A supported N-containing heterocyclic catalyst and a preparation method and application thereof

Abstract

The application discloses a supported N-containing heterocyclic catalyst and a preparation method and application thereof. The supported N-containing heterocyclic catalyst comprises a carrier and a plurality of active ends, wherein the plurality of active ends are grafted on the carrier, and the structure of the active end is shown as formula (I): in the formula (I), R 1 , R 2 , R 3 , R 4 are each independently selected from one of hydrogen, an alkyl group, an aromatic group and an ester group, A + represents an N-containing heterocyclic cation, n>0, R1 is selected from an alkylene group, R2 is selected from a hydroxyl group, a carboxyl group, an amino group or hydrogen, and X ‑ is an anion. The supported N-containing heterocyclic catalyst can be used in an addition reaction of an alkylene oxide and carbon dioxide to prepare an alkylene carbonate, has high catalyst activity, good stability, and the product after the reaction is easy to separate; the catalyst can be continuously used for multiple times, and has a long service life.

Description

Technical Field

[0001] This invention belongs to the field of catalysts, and particularly relates to cycloaddition reaction catalysts, especially to a supported N-containing heterocyclic catalyst, its preparation method and application. Background Technology

[0002] Alkyl carbonates, such as ethylene carbonate (EC) and propylene carbonate (PC), are widely used green chemical products, serving as high-performance organic solvents and fine chemical intermediates. For example, propylene carbonate is widely used as a solvent in textiles, printing, polymer synthesis, and electrochemistry, and also as a raw material for cosmetics and pharmaceuticals, as well as an intermediate for corresponding diols. Furthermore, with the widespread use of lithium batteries in recent years, propylene carbonate has also been applied to lithium battery electrolytes, and its usage has been increasing year by year. In addition, it is also used as a raw material for the production of dimethyl carbonate. The industrial production of aliphatic polycarbonates and their various copolymers, as biodegradable biomaterials, has attracted considerable attention.

[0003] The production of propylene carbonate mainly includes urea alcoholysis, transesterification, and propylene oxide / carbon dioxide addition. Among these, the cyclopropane / carbon dioxide addition method is currently the mainstream process. This process directly utilizes carbon dioxide, a greenhouse gas, to alleviate carbon dioxide emissions. However, due to the harsh reaction conditions, the production cost is relatively high, and most catalysts are homogeneous, leading to difficulties in product separation. Therefore, the development of heterogeneous catalysts is of greater significance.

[0004] Compared to homogeneous catalysts, heterogeneous catalysts facilitate the separation of subsequent products from the catalyst, and are easily regenerated and can be reused multiple times. Currently developed heterogeneous catalysts for the addition of epoxides and carbon dioxide mainly include metal oxides, metal-organic frameworks, carbon materials, and supported ionic liquids.

[0005] CN101511810A reports a zinc halide catalyst supported on a solid support, which is a quaternary phosphorus or quaternary ammonium ion exchange resin. The activity of this catalytic system decreases rapidly after being reused.

[0006] CN105503608A discloses a supported hydroxyimidazolium ionic liquid with an ion exchange resin as the support. At a reaction temperature of 120℃ and a reaction pressure of 2.0 MPa for 3 hours, the conversion rate of ethylene oxide is 98.6%, and the selectivity of ethylene carbonate is 99.7%. However, this catalyst requires the use of expensive hydroxy halides for preparation, and its recyclability is insufficient, showing a certain decline after 5 cycles.

[0007] Although heterogeneous catalytic systems have many advantages, they still have some shortcomings, such as catalyst performance, production cost, and the universality of raw materials. Therefore, researching and developing a highly active, stable, and easily separable heterogeneous catalytic system to improve the catalytic performance of heterogeneous catalysts remains a hot topic in epoxide / carbon dioxide addition reaction research. Summary of the Invention

[0008] To overcome the problems existing in the prior art, the present invention provides a supported N-containing heterocyclic catalyst, its preparation method and application. The catalyst can be used in the addition reaction of epoxide alkane-carbon dioxide to prepare alkylene carbonate, and has the advantages of good catalyst activity, high stability, easy separation of reaction products, and continuous recycling of the catalyst multiple times.

[0009] One objective of this invention is to provide a supported nitrogen-containing heterocyclic catalyst, comprising a support and a plurality of active ends, wherein the plurality of active ends are grafted onto the support, and the structure of the active ends is shown in formula (I):

[0010]

[0011] In equation (I), R 1 R 2 R 3 R 4 Each is independently selected from one of hydrogen, alkyl, aromatic, or ester groups, A + This indicates a heterocyclic cation containing N, where n > 0, R1 is selected from alkylene groups, R2 is selected from hydroxyl, carboxyl, amino, or hydrogen groups, and X - It is an anion.

[0012] In this invention, the carrier and the active end are connected by covalent bonds, wherein * in formula (I) is a binding site.

[0013] In a preferred embodiment, in formula (I), R 1 R 2 R 3 R 4 Each is independently selected from one of hydrogen, C1-C30 alkyl, C6-C30 aryl, or C2-C30 ester groups, A + Selected from imidazole cations, pyrazole cations, pyrrolidine cations, piperidine cations, piperazine cations, pyrimidine cations, pyrazine cations, pyridazine cations, or triazine cations, n = 4–100, R1 selected from C1–C6 alkylene groups, R2 selected from hydroxyl, carboxyl, amino, or hydrogen groups, X - It is selected from one of the halogen anions and organic acid anions.

