CN108047457B - Preparation method and application of metal organic framework for catalyzing carbon dioxide to be epoxy carbonate - Google Patents

Abstract

A preparation method and application of a metal organic framework for catalyzing carbon dioxide to be epoxy carbonate under mild conditions. The catalysis steps are as follows: 1) Mn-MOF and a cocatalyst tetrabutylammonium bromide are weighed into a Schlenk bottle. 2) The branch of the Schlenk flask was connected to a vacuum line and degassed, and a balloon of carbon dioxide at 1atm was connected to the branch. 3) The substrate was added to a Schlenk flask and placed in a 60 ℃ oil bath for 24 h. 3) After the reaction is finished, a corresponding crude product is obtained, and the yield is about 90% after purification. Mn-MOF was filtered and used for the next cycle of reaction. The invention has the advantages that: the catalyst is simple to prepare, has better structural stability and high catalytic activity, can be recycled, and achieves the aim of sustainable production; the preparation process of the epoxy carbonate is simple, has low requirement on equipment, wide raw material source and low cost, and is easy for industrial large-scale production.

Description

Preparation method and application of metal organic framework for catalyzing carbon dioxide to be epoxy carbonate

Technical Field

The invention relates to a metal organic framework material for catalytic conversion of carbon dioxide, in particular to a preparation method and application of a manganese metal organic framework material with ultrahigh catalytic activity on carbon dioxide.

Background

Metal-organic framework Materials (MOFs) are widely used in the fields of catalytic reaction, drug release, fluorescence, gas adsorption and separation, etc. due to their structural and functional diversity, porosity, large specific surface area and unsaturated metal sites. However, most MOFs have small pores and unstable structures, which limits their application in the field of catalysis.

Carbon dioxide is a non-toxic, renewable, low cost source of C1 that can be chemically produced to provide a high value product. Carbon dioxide emissions are primarily derived from the combustion of petroleum, natural gas, and coal. However, in recent years, the content of carbon dioxide has increased dramatically, and a large amount of carbon dioxide is discharged with a series of environmental problems, such as greenhouse effect, glacier melting, and sea level rising. At present, the application of carbon dioxide mainly focuses on physical utilization, such as manufacturing aerated beverages, serving as inert gas for metal protection welding, keeping vegetables and fruits fresh and cold storage and the like. In the aspect of chemical utilization, carbon dioxide is mainly used for synthesizing urea, methanol, formic acid and derivatives thereof, but the carbon dioxide has high requirements on equipment, is immature in technical aspect and has high cost. Therefore, the emission reduction, capture and utilization of carbon dioxide also become the most concerned high and new technology nowadays, and is one of the global challenges facing the century.

Disclosure of Invention

The invention aims to solve the problems and provides a preparation process and application of a manganese metal organic framework material with ultrahigh catalytic activity on carbon dioxide. The preparation method is simple, wide in raw material source, low in cost and easy for industrial large-scale production.

The technical scheme of the invention is as follows:

a preparation method of a manganese metal organic framework material comprises the following steps:

dissolving 2,4, 6-tri [ (p-carboxyphenyl) amino ] -1,3, 5-triazine and manganese chloride in N, N-dimethylacetamide, adding distilled water, placing in a reaction kettle with a polytetrafluoroethylene lining, reacting at 120 ℃ for 72 hours, and slowly cooling to room temperature at a rate of 5 ℃/h to obtain colorless rod-shaped crystals Mn-MOF, wherein the yield is 83%. The raw material 2,4, 6-tri [ (p-carboxyphenyl) amino ] -1,3, 5-triazine, manganese chloride, nitrogen-dimethyl acetamide and distilled water are used in the ratio of 73.0mg:12.6mg:3mL of: 0.75mL, the volume of the polytetrafluoroethylene liner was 25 mL.

