A gas treatment material and a method for producing the same

Abstract

The application discloses a preparation method of a gas treatment material, which comprises the following steps: (1) dispersing monomers in a solvent to obtain a monomer solution, wherein the monomers are a combination of dichloromethyl pyrazine and dichloromethyl dipyrazine; (2) adding a catalyst into the monomer solution obtained in the step (1), and then heating to perform a reaction to obtain a crude product; the reaction is performed under an inert gas atmosphere, and continuous stirring is kept during the reaction; and (3) filtering the crude product obtained in the step (2), and then washing and drying to obtain the gas treatment material; wherein the chloromethyl groups of the dichloromethyl pyrazine and the dichloromethyl dipyrazine are connected to carbon atoms of the pyrazine. The gas treatment material has a high specific surface area and a high physical adsorption capacity.

Description

Technical Field

[0001] This invention relates to a gas treatment material and its preparation method, particularly a hypercrosslinked polymer-based gas treatment material and its preparation method. Technical Background

[0002] In daily work and production, we inevitably come into contact with various gases. Some gases are necessary for the human body, while others are harmful, thus requiring gas treatment, including separation, adsorption, and storage. For example, most volatile organic compounds are harmful to the body and can enter the body through respiration and skin, causing damage to many organs; therefore, these gases need to be adsorbed and separated. Hydrogen, for instance, is a green energy source that is abundant, widely available, and has high energy density, and hydrogen storage is crucial for its applications. Many of these gas treatment applications involve porous materials with high specific surface areas.

[0003] Porous materials can be classified into three main categories from a compositional perspective: inorganic porous materials, inorganic-organic hybrid porous materials, and organic porous polymer materials. Inorganic porous materials include activated carbon, zeolites, and porous alumina. To improve the performance of inorganic porous materials, various techniques exist for their modification. Organic porous polymers are polymer materials composed of organic building blocks interconnected by covalent bonds, possessing advantages such as chemical stability, high specific surface area, large pore volume, and tunable pore structure. Monomers and pore structures can be selectively chosen based on the target gas. Hypercrosslinked polymers are a very common type of porous polymer.

[0004] CN 106378109 A discloses a porous polycarbazole polymer or its methanesulfonate and a method for preparing the same, wherein the polymer has an average pore size of 1.5-25 nm and a specific surface area of ​​600-1200 cm². 2 The porous polycarbazole polymer methanesulfonate exhibits a carbon dioxide adsorption capacity of 3.96 mmol / g at 273 K and 800 mmHg. This suggests applications of the polycarbazole polymer methanesulfonate in chemical catalysis, gas adsorption, or molecular separation.

[0005] CN 103059270 A discloses a 1,3,5-triazine-based nanoporous organic aromatic heterocyclic polymer and its preparation method. The polymer is prepared by a Friedel-Crafts reaction of 2,4,6-trichloro-1,3,5-triazine and an aromatic compound under Lewis acid catalysis. The specific surface area of ​​the obtained polymer can reach up to 10¹⁰ m². 2 / g, with a maximum adsorption capacity of 55cm³ for carbon dioxide. 3 / g. This polymer can be used in fields such as gas storage, catalyst support, and selective ion separation.

[0006] Existing technologies still exist for developing a gas treatment material with a high specific surface area and both physical and chemical adsorption capabilities. Summary of the Invention

[0007] The technical problem solved by this application is to provide a gas treatment material with high specific surface area and high adsorption performance.

[0008] This invention provides a method for preparing a gas treatment material, comprising the following steps:

[0009] (1) A monomer solution is obtained by dispersing the monomer in a solvent, wherein the monomer is a combination of dichloromethylpyrazine and dichloromethylbipyrazine;

[0010] (2) Add a catalyst to the monomer solution obtained in step (1), and then heat to react to obtain a crude product; the reaction is carried out under an inert gas atmosphere and the reaction is continuously stirred.

[0011] (3) The crude product obtained in step (2) is filtered, then washed and dried to obtain the gas treatment material;

[0012] In this embodiment, the chloromethyl group of dichloromethylpyrazine and dichloromethylbipyrazine is attached to the carbon atom of the pyrazine.

[0013] The two chloromethyl groups of the dichloromethylpyrazine are in the para or meta position, for example, 2,5-dichloromethylpyrazine.

[0014] The two chloromethyl groups of the dichloromethyl bipyrazine are located on two different nitrogen-containing heterocycles, for example, 6,6'-dichloromethyl-2,2'-bipyrazine.

[0015] Dichloromethylpyrazine and dichloromethylbipyrazine can be prepared by referring to existing techniques, for example, by chlorinating dimethylpyrazine and dimethylbipyrazine.

[0016] For example, 2,5-dichloromethylpyrazine is prepared by adding 2,5-dimethylpyrazine and N-chlorosuccinimide in a molar ratio of 1:2 to a solvent and reacting them in the presence of a free radical initiator.

[0017] For example, 6,6'-dichloromethyl-2,2'-bipyrazine is prepared by adding 6,6'-dimethyl-2,2'-bipyrazine and trichloroisocyanuric acid (TCC) in a solvent at a molar ratio of 1:2, and reacting in the presence of a free radical initiator.

[0018] The molar ratio of dichloromethylpyrazine to dichloromethylbipyrazine is 1:10 to 10:1, preferably 1:5 to 5:1, such as 1:5, 5:1, 1:4, 4:1, 1:3, 3:1, 1:2, 2:1 or 1:1.

