Catalyst for preparing cyclic carbonate through cycloaddition as well as preparation method and application of catalyst

Abstract

The invention discloses a catalyst for preparing cyclic carbonate through cycloaddition as well as a preparation method and application of the catalyst. The catalyst for preparing cyclic carbonate through cycloaddition is macroporous ion exchange resin; the macroporous ion exchange resin is prepared by sequentially carrying out chloromethylation, quaternary phosphating and optional transformation on a macroporous resin matrix; the spherical or sphere-like porous channel is formed in the spherical or sphere-like porous channel. The catalyst disclosed by the invention shows high activity and stability in a reaction for preparing alkylene carbonate through cycloaddition of an epoxy compound and CO2.

Description

Technical Field

[0001] The present invention relates to the technical field of ion exchange resins, and particularly to a catalyst for the cycloaddition to prepare cyclic carbonates, a preparation method thereof, and an application thereof. Background Art

[0002] The cycloaddition of epoxides and CO 2 to prepare cyclic carbonates has important practical significance. This is mainly because on the one hand, it realizes the conversion of CO 2 into chemicals, which is very conducive to the implementation of China's dual-carbon strategy; on the other hand, the product cyclic carbonate is a widely used chemical raw material, which can be used as an intermediate for fine chemical synthesis, an aprotic polar solvent, an electrolyte for lithium-ion batteries, a monomer for polymerization reactions, and an intermediate for many chemicals and drugs.

[0003] So far, a variety of catalysts have been developed, such as homogeneous alkali metal halides (ChemSusChem, 2012, 5, 652), ionic liquids (RSC Adv., 2014, 4, 2360), metal Schiff base complexes (Chem. Commun., 2010, 46, 4580), metal porphyrin complexes (Angew. Chem. Int. Ed., 2015, 54, 134), and heterogeneous ionic liquid porous polymers (Chem. Asian J., 2017, 12, 557), ion exchange resins (Green Chem., 2005, 7, 518), and metal-organic framework complexes (J. Am. Chem. Soc., 2014, 136, 15861.), etc. Among them, homogeneous catalysts have the disadvantages of difficult product separation, large catalyst dosage, difficult recovery and reuse, and environmental pollution; while heterogeneous catalysts have many advantages such as easy separation from products, easy regeneration, and recyclability. However, most of the existing heterogeneous catalysts have problems such as a significant decrease in catalytic activity after being reused.

[0004] Therefore, for the reaction of the cycloaddition of epoxides and CO 2 to prepare alkylene carbonate, it is necessary to develop a heterogeneous catalyst with high activity and high stability. Summary of the Invention

[0005] To solve the problems existing in the prior art, the present invention provides a catalyst for the cycloaddition to prepare cyclic carbonates, a preparation method thereof, and an application thereof. The catalyst of the present invention exhibits high activity and stability in the reaction of the cycloaddition of epoxides and CO 2 to prepare alkylene carbonate, and the preparation method of the catalyst of the present invention is simple and feasible, which can provide a reference for the preparation of other catalysts with higher performance.

[0006] One of the objectives of the present invention is to provide a catalyst for the cycloaddition reaction to produce cyclic carbonates, which is a macroporous ion exchange resin; the macroporous ion exchange resin is prepared by successively performing chloromethylation, quaternary phosphination, and optional transformation on a macroporous resin matrix; it has spherical or quasi-spherical pores. The macroporous ion exchange resin has a uniform and adjustable pore size, and its unique pore structure is very conducive to mass diffusion.

[0007] In a preferred embodiment of the present invention,

[0008] the most probable pore size of the macroporous ion exchange resin is 20 - 500 nm, preferably 70 - 200 nm, more preferably 70 - 120 nm; and / or,

[0009] the macroporous ion exchange resin is spherical or quasi-spherical particles, preferably, its particle size is 350 - 600 μm; and / or,

[0010] the macroporous resin matrix is prepared using modified silica as a pore-forming agent; in the present invention, using modified silica as a pore-forming agent (template or pore-forming agent), a macroporous resin matrix with spherical or quasi-spherical pores, uniform and adjustable pore size is successfully synthesized; and / or,

[0011] the macroporous ion exchange resin contains a functional group with the general formula -P + R 1 R 2 R 3 X - wherein, R 1 、R 2 、R 3 are each independently selected from at least one of methyl, ethyl, propyl, n-butyl, aryl, and X - is an anion or an anion group; the functional group -P + R 1 R 2 R 3 X - is chemically bonded to the macroporous resin matrix; preferably,

[0012] the R 1 、R 2 、R 3 are each independently selected from at least one of methyl, n-butyl, phenyl; and / or,

[0013] the X - is at least one of halide ions, organic acid root ions, preferably at least one of fluoride ions, chloride ions, bromide ions, iodide ions, acetate ions, formate ions, hydrogen oxalate ions.

[0014] In a preferred embodiment of the present invention,

[0015] The most probable particle size of the modified silica is 20 to 500 nm, preferably 70 to 200 nm, more preferably 70 to 120 nm; and / or,

[0016] The modified silica is obtained by modifying silica nanoparticles with a silane coupling agent containing a double bond. The change in the size of the silica nanoparticles before and after modification is very small and can be ignored.

