Preparation and application performance of PIL-OH-Vinyl-COF composite material containing dihydrogen bond donor

Abstract

The invention discloses a PIL-COF composite material containing a dihydrogen bond donor and a preparation method of the PIL-COF composite material. The preparation method of the composite material comprises the following steps: firstly, constructing a novel COF material (OH-Vinyl-COF) containing vinyl and hydroxyl groups; and then copolymerizing an amino ionic liquid with the hydroxyl group and the amino group to prepare the PIL-COF material (PIL-OH-Vinyl-COF) containing the hydroxyl group and the amino group. The catalytic performance of the PIL-OH-Vinyl-COF material on CO2 and epoxy chloropropane is investigated, and the result shows that the PIL-OH-Vinyl-COF material containing the dihydrogen bond donor has more excellent catalytic performance. According to optimization of reaction conditions, the PIL-OH-Vinyl-COF material is used as a catalyst, and when the reaction temperature is 110 DEG C and the CO2 pressure is 0.8 MPa, the yield of cyclic carbonate is as high as 94.07%. In addition, the PIL-OH-Vinyl-COF material has excellent recyclability, and also has certain catalytic activity on the cycloaddition reaction of other epoxides. According to the invention, the ionic liquid containing the hydrogen bond donor-NH2 is grafted to the COF material containing the hydrogen bond donor-OH in a vinyl copolymerization manner, the PIL-COF composite material containing the dihydrogen bond donor is prepared, efficient catalytic conversion of CO2 under mild conditions without a promoter is realized, and the PIL-COF composite material containing the dihydrogen bond donor has a remarkable application prospect.

Description

[0001] This invention belongs to the field of metal-free catalyst preparation and application technology. Specifically, it relates to a method for preparing a COF composite material containing a hydrogen-bonded donor (-NH2) polyionic liquid and a hydrogen-bonded donor (-OH) for use in CO2 cycloaddition reactions, and its catalytic performance. Background of the Invention

[0002] Excessive emissions of carbon dioxide (CO2) into the atmosphere have caused severe environmental pollution and an energy crisis. CO2 capture and resource utilization technologies are effective means to solve these problems. Therefore, the green process for preparing high-value-added cyclic carbonates through CO2 cycloaddition reactions has become a research hotspot in this field. Highly efficient, environmentally friendly, and stable heterogeneous catalysts are the core of this green process. In recent years, covalent organic framework materials (COFs) have been widely used in the field of CO2 catalytic conversion due to their unique structural characteristics and excellent stability. However, problems such as insufficient active sites and limited catalytic efficiency in COF materials still need to be solved.

[0003] In CO2 cycloaddition reactions, Lewis alkali metals are generally used as catalytic sites to activate epoxides. However, these metals are prone to leakage, causing environmental pollution. Hydrogen bond donors (-OH, -COOH, and -NH2) can also activate epoxides and are therefore considered environmentally friendly alternatives to Lewis alkali metals. Compared to -OH and -COOH, -NH2 has weaker hydrogen bonding ability. Nevertheless, as a Lewis base, -NH2 can effectively adsorb and activate carbon dioxide to form amino carbonate intermediates. Currently, ionic liquids containing hydrogen bond donors (HBD ILs) are considered promising catalysts for CO2 cycloaddition reactions due to their tunable active sites and excellent catalytic performance. However, most HBD ILs contain only one type of hydrogen bond donor group, resulting in unsatisfactory polarization and thus affecting their catalytic performance. In the CO2 cycloaddition reaction, the introduction of both -OH and -NH2 hydrogen bond donors not only further enhances the ring-opening properties of the epoxide, but also demonstrates a unique synergistic effect between -OH and -NH2, which can activate the epoxide while simultaneously promoting CO2 activation. Currently, research on enhancing the CO2 cycloaddition reaction using the synergistic effect of dual hydrogen bond donors is limited. Therefore, it is necessary to develop catalysts containing dual hydrogen bond donors for application in the CO2 cycloaddition reaction. Summary of the Invention