The invention also provides an application of Mn-MOF in catalyzing carbon dioxide to be converted into epoxy carbonate, which comprises the following steps:

1) in a glove box, weighing the Mn-MOF catalyst prepared by the method, and putting a cocatalyst tetrabutylammonium bromide into a Schlenk bottle, wherein the dosage ratio of Mn-MOF to tetrabutylammonium bromide is 100mg:3.6 mmol;

2) taking the Schlenk bottle out of the glove box, connecting a branch pipe of the Schlenk bottle with a vacuum line, degassing, and connecting a carbon dioxide balloon with 1atm with the branch pipe to fill the Schlenk bottle with carbon dioxide gas;

3) respectively injecting 5.0mmol of substrates of styrene oxide, 2- (chloromethyl) oxirane, 3-phenoxy-1, 2-epoxypropane, 3- (1-naphthoxy) -1, 2-epoxypropane and benzyl glycidyl ether into a Schlenk bottle by using an injector, placing the Schlenk bottle in an oil bath at 60 ℃, and reacting for 24 hours;

4) after the reaction is finished, obtaining a crude product, and then passing through a silica gel column to obtain a pure product; the recovery yield reaches 90 percent.

Wherein the catalyst Mn-MOF is filtered and reused for the next catalytic reaction.

The invention has the advantages that:

the catalyst has the advantages of simple preparation method, wide raw material source, low cost and easy industrial amplification production; the Mn-MOF prepared by the method has enrichment performance and catalytic activity on carbon dioxide, and can convert the carbon dioxide into epoxy carbonate under mild conditions. The catalyst has better structural stability and high catalytic activity, can still keep complete after being recycled for 5 times, has no reduction of catalytic efficiency, can be recycled, realizes industrial circulation and achieves the purpose of sustainable production.

Drawings

FIG. 1 is a schematic diagram of the synthesis of Mn-MOF.

FIG. 2 is a three-dimensional structure stacking diagram of Mn-MOF.

FIG. 3 is an X-ray powder diffraction pattern of Mn-MOF after 24 hours immersion in a common solvent.

FIG. 4 is an X-ray powder diffraction pattern of Mn-MOF catalytic cycling 5 times.

FIG. 5 is a graph of the yields of Mn-MOF catalytic cycles 5 times.

FIG. 6 is Mn-MOF catalyzed CO₂Is a schematic representation of an epoxy carbonate.

Detailed Description

For a more detailed description of the present invention, a specific embodiment is presented for purposes of illustration, and the exemplary embodiment is intended to provide a reference to the specific embodiment, but not intended to limit the invention.

Example 1:

a preparation method of a manganese metal organic framework material, and a synthetic route is shown in figure 1.

Dissolving 2,4, 6-tri [ (p-carboxyphenyl) amino ] -1,3, 5-triazine and manganese chloride in N, N-dimethylacetamide, adding distilled water, placing in a reaction kettle with a polytetrafluoroethylene lining, reacting at 120 ℃ for 72 hours, and slowly cooling to room temperature at a rate of 5 ℃/h to obtain colorless rod-shaped crystals Mn-MOF, wherein the yield is 83%. The dosage ratio of the raw material 2,4, 6-tri [ (p-carboxyphenyl) amino ] -1,3, 5-triazine, manganese chloride, nitrogen-dimethyl acetamide and distilled water is 73.0mg:12.6mg:3mL:0.75mL, and the volume of the polytetrafluoroethylene lining is 25 mL.

The invention relates to a heterogeneous catalysis system, the preparation of the catalyst is an important index for evaluating the catalyst, and the preparation method of the catalyst is simple, low in cost and easy for industrial production.

FIG. 1 is a schematic diagram of the preparation and synthesis of Mn-MOF in the present example, and the catalyst has the advantages of simple preparation method, low raw material cost and easy industrial production.

Fig. 2 is a three-dimensional structure stacking diagram of the Mn-MOF prepared in this example, and the catalyst has three one-dimensional pore channels, and has a certain adsorption effect on carbon dioxide, so as to achieve an enrichment effect and efficiently catalyze and convert carbon dioxide.

FIG. 3 shows the X-ray powder diffraction pattern of Mn-MOF after 24 hours immersion in a common solvent.

The structural stability of the catalyst is an important index for evaluating the catalytic performance, and after Mn-MOF is soaked in a common solvent for 24 hours, an X-ray diffraction pattern is well matched with a simulated pattern, which shows that Mn-MOF has better stability to the solvent.

Example 2

The application of Mn-MOF prepared in example 1 in catalyzing carbon dioxide to epoxy carbonate comprises the following steps:

1) in a glove box, the Mn-MOF catalyst prepared in example 1 and tetrabutylammonium bromide as cocatalyst were weighed into a Schlenk flask. The dosage ratio of Mn-MOF to tetrabutylammonium bromide is 100mg:3.6 mmol.