[0019] The solvent is a common organic solvent in the art, such as chloroalkane solvents, preferably dichloromethane, dichloroethane, etc.

[0020] The inert gas is a common inert gas in the art, such as nitrogen or argon.

[0021] The catalyst is a Lewis acid catalyst, such as SnCl4, FeCl3, or AlCl3.

[0022] The reaction temperature in step (2) is 40-140℃, preferably 60-120℃, such as 60℃, 70℃, 80℃, 90℃, 100℃, 110℃ or 120℃; the reaction time is 10-50 hours.

[0023] This invention also provides a gas treatment material, which is prepared by the method provided by this invention. This gas treatment material has a high specific surface area and high physical adsorption capacity, while also introducing a large number of nitrogen atoms. The nitrogen atoms can chemically adsorb onto the material, further enhancing the material's adsorption capacity. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments, which is intended to help readers better understand the technical solutions of the present invention and does not constitute any limitation on the scope of implementation of the technical solutions of the present invention.

[0025] Preparation Example A

[0026] Preparation of 2,5-dichloromethylpyrazine.

[0027] 0.3 mol of 2,5-dimethylpyrazine, 2 g of benzoyl peroxide, and 0.6 mol of N-chlorosuccinimide were heated in anhydrous tetrachloromethane and refluxed with stirring for 1 day. After the reaction was complete, the mixture was cooled to 0-5°C. The succinimide was removed by filtration, and the precipitate was washed with tetrachloromethane. The filtrates were combined, and then distilled under reduced pressure to obtain an oily liquid. The oily liquid was separated and purified by column chromatography to obtain the product.

[0028] Preparation Example B

[0029] Preparation of 6,6'-dichloromethyl-2,2'-bipyrazine

[0030] 0.3 mol of 6,6'-dimethyl-2,2'-bipyrazine, 2.3 g of AIBN, and 0.6 mol of trichloroisocyanuric acid (TCC) were heated in anhydrous tetrachloromethane and refluxed with stirring for 1 day. After the reaction was complete, the solvent was removed by vacuum distillation to obtain a crude solid product. The crude solid product was separated and purified by column chromatography to obtain the final product.

[0031] Preparation of Examples and Comparative Examples

[0032] The monomer was dissolved in 100 mL of dichloroethane to obtain a monomer solution. FeCl3 catalyst was added to the monomer solution, and the mixture was then heated to 90 °C and stirred for 24 hours under a nitrogen atmosphere at 90 °C. The reaction solution was filtered to obtain a precipitate. The precipitate was washed once with deionized water, three times with methanol, and twice with diethyl ether. Finally, it was dried at 60 °C for 24 hours to obtain the final gas treatment material.

[0033] The adsorption capacity of carbon dioxide on the material at 273 K and 1 bar was determined using a Tristar II 3020 micrometer from Micromeritics, USA. Prior to measurement, the material was degassed at 120 °C for 24 h.

[0034] The monomer dosage and adsorption performance measurement results of the prepared gas treatment materials in the examples and comparative examples are listed in Table 1.

[0035] Table 1

[0036]

[0037] The monomers in Examples 1-7 were combinations of 2,5-dichloromethylpyrazine and 6,6'-dichloromethyl-2,2'-bipyrazine, while the monomers in Comparative Examples 1-5 were combinations of 2,5-dichloromethylpyrazine and 4,4'-dichloromethylbipyridine. Comparing the data from the Examples and Comparative Examples shows that the material using the monomer combinations from the Examples exhibits a higher adsorption capacity than the Comparative Examples.

Claims

1. A method for preparing a gas treatment material, characterized in that, Includes the following steps: (1) A monomer solution is obtained by dispersing the monomer in a solvent, wherein the monomer is a combination of dichloromethylpyrazine and dichloromethylbipyrazine; (2) Add a catalyst to the monomer solution obtained in step (1), and then heat to react to obtain a crude product; the reaction is carried out under an inert gas atmosphere and the reaction is continuously stirred. (3) The crude product obtained in step (2) is filtered, then washed and dried to obtain the gas treatment material; In this embodiment, the chloromethyl group of dichloromethylpyrazine and dichloromethylbipyrazine is attached to the carbon atom of the pyrazine; The two chloromethyl groups of the dichloromethylpyrazine are located in the para or meta position; The two chloromethyl groups of the dichloromethylbipyrazine are located on two different nitrogen-containing heterocycles; The dichloromethylpyrazine is 2,5-dichloromethylpyrazine, and the dichloromethylbipyrazine is 6,6'-dichloromethyl-2,2'-bipyrazine; The molar ratio of dichloromethylpyrazine to dichloromethylbipyrazine is 1:10 to 10:1; The catalyst is SnCl4, FeCl3, or AlCl3; The reaction temperature in step (2) is 40-140℃ and the reaction time is 10-50 hours.

2. A gas treatment material, which is prepared by the gas treatment material preparation method according to claim 1.

3. An application of the gas treatment material as described in claim 2, characterized in that, The gas treatment material is used as a gas adsorption material.

4. The application as described in claim 3, characterized in that, The gas adsorption material is used to adsorb sulfur dioxide, nitrogen, carbon dioxide, methane, hydrogen, formaldehyde, or toluene.

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