Halogen-non-halogen ionic liquid composite intercalation material and method for catalyzing CO2 to synthesize carbonic ester by using halogen-non-halogen ionic liquid composite intercalation material

Abstract

The invention discloses a method for synthesizing carbonic ester through high-selectivity catalysis of CO2 by taking a halogen-non-halogen ionic liquid composite layered double hydroxide intercalation material structure as a multi-ion buffer catalysis system. The method comprises the following steps: preparing an ionic liquid containing the same cation but different anions (halogen and non-halogen), compounding the ionic liquid with a layered double hydroxide intercalation material to construct a halogen-non-halogen ion buffer catalyst, and catalyzing the reaction of synthesizing carbonic ester from CO2. The application of inhibiting halogenation side reaction and synthesizing carbonic ester with high selectivity can be realized. The halogen-non-halogen composite intercalation material system designed by the invention is simple in preparation method and has the functions of halogen and non-halogen basic ions, and the intercalation structure provides a buffer ordered effect of ion active sites, so that the problem of selectivity of a carbonate product synthesized by catalyzing CO2 through halide ions is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of CO2 resource utilization and the construction of a carbonate synthesis system, and particularly to the development of halogen-non-halogen ionic liquid composite intercalation materials and a method for catalytically synthesizing carbonates from CO2 with high activity and high selectivity. An ionic liquid composite aluminum-based layered double hydroxide intercalation material with the same cation, halogen and non-halogen double anions is used to synergistically promote the formation of carbonates, effectively avoid the generation of halogenated by-products, and regulate the main and side reaction paths to improve the selectivity of preparing carbonates. Background Art

[0002] Halogen ionic liquids are classic catalysts for the reaction of synthesizing carbonates from CO2. The positive and negative ions can be adjusted and act synergistically, with good catalytic activity, making them have good application prospects in the resource utilization of CO2. The key to the development of the reaction for synthesizing carbonates from CO2 conversion lies in improving catalytic activity and promoting raw material conversion. However, the regulation of the main and side reactions still needs to be further studied. Although halogen ionic liquid catalysts are efficient, they still have the defect of unavoidable halogenated by-products. The generation of halogenated alcohols will lead to a decrease in the selectivity of reaction products, loss of ionic liquid components, affecting the catalyst life and catalytic efficiency. At the same time, halogenated by-products will increase the difficulty of product purification, and will also cause corrosion of the pipe wall and damage to instruments and equipment, seriously affecting the potential applicability of the reaction system. Layered double hydroxides (LDHs) are a general term for hydrotalcite and hydrotalcite-like compounds, and are intercalated and assembled supramolecular materials with alkalinity. The chemical composition of the main layer board of LDHs is closely related to factors such as the characteristics of its layer board cations, layer board charge density or anion exchange capacity, and supramolecular intercalation structure. Its chemical composition can be expressed as [M 2+ 1-x M 3+ x (OH)2] x+ [(A n- ) x / n ·mH2O] x- . In the crystal structure of LDHs, the positively charged hydroxide layer board and the interlayer anions that balance its charge constitute an adjustable chemical composition. Guest ions can also be introduced between the layer boards to construct a composite structure, realizing the ordered buffering and confinement effects of various ions. Its special intercalation structure, multi-ion sites and alkaline characteristics make it have good application prospects in the energy and catalytic fields. In view of the above background, the present invention aims to develop an ionic liquid composite layered double hydroxide multifunctional buffering system for regulating the reaction path in the process of synthesizing carbonates from CO2, and realize a green and efficient method for synthesizing carbonates that promotes the main reaction and inhibits the side reaction. Summary of the Invention