[0017] In a preferred embodiment of the present invention,

[0018] The silane coupling agent containing a double bond is selected from at least one of allyl triethoxysilane, allyl trimethoxysilane, 3-butenyl triethoxysilane, vinyl triethoxysilane, vinyl trimethoxysilane, diethoxymethylvinylsilane, and methylvinyldimethoxysilane; and / or,

[0019] The most probable particle size of the silica nanoparticles is 20 to 500 nm, preferably 70 to 200 nm, more preferably 70 to 120 nm; and / or,

[0020] The silica nanoparticles can be obtained commercially or prepared by any method of the prior art. In the present invention, it is preferred that the silica nanoparticles are obtained by hydrolysis and polycondensation of a silicate compound; preferably,

[0021] The preparation process of the silica nanoparticles may specifically include the following steps: mixing an alcohol, water and a catalyst evenly, and then adding a silicate compound to react to obtain the silica nanoparticles before modification; wherein, the alcohol is preferably at least one of absolute ethanol and absolute methanol, and / or, the catalyst is preferably at least one of ammonia water and sodium carbonate, and / or, the volume ratio of the alcohol to water is (1 to 15):1, and / or, the mass ratio of the catalyst to water is (0.01 to 1):1, and / or, the volume ratio of the silicate compound to water is (0.1 to 0.8):1, and / or, the reaction temperature is preferably 10 to 60 °C, and the reaction time is preferably 0.1 to 5 h; preferably, the reaction is carried out under stirring, and the stirring rate is preferably 300 to 800 rpm.

[0022] The silicate compound is selected from at least one of methyl silicate, ethyl silicate, propyl silicate, and butyl silicate; and / or, the volume ratio of the silane coupling agent containing a double bond to the silicate compound is 0.1 to 0.8, preferably 0.2 to 0.4; and / or,

[0023] The conditions for modification include: the temperature is 10 to 60 °C, preferably 20 to 40 °C; and / or, the time is 0.1 to 12 h, preferably 0.5 to 5 h.

[0024] A second object of the present invention is to provide a preparation method of a catalyst for cycloaddition to prepare cyclic carbonates according to one object of the present invention, which includes preparing a macroporous resin matrix using modified silica as a pore-forming agent, and then successively performing chloromethylation, quaternary phosphination and optionally transformation steps on the macroporous resin matrix.

[0025] In a preferred embodiment of the present invention,

[0026] the method includes:

[0027] (1) Polymerizing components including a monomer, a comonomer, modified silica, an optional carbon nanomaterial, and a dispersant under the action of an initiator, and then dispersing the polymerized product into an acid or base solution for treatment to obtain the macroporous resin matrix;

[0028] (2) Successively performing a chloromethylation reaction, quaternary phosphination and optionally transformation on the macroporous resin matrix obtained in step (1) to obtain the macroporous ion exchange resin.

[0029] In a preferred embodiment of the present invention,

[0030] in step (1),

[0031] the monomer is selected from at least one of styrene and its derivatives, preferably at least one of styrene, α-methylstyrene, and 4-butylstyrene; and / or,

[0032] the comonomer is selected from at least one of diene-based benzenes, preferably at least one of diisopropenylbenzene and divinylbenzene; and / or,

[0033] the carbon nanomaterial is a conventional carbon nanomaterial in the prior art in this field, and its size is also a conventional size. Those skilled in the art can select according to actual situations. In the present invention, the carbon nanomaterial is preferably selected from at least one of graphene and carbon nanotubes; and / or,

[0034] the dispersant is selected from at least one of polyvinyl alcohol, gelatin, starch, methylcellulose, bentonite, and calcium carbonate, preferably at least one of polyvinyl alcohol and gelatin; and / or,

[0035] the initiator is selected from at least one of peroxide initiators and azo initiators, preferably at least one of benzoyl peroxide, azobisisobutyronitrile, lauroyl peroxide, and cumene hydroperoxide, more preferably at least one of benzoyl peroxide and azobisisobutyronitrile; and / or,

[0036] The mass ratio of the monomer, comonomer, optional carbon nanomaterial, modified silica, dispersant, and initiator is 1:(0.01 - 0.05):(0 - 0.1):(0.001 - 0.2):(0.04 - 0.15):(0.001 - 0.1), preferably 1:(0.01 - 0.03):(0 - 0.05):(0.001 - 0.1):(0.04 - 0.1):(0.001 - 0.01); and / or,

[0037] The polymerization conditions include: the temperature is 40 - 120°C, and the time is 10 - 72 hours; preferably, the polymerization is carried out in a stepwise temperature-raising manner. Preferably, pre-polymerization is carried out by stirring at 40 - 50°C for 0.5 - 2 h, then the temperature is raised to 60 - 85°C for reaction for 1 - 24 h, then the temperature is raised to 85 - 95°C for reaction for 1 - 24 h, and finally the temperature is raised to 95 - 120°C for reaction for 1 - 24 h; and / or,

[0038] In a preferred embodiment of the present invention,

[0039] In step (1),

[0040] The acid is hydrofluoric acid; and / or,

[0041] The base is at least one of ammonia water, carbonates of alkali metals, and hydroxides of alkali metals, preferably at least one of ammonia water, sodium carbonate, sodium hydroxide, and potassium hydroxide; and / or,

[0042] The acid or base is used in the form of an aqueous solution, and its concentration is preferably 0.005 - 1.0 mol / L, more preferably 0.05 - 1.0 mol / L; the amount of the acid or base solution is at least such that the resin beads before acid or base treatment are completely dispersed in the acid or base solution. Preferably, the amount of the acid or base solution is 5 - 40 mL of the acid or base solution corresponding to 1 g of the resin beads before acid or base treatment;

[0043] The conditions of the treatment include: the temperature is 10 - 100°C, preferably 60 - 100°C; and / or, the time is 0.5 - 12 h, preferably 0.5 - 3 h; preferably, the treatment includes a stirring reaction step, and the stirring rate is preferably 300 - 800 rpm.

