M, and 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 application is shown as follows:

[0007]

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

[0009]

[0010] Wherein, R=OC2H5, CH3, OCH2C≡CH, which respectively correspond to TAM-DETP, TAM-DMTA and TAM-BPTA. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 : Scanning electron microscope graph of TAM-DETP;

[0012] Figure 2 : Scanning electron microscope graph of TAM-DMTA;

[0013] Figure 3 : Scanning electron microscope graph of TAM-BPTA;

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

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

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

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

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

[0019] Figure 9 Infrared spectrum of TAM-BPTA;

[0020] Figure 10 Nitrogen adsorption and desorption curves of TAM-DETP;

[0021] Figure 11 Nitrogen adsorption and desorption curves of TAM-DMTA;

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

[0023] Figure 13 Ethylene / ethane separation ratio curves of TAM-DETP at 298 K.

[0024] Figure 14 Carbon dioxide and methane adsorption isotherms of TAM-BPTA at 273 K.

[0025] Figure 15 Carbon dioxide and methane adsorption isotherms of TAM-BPTA at 298 K.

[0026] Figure 16 Carbon dioxide / methane separation ratio curves of TAM-BPTA at 273 K.

[0027] Figure 17 Carbon dioxide / methane separation ratio curves of TAM-BPTA at 298 K.

[0028] Figure 1 The scanning electron microscope image of TAM-DETP of the present application is shown in the figure corresponding to Example 1; it can be seen from the figure that TAM-DETP is peach-nucleus-shaped, with a size of about 3 μm;

[0029] Figure 2 The scanning electron microscope image of TAM-DMTA of the present application is shown in the figure corresponding to Example 2; it can be seen from the figure that TAM-DMTA is wedge-shaped, with a size of about 0.5 μm;

[0030] Figure 3The scanning electron microscope image of the TAM-BPTA of the present application is shown in Figure 3, which corresponds to Example 3. It can be seen from the figure that the TAM-BPTA is wedge-shaped, and the size thereof is about 1 μm;

[0031] Figure 4 The X-ray powder diffraction pattern of the TAM-DETP of the present application is shown in Figure 2, which corresponds to Example 1. It can be seen from the figure that the TAM-DETP has good crystallinity, and is a long-range ordered crystalline porous material;

[0032] Figure 5 The X-ray powder diffraction pattern of the TAM-DMTA of the present application is shown in Figure 4, which corresponds to Example 2. It can be seen from the figure that the TAM-DMTA has good crystallinity, and is a long-range ordered crystalline porous material;

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

[0034] Figure 7 The infrared spectrum of the TAM-DETP of the present application and the corresponding monomers is shown in Figure 1, which corresponds to Example 1. It can be seen from the figure that the stretching vibration peak of N-H of tetra(4-aminophenyl)methane after the reaction corresponds to 3343 cm -1 , and the absorption peak of C=O of 2,5-diethoxyterephthaldehyde corresponds to 1681 cm -1 disappears, and a characteristic absorption peak of C=N double bond appears at 1614 cm -1 . This indicates that tetra(4-aminophenyl)methane and aldehyde monomers react to form an imine-linked polymer with high purity;

[0035] Figure 8 The infrared spectrum of the TAM-DMTA of the present application and the corresponding monomers is shown in Figure 5, which corresponds to Example 2. It can be seen from the figure that the stretching vibration peak of N-H of tetra(4-aminophenyl)methane after the reaction corresponds to 3343 cm -1 , and the absorption peak of C=O of 2,5-dimethylterephthaldehyde corresponds to 1682 cm -1 disappears, and a characteristic absorption peak of C=N double bond appears at 1600 cm -1 . This indicates that tetra(4-aminophenyl)methane and aldehyde monomers react to form an imine-linked polymer with high purity;

[0036] Figure 9 The infrared spectrum of the TAM-BPTA of the present application and the corresponding monomers is shown in Figure 7, which corresponds to Example 3. It can be seen from the figure that the stretching vibration peak of N-H of tetra(4-aminophenyl)methane after the reaction corresponds to 3343 cm -1the C=0 stretch of 2,5-bis(prop-2-yn-l-yloxy)terephthalaldehyde at 1681 cm -1 The C=N double bond characteristic absorption peak at 1616 cm -1

[0037] Figure 10 Figure 1 shows the nitrogen adsorption and desorption isotherms of TAM-DETP, corresponding to Example 1. The BET specific surface area of TAM-DETP is 1356 m 2 g1.