[0004] This invention provides a novel method for preparing a hydrogen-bonded (-NH2) polyionic liquid and a hydrogen-bonded (-OH) COF composite material (PIL-X-Vinyl-COF) and its catalytic application. First, using a vinyl copolymerization method, an amino-containing imidazole ionic liquid is copolymerized within the pores of different COF materials to construct an ionic COF material with multiple active sites. Second, its catalytic performance in the cycloaddition reaction of epoxides and CO2 is investigated. PIL-OH-Vinyl-COF exhibits high epichlorohydrin conversion and cyclic carbonate yield. Furthermore, this type of catalyst demonstrates excellent chemical stability and substrate universality.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] The specific implementation plan is as follows:

[0007] This invention proposes a novel PIL-X-Vinyl-COF composite material, the structural formula of which is shown below:

[0008]

[0009] Wherein, X is one of OH, H, and C2H3. This composite material exhibits good catalytic performance in the cycloaddition reaction of epoxides with carbon dioxide.

[0010] One method for preparing a PIL-X-Vinyl-COF composite material includes the following steps:

[0011] (1) Preparation process of Vinyl-COF-120℃ material:

[0012] First, 2,5-divinyl-terephthalaldehyde and 1,3,5-tris(4-aminophenyl)triazine were weighed out sequentially and mixed, then added to a mixed solvent. After sonication, 6M acetic acid was added, and the mixture was subjected to a freeze-degassing-thawing process three times. After sealing, the mixture was placed in an oven at 120°C for reaction. After cooling to room temperature, the mixture was centrifuged, washed, and dried to obtain Vinyl-COF-120°C.

[0013] (2) Preparation process of OH-Vinyl-COF and PDA-Vinyl-COF materials:

[0014] First, 2,5-divinylterephthalaldehyde, 2,5-hydroxyterephthalaldehyde, and 1,3,5-tris(4-aminophenyl)triazine were weighed out sequentially and mixed, then added to a mixed solvent. After sonication, 6M acetic acid was added, and the mixture was subjected to a freeze-degassing-thawing process three times. After sealing, the mixture was placed in an oven at 120°C for reaction. After cooling to room temperature, the mixture was centrifuged, washed, and dried to obtain OH-Vinyl-COF.

[0015] The preparation process of PDA-Vinyl-COF is similar to that of OH-Vinyl-COF, except that terephthalaldehyde is used instead of 2,5-hydroxyterephthalaldehyde.

[0016] (3) Preparation process of PIL-Vinyl-COF-120℃, PIL-OH-Vinyl-COF and PIL-PDA-Vinyl-COF composite materials:

[0017] The Vinyl-COF-120℃, OH-Vinyl-COF, and PDA-Vinyl-COF materials prepared above were added to an appropriate amount of solvent, and then an ionic liquid and the initiator azobisisobutyronitrile were added. The mixture was reacted at 50-100℃ for 6-48 hours, cooled to room temperature, filtered, and the filter cake was washed and dried to obtain novel PIL-Vinyl-COF-120℃, PIL-OH-Vinyl-COF, and PIL-PDA-Vinyl-COF composite materials.

[0018] In the preparation process of PIL-X-Vinyl-COF composite material, the solvent used can be one of acetonitrile, acetone, methanol, or ethanol.

[0019] In the preparation process of Vinyl-COF-120℃, OH-Vinyl-COF and PDA-Vinyl-COF materials, the reaction solvent used can be one of dioxane / trimethylbenzene, o-dichlorobenzene / n-butanol, or o-dichlorobenzene / benzyl alcohol, and the ratio of the mixed solution is 1 to 1 / 6.

[0020] In the preparation process of Vinyl-COF-120℃, OH-Vinyl-COF and PDA-Vinyl-COF materials, the washing solvent used can be one or two of tetrahydrofuran, acetone, ethanol, methanol and dichloromethane.

[0021] This composite material can be used to catalyze the cycloaddition reaction of epoxy compounds with carbon dioxide. Its characteristics include: adding the material to an epoxy compound, then introducing carbon dioxide to a pressure of 0.5-1.2 MPa, reacting at 25℃-150℃ for 6-24 h, cooling, filtering, and analyzing the reaction conversion and selectivity of the filtrate using gas phase analysis. The molar ratio of epoxide to composite material is 5-50:1. The epoxy compound used can be one of epichlorohydrin, epistyrene, propylene oxide, epimethylpropane, or epiethylpropane.