[0014] In a further preferred embodiment, in formula (I), R1 R 2 R 3 R 4 Each is independently selected from one of hydrogen, C1-C20 alkyl, C6-C20 aryl, or C2-C20 ester groups, A + Selected from imidazole cations, pyrrolidine cations, piperidine cations, or piperazine cations (e.g., imidazole cations), n = 5 to 20, R1 selected from C1 to C4 alkylene groups (preferably methylene, ethylene, propylene, or butylene, e.g., ethylene), R2 selected from hydrogen, X - It is one of chloride ions, bromide ions, iodide ions, and formate ions.

[0015] For example, in equation (I), n = 5, 6, 8, 10, 12, 14, 16, 18 or 20.

[0016] In a preferred embodiment, the carrier is a styrene-based crosslinked copolymer resin containing inorganic nanomaterials.

[0017] In a further preferred embodiment, the inorganic nanomaterial is selected from at least one of carbon nanotubes, graphene, POSS compounds, graphite, and fullerene.

[0018] In a further preferred embodiment, based on 100wt% of the total weight of the styrene-based crosslinked copolymer resin containing inorganic nanomaterials, the weight content of inorganic nanomaterials is 0.1wt%-4wt%, preferably 0.1wt%-3wt%, and more preferably 0.2wt%-2wt%.

[0019] For example, based on 100 wt% of the total weight of the styrene-based crosslinked copolymer resin containing inorganic nanomaterials, the weight of the inorganic nanomaterials is 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%, 1 wt%, 1.4 wt%, 1.8 wt%, 2.2 wt%, 2.6 wt%, 2.8 wt%, 3.2 wt%, 3.6 wt%, or 4 wt%.

[0020] In a preferred embodiment, the styrene-based crosslinked copolymer resin containing inorganic nanomaterials is obtained as follows: styrene monomers, crosslinking agents, inorganic nanomaterials, and initiators are mixed and copolymerized to obtain the styrene-based crosslinked copolymer resin containing inorganic nanomaterials.

[0021] In a further preferred embodiment, the styrene monomer is selected from styrene and its derivatives, preferably from at least one of styrene, halogenated styrene (e.g., chlorostyrene), halogenated alkylstyrene (e.g., p-chloromethylstyrene), α-methylstyrene, and alkoxy-substituted styrene.

[0022] In a further preferred embodiment, the crosslinking agent is selected from at least one of divinylbenzene, ethylene glycol dimethacrylate, diallylbenzene, and divinylphenylmethane.

[0023] In a preferred embodiment, based on 100 wt% of the supported N-containing heterocyclic catalyst, the content of the support is 5-50 wt%, and the content of the active end is 50-95 wt%.

[0024] In a further preferred embodiment, based on 100 wt% of the supported N-containing heterocyclic catalyst, the content of the support is 10-40 wt%, and the content of the active end is 60-90 wt%.

[0025] For example, based on 100 wt% of the supported N-containing heterocyclic catalyst, the content of the support is 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, or 50 wt%, and the content of the active end is 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, or 95 wt%.

[0026] The supported N-containing heterocyclic catalyst of the present invention has a higher concentration of active centers on its surface. Thus, when applied to the preparation of cyclic carbonates, the reactants do not need to diffuse into the interior of the catalyst spheres because the surface itself has higher reactivity.

[0027] A second objective of this invention is to provide a method for preparing a supported N-containing heterocyclic catalyst, preferably used for preparing the supported N-containing heterocyclic catalyst described in one objective of this invention, wherein the preparation method includes:

[0028] (1) First, obtain the styrene crosslinked copolymer resin containing inorganic nanomaterials, and optionally perform halomethylation treatment on it (the styrene crosslinked copolymer resin containing inorganic nanomaterials); (2) In the presence of a catalyst and ligand, graft (or polymerize) styrene monomers onto the product of step (1), and then optionally perform halomethylation treatment.

[0029] (3) The product of step (2) is subjected to N heterocyclization reaction and ion exchange treatment in sequence to obtain the supported N-containing heterocyclic catalyst.

[0030] The halomethylation treatment includes chloromethylation and / or bromomethylation, preferably chloromethylation. In this invention, the chloromethylation treatment can be carried out using a chloromethylation reaction disclosed in the prior art, such as chloromethyl ether-zinc chloride or formaldehyde-hydrogen chloride-zinc chloride, as long as the chloromethylation of the benzene ring can be achieved. The chloromethyl ether refers to a chloromethyl alkyl ether, for example, selected from chloromethyl methyl ether and / or chloromethyl diethyl ether.

[0031] In a preferred embodiment, the styrene-based crosslinked copolymer resin containing inorganic nanomaterials is obtained as follows: raw materials including styrene monomers, crosslinking agents, inorganic nanomaterials, and initiators are mixed and copolymerized to obtain the styrene-based crosslinked copolymer resin containing inorganic nanomaterials.

[0032] In a further preferred embodiment, the styrene monomer is selected from styrene and its derivatives, preferably from at least one of styrene, p-chloromethylstyrene, α-methylstyrene, and alkoxy-substituted styrene; and / or, the crosslinking agent is selected from at least one of divinylbenzene, ethylene glycol dimethacrylate, diallylbenzene, and divinylphenylmethane; and / or, the initiator is selected from at least one of benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, lauroyl peroxide, or cumene hydroperoxide.

[0033] In a further preferred embodiment, based on 100 wt% of the total weight of the raw materials, the inorganic nanomaterials contain 0.1 wt%-4 wt%, preferably 0.1 wt%-3 wt%, more preferably 0.2 wt%-2 wt%; and / or, the styrene monomer contains 82 wt%-95 wt%; and / or, the crosslinking agent contains 2 wt%-15 wt%; and / or, the initiator contains 0.1 wt%-3 wt%.