[0038] Figure 11 Figure 2 shows the nitrogen adsorption and desorption isotherms of TAM-DMTA, corresponding to Example 2. The BET specific surface area of TAM-DMTA is 191 m 2 g1.

[0039] Figure 12 Figure 3 shows the ethylene and ethane adsorption isotherms of TAM-DETP at 298 K, corresponding to Example 1. The ethylene and ethane uptake of TAM-DETP at 1 bar are 30.09 cm -3 g -1 and 18.31 cm -3 g -1 , respectively.

[0040] Figure 13 Figure 4 shows the ethylene / ethane selectivity ratio curve of TAM-DETP at 298 K, corresponding to Example 1. The ethylene / ethane selectivity ratio of TAM-DETP at 100 kPa is 3.

[0041] Figure 14 Figure 5 shows the carbon dioxide and methane adsorption isotherms of TAM-BPTA at 273 K, corresponding to Example 3. The carbon dioxide and methane uptake of TAM-BPTA at 1 bar are 61.92 cm -3 g -1 and 12.40 cm -3 g -1 , respectively.

[0042] Figure 15 Figure 6 shows the carbon dioxide and methane adsorption isotherms of TAM-BPTA at 298 K, corresponding to Example 3. The carbon dioxide and methane uptake of TAM-BPTA at 1 bar are 50.30 cm -3 g -1 and 6.73 cm -3 g -1 , respectively.

[0043] ​Figure 16 The carbon dioxide / methane separation ratio curve of TAM-BPTA at 273 K is shown in FIG. 3, corresponding to Example 3. The carbon dioxide / methane separation ratio of TAM-BPTA at 100 kPa is 23.

[0044] Figure 17 The carbon dioxide / methane separation ratio curve of TAM-BPTA at 298 K is shown in FIG. 4, corresponding to Example 3. The carbon dioxide / methane separation ratio of TAM-BPTA at 100 kPa is 44. DETAILED DESCRIPTION

[0045] Example 1:

[0046] Preparation of TAM-DETP: Tetra(4-aminophenyl)methane (1 mmol) and 2,5-diethoxyl- terephthaldehyde (2 mmol) were weighed into a vial, 2 mL mesitylene was added, and the solution was sonicated for 30 minutes to ensure homogeneity. To the above solution, 0.2 mL of 3 M acetic acid solution was added, followed by two cycles of "freeze-pump-thaw" under liquid nitrogen and argon atmosphere, with a freezing temperature of 77 K and thawing to room temperature. The vial was then sealed under vacuum and reacted at 120 °C for 72 hours. After the temperature of the vial was reduced to room temperature, the vial was slowly opened. The reaction solution was vacuum filtered to obtain the sample, which was then soaked in anhydrous tetrahydrofuran for 1 day, with the anhydrous tetrahydrofuran solvent being replaced every 8 hours. After drying in a vacuum drying oven (temperature of 100 °C, drying for 12 hours), TAM-DETP (19 mg) was obtained.

[0047] Example 2:

[0048] Preparation of TAM-DETP: Tetra(4-aminophenyl)methane (1 mmol) and 2,5-diethoxyl- terephthaldehyde (2 mmol) were weighed into a vial, 2 mL mesitylene was added, and the solution was sonicated for 30 minutes to ensure homogeneity. To the above solution, 0.2 mL of 3 M acetic acid solution was added, followed by two cycles of "freeze-pump-thaw" under liquid nitrogen and argon atmosphere, with a freezing temperature of 77 K and thawing to room temperature. The vial was then sealed under vacuum and reacted at 120 °C for 72 hours. After the temperature of the vial was reduced to room temperature, the vial was slowly opened. The reaction solution was vacuum filtered to obtain the sample, which was then soaked in anhydrous tetrahydrofuran for 1 day, with the anhydrous tetrahydrofuran solvent being replaced every 8 hours. After drying in a vacuum drying oven (temperature of 100 °C, drying for 12 hours), TAM-DETP (19 mg) was obtained.