[0022] Comparative example:

[0023] Preparation and catalytic performance testing of OH-Vinyl-COF catalyst:

[0024] 0.1 mmol of 2,5-divinyl terephthalaldehyde, 0.1 mmol of 2,5-dihydroxy terephthalaldehyde, and 0.15 mmol of 1,3,5-tris(4-aminophenyl)triazine were sequentially placed into a Schlenk tube, and 2 mL of a mixed solvent (dioxane / trimethylbenzene, 1 mL / 1 mL) was added. After sonication, 0.1 mL of 6M acetic acid solution was added, followed by sonication again. After degassing three times, the mixture was reacted at 120 °C for 72 h. After the reaction was completed, the mixture was centrifuged, washed three times sequentially with tetrahydrofuran and acetone, and dried overnight at 60 °C.

[0025] 0.6 mL of epichlorohydrin and 20 mg of COF catalyst were weighed into a 50 mL autoclave. After purging with nitrogen three times, 0.8 MPa of CO2 was introduced. The autoclave was sealed and heated to 100 °C for 12 h. After cooling, the autoclave was filtered. The filtrate was analyzed by gas chromatography, and the conversion rate was 8.32%, and the yield was 8.32%.

[0026] Example 1:

[0027] Preparation and catalytic performance testing of PIL-OH-Vinyl-COF catalyst:

[0028] 0.1 mmol of 2,5-divinyl terephthalaldehyde, 0.1 mmol of 2,5-dihydroxy-terephthalaldehyde, and 0.15 mmol of 1,3,5-tris(4-aminophenyl)triazine were sequentially placed into a Schlenk tube, and 2 mL of a mixed solvent (dioxane / trimethylbenzene, 1 mL / 1 mL) was added. After sonication, 0.1 mL of 6M acetic acid solution was added, followed by sonication again. After degassing three times, the mixture was reacted at 120 °C for 72 h. After the reaction, the mixture was centrifuged, washed three times sequentially with tetrahydrofuran and acetone, and dried overnight at 60 °C. 18 mg of Vim-NH2 was weighed and dispersed in 10 mL of acetonitrile. After stirring for a while, 22 mg of COF was added, and after stirring for a while, 10 mg of AIBN was added. The mixture was reacted at 90 °C under N2 conditions for 24 h, washed with methanol, and dried overnight at 60 °C.

[0029] 0.6 mL of epichlorohydrin and 20 mg of PIL-OH-Vinyl-COF catalyst were weighed into a 50 mL autoclave. After purging with nitrogen three times, 0.8 MPa CO2 was introduced. The autoclave was sealed and heated to 100 °C for 12 h. After cooling, the autoclave was filtered. The filtrate was analyzed by gas chromatography, and the conversion rate was 68.1%, and the yield was 68.1%.

[0030] Example 2:

[0031] Preparation and catalytic performance testing of PDA-OH-Vinyl-COF catalyst:

[0032] 0.1 mmol of 2,5-divinyl terephthalaldehyde, 0.1 mmol of terephthalaldehyde, and 0.15 mmol of 1,3,5-tris(4-aminophenyl)triazine were sequentially placed into a Schlenk tube, and 2 mL of a mixed solvent (dioxane / trimethylbenzene, 1 mL / 1 mL) was added. After sonication, 0.1 mL of 6M acetic acid solution was added, followed by sonication again. After degassing three times, the mixture was reacted at 120 °C for 72 h. After the reaction, the mixture was centrifuged, washed three times sequentially with tetrahydrofuran and acetone, and dried overnight at 60 °C. 18 mg of Vim-NH2 was weighed and dispersed in 10 mL of acetonitrile. After stirring for a while, 22 mg of COF was added, and after stirring for a while, 10 mg of AIBN was added. The mixture was reacted at 90 °C under N2 conditions for 24 h, washed with methanol, and dried overnight at 60 °C.