[0034] For example, based on a total weight of 100 wt% of the raw materials, the weight content of inorganic nanomaterials is 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%, 1 wt%, 1.4 wt%, 1.8 wt%, 2.2 wt%, 2.6 wt%, 2.8 wt%, 3.2 wt%, 3.6 wt%, or 4 wt%; and / or, the mass content of the styrene monomers is 82 wt%, 83 wt%, 84 wt%, 85 wt%, or 86 wt%. The crosslinking agent content is 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, or 15 wt%; and / or the initiator content is 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, or 3 wt%.

[0035] In a preferred embodiment, when preparing the styrene-based crosslinked copolymer resin containing inorganic nanomaterials, the raw material further includes gelatin, preferably a dissolved aqueous solution of gelatin.

[0036] In this invention, the conditions for preparing the styrene-based crosslinked copolymer resin containing inorganic nanomaterials can be the commonly used conditions disclosed in the prior art.

[0037] In a preferred embodiment, in step (1), when the styrene-based crosslinked copolymer resin containing inorganic nanomaterials is prepared by using halogen-substituted styrene and / or halogen-substituted alkyl styrene as styrene monomers, the obtained styrene-based crosslinked copolymer resin containing inorganic nanomaterials is directly subjected to the treatment in step (2), that is, without halogen methylation treatment.

[0038] In another preferred embodiment, in step (1), when the styrene crosslinked copolymer resin containing inorganic nanomaterials is prepared using other styrene monomers besides halogen-substituted styrene and halogen-substituted alkyl styrene, the obtained styrene crosslinked copolymer resin containing inorganic nanomaterials is subjected to halomethylation treatment before proceeding to step (2).

[0039] In a preferred embodiment, in step (2), when the styrene monomer is selected from halogenated styrene and / or halogenated alkyl styrene, step (3) is performed directly after the grafting is completed, i.e., no further halomethylation treatment is performed.

[0040] In another preferred embodiment, in step (2), when the styrene monomer is selected from other styrene monomers besides halogenated styrene and halogenated alkyl styrene, halomethylation is performed after the grafting is completed, and then step (3) is performed.

[0041] In a preferred embodiment, in step (2), the catalyst is selected from cuprous halides, preferably from cuprous chloride and / or bromide ketones; and / or, the ligand is selected from nitrogen-based ligands, preferably from at least one of 2,2'-bipyridine, PMDETA, pyridinium imine, DETA, TREN, and CYCLAM.

[0042] In a further preferred embodiment, in step (2), the molar ratio of the catalyst to the ligand is 1:(1-10), preferably 1:(2-5).

[0043] For example, in step (2), the molar ratio of the catalyst to the ligand is 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10.

[0044] In a preferred embodiment, in step (2), the grafting (or polymerization) is carried out under a protective atmosphere, such as nitrogen.

[0045] In a preferred embodiment, in step (2), the total weight ratio of the catalyst and ligand to the product of step (1) is (0.08–0.4):1, preferably (0.1–0.3):1, for example 0.08:1, 0.09:1, 0.1:1, 0.12:1, 0.14:1, 0.16:1, 0.18:1, 0.2:1, 0.22:1, 0.24:1, or 0.25:1, 0.3:1, 0.35:1, or 0.4:1.

[0046] In a preferred embodiment, the weight ratio of the styrene monomer to the product of step (1) is (1-6):1, preferably (2-5):1, for example 1:1, 2:1, 3:1, 4:1, 5:1 or 6:1.

[0047] In this invention, the grafting (or polymerization) conditions in step (2) can be the commonly used conditions disclosed in the prior art, such as 0.2 to 6 hours at 70 to 150°C.

[0048] In this invention, chloromethyl ether and zinc chloride are preferably used for the chloromethylation reaction. Preferably, the weight ratio of chloromethyl ether to the raw material to be chloromethylated is (2-6):1, for example, 2:1, 3:1, 4:1, 5:1 or 6:1; the weight ratio of zinc chloride to the raw material to be chloromethylated is (0.2-1):1, for example, 0.2:1, 0.4:1, 0.6:1, 0.8:1 or 1:1. The chloromethyl ether refers to a chloromethyl alkyl ether, for example selected from chloromethyl methyl ether and / or chloromethyl ethyl ether.

[0049] In a preferred embodiment, in step (3), the N-heterocyclization reaction is carried out using an N-containing heterocyclic compound.

[0050] In a further preferred embodiment, the N-containing heterocyclic compound is selected from at least one of substituted or unsubstituted imidazoles, substituted or unsubstituted pyrazoles, substituted or unsubstituted pyrrolidines, substituted or unsubstituted piperidines, substituted or unsubstituted piperazines, substituted or unsubstituted pyrimidines, substituted or unsubstituted pyrazines, substituted or unsubstituted pyridazines, and substituted or unsubstituted triazines, preferably at least one of substituted or unsubstituted imidazoles, substituted or unsubstituted pyrrolidines, substituted or unsubstituted piperidines, and substituted or unsubstituted piperazines.

[0051] Preferably, the substitution is alkyl substitution or aryl substitution, preferably C1-C10 alkyl substitution or C6-C15 aryl substitution.

[0052] In a further preferred embodiment, the weight ratio of the N-containing heterocyclic compound to the product of step (2) is (0.4-3):1, preferably (0.8-2):1.

[0053] For example, the weight ratio of the N-containing heterocyclic compound to the product of step (2) is 0.4:1, 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.8:1, 2:1, 2.2:1, 2.5:1, 2.8:1 or 3:1.

[0054] In a preferred embodiment, the N-heterocyclization reaction in step (3) is carried out in an organic solvent.

[0055] In a further preferred embodiment, the organic solvent is selected from at least one of acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and tetrahydrofuran.