[0044] In the present invention, the treatment is to remove the silica nanoparticles in the resin, so as to generate macroporous channels in the resin that are spherical or quasi-spherical, with uniform and adjustable pore sizes; the channels of the macroporous resin matrix prepared by this method are basically not deformed or only slightly deformed relative to the shape of the modified silica (pore-forming agent), and the pore size of the macroporous resin matrix can be conveniently regulated by regulating the size of the silica nanoparticles;

[0045] In a preferred embodiment of the present invention,

[0046] In step (2),

[0047] The chloromethylation reagent used for chloromethylation is a conventional chloromethylation reagent in the art, preferably at least one selected from chloromethyl methyl ether, chloromethyl ethyl ether, and chloromethyl ethyl ether, more preferably at least one of chloromethyl methyl ether and chloromethyl ethyl ether; and / or,

[0048] The conditions for chloromethylation include: the temperature is 30 to 60 °C, preferably 30 to 50 °C, and / or the time is 8 to 30 h, preferably 8 to 15 h; and / or,

[0049] The general formula of the phosphating agent used for quaternary phosphating is PR 1 R 2 R 3 , where R 1 , R 2 , R 3 are each independently selected from at least one of methyl, ethyl, propyl, n-butyl, and aryl, preferably at least one of methyl, n-butyl, and phenyl; the phosphating agent is preferably at least one of dimethylphenylphosphine, tributylphosphine, and triphenylphosphine; and / or,

[0050] The conditions for quaternary phosphating include: reacting at the reflux temperature for 10 to 72 h, preferably reacting for 12 to 36 h; and / or,

[0051] The transformation agent used for transformation is a conventional transformation agent in the art, preferably at least one salt solution containing at least one of halogen ions and organic acid root ions, more preferably at least one salt solution containing at least one of fluoride ions, bromide ions, iodide ions, acetate ions, formate ions, and hydrogen oxalate ions; and / or,

[0052] The conditions for transformation include: the temperature is 20 to 60 °C, preferably 20 to 35 °C, and / or the time is 4 to 72 h, preferably 12 to 36 h.

[0053] The present invention can adopt the following specific technical solutions:

[0054] A method for synthesizing a macroporous composite ion exchange resin, comprising the following steps:

[0055] 1) First, synthesize silica nanoparticles, and then modify them with a silane coupling agent containing a double bond to obtain modified silica;

[0056] 2) Polymerize the modified silica prepared in step 1) with a monomer, a comonomer, an optional carbon nanomaterial, and a dispersant under the action of an initiator, and then disperse the obtained resin beads into an acid or base solution for treatment for 0.5 to 12 h to obtain a macroporous resin matrix;

[0057] 3) The macroporous resin matrix prepared in step 2) is successively subjected to chloromethylation, quaternary phosphination, and optional transformation to obtain the macroporous ion exchange resin.

[0058] In the above technical solution, preferably, in step 3), a chloromethylating agent and a zinc chloride catalyst are added to the macroporous resin matrix for a functionalization reaction. After the reaction is completed, it is washed with methanol and water and dried to obtain macroporous chlorinated beads.

[0059] In the above technical solution, preferably, the weight of the chloromethylating agent is 200-500% of the weight of the macroporous resin matrix, and the weight of the zinc chloride catalyst is 20-70% of the weight of the macroporous resin matrix.

[0060] In the above technical solution, preferably, a swelling agent, a phosphinating agent, and nickel bromide are added to the macroporous chlorinated beads for a functionalization reaction; after the reaction is completed, it is washed with water and dried, and optionally, a transforming agent is added for transformation, and then washed with water until neutral.

[0061] In the above technical solution, preferably, the swelling agent is selected from at least one of dichloromethane, 1,2-dichloroethane, chloroform, benzonitrile, toluene, tetrahydrofuran, and dimethylformamide. Preferably, it is one of dichloromethane or tetrahydrofuran;

[0062] In the above technical solution, preferably, the weight of the swelling agent is 200-700% of the weight of the macroporous chlorinated beads.

[0063] In the above technical solution, preferably, the weight of the phosphinating agent is 70-250% of the weight of the macroporous chlorinated beads, and the weight of nickel bromide is 50-200% of the weight of the macroporous chlorinated beads.

[0064] In the above technical solution, preferably, the transforming agent is used in the form of a solution, and its concentration is preferably 0.01-2 mol / L.

[0065] In the present invention, the conditions for chloromethylation, quaternary phosphination, and transformation can all adopt the conventional conditions in the art, and those skilled in the art can adjust according to the actual situation.