[0033] 0.6 mL of epichlorohydrin and 20 mg of COF catalyst were weighed into a 50 mL autoclave. After purging with nitrogen three times, CO2 was introduced at 0.8 MPa. The autoclave was sealed and heated to 100 °C for 12 h. After cooling, the autoclave was filtered. The filtrate was analyzed by gas chromatography, and the conversion rate was 66.04%, and the yield was 66.04%.

[0034] Example 3:

[0035] Preparation and catalytic performance testing of PIL-Vinyl-COF-120℃ catalyst:

[0036] 0.1 mmol of 2,5-divinyl terephthalaldehyde and 0.15 mmol of 1,3,5-tris(4-aminophenyl)triazine were sequentially placed in a Schlenk tube, and 2 mL of a mixed solvent (dioxane / trimethylbenzene, 1 mL / 1 mL) was added. After sonication, 0.1 mL of 6M acetic acid solution was added, followed by sonication again. After degassing three times, the mixture was reacted at 120 °C for 72 h. After the reaction, the mixture was centrifuged, washed three times sequentially with tetrahydrofuran and acetone, and dried overnight at 60 °C. 9 mg of Vim-NH2 was weighed and dispersed in 10 mL of acetonitrile. After stirring for a while, 31 mg of COF was added, and after stirring for a while, 10 mg of AIBN was added. The mixture was reacted at 90 °C under N2 conditions for 24 h, washed with methanol, and dried overnight at 60 °C.

[0037] 0.6 mL of epichlorohydrin and 20 mg of COF catalyst were weighed into a 50 mL autoclave. After purging with nitrogen three times, CO2 at 0.8 MPa was introduced. The autoclave was sealed and heated to 100 °C for 12 h. After cooling, the autoclave was filtered. The filtrate was analyzed by gas chromatography, and the conversion rate was 57.46%, and the yield was 57.46%.

[0038] Example 4:

[0039] Preparation and catalytic performance testing of PIL-OH-Vinyl-COF catalyst:

[0040] 0.1 mmol of 2,5-divinyl terephthalaldehyde, 0.1 mmol of 2,5-dihydroxy-terephthalaldehyde, and 0.15 mmol of 1,3,5-tris(4-aminophenyl)triazine were sequentially placed into a Schlenk tube, and 2 mL of a mixed solvent (dioxane / trimethylbenzene, 1 mL / 1 mL) was added. After sonication, 0.1 mL of 6M acetic acid solution was added, followed by sonication again. After degassing three times, the mixture was reacted at 120 °C for 72 h. After the reaction, the mixture was centrifuged, washed three times sequentially with tetrahydrofuran and acetone, and dried overnight at 60 °C. 18 mg of Vim-NH2 was weighed and dispersed in 10 mL of acetonitrile. After stirring for a while, 22 mg of COF was added, and after stirring for a while, 10 mg of AIBN was added. The mixture was reacted at 90 °C under N2 conditions for 24 h, washed with methanol, and dried overnight at 60 °C.

[0041] Weigh 0.6 mL of 1,2-epoxyhexane and 20 mg of COF catalyst into a 50 mL autoclave. After purging with nitrogen three times, introduce CO2 at 1.2 MPa. Seal the autoclave and heat to 100 °C for 12 h. After cooling, filter the autoclave. The filtrate was analyzed by gas chromatography, and the conversion rate was 64.04%, and the yield was 64.04%.

[0042] Example 5:

[0043] Preparation and catalytic performance testing of PIL-OH-Vinyl-COF catalyst:

[0044] 0.1 mmol of 2,5-divinyl terephthalaldehyde, 0.1 mmol of 2,5-dihydroxy-terephthalaldehyde, and 0.15 mmol of 1,3,5-tris(4-aminophenyl)triazine were sequentially placed into a Schlenk tube, and 2 mL of a mixed solvent (dioxane / trimethylbenzene, 1 mL / 1 mL) was added. After sonication, 0.1 mL of 6M acetic acid solution was added, followed by sonication again. After degassing three times, the mixture was reacted at 120 °C for 72 h. After the reaction, the mixture was centrifuged, washed three times sequentially with tetrahydrofuran and acetone, and dried overnight at 60 °C. 18 mg of Vim-NH2 was weighed and dispersed in 10 mL of acetonitrile. After stirring for a while, 22 mg of COF was added, and after stirring for a while, 10 mg of AIBN was added. The mixture was reacted at 90 °C under N2 conditions for 24 h, washed with methanol, and dried overnight at 60 °C.