[0056] In a further preferred embodiment, the weight ratio of the organic solvent to the product of step (2) is (3-10):1, preferably (3-6):1.

[0057] For example, the weight ratio of the organic solvent to the product of step (2) is 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1.

[0058] In a preferred embodiment, in step (3), the N heterocyclization reaction is carried out at a temperature of 50–150 °C for a time of 12–36 h.

[0059] For example, in step (3), the temperature of the N heterocyclization reaction is 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C, and the time is 12h, 15h, 18h, 20h, 22h, 25h, 28h, 30h, 32h, 34h or 36h.

[0060] In a preferred embodiment, a post-treatment, preferably washing, is performed after the N-heterocyclization reaction.

[0061] In a further preferred embodiment, washing is performed sequentially using organic solvent I, an aqueous solution of inorganic acid, water, and organic solvent II.

[0062] In a further preferred embodiment, the organic solvent I is selected from at least one of ethyl acetate, methyl formate, and methyl acetate; and / or, the inorganic acid aqueous solution is selected from at least one of hydrochloric acid aqueous solution, sulfuric acid aqueous solution, and nitric acid aqueous solution; and / or, the organic solvent II is selected from at least one of methanol, ethanol, and propanol.

[0063] In a preferred embodiment, the ion exchange treatment in step (3) is carried out in a saline aqueous solution.

[0064] In a further preferred embodiment, the salt is selected from at least one of halogen salts, sodium formate, potassium formate, magnesium formate, calcium formate, sodium acetate, potassium acetate, magnesium acetate, and calcium acetate; preferably, the concentration of the salt-containing aqueous solution is 0.05 to 2 mol / L, more preferably 0.1 to 1 mol / L.

[0065] In a further preferred embodiment, the ion exchange treatment is performed for 3 to 24 hours, preferably 5 to 10 hours.

[0066] For example, the ion exchange treatment is performed for 3h, 5h, 8h, 10h, 12h, 15h, 18h, 20h, 22h or 24h.

[0067] The third objective of this invention is to provide a supported N-containing heterocyclic catalyst obtained by the preparation method described in the second objective of this invention.

[0068] The fourth objective of this invention is to provide the application of the supported N-containing heterocyclic catalyst described in the first objective of this invention, or the supported N-containing heterocyclic catalyst obtained by the preparation method described in the second objective of this invention, in the preparation of cyclic carbonates by the cycloaddition reaction of alkyl epoxides / carbon dioxide.

[0069] Preferably, the epoxide alkane has the following general formula:

[0070]

[0071] Among them, R3-R6 may be the same or different, and each is independently selected from hydrogen, C1-C6 haloalkyl or C6-C 10 The aryl group is preferably selected from hydrogen, methyl, ethyl, propyl, butyl, or phenyl; preferably, the alkylene oxide is selected from ethylene oxide or propylene oxide.

[0072] In a preferred embodiment, the weight ratio of the catalyst to the epoxide is (0.001-1):1, preferably (0.1-0.3):1.

[0073] For example, the weight ratio of the catalyst to the epoxide is 0.001:1, 0.01:1, 0.05:1, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, or 1:1.

[0074] In a preferred embodiment, the temperature of the cycloaddition reaction is 60-180°C, preferably 100-160°C.

[0075] For example, the cycloaddition reaction is performed at temperatures of 60°C, 80°C, 100°C, 120°C, 140°C, 160°C, or 180°C.

[0076] In a preferred embodiment, the pressure of the cycloaddition reaction is 0.1-10.0 MPa, preferably 2.0-5.0 MPa.

[0077] For example, the pressure of the cycloaddition reaction is 0.1 MPa, 0.5 MPa, 1 MPa, 2 MPa, 4 MPa, 6 MPa, 8 MPa or 10.0 MPa.

[0078] In a preferred embodiment, the cycloaddition reaction takes 1-12 hours, for example, 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, or 12 hours.

[0079] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In the following, various technical solutions can, in principle, be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0080] Compared with the prior art, the present invention has the following beneficial effects:

[0081] (1) The supported N-containing heterocyclic catalyst of the present invention has more N-containing heterocyclic active sites on its surface;

[0082] (2) The supported N-containing heterocyclic catalyst described in this invention can be used in the addition reaction of epoxides and carbon dioxide to prepare alkylene carbonates. The catalyst has high activity, good stability, and the product after reaction is easy to separate. The catalyst can be used continuously multiple times and has a long service life.

[0083] (3) The supported N-containing heterocyclic catalyst described in this invention has the advantages of high conversion rate of alkylene oxide and high selectivity of alkylene carbonate when used in the addition reaction of alkylene oxide with carbon dioxide to prepare alkylene carbonate. Attached Figure Description

[0084] Figure 1 The infrared spectrum of the composite imidazole microspheres obtained in Example 1 is shown. Detailed Implementation

[0085] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection 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 are still within the scope of protection of the present invention.

[0086] It should also be noted that the various specific technical features described in the following embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the various possible combinations will not be described separately in this invention.

[0087] Furthermore, various embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention. The resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0088] Unless otherwise specified, the raw materials used in the examples and comparative examples are all publicly available in the prior art, such as those that can be directly purchased or prepared according to publicly available methods. The chloromethyl ether mentioned in the examples and comparative examples is chloromethyl methyl ether.

[0089] In the examples, the chlorine content was determined by the oxygen flask-mercury metric method.