2) The Schlenk bottle was taken out of the glove box, the branch tube of the Schlenk bottle was connected to a vacuum line and degassed, and a carbon dioxide balloon of 1atm was connected to the branch tube to fill the Schlenk bottle with carbon dioxide gas.

3) Styrene oxide, 2- (chloromethyl) oxirane, 3-phenoxy-1, 2-epoxypropane, 3- (1-naphthyloxy) -1, 2-epoxypropane and benzyl glycidyl ether were each injected into a Schlenk flask by a syringe in an amount of 5.0mmol, and the Schlenk flask was put in an oil bath at 60 ℃ to react for 24 hours.

3) After completion of the reaction, crude epoxy carbonate was obtained, which was then passed through a silica gel column to obtain pure epoxy carbonate in recovery yields of 93.7%, 94.5%, 91.0%, 87.0% and 94.3%.

The catalyst Mn-MOF was filtered and reused for the next catalytic reaction.

FIG. 4 shows an X-ray powder diffraction pattern of Mn-MOF catalysis cycling 5 times.

The invention relates to a heterogeneous catalysis system, and the service life of a catalyst is an important index for evaluating the catalytic performance. Under the optimal reaction condition, after the Mn-MOF is recycled for 5 times, the X-ray powder diffraction pattern of the Mn-MOF is well matched with a simulation diagram, which shows that the framework of the Mn-MOF is kept intact and has better structural stability.

FIG. 5 shows the yield of Mn-MOF catalytic cycles 5 times.

The invention relates to a heterogeneous catalysis system, and the catalytic activity of a catalyst is an important index for evaluating the catalytic performance. Under the optimal reaction condition, the catalytic activity of the Mn-MOF is not reduced after the Mn-MOF is recycled for 5 times, which indicates that the Mn-MOF is an excellent heterogeneous catalyst for the reaction.

The above description is intended to be illustrative of the preferred embodiments and not to limit the scope of the patent claims, which are intended to include all substantially equivalent alternatives, process optimizations, and modifications and combinations of conditions within the scope of the patent claims. A few terms are necessary in the description and illustration, nor are they intended to be limiting of the invention.

Claims (2)

1. The preparation method of the manganese metal organic framework material is characterized by comprising the following steps of:

dissolving 2,4, 6-tri [ (p-carboxyphenyl) amino ] -1,3, 5-triazine and manganese chloride in nitrogen, nitrogen-dimethylacetamide, adding distilled water, placing in a reaction kettle with a polytetrafluoroethylene lining, reacting at 120 ℃ for 72 hours, and slowly cooling to room temperature at a rate of 5 ℃/h to obtain a colorless rod-shaped crystal Mn-MOF, wherein the yield is 83%; the raw material 2,4, 6-tri [ (p-carboxyphenyl) amino ] -1,3, 5-triazine, manganese chloride, nitrogen-dimethyl acetamide and distilled water are used in the ratio of 73.0mg:12.6mg:3mL of: 0.75mL, the volume of the polytetrafluoroethylene liner was 25 mL.

2. Use of Mn-MOF prepared by the method of claim 1 for catalyzing the conversion of carbon dioxide to epoxycarbonates, characterized in that said use comprises the steps of:

1) weighing Mn-MOF catalyst prepared by the method of claim 1 in a glove box, and tetrabutylammonium bromide serving as a cocatalyst in a Schlenk bottle, wherein the dosage ratio of the Mn-MOF to the tetrabutylammonium bromide is 100mg:3.6 mmol;

2) taking the Schlenk bottle out of the glove box, connecting a branch pipe of the Schlenk bottle with a vacuum line, degassing, and connecting a carbon dioxide balloon with 1atm with the branch pipe to fill the Schlenk bottle with carbon dioxide gas;

3) respectively injecting 5.0mmol of substrates of styrene oxide, 2- (chloromethyl) oxirane, 3-phenoxy-1, 2-epoxypropane, 3- (1-naphthoxy) -1, 2-epoxypropane and benzyl glycidyl ether into a Schlenk bottle by using an injector, placing the Schlenk bottle in an oil bath at 60 ℃, and reacting for 24 hours;

4) after the reaction is finished, obtaining a crude product, and then passing through a silica gel column to obtain a pure product; the recovery yield reaches 90 percent.

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