[0045] 0.6 mL of epichlorohydrin and 30 mg of COF catalyst were weighed into a 50 mL autoclave. After purging with nitrogen three times, 0.8 MPa of CO2 was introduced. The autoclave was sealed and heated to 100 °C for 12 h. After cooling, the autoclave was filtered. The filtrate was analyzed by gas chromatography, and the conversion rate was 94.07%, and the yield was 94.07%.

[0046] Example 6:

[0047] Preparation and catalytic performance testing of PIL-OH-Vinyl-COF catalyst:

[0048] 0.1 mmol of 2,5-divinyl terephthalaldehyde, 0.1 mmol of 2,5-dihydroxy-terephthalaldehyde, and 0.15 mmol of 1,3,5-tris(4-aminophenyl)triazine were sequentially placed into a Schlenk tube, and 2 mL of a mixed solvent (dioxane / trimethylbenzene, 1 mL / 1 mL) was added. After sonication, 0.1 mL of 6M acetic acid solution was added, followed by sonication again. After degassing three times, the mixture was reacted at 120 °C for 72 h. After the reaction, the mixture was centrifuged, washed three times sequentially with tetrahydrofuran and acetone, and dried overnight at 60 °C. 18 mg of Vim-NH2 was weighed and dispersed in 10 mL of acetonitrile. After stirring for a while, 22 mg of COF was added, and after stirring for a while, 10 mg of AIBN was added. The mixture was reacted at 90 °C under N2 conditions for 24 h, washed with methanol, and dried overnight at 60 °C.

[0049] 0.6 mL of epoxide-bromopropane and 20 mg of COF catalyst were weighed into a 50 mL autoclave. After purging with nitrogen three times, 0.6 MPa of CO2 was introduced. The autoclave was sealed and heated to 90 °C for 6 h. After cooling, the autoclave was filtered. The filtrate was analyzed by gas chromatography, and the conversion rate was 42.37%, and the yield was 42.37%.

[0050] Example 7:

[0051] Preparation and catalytic performance testing of PIL-OH-Vinyl-COF catalyst:

[0052] 0.1 mmol of 2,5-divinyl terephthalaldehyde, 0.1 mmol of 2,5-dihydroxy-terephthalaldehyde, and 0.15 mmol of 1,3,5-tris(4-aminophenyl)triazine were sequentially placed into a Schlenk tube, and 2 mL of a mixed solvent (dioxane / trimethylbenzene, 1 mL / 1 mL) was added. After sonication, 0.1 mL of 6M acetic acid solution was added, followed by sonication again. After degassing three times, the mixture was reacted at 120 °C for 72 h. After the reaction, the mixture was centrifuged, washed three times sequentially with tetrahydrofuran and acetone, and dried overnight at 60 °C. 18 mg of Vim-NH2 was weighed and dispersed in 10 mL of acetonitrile. After stirring for a while, 22 mg of COF was added, and after stirring for a while, 10 mg of AIBN was added. The mixture was reacted at 90 °C under N2 conditions for 24 h, washed with methanol, and dried overnight at 60 °C.

[0053] 0.6 mL of 1,2-epoxybutane and 30 mg of COF catalyst were weighed into a 50 mL autoclave. After purging with nitrogen three times, CO2 at 1.2 MPa was introduced. The autoclave was sealed and heated to 25 °C for 24 h. After cooling, the autoclave was filtered. The filtrate was analyzed by gas chromatography, and the conversion rate was 38.51%, and the yield was 38.51%. Attached Figure Description

[0054] Figure 1 For comparison, XRD patterns of COF prepared by solvothermal method in Examples 1 and 2 are shown.

[0055] Figure 2 The infrared spectra of OH-Vinyl-COF, PIL-OH-Vinyl-COF and ionic liquids in comparative examples and Example 1 are shown, with the 900-1000 peak indicating their vinyl groups.