[0066] The third object of the present invention is to provide a catalyst for cycloaddition to prepare cyclic carbonates of the first object of the present invention or a catalyst for cycloaddition to prepare cyclic carbonates obtained by the preparation method of the second object of the present invention in the cycloaddition of epoxides and CO 2 Application in the cycloaddition to prepare cyclic carbonates.

[0067] In a preferred embodiment of the present invention,

[0068] The mass ratio of the catalyst to the epoxide is (0.05 to 0.25):1, preferably (0.1 to 0.2):1; and / or,

[0069] The conditions for the cycloaddition include: a reaction temperature of 80 to 200 °C, preferably 150 to 180 °C, and / or, a reaction time of 2 to 8 hours, preferably 3 to 6 hours, and / or, a reaction pressure of 2.0 to 10 MPa.

[0070] Advantages of the present invention:

[0071] (1) The pores of the catalyst of the present invention are spherical, with uniform and adjustable pore sizes, which are very conducive to mass diffusion, thereby enhancing the activity and stability of the catalyst. The pores of the macroporous resin of the present invention are basically not deformed or only slightly deformed compared to the shape of the modified silica nanoparticles, and the pore size of the macroporous resin can be conveniently adjusted by controlling the size of the modified silica nanoparticles. (2) The method provided by the present invention is simple and feasible. (3) The catalyst of the present invention exhibits high activity and stability in the addition reaction of epoxyalkanes and carbon dioxide. The conversion rate of ethylene oxide and the selectivity of ethylene carbonate are as high as 99.6%, and the performance remains basically unchanged after 5 cycles of use. Description of the drawings

[0072] Figure 1 is the SEM photograph of the macroporous ion exchange resin prepared in Example 1.

[0073] Figure 2 is the SEM photograph of the ion exchange resin prepared in Comparative Example 2. Detailed implementation manners

[0074] The present invention will be specifically described below in conjunction with specific examples and the accompanying drawings. It is necessary to point out here that the following examples are only for further illustration of the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the protection scope of the present invention.

[0075] The raw materials used in the examples and comparative examples, if not specifically defined, are those disclosed in the prior art. For example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0076] The morphology of the resins prepared in the examples and comparative examples was measured by a scanning electron microscope (SEM); the size of the SiO 2 nanoparticles was measured by a nanoparticle size and zeta potential analyzer (NanoZS90); the pore diameter of the resin pores was measured by a mercury porosimeter Pascal140 / 240.

[0077]

Example 1

[0078] 71.4 mL of absolute ethanol, 10 mL of deionized water, and 1.57 mL of ammonia water (ammonia water concentration 14.84 mol / L) were uniformly mixed and placed in a water bath at 30 °C for magnetic stirring, and the stirring speed was 400 rpm. After the temperature was balanced, 3 mL of tetraethyl orthosilicate was quickly added to the above reaction solution, and the reaction was carried out for 1 h to obtain solid SiO 2 nanoparticles with the most probable particle size of 100 nm. Then, 1 mL of allyltriethoxysilane was added and the reaction was continued for 1 h. After centrifugation, it was washed thoroughly with ethanol and dried to obtain modified SiO 2 .

[0079] 52 g of styrene, 1.0 g of divinylbenzene, 0.5 g of benzoyl peroxide, 5.0 g of modified SiO 2 and 1.0 g of multi-walled carbon nanotubes (Macklin, product number C805976) were ultrasonically dispersed for 1 h to obtain solution X. 5 g of gelatin was dissolved in 260 mL of deionized water and ultrasonically dispersed evenly. Solution X was added to the gelatin aqueous solution, and pre-polymerization was carried out by stirring at 400 rpm at 40 °C for 2 h, gradually heated to 80 °C, reacted for 5 h, then heated to 90 °C and reacted for 5 h, and finally heated to 98 °C and reacted for 6 h. After the reaction was completed, the upper liquid was poured out, washed with hot water, filtered, dried at 80 °C, and sieved. Resin beads with a particle size in the range of 350 - 600 μm were collected. Then, the obtained resin beads were dispersed in 1000 mL of 0.6 mol / L Na 2 CO 3 aqueous solution, and stirred and reacted at 400 rpm at 80 °C for 1 h. The product was collected, washed thoroughly with water, and dried to obtain a macroporous resin matrix.

[0080] 40 g of the macroporous resin matrix was taken, 150 mL of chloromethyl ethyl ether was added, and after standing at room temperature for 2 h, 10 g of zinc chloride was added under stirring at 400 rpm, heated to 40 °C, and reacted for 10 h. After the reaction was completed, it was cooled to room temperature and the reaction solution was poured out. It was washed repeatedly with methanol and then washed with water and dried to obtain macroporous chlorinated beads. 40 g of chlorinated beads, 28 g of dimethylphenylphosphine, 16 g of nickel bromide, and 200 mL of benzonitrile were taken and refluxed for 24 h. After the reaction was completed, it was washed thoroughly with dichloromethane, acetone, and water in sequence and dried to obtain macroporous ion exchange resin A (catalyst A). The particle size of the obtained catalyst A was 350 - 600 μm; the SEM photograph of the obtained catalyst A was as Figure 1 shown. It can be seen that the pore channels of catalyst A are spherical or quasi-spherical, and their pore sizes are uniform. The most probable pore size was measured to be 99 nm. The general formula of the functional groups on catalyst A is -P + (CH 3 ) 2 (C 6 H 5 )Cl - .