[0090]

Example 1

[0091] 60.0 g of styrene, 4.5 g of divinylbenzene, and 0.6 g of benzoyl peroxide initiator were placed in a 500 mL three-necked flask and stirred at 60 °C for 1.0 h. Then, 0.7 g of octavinyl POSS was added, and stirring continued for 1 h for prepolymerization. 300 mL of deionized water containing 2.9 g of gelatin was added. The stirring speed was adjusted, and the temperature was gradually increased to 78 °C for 4 h; then increased to 90 °C for 4 h; and finally increased to 98 °C for 5 h. After the reaction was complete, the supernatant was decanted, washed with 80 °C hot water, then washed with cold water, filtered, dried in a vacuum oven at 60 °C, sieved, and composite microspheres with a particle size in the range of 0.35–0.60 mm were collected.

[0092] 40 g of composite microspheres and 180 ml of chloromethyl ether were placed in a 500 ml three-necked flask and allowed to stand at room temperature for 3 hours. Then, stirring was started, and 16 g of zinc chloride was added as a catalyst. The temperature was raised to 60 °C and the reaction was carried out for 4 hours. After chloromethylation was completed, the mixture was cooled to room temperature, the chlorination mother liquor was filtered out, and the mixture was washed repeatedly with methanol. The mixture was then dried in a vacuum oven at 60 °C for 10 hours to obtain 46 g of composite chlorine microspheres (with a chlorine content of 10 wt% and 0.113 mol).

[0093] 40 g of composite chloride spheres and 150 ml of toluene were placed in a 500 ml flask and allowed to swell for 1 hour. Then, 80 g of styrene and 12 g of cuprous chloride / 2,2'-bipyridine (molar ratio 1:2) were added. The air in the flask was completely replaced with high-purity nitrogen, and the reaction was carried out at 110 °C for 2 hours. After the reaction was complete, the mixture was washed with tetrahydrofuran to obtain composite modified resin A2, whose surface was grafted with a layer of styrene with the structure shown below:

[0094] In the formula, n = 6.8

[0095] Add 50 g of composite modified resin and 250 ml of chloromethyl ether to a 500 ml three-necked flask, let stand at room temperature for 2 hours, then start stirring. Add 22 g of zinc chloride as a catalyst, heat to 50 °C and react for 10 hours. After chloromethylation is complete, cool to room temperature, filter out the chlorination mother liquor, wash repeatedly with methanol, and dry in a vacuum oven at 60 °C for 10 hours to obtain composite modified chlorine balls (chlorine content of 15 wt%). The surface of these balls is grafted with a layer of chloromethylated styrene with the structure shown below:

[0096]

[0097] Add 40 g of composite modified chlorine spheres, 80 g of N-methylimidazole and 200 ml of acetonitrile to a 500 ml three-necked flask, react at 85 °C for 12 hours, cool to room temperature, filter, wash successively with ethyl acetate, 0.1 mol / L HCl, deionized water and methanol, and then dry under vacuum at 80 °C for 24 hours to obtain composite imidazole microspheres.

[0098] Infrared detection of the composite imidazole microspheres obtained in Example 1 revealed characteristic peaks containing benzene rings, imidazole groups, etc.

[0099] In a 1000 ml three-necked flask, 40 g of composite imidazole microspheres and 500 ml of 0.2 mol / L NaBr deionized water solution were added to carry out an ion exchange reaction at room temperature for 8 hours. The solution was then washed with deionized water until the pH of the washing solution was 7, and then dried under vacuum to obtain the nanocomposite ion exchange resin catalyst Cat-1.

[0100] In the nanocomposite ion exchange resin catalyst Cat-1, the weight content of the styrene crosslinked copolymer resin containing inorganic nanomaterials is 15.5 wt%, and the weight content of the molecular chain shown in formula (I) is 84.5 wt% (calculated based on the theoretical value after the chlorine content was determined).

[0101]

Example 2

[0102] The process of Example 1 was repeated, except that "0.2 mol / L NaBr deionized water solution" was replaced with "0.8 mol / L NaCl deionized water solution", while other conditions remained unchanged, to obtain catalyst Cat-2.

[0103]

Example 3

[0104] The process of Example 1 was repeated, except that "0.2 mol / L NaBr deionized water solution" was replaced with "0.5 mol / L NaI deionized water solution", while other conditions remained unchanged, to obtain catalyst Cat-3.

[0105]

Example 4

[0106] The process of Example 1 was repeated, except that an equimolar amount of N-propylimidazole was used to replace N-methylimidazole, while other conditions remained unchanged, to obtain catalyst Cat-4.

[0107] Infrared detection of the composite imidazole microspheres obtained in Example 4 revealed characteristic peaks containing benzene rings, imidazole groups, etc.

[0108]

Example 5

[0109] The process of Example 1 was repeated, except that an equimolar amount of N-methylpyrrolidine was used to replace the N-methylimidazole, while other conditions remained unchanged, to obtain catalyst Cat-5.

[0110] Infrared detection of the composite microspheres obtained in Example 5 revealed characteristic peaks containing benzene rings, pyrrole groups, etc.

[0111]

Example 6

[0112] 60 g of styrene, 5 g of divinylbenzene, and 0.7 g of benzoyl peroxide initiator were placed in a 500 mL three-necked flask and stirred at 60 °C for 1.0 h. Then, 1.5 g of multi-walled carbon nanotubes were added, and stirring continued for 1 h for prepolymerization. 300 mL of deionized water containing 3 g of gelatin was added. The stirring speed was adjusted, and the temperature was gradually increased to 78 °C for 4 h; then increased to 90 °C for 4 h; and finally increased to 98 °C for 5 h. After the reaction was complete, the supernatant was poured off, washed with 80 °C hot water, then washed with cold water, filtered, dried in a vacuum oven at 60 °C, sieved, and composite microspheres with a particle size in the range of 0.35–0.60 mm were collected.