[0056] Figure 3 This is the solid-state NMR spectrum of Example 1.

[0057] Figure 4 The CO2 adsorption-desorption isotherms are shown in the comparative example and Example 1.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the disclosed technical content to create equivalent embodiments. Any modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. This invention proposes a novel PIL-X-Vinyl-COF composite material, the structural formula of which is shown below: in, X is one of OH, H, or C2H3. The composite material exhibits good catalytic performance in the cycloaddition reaction of epoxy compounds with carbon dioxide.

2. The method for preparing a PIL-X-Vinyl-COF composite material according to claim 1, characterized in that, Includes the following steps: (1) Preparation process of Vinyl-COF-120℃ material: First, 2,5-divinyl-terephthalaldehyde and 1,3,5-tris(4-aminophenyl)triazine were weighed out sequentially and mixed, then added to a mixed solvent. After sonication, 6M acetic acid was added, and the mixture was subjected to a freeze-degassing-thawing process three times. After sealing, the mixture was placed in an oven at 120°C for reaction. After cooling to room temperature, the mixture was centrifuged, washed, and dried to obtain Vinyl-COF-120°C. (2) Preparation process of OH-Vinyl-COF and PDA-Vinyl-COF materials: First, 2,5-divinylterephthalaldehyde, 2,5-hydroxyterephthalaldehyde, and 1,3,5-tris(4-aminophenyl)triazine were weighed out sequentially and mixed, then added to a mixed solvent. After sonication, 6M acetic acid was added, and the mixture was subjected to a freeze-degassing-thawing process three times. After sealing, the mixture was placed in an oven at 120°C for reaction. After cooling to room temperature, the mixture was centrifuged, washed, and dried to obtain OH-Vinyl-COF. The preparation process of PDA-Vinyl-COF is similar to that of OH-Vinyl-COF, except that terephthalaldehyde is used instead of 2,5-hydroxyterephthalaldehyde. (3) Preparation process of PIL-Vinyl-COF-120℃, PIL-OH-Vinyl-COF and PIL-PDA-Vinyl-COF composite materials: The Vinyl-COF-120℃, OH-Vinyl-COF, and PDA-Vinyl-COF materials prepared above were added to an appropriate amount of solvent, and then an ionic liquid and the initiator azobisisobutyronitrile were added. The mixture was reacted at 50-100℃ for 6-48 hours, cooled to room temperature, filtered, and the filter cake was washed and dried to obtain novel PIL-Vinyl-COF-120℃, PIL-OH-Vinyl-COF, and PIL-PDA-Vinyl-COF composite materials.

3. In the preparation process of the PIL-X-Vinyl-COF composite material as described in claim 2, the solvent used can be one of acetonitrile, acetone, methanol, and ethanol.

4. In the preparation process of Vinyl-COF-120℃, OH-Vinyl-COF and PDA-Vinyl-COF materials as described in claim 2, the reaction solvent used can be one of dioxane / trimethylbenzene, o-dichlorobenzene / n-butanol, or o-dichlorobenzene / benzyl alcohol, and the ratio of the mixed solution is 1 to 1 / 6.

5. In the preparation process of Vinyl-COF-120℃, OH-VinyI-COF and PDA-Vinyl-COF materials as described in claim 2, the washing solvent used can be one or two of tetrahydrofuran, acetone, ethanol, methanol and dichloromethane.

6. As shown in claim 1, the composite material can be used to catalyze the cycloaddition reaction of epoxides with carbon dioxide. Its characteristics are: The material was added to an epoxy compound, and then carbon dioxide was introduced to a pressure of 0.5-1.2 MPa. The reaction was carried out at 25℃-150℃ for 6-24 hours. After cooling, the mixture was filtered, and the reaction conversion and selectivity of the filtrate were analyzed by gas phase analysis. The molar ratio of epoxide to composite material was 5-50:

1.

7. As described in claim 6, the epoxy compound used may be one of epichlorohydrin, epistyrene, propylene oxide, methyl propylene oxide, and ethyl propylene oxide.

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