[0081]

Example 2

[0082] 71.4 mL of absolute ethanol, 10 mL of deionized water, and 3 mL of ammonia water (ammonia water concentration 14.84 mol / L) were uniformly mixed and placed in a water bath at 30 °C for magnetic stirring, and the stirring speed was 400 rpm. After the temperature was balanced, 3 mL of tetraethyl orthosilicate was quickly added to the above reaction solution, and the reaction was carried out for 1 h to obtain solid SiO 2 nanoparticles with the most probable particle size of 80 nm. 1 mL of allyltriethoxysilane was added and the reaction was continued for 1 h. After centrifugation, it was washed thoroughly with ethanol and dried to obtain modified SiO 2 .

[0083] 52 g of styrene, 1.0 g of divinylbenzene, 0.5 g of benzoyl peroxide, 3.0 g of modified SiO 2 and 1.1 g of graphene (Maclean, product number G835835) were ultrasonically dispersed for 1 h to obtain solution X. 5 g of gelatin was dissolved in 260 mL of deionized water and ultrasonically dispersed evenly. Solution X was added to the gelatin aqueous solution, and pre-polymerization was carried out by stirring at 400 rpm at 40 °C for 2 h, gradually heated to 80 °C, reacted for 5 h, then heated to 90 °C and reacted for 5 h, and finally heated to 98 °C and reacted for 6 h. After the reaction was completed, the upper liquid was poured out, washed with hot water, filtered, dried at 80 °C, and sieved to collect resin beads with a particle size in the range of 350 - 600 μm. Then the obtained resin beads were dispersed in 1000 mL of an aqueous solution of 0.05 mol / L NaOH, and stirred and reacted at 400 rpm at 80 °C for 1 h. The product was collected, washed thoroughly with water, and dried to obtain a macroporous resin matrix.

[0084] 40 g of the macroporous resin matrix was taken, 150 mL of chloromethyl ethyl ether was added, and after standing at room temperature for 2 h, 10 g of zinc chloride was added with stirring at 400 rpm, heated to 40 °C, and reacted for 10 h. After the reaction was completed, it was cooled to room temperature and the reaction solution was poured out. After repeated washing with methanol and then water washing and drying, macroporous chlorinated beads were obtained. 40 g of chlorinated beads, 40 g of tributylphosphine, 16 g of nickel bromide, and 200 mL of dichloromethane were taken and refluxed for 24 h. After the reaction was completed, it was washed thoroughly with dichloromethane, acetone, and water in sequence, dried, and then added to 500 mL of an aqueous solution of 0.1 mol / L NaBr and stirred at 400 rpm at room temperature for 24 h. After thorough washing with deionized water and drying, macroporous ion exchange resin B (catalyst B) was obtained. The particle size of the obtained catalyst B was 350 - 600 μm; the pore channels of the obtained catalyst B were spherical or quasi-spherical, and their pore sizes were uniform. The most probable pore size was measured to be 80 nm. The general formula of the functional groups on catalyst B was -P + (C 4 H 9 ) 3 Br- .

[0085]

Example 3

[0086] 71.4 mL of absolute ethanol, 10 mL of deionized water and 3 mL of ammonia water (ammonia water concentration 14.84 mol / L) were uniformly mixed and placed in a water bath at 30 °C for magnetic stirring, and the stirring speed was 400 rpm. After the temperature was balanced, 4 mL of tetraethyl orthosilicate was quickly added to the above reaction solution, and the reaction was carried out for 1 h to obtain solid SiO 2 nanoparticles, the most probable particle size of which was 90 nm. 1 mL of allyltriethoxysilane was added and the reaction continued for 1 h. After centrifugation, it was washed thoroughly with ethanol and dried to obtain modified SiO 2 .

[0087] 52 g of styrene, 1.0 g of divinylbenzene, 0.5 g of benzoyl peroxide, 4.0 g of modified SiO 2 and 0.9 g of single-walled carbon nanotubes (Maclean, product number C822928) were ultrasonically dispersed for 1 h to obtain solution X. 5 g of gelatin was dissolved in 260 mL of deionized water and ultrasonically dispersed evenly. Solution X was added to the gelatin aqueous solution, and pre-polymerization was carried out by stirring at 400 rpm at 40 °C for 2 h, gradually heated to 80 °C, reacted for 5 h, then heated to 90 °C and reacted for 5 h, and finally heated to 98 °C and reacted for 6 h. After the reaction was completed, the upper liquid was poured out, washed with hot water, filtered, dried at 80 °C, and sieved to collect resin beads with a particle size in the range of 350 - 600 μm. Then the obtained resin beads were dispersed in 1000 mL of an aqueous solution of 0.01 mol / L KOH, and stirred and reacted at 400 rpm at 80 °C for 1 h. The product was collected, washed thoroughly with water, and dried to obtain a macroporous resin matrix.

[0088] 40 g of the macroporous resin matrix was taken, 150 mL of chloromethyl ethyl ether was added, and after standing at room temperature for 2 h, 10 g of zinc chloride was added with stirring at 400 rpm, heated to 40 °C, and reacted for 10 h. After the reaction was completed, it was cooled to room temperature and the reaction solution was poured out. It was repeatedly washed with methanol and then washed with water and dried to obtain macroporous chlorinated beads. 40 g of chlorinated beads, 50 g of triphenylphosphine, 16 g of nickel bromide and 200 mL of tetrahydrofuran were taken and refluxed for 24 h. After the reaction was completed, it was washed thoroughly with dichloromethane, acetone and water in turn, dried and added to 500 mL of an aqueous solution of 1 mol / L NaF, stirred at 400 rpm at room temperature for 24 h, washed thoroughly with deionized water, and dried to obtain macroporous ion exchange resin C (catalyst C). The particle size of the obtained catalyst C was 350 - 600 μm; the pore channels of the obtained catalyst C were spherical or quasi-spherical, and their pore sizes were uniform, and the most probable pore size was measured to be 89 nm. The general formula of the functional groups on catalyst C was -P + (C 6 H 5 )3 F - 。

[0089]

Comparative Example 1

Compared with Example 1, 1 mL of allyltriethoxysilane was not added for the reaction

[0090] 71.4 mL of absolute ethanol, 10 mL of deionized water and 1.57 mL of ammonia water (ammonia water concentration 14.84 mol / L) were uniformly mixed and placed in a water bath at 30 °C for magnetic stirring, and the stirring speed was 400 rpm. After the temperature was balanced, 3 mL of tetraethyl orthosilicate was quickly added to the above reaction solution, and the reaction was carried out for 1 h to obtain solid SiO 2 nanoparticles, which were centrifuged, washed thoroughly with ethanol and dried.

[0091] 52 g of styrene, 1.0 g of divinylbenzene, 0.5 g of benzoyl peroxide, 5.0 g of SiO 2 nanoparticles and 1.0 g of multi-walled carbon nanotubes (Maclean, product number C805976) were ultrasonically dispersed for 1 hour to obtain solution X, and it was found that the SiO 2 nanoparticles were difficult to disperse evenly. 5 g of gelatin was dissolved in 260 mL of deionized water and ultrasonically dispersed evenly. Solution X was added to the gelatin aqueous solution, and pre-polymerization was carried out by stirring at 400 rpm at 40 °C for 2 hours, gradually heated to 80 °C, reacted for 5 hours, then heated to 90 °C and reacted for 5 hours, and finally heated to 98 °C and reacted for 6 hours. During the whole reaction process, most of the silica nanoparticles were distributed outside the suspension polymerization spheres. After the reaction was completed, the upper layer liquid was poured out, washed with hot water, filtered, dried at 80 °C, and sieved to collect resin spheres with a particle size in the range of 350 - 600 μm. Then the obtained resin spheres were dispersed in 1000 mL of 0.6 mol / L Na 2 CO 3 aqueous solution, and stirred and reacted at 400 rpm at 80 °C for 1 hour, washed thoroughly with water and dried.

[0092] 40 g of the above-treated resin spheres were taken, 150 mL of chloromethyl ethyl ether was added, and after standing at room temperature for 2 h, 10 g of zinc chloride was added with stirring at 400 rpm, heated to 40 °C, and reacted for 10 h. After the reaction was completed, it was cooled to room temperature, the reaction solution was poured out, washed repeatedly with methanol and then washed with water and dried to obtain chlorinated beads. 40 g of chlorinated beads, 28 g of dimethylphenylphosphine, 16 g of nickel bromide and 200 mL of benzonitrile were taken and refluxed for 24 hours. After the reaction was completed, they were washed thoroughly with dichloromethane, acetone and water in turn, and dried to obtain catalyst D. The obtained catalyst D was basically pore-free.

[0093]

Comparative Example 2

Compared with Example 1, the macroporous pore former was toluene

[0094] Take 52 g of styrene, 1.0 g of divinylbenzene, 0.5 g of benzoyl peroxide, 5.0 g of toluene and 1.0 g of multi-walled carbon nanotubes (Macklin, product number C805976), and ultrasonically disperse them for 1 hour to obtain solution X. Dissolve 5 g of gelatin in 260 mL of deionized water and ultrasonically disperse it evenly. Add solution X to the aqueous gelatin solution, stir at 400 rpm at 40 °C for 2 hours for prepolymerization, gradually raise the temperature to 80 °C, react for 5 hours, then raise the temperature to 90 °C and react for 5 hours, and finally raise the temperature to 98 °C and react for 6 hours. After the reaction is completed, pour out the upper liquid, wash it with hot water, filter it, dry it at 80 °C, and sieve it to collect resin beads with a particle size in the range of 350 - 600 μm. Then disperse the obtained resin beads into 1000 mL of an aqueous solution of 0.6 mol / L Na 2 CO 3 , stir and react at 400 rpm at 80 °C for 1 hour, wash it thoroughly with water and then dry it.

[0095] Take 40 g of the above-treated resin beads, add 150 mL of chloromethyl ethyl ether, let it stand at room temperature for 2 h, then stir and add 10 g of zinc chloride at 400 rpm, raise the temperature to 40 °C, react for 10 h, after the reaction is completed, cool it to room temperature, pour out the reaction solution, wash it repeatedly with methanol and then wash it with water and dry it to obtain macroporous chlorinated beads. Take 40 g of chlorinated beads, 28 g of dimethylphenylphosphine, 16 g of nickel bromide and 200 mL of benzonitrile, and reflux and react for 24 hours. After the reaction is completed, wash it thoroughly with dichloromethane, acetone and water in turn, and dry it to obtain catalyst E. The SEM photograph of the obtained catalyst E is as shown in Figure 2 shown, it can be seen from Figure 2 that the pores generated by traditional pore-forming agents have no fixed shape and are uneven in size.

[0096]

Test Example 1 - 9

[0097] Use the prepared catalyst for the addition reaction of epoxides and carbon dioxide: Under the protection of high-purity nitrogen, add 50.0 g of ethylene oxide and a certain amount of catalyst to a 300 mL autoclave, fill it with 1.0 MPa CO 2 , raise the temperature to 100 - 180 °C, and then fill it with CO 2 to maintain the reaction pressure at 2.0 - 10 MPa. After reacting for 4 - 5 hours, measure the conversion rate of EO and the selectivity of EC.

[0098] Table 1 Activity evaluation results of catalysts A - C in the addition reaction of epoxides and carbon dioxide

[0099]

[0100]

Comparative Example 3 - 4

[0101] Investigate the performance of catalysts D and E under the same conditions.

[0102] Table 2 Activity evaluation results of catalysts D and E in the addition reaction of epoxide and carbon dioxide

[0103]

[0104]

[0105]

Test Example 10 - 13

[0106] Filter, wash, and dry the catalyst A used in

Test Example 1

Test Example 1

[0107] Table 3 Recyclability of catalyst A

[0108] Test Example Catalyst Number of Cycles Conversion Rate CEO / 100% Selectivity SEC / 100% 10 A 2 99.3 99.7 11 A 3 99.2 99.6 12 A 4 99.3 99.6 14 A 5 99.2 99.5

[0109]

Comparative Example 5 - 8

[0110] Evaluate the recyclability of catalysts D and E under the same conditions, and the results are shown in Table 4.

[0111] Table 4 Recyclability of catalysts D and E

[0112] Comparative Example Catalyst Number of Cycles Conversion Rate CEO / 100% Selectivity SEC / 100% 5 D 2 92.6 96.7 6 D 3 91.8 95.5 7 E 2 94.1 97.7 8 E 3 93.3 96.9

[0113] It can be seen from Example 1, Comparative Example 1 and Tables 1 - 4 that: in Comparative Example 1, since the SiO 2 nanoparticles without being modified by a silane coupling agent containing double bonds were directly used as pore - forming agents, the resulting resin was basically pore - free, so its catalytic activity and stability were both inferior to those of the macroporous ion - exchange resin of the present invention. It can be seen from Example 1, Comparative Example 2 and Tables 1 - 4 that: compared with the ion - exchange resin obtained by traditional pore - forming agents, the catalytic activity and stability of the macroporous ion - exchange resin prepared by the present invention using modified SiO 2 as a pore - forming agent have been greatly improved.

[0114] The above are only the preferred examples of the present invention. It should be pointed out that for those of ordinary skill in the art, under the technical inspiration provided by the present invention, as common general knowledge in the art, other equivalent variations and improvements can also be made, which should also be regarded as the protection scope of the present invention.

Claims

1. A catalyst for preparing cyclic carbonate by cycloaddition, which is a macroporous ion exchange resin; the macroporous ion exchange resin is prepared by sequentially subjecting a macroporous resin matrix to chloromethylation, quaternary phosphination and optional transformation; the macroporous ion exchange resin has spherical or quasi-spherical pores.

2. The catalyst according to claim 1, characterized in that: The macroporous ion exchange resin has a minimum pore size of 20 to 500 nm, preferably 70 to 200 nm; and / or, The macroporous ion exchange resin is a spherical or quasi-spherical particle, preferably, the particle size is 350-600 μm; and / or, The macroporous resin matrix is ​​prepared by using modified silica as a pore-forming agent; and / or, The macroporous ion exchange resin comprises a general formula of -P + R1R2R3X - wherein R1, R2, and R3 are independently selected from at least one of methyl, ethyl, propyl, n-butyl, and aryl, and X - is an anion or anionic group; preferably, The R1, R2, and R3 are independently selected from at least one of methyl, n-butyl, and phenyl; and / or, The X - It is at least one of a halide ion and an organic acid ion, and preferably at least one of a fluoride ion, a chloride ion, a bromide ion, an iodide ion, an acetate ion, a formate ion, and a hydrogen oxalate ion.

3. The catalyst according to claim 2, characterized in that: The modified silicon dioxide has a minimum particle size of 20 to 500 nm, preferably 70 to 200 nm; and / or, The modified silicon dioxide is obtained by modifying silicon dioxide nanoparticles with a silane coupling agent containing double bonds.

4. The catalyst according to claim 3, characterized in that: The double bond-containing silane coupling agent is selected from at least one of allyltriethoxysilane, allyltrimethoxysilane, 3-butenetriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, diethoxymethylvinylsilane and methylvinyldimethoxysilane; and / or, The most possible particle size of the silicon dioxide nanoparticles is 20 to 500 nm, preferably 70 to 200 nm; and / or, The silicon dioxide nanoparticles are obtained by hydrolysis and polycondensation of silicate compounds; preferably, the silicate compounds are selected from at least one of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate; and / or, the volume ratio of the double-bond silane coupling agent to the silicate compound is 0.1 to 0.8, preferably 0.2 to 0.4; and / or, The modification conditions include: a temperature of 10 to 60° C., preferably 20 to 40° C.; and / or a time of 0.1 to 12 hours, preferably 0.5 to 5 hours.

5. A method for preparing a catalyst as claimed in any one of claims 1 to 4, comprising the steps of preparing a macroporous resin matrix using modified silica as a pore-forming agent, and then sequentially subjecting the macroporous resin matrix to chloromethylation, quaternary phosphination and optional transformation.

6. The preparation method according to claim 5, characterized in that The method comprises: (1) polymerizing the components including monomers, comonomers, modified silica, optional carbon nanomaterials, and dispersants under the action of an initiator and then dispersing them in an acid or alkaline solution for treatment to obtain the macroporous resin matrix; (2) The macroporous resin matrix obtained in step (1) is subjected to chloromethylation, quaternary phosphation and optional transformation in sequence to obtain the macroporous ion exchange resin.

7. The preparation method according to claim 6, characterized in that: In step (1), The monomer is at least one selected from styrene and its derivatives, preferably at least one selected from styrene, α-methylstyrene, and 4-butylstyrene; and / or, The comonomer is selected from at least one of divinylbenzenes, preferably at least one of diisopropenylbenzene and divinylbenzene; and / or, The carbon nanomaterial is selected from at least one of graphene and carbon nanotubes; and / or, The dispersant is selected from at least one of polyvinyl alcohol, gelatin, starch, methyl cellulose, bentonite, and calcium carbonate, preferably at least one of polyvinyl alcohol and gelatin; and / or, The initiator is selected from at least one of a peroxide initiator and an azo initiator, preferably at least one of benzoyl peroxide, azobisisobutyronitrile, lauroyl peroxide, and cumene hydroperoxide; and / or, The mass ratio of the monomer, comonomer, optional carbon nanomaterial, modified silica, dispersant and initiator is 1: (0.01-0.05): (0-0.1): (0.001-0.2): (0.04-0.15): (0.001-0.1), preferably 1: (0.01-0.03): (0-0.05): (0.001-0.1): (0.04-0.1): (0.001-0.01); and / or, The polymerization conditions include: a temperature of 40 to 120° C. and a time of 10 to 72 hours; preferably, the polymerization is carried out in a step-by-step heating manner, preferably stirring at 40 to 50° C. for 0.5 to 2 hours for prepolymerization, then heating to 60 to 85° C. for reaction for 1 to 24 hours, then heating to 85 to 95° C. for reaction for 1 to 24 hours, and finally heating to 95 to 120° C. for reaction for 1 to 24 hours.

8. The preparation method according to claim 6, characterized in that: In step (1), The acid is hydrofluoric acid; and / or, The base is at least one of ammonia water, alkali metal carbonate, and alkali metal hydroxide, preferably at least one of ammonia water, sodium carbonate, sodium hydroxide, and potassium hydroxide; and / or, The acid or base is used in the form of an aqueous solution, and its concentration is preferably 0.005 to 1.0 mol / L, more preferably 0.05 to 1.0 mol / L; and / or, The treatment conditions include: a temperature of 10 to 100° C., preferably 60 to 100° C.; and / or a treatment time of 0.5 to 12 hours, preferably 0.5 to 3 hours.

9. The preparation method according to claim 6, characterized in that: In step (2), The chloromethylation agent used in the chloromethylation is selected from at least one of chloromethyl ether, chloroethyl ether and chloromethyl ethyl ether, preferably at least one of chloromethyl ether and chloromethyl ethyl ether; and / or, The chloromethylation conditions include: a temperature of 30 to 60° C., preferably 30 to 50° C., and / or a time of 8 to 30 hours, preferably 8 to 15 hours; and / or, The general formula of the phosphating agent used in the quaternary phosphating is PR 1 R 2 R 3 , where R 1 , R 2 , R 3 are independently selected from at least one of methyl, ethyl, propyl, n-butyl and aryl, preferably at least one of methyl, n-butyl and phenyl; and / or, The quaternization conditions include: reacting at reflux temperature for 10 to 72 hours, preferably reacting for 12 to 36 hours; and / or, The transformation agent used in the transformation is selected from at least one salt solution containing at least one of halide ions and organic acid ions, preferably at least one salt solution containing at least one of fluoride ions, bromide ions, iodide ions, acetate ions, formate ions, and hydrogen oxalate ions; and / or, The transformation conditions include: a temperature of 20 to 60° C., preferably 20 to 35° C., and / or a time of 4 to 72 hours, preferably 12 to 36 hours.

10. Use of the catalyst according to any one of claims 1 to 4 or the catalyst prepared by the method according to any one of claims 5 to 9 in the preparation of cyclic carbonates by cycloaddition of epoxides and CO2.

11. The use according to claim 10, characterized in that: The mass ratio of the catalyst to the epoxy compound is (0.05-0.25):1, preferably (0.1-0.2):1; and / or, The conditions for the cycloaddition include: a reaction temperature of 80 to 200° C., and / or a reaction time of 2 to 8 hours, and / or a reaction pressure of 2.0 to 10 MPa.

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