[0113] 40 g of composite microspheres and 120 ml of chloromethyl ether were placed in a 500 ml three-necked flask and allowed to stand at room temperature for 3 hours. Then, stirring was started, and 24 g of zinc chloride was added as a catalyst. The temperature was raised to 60 °C and the reaction was carried out for 4 hours. After chloromethylation was completed, the mixture was cooled to room temperature, the chlorination mother liquor was filtered out, and the mixture was washed repeatedly with methanol. The mixture was then dried in a vacuum oven at 60 °C for 10 hours to obtain 46 g of composite chlorine microspheres.

[0114] 40 g of composite chloride spheres and 150 ml of toluene were placed in a 500 ml flask and allowed to swell for 1 hour. Then, 160 g of styrene and 10 g of cuprous chloride / 2,2'-bipyridine (molar ratio 1:2) were added. The air in the flask was completely replaced with high-purity nitrogen, and the reaction was carried out at 110 °C for 2 hours. After the reaction was complete, the mixture was washed with tetrahydrofuran to obtain a composite modified resin with a styrene layer grafted onto its surface, as shown below:

[0115] Add 50 g of composite modified resin and 190 ml of chloromethyl ether to a 500 ml three-necked flask, let stand at room temperature for 2 hours, then start stirring. Add 15 g of zinc chloride as a catalyst, heat to 50 °C and react for 10 hours. After chloromethylation is complete, cool to room temperature, filter out the chlorination mother liquor, wash repeatedly with methanol, and dry in a vacuum oven at 60 °C for 10 hours to obtain composite modified chlorine spheres with a layer of chloromethylated styrene grafted onto its surface as shown below:

[0116] 40 g of composite modified chlorine spheres, 44 g of N-ethylimidazole and 240 g of N,N-dimethylformamide were added to a 500 ml three-necked flask and reacted at 100 °C for 15 hours. After cooling to room temperature, the mixture was filtered and washed successively with ethyl acetate, 0.1 mol / L HCl, deionized water and methanol. Then it was dried under vacuum at 80 °C for 24 hours to obtain composite imidazole microspheres.

[0117] Infrared detection of the composite imidazole microspheres obtained in Example 6 revealed characteristic peaks containing benzene rings, imidazole groups, etc.

[0118] In a 1000ml three-necked flask, 40g of composite imidazole microspheres and 500ml of 1mol / L NaBr deionized water solution were added to carry out an ion exchange reaction at room temperature for 5 hours with stirring. The solution was then washed with deionized water until the pH of the washing solution was 7, and then dried under vacuum to obtain the nanocomposite ion exchange resin catalyst.

[0119]

Example 7

[0120] 55 g of styrene, 3.2 g of divinylbenzene, and 0.5 g of benzoyl peroxide initiator were placed in a 500 mL three-necked flask and stirred at 60 °C for 1.0 h. Then, 2.5 g of graphene was added, and stirring continued for 1 h for prepolymerization. 300 mL of deionized water containing 3 g of gelatin was added. The stirring speed was adjusted, and the temperature was gradually increased to 78 °C for 4 h; then increased to 90 °C for 4 h; and finally increased to 98 °C for 5 h. After the reaction was complete, the supernatant was poured off, washed with 80 °C hot water, then washed with cold water, filtered, dried in a vacuum oven at 60 °C, sieved, and composite microspheres with a particle size in the range of 0.35–0.60 mm were collected.

[0121] 40 g of composite microspheres and 220 ml of chloromethyl ether were placed in a 500 ml three-necked flask and allowed to stand at room temperature for 3 hours. Then, stirring was started, and 32 g of zinc chloride was added as a catalyst. The temperature was raised to 60 °C and the reaction was carried out for 4 hours. After chloromethylation was completed, the mixture was cooled to room temperature, the chlorination mother liquor was filtered out, and the mixture was washed repeatedly with methanol. The mixture was then dried in a vacuum oven at 60 °C for 10 hours to obtain 46 g of composite chlorine microspheres.

[0122] 40 g of composite chloride spheres and 150 ml of toluene were placed in a 500 ml flask and allowed to swell for 1 hour. Then, 240 g of styrene and 6 g of cuprous chloride / 2,2'-bipyridine (molar ratio 1:2) were added. The air in the flask was completely replaced with high-purity nitrogen, and the reaction was carried out at 110 °C for 2 hours. After the reaction was complete, the mixture was washed with tetrahydrofuran to obtain a composite modified resin with a styrene layer grafted onto its surface, as shown below:

[0123] Add 50 g of composite modified resin and 140 ml of chloromethyl ether to a 500 ml three-necked flask, let stand at room temperature for 2 hours, then start stirring. Add 30 g of zinc chloride as a catalyst, heat to 50 °C and react for 10 hours. After chloromethylation is complete, cool to room temperature, filter out the chlorination mother liquor, wash repeatedly with methanol, and dry in a vacuum oven at 60 °C for 10 hours to obtain composite modified chlorine spheres with a layer of chloromethylated styrene grafted onto its surface as shown below:

[0124] 40 g of composite modified chlorine spheres, 67 g of N-propylimidazolium and 120 g of N,N-dimethylacetamide were added to a 500 ml three-necked flask and reacted at 120 °C for 20 hours. After cooling to room temperature, the mixture was filtered and washed successively with ethyl acetate, 0.1 mol / L HCl, deionized water and methanol. Then it was dried under vacuum at 80 °C for 24 hours to obtain composite imidazolium microspheres.

[0125] Infrared detection of the composite imidazole microspheres obtained in Example 7 revealed characteristic peaks containing benzene rings, imidazole groups, etc.