[0003] In view of the problem that a large number of halogenated by-products are generated during the catalytic process of halogen ionic liquids, the present invention designs and constructs a halogen-non-halogen ionic liquid composite layered double metal hydroxide intercalation material as a multi-ion buffer catalytic system for synergistically improving the product selectivity and catalytic activity in the process of synthesizing carbonates from CO2. The method prepares ionic liquids containing the same cations but different anions (halogen and non-halogen), and then constructs a composite material with a layered double hydroxide intercalation material to form a halogen-non-halogen ionic buffer material catalyst. The intercalation structure of this material provides a buffering function for ionic active sites, enabling the orderly interaction of various ions such as halogen ions, organic basic non-halogen ions, and inorganic basic ions, and having the multi-site functions of both halogen and non-halogen ions. On the one hand, it improves the catalytic activity of synthesizing carbonates from CO2, and on the other hand, the multi-basic sites of the composite material can effectively inhibit side reactions, simultaneously solving the problems of product selectivity and catalytic activity of ionic liquids in the synthesis of carbonates from CO2. It realizes the efficient utilization of CO2 and the synthesis of carbonates under green conditions, and has high industrial value.

[0004] To achieve this purpose, the present invention adopts the following technical solutions:

[0005] The present invention provides a design strategy, preparation method and catalytic application of a halogen-non-halogen ionic liquid composite double metal hydroxide intercalation material for the reaction of synthesizing carbonates from CO2. The halogen-non-halogen ionic liquid composite double metal hydroxide intercalation material is characterized in that the basic structural unit includes: a layered aluminum-based double metal hydroxide, and the interlayer composite contains a halogen-non-halogen ionic liquid with the same positive ion and two negative ions.

[0006] The structural formula of the halogen-non-halogen ionic liquid (A2NX)IL is as follows:

[0007] Among them, R 1 , R 2 , R 3 , R 4 are all independently selected from alkyl groups of C1-C 10 , including: CH3, C2H5, C3H7, C4H9, C5H 11 , C6H 13 , C7H 15 , C8H 17 , C9H 19 , C 10 H 21 in one of them, the positive ion center A is P or N, that is, the cation is one of quaternary phosphonium salts or quaternary ammonium salts, and X - in the two negative ions is Cl - , Br -One of them, and the other nitrogen anion is one of six imide nitrogen anions and six cyano pyrrole nitrogen anions.

[0008]

[0009] The preparation method of the halogen-non-halogen dual cation and dual anion ionic liquid in the present invention is as follows: Using quaternary phosphonium hydroxide or quaternary ammonium hydroxide to react with imide or cyano pyrrole, after stirring, separating, and washing, an ionic liquid with quaternary phosphonium salt or quaternary ammonium salt as the cation and imide nitrogen anion or cyano pyrrole nitrogen anion as the anion is obtained. Then, this ionic liquid is mixed with an equimolar amount of quaternary phosphonium salt or quaternary ammonium salt of halogen anion with the same cation, and after stirring, separating, washing, and drying, the halogen-non-halogen dual cation and dual anion ionic liquid (A2NX)IL can be successfully prepared.

[0010] The metal center of the aluminum-based double metal hydroxide for preparing the intercalation material provided by the present invention is one of MgAl double metal or ZnAl double metal. The synthesis steps are as follows: The halogen-non-halogen dual cation and dual anion ionic liquid (A2NX)IL and the MgAl-LDH or ZnAl-LDH intercalation structure are dissolved in deionized water, then the solution is ultrasonically dissolved, stirred at room temperature for 24 h, rotary evaporated at 45 °C for 1 h, and then vacuum dried in a vacuum drying oven at 45 °C for 24 h to obtain the (A2NX)IL-(MAl)LDH material in which the halogen-non-halogen ionic liquid is combined with MgAl-LDH / ZnAl-LDH. Its basic structure schematic diagram is as Figure 1 shown, and the preparation method flow chart is as Figure 2 shown.

[0014] The present invention provides a method for synthesizing carbonate from CO2 using a halogen-non-halogen ionic liquid composite double metal hydroxide intercalation material (A2NX)IL-(MAl)LDH. This composite structure can promote the main reaction of CO2 to carbonate and inhibit the halogenation reaction of epoxide, reduce and gradually avoid the generation of halogenated by-products. The general reaction formula of the method is:

[0015]

[0016] R is one of a substituted or unsubstituted C1-C 18 linear or branched alkyl group, a substituted or unsubstituted C3-C 18 cycloalkyl group, a substituted or unsubstituted C3-C 18 heterocycloalkyl group, a substituted or unsubstituted C6-C 18 aryl group.