[0049] Example 3:

[0050] Preparation of TAM-BPTA: Tetra(4-aminophenyl)methane (1 mmol) and 2,5-bis(prop-2-yn-1-yloxy)benzene-1,4-dicarboxaldehyde (2 mmol) were weighed into a reaction vessel, and 2 mL of mesitylene was added. The solution was ultrasonicated for 30 min to ensure homogeneity. To the above solution, 0.2 mL of 3 M acetic acid was added, and then the "freeze-pump-thaw" cycle was performed twice under liquid nitrogen and argon atmosphere, with a freezing temperature of 77 K and thawing to room temperature. The reaction vessel was then sealed under vacuum and heated at 120 °C for 72 h. After the temperature of the reaction vessel was decreased to room temperature, the vessel was slowly opened. The reaction solution was filtered under vacuum to obtain the sample, which was then soaked in anhydrous tetrahydrofuran for 1 day, with the anhydrous tetrahydrofuran being replaced every 8 h. After drying in a vacuum oven (100 °C for 12 h), TAM-BPTA (23 mg) was obtained.

[0051] In summary, TAM-DETP, TAM-DMTA and TAM-BPTA were synthesized by the Schiff base reaction of tetra(4-aminophenyl)methane with 2,5-diethoxybenzene-1,4-dicarboxaldehyde, 2,5-dimethylbenzene-1,4-dicarboxaldehyde and 2,5-bis(prop-2-yn-1-yloxy)benzene-1,4-dicarboxaldehyde, respectively, in the presence of acetic acid as the catalyst. X-ray powder diffraction proved that they have good crystallinity and are long-range ordered crystalline porous materials. The BET specific surface area of TAM-DETP is 1356 m 2 g -1 , and that of TAM-DMTA is 191 m 2 g -1 . The ethylene and ethane adsorption capacities of TAM-DETP are 30.09 cm -3 g -1 and 18.31 cm -3 g -1 , respectively, at 298 K and 1 bar. The ethylene / ethane separation ratio of TAM-DETP is 3 at 298 K and 100 kPa. The carbon dioxide and methane adsorption capacities of TAM-BPTA are 61.92 cm -3 g -1 and 12.40 cm -3 g -1 , respectively, at 273 K and 1 bar. The carbon dioxide and methane adsorption capacities of TAM-BPTA are 50.30 cm -3 g -1 and 6.73 cm -3 g -1The separation ratio of carbon dioxide / methane of TAM-BPTA is 23 at 273 K and 100 kPa; the separation ratio of carbon dioxide / methane of TAM-BPTA is 44 at 298 K and 100 kPa.

[0052] The above, for those skilled in the art, can make other various corresponding changes and modifications according to the technical solutions and technical concepts of the application, and all these changes and modifications belong to the protection scope required by the application.

Claims

1. A functionalized three-dimensional covalent organic framework material characterized in that: The structural formula is shown as follows, ； R = OC2H5, CH3, OCH2C≡CH, corresponding to TAM-DETP, TAM-DMTA and TAM-BPTA respectively; and the functionalized three-dimensional covalent organic framework material is prepared by the following method, The organic aldehyde monomer and the organic amine monomer are dissolved in an organic solution and dispersed into a homogeneous solution by ultrasonic; the acid catalyst is added into the obtained homogeneous solution and uniformly dispersed, then the "freezing-vacuumizing-thawing" cycle operation is carried out 2-4 times under liquid nitrogen and argon atmosphere, the freezing temperature is 77 K, and the thawing is to room temperature; then the reaction is carried out at 110-130 ℃ under vacuum sealing condition for 60-80 hours; 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-diethoxyterephthaldehyde, 2,5-dimethylterephthaldehyde and 2,5-bis(prop-2-yn-1-yloxy)terephthaldehyde, the organic amine monomer is tetra(4-aminophenyl)methane; the molar ratio of aldehyde group in the organic aldehyde to amino group in the organic amine is 2:1; the acid catalyst is acetic acid, and the concentration thereof is 3-9 M; and the organic solution is mesitylene.

2. The functionalized three-dimensional covalent organic framework material of claim 1 is applied in gas adsorption and separation.

3. Use of the functionalized three-dimensional covalent organic framework material according to claim 2 for gas adsorption and separation, characterized in that: The gas is ethylene, ethane, methane or carbon dioxide. The gas is ethylene, ethane, methane or carbon dioxide.

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