[0126] In a 1000ml three-necked flask, 40g of composite imidazole microspheres and 500ml of 0.1mol / L NaCl deionized water solution were added to carry out an ion exchange reaction at room temperature for 20 hours with stirring. The solution was then washed with deionized water until the pH of the washing solution was 7, and then dried under vacuum to obtain the nanocomposite ion exchange resin catalyst.

[0127] Comparative Example 1

[0128] The process of Example 1 was repeated, except that after obtaining the composite chlorine spheres A1, styrene grafting was not performed. Instead, the composite microspheres A1 were directly subjected to N-heterocyclic reaction and ion exchange treatment.

[0129] 60.0 g of styrene, 4.5 g of divinylbenzene, and 0.6 g of benzoyl peroxide initiator were placed in a 500 mL three-necked flask and stirred at 60 °C for 1.0 h. Then, 0.7 g of octavinyl POSS was added, and stirring continued for 1 h for prepolymerization. 300 mL of deionized water containing 2.9 g of gelatin was added. The stirring speed was adjusted, and the temperature was gradually increased to 78 °C for 4 h; then increased to 90 °C for 4 h; and finally increased to 98 °C for 5 h. After the reaction was complete, the supernatant was decanted, washed with 80 °C hot water, then washed with cold water, filtered, dried in a vacuum oven at 60 °C, sieved, and composite microspheres with a particle size in the range of 0.35–0.60 mm were collected.

[0130] 40 g of composite microspheres and 180 ml of chloromethyl ether were placed in a 500 ml three-necked flask and allowed to stand at room temperature for 3 hours. Then, stirring was started, and 16 g of zinc chloride was added as a catalyst. The temperature was raised to 60 °C and the reaction was carried out for 4 hours. After chloromethylation was completed, the mixture was cooled to room temperature, the chlorination mother liquor was filtered out, and the mixture was washed repeatedly with methanol. The mixture was then dried in a vacuum oven at 60 °C for 10 hours to obtain 46 g of composite chlorine microspheres (with a chlorine content of 10 wt% and 0.113 mol).

[0131] Add 40 g of composite chlorine microspheres, 80 g of N-methylimidazole and 200 ml of acetonitrile to a 500 ml three-necked flask, react at 85 °C for 12 hours, cool to room temperature, filter, wash successively with ethyl acetate, 0.1 mol / L HCl, deionized water and methanol, and then dry under vacuum at 80 °C for 24 hours to obtain composite imidazole microspheres D1.

[0132] In a 1000 ml three-necked flask, 40 g of composite imidazole microspheres D1 and 500 ml of 0.2 mol / L NaBr deionized water solution were added to carry out an ion exchange reaction at room temperature for 24 hours with stirring. The solution was then washed with deionized water until the pH of the washing solution was 7, and after vacuum drying, the nanocomposite ion exchange resin catalyst Cat-D1 was obtained.

[0133] [Example 8] Preparation of cyclic carbonates by addition reaction of epoxides / carbon dioxide

[0134] The catalyst Cat-1 prepared in [Example 1] was used in the addition reaction of alkyl epoxides with carbon dioxide. The conditions for the addition reaction were as follows: in a 300 mL autoclave, the protective gas was high-purity nitrogen, the amount of ethylene oxide added was 40 g, and the amount of catalyst Cat-1 was 2.5 g. CO2 was first introduced at 1.0 MPa, and the temperature was gradually increased to 120 °C. Then CO2 was introduced to continue the reaction while maintaining the pressure of the reaction system at 2.0 MPa. After 2 hours of reaction, the catalyst Cat-1 was removed by filtration. The conversion rate of ethylene oxide (CEO) was 99.0%, and the selectivity of ethylene carbonate (SEC) was 99.7%.

[0135] The addition reaction of alkyl epoxides with carbon dioxide using catalysts obtained in other examples also has the advantages of high conversion of ethylene oxide and high selectivity of ethylene carbonate.

[0136] [Comparative Example 2] Preparation of cyclic carbonates by addition reaction of epoxides / carbon dioxide

[0137] The catalyst Cat-D1 prepared in Comparative Example 1 was used for the addition reaction of alkyl epoxides with carbon dioxide. The conditions for the addition reaction were as follows: in a 300 mL autoclave, the protective gas was high-purity nitrogen, the amount of ethylene oxide added was 40 g, and the amount of catalyst Cat-D1 was 2.5 g. CO2 was first introduced at 1.0 MPa, the temperature was gradually increased to 120 °C, and then CO2 was continued to be introduced for the reaction, while maintaining the pressure of the reaction system at 2.0 MPa. After 2 hours of reaction, the catalyst Cat-D1 was removed by filtration. The conversion rate of ethylene oxide (CEO) was 94.2%, and the selectivity of ethylene carbonate (SEC) was 99.2%.

[0138] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A supported N-containing heterocycle-based catalyst comprising a support and a plurality of active termini, wherein, The plurality of active ends are grafted onto the carrier, and the structure of the active ends is shown in formula (I): Formula (I) In formula (I), R 1 , R 2 , R 3 , R 4 are each independently selected from one of hydrogen, alkyl, aryl, ester, A + represents a N-containing heterocyclic cation, n = 4-100, R1 is selected from an alkylene group, R2 is selected from a hydroxyl group, a carboxyl group, an amino group or hydrogen, X - is an anion; the content of the carrier is 5-50 wt%, and the content of the active end is 50-95 wt%, based on 100 wt% of the supported N-containing heterocyclic catalyst.

2. The supported N-heterocyclic ring-based catalyst according to claim 1, wherein In formula (I), R 1 , R 2 , R 3 , R 4 are each independently selected from one of hydrogen, C1-C30 alkyl, C6-C30 aryl, C2-C30 ester, A + is selected from one of imidazolium, pyrazolium, pyrrolidinium, piperidinium, piperazinium, pyrimidinium, pyrazinium, pyridazinium or triazinium cation, n = 4-100, R1 is selected from C1-C6 alkylene, R2 is selected from hydroxyl, carboxyl, amino or hydrogen, X - is selected from one of halide, organic acid anion.

3. The supported N-heterocyclic ring-based catalyst according to claim 1, wherein The carrier is a styrene-based crosslinked copolymer resin containing inorganic nanomaterials.

4. The supported N-heterocyclic ring-based catalyst according to claim 3, wherein The inorganic nanomaterial is selected from at least one of carbon nanotubes, graphene, POSS compounds, graphite, and fullerene.

5. The supported N-heterocyclic ring-based catalyst according to claim 4, wherein Based on a total weight of 100wt% of the styrene-based crosslinked copolymer resin containing inorganic nanomaterials, the weight content of inorganic nanomaterials is 0.1wt%-4wt%.

6. The supported N-heterocyclic ring-based catalyst of claim 3, wherein The styrene-based crosslinked copolymer resin containing inorganic nanomaterials is obtained as follows: components including styrene monomers, crosslinking agents, inorganic nanomaterials, and initiators are mixed and copolymerized to obtain the styrene-based crosslinked copolymer resin containing inorganic nanomaterials.

7. A process for producing a supported N-containing heterocyclic catalyst as claimed in any one of claims 1 to 6, wherein The preparation method includes: (1) First, a styrene-based crosslinked copolymer resin containing inorganic nanomaterials is obtained, and then subjected to halomethylation treatment. The styrene-based crosslinked copolymer resin containing inorganic nanomaterials is obtained as follows: raw materials including styrene monomers, crosslinking agents, inorganic nanomaterials, and initiators are mixed and copolymerized to obtain the styrene-based crosslinked copolymer resin containing inorganic nanomaterials. The styrene monomers used are other styrene monomers except for halogen-substituted styrene and halogen-substituted alkyl styrene. (2) In the presence of a catalyst and ligand, styrene monomers are grafted onto the product of step (1), followed by halomethylation. (3) The product of step (2) is subjected to N heterocyclization reaction and ion exchange treatment in sequence to obtain the supported N-containing heterocyclic catalyst; in step (3), the N heterocyclization reaction is carried out using N-containing heterocyclic compounds.

8. The preparation method according to claim 7, characterized in that, The styrene monomer is selected from at least one of styrene, α-methylstyrene, and alkoxy-substituted styrene; and / or the crosslinking agent is selected from at least one of divinylbenzene, ethylene glycol dimethacrylate, and diallylbenzene; and / or the initiator is selected from at least one of benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, lauroyl peroxide, or cumene hydroperoxide.

9. The method of claim 7, wherein Based on a total weight of 100wt% of the raw materials, the inorganic nanomaterials contain 0.1wt%-4wt% by weight; and / or the styrene monomer contains 82wt%-95wt% by weight; and / or the crosslinking agent contains 2wt%-15wt% by weight; and / or the initiator contains 0.1wt%-3wt% by weight.

10. The preparation method according to claim 7, characterized in that, In step (2), the molar ratio of the catalyst to the ligand is 1:(1~10); And / or, In step (2), the total weight of the catalyst and ligand is in the weight ratio of the product of step (1) to (0.08~0.4):1, and the weight ratio of the styrene monomer to the product of step (1) is (1~6):

1.

11. The preparation method according to claim 10, characterized in that, The catalyst is selected from cuprous halides, and / or the ligand is selected from nitrogen-based ligands.

12. The preparation method according to claim 10, characterized in that, The ligand is selected from at least one of 2,2'-bipyridine, PMDETA, pyridine imine, DETA, TREN, CYCLAM.

13. The preparation method according to claim 7, wherein, The N-containing heterocyclic compound is selected from at least one of substituted or unsubstituted imidazole, substituted or unsubstituted pyrazole, substituted or unsubstituted pyrrolidine, substituted or unsubstituted piperidine, substituted or unsubstituted piperazine, substituted or unsubstituted pyrimidine, substituted or unsubstituted pyrazine, substituted or unsubstituted pyridazine, and substituted or unsubstituted triazine.

14. The method of claim 7, wherein, The weight ratio of the N-containing heterocyclic compound to the product of step (2) is (0.4-3):

1.

15. The preparation method according to any one of claims 7-14, wherein, The N-heterocyclization reaction in step (3) is carried out in an organic solvent; and / or, In step (3), the temperature of the N-heterocyclization reaction is 50-150°C, and the time is 12-36 h; and / or, In step (3), a post-treatment is carried out after the N-heterocyclization reaction; and / or, In step (3), the ion exchange treatment is carried out in a salt-containing aqueous solution.

16. The preparation method according to claim 15, wherein, The organic solvent is selected from at least one of acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and tetrahydrofuran; and / or, In step (3), a washing is carried out after the N-heterocyclization reaction; and / or, In step (3), the ion exchange treatment is carried out for 3-24 h.

17. The preparation method according to claim 15, characterized in that, The weight ratio of the organic solvent to the product of step (2) is (3-10):

1.

18. A supported N-containing heterocyclic catalyst prepared by the preparation method according to any one of claims 7-17.

19. Use of the supported N-containing heterocyclic catalyst according to any one of claims 1-6 or the supported N-containing heterocyclic catalyst prepared by the preparation method according to any one of claims 7-18 in a reaction for preparing a cyclic carbonate by an alkylene oxide / carbon dioxide cycloaddition reaction.

Images