[0017] The present invention provides a method for applying a halogen-non-halogen ionic liquid composite double metal hydroxide intercalation material to the synthesis of carbonates from CO2. The reaction operation steps are as follows: An epoxide and a halogen-non-halogen ionic liquid composite intercalation material (A2NX)IL-(MAl)LDH are added to a closed high-pressure reaction kettle. Under the conditions of a temperature of 90-150 °C and filling CO2 to make the pressure in the kettle 2-5 MPa, the reaction is carried out for 2-6 h. After the reaction, the cyclic carbonate product is obtained with high efficiency and high selectivity. The selectivity of the target product is significantly improved, and only trace amounts or no formation of haloalcohols is detected. After the composite catalyst is reused 5 times, its catalytic activity does not decrease significantly.

[0018] Preferably, the reaction temperature of the cycloaddition reaction is 90-150 °C, such as 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, etc.

[0019] Preferably, the reaction time of the cycloaddition reaction is 2-6 h, such as 2 h, 3 h, 4 h, 5 h, 6 h, etc.

[0020] Preferably, the reaction pressure of the cycloaddition reaction is 2-5 MPa, such as 2.0 MPa, 2.5 MPa, 3.0 MPa, 3.5 MPa, 4.0 MPa, 4.5 MPa, 5.0 MPa, etc.

[0021] The numerical ranges described in the present invention not only include the point values exemplified above, but also any point values between the above numerical ranges not exemplified. Due to space limitations and for the sake of brevity, the specific point values included in the described ranges are not exhaustively listed in the present invention.

[0022] The present invention has the following beneficial effects: The present invention provides a method for realizing the efficient catalysis of the synthesis of carbonates and effectively inhibiting the by-product of haloalcohols by adopting a halogen-non-halogen ionic liquid composite double metal hydroxide intercalation structure. The composite material as a catalyst has a simple preparation method and a novel structure. The designed double ionic liquid composite double metal hydroxide intercalation structure of the present invention combines the functions of halogen and non-halogen basic ions, not only exhibits excellent catalytic efficiency, but also solves the problem of the selectivity of the product of the synthesis of carbonates from CO2 catalyzed by halide ions through the ordered buffering effect of ionic active sites. No by-product haloalcohol is detected in the reaction system, and the yield of carbonate can reach up to ~97%. The composite catalyst has potential applications in the field of environmentally friendly CO2 resource utilization and the synthesis of organic carbonates. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the structure of the halogen-non-halogen ionic liquid composite intercalation material (A2NX)IL-(MAl)LDH.

[0024] Figure 2 It is a flow chart of the preparation method of the halogen-non-halogen ionic liquid composite intercalation material (A2NX) IL-(MAl) LDH. Figure 3 It is a scanning electron microscope image of the zinc-aluminum hydroxide intercalation material (ZnAl) LDH(a) and the composite intercalation material [PBu4]2[N IMD-1 Br]-(ZnAl) LDH(b). Specific embodiments

[0025] The technical solution of the present invention will be further described below through specific embodiments. However, the present invention is not limited to the following embodiments.

[0026] The preparation of the halogen-non-halogen ionic liquid (A2NX) IL includes Examples 1 to 15:

[0027] Example 1

[0028] Preparation of [PBu4]2[N IMD-1 Br] containing tetrabutylphosphonium cation, IMD-1 nitrogen anion and bromide ion

[0029] Add the aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) into a 100 mL single-necked round-bottom flask, then add 1,2-cyclohexanedicarboximide IMD-1 (4 mmol). Place the flask in a water bath and stir the reaction mixture at room temperature for 24 h. After the reaction is completed, perform rotary evaporation for 2 h, then wash it with ether / ethyl acetate multiple times, and then dry it under vacuum for 12 h to obtain the 1,2-cyclohexanedicarboximide nitrogen negative tetrabutylphosphonium salt ionic liquid. Then, mix equimolar amounts of tetrabutylphosphonium bromide and the ionic liquid prepared above and dissolve them in ethanol. After stirring at room temperature, perform rotary evaporation separation, washing, and drying to obtain the double positive and double negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium cation, 1,2-cyclohexanedicarboximide IMD-1 nitrogen anion and bromide ion.

[0030] Example 2

[0031] Preparation of [POctyl4]2[N IMD-1 Br] containing tetraoctylphosphonium cation, IMD-1 nitrogen anion and bromide ion

[0032] Add aqueous solution of tetraoctylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) into a 100 mL single-necked round-bottom flask, then add 1,2-cyclohexanedicarboximide IMD-1 (4 mmol). Place the flask in a water bath and stir the reaction mixture at room temperature for 24 h. After the reaction is completed, perform rotary evaporation for 2 h, wash with ether / ethyl acetate multiple times, and then dry under vacuum for 12 h to obtain 1,2-cyclohexanedicarboximide nitrogen-negative tetraoctylphosphonium salt ionic liquid. Then mix tetraoctylphosphonium bromide and the above-prepared ionic liquid in equimolar amounts and dissolve them in ethanol. After stirring at room temperature, perform rotary evaporation for separation, washing, and drying to obtain a double-positive and double-negative halogen-non-halogen ionic liquid containing tetraoctylphosphonium positive ions, 1,2-cyclohexanedicarboximide IMD-1 nitrogen-negative ions, and bromide ions.

[0033] Example 3

[0034] [PBu4]2[N containing tetrabutylphosphonium salt positive ions, IMD-2 nitrogen-negative ions, and bromide ions IMD-2 Preparation of

[0035] Add aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) into a 100 mL single-necked round-bottom flask, then add 1,2-cyclopentanedicarboximide IMD-2 (4 mmol). Place the flask in a water bath and stir the reaction mixture at room temperature for 24 h. After the reaction is completed, perform rotary evaporation for 2 h, then wash with ether / ethyl acetate multiple times, and dry under vacuum for 12 h to obtain 1,2-cyclopentanedicarboximide nitrogen-negative tetrabutylphosphonium salt ionic liquid. Then mix tetrabutylphosphonium bromide and the above-prepared ionic liquid in equimolar amounts and dissolve them in ethanol. After stirring at room temperature, perform rotary evaporation for separation, washing, and drying to obtain a double-positive and double-negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium positive ions, 1,2-cyclopentanedicarboximide IMD-2 nitrogen-negative ions, and bromide ions.

[0036] Example 4

[0037] [PBu4]2[N containing tetrabutylphosphonium salt positive ions, IMD-3 nitrogen-negative ions, and bromide ions IMD-3 Preparation of

[0038] Add aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) into a 100 mL single-necked round-bottom flask, then add 3,4-pyridinedicarboximide IMD-3 (4 mmol). Place the flask in a water bath and stir the reaction mixture at room temperature for 24 h. After the reaction is completed, perform rotary evaporation for 2 h, then wash it with ether / ethyl acetate multiple times, and then dry it under vacuum for 12 h to obtain 3,4-pyridinedicarboximide tetrabutylphosphonium azide ionic liquid. Then mix tetrabutylphosphonium bromide and the above-prepared ionic liquid in equimolar amounts and dissolve them in ethanol. After stirring at room temperature, perform rotary evaporation for separation, washing, and drying to obtain a double-positive and double-negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium cation, 3,4-pyridinedicarboximide IMD-3 azide anion, and bromide ion.

[0039] Example 5

[0040] [PBu4]2[N containing tetrabutylphosphonium salt cation, IMD-4 azide anion, and bromide ion IMD-4 Preparation of

[0041] Add aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) into a 100 mL single-necked round-bottom flask, then add o-benzenesulfonylimide (saccharin) IMD-4 (4 mmol). Place the flask in a water bath and stir the reaction mixture at room temperature for 24 h. After the reaction is completed, perform rotary evaporation for 2 h, then wash it with ether / ethyl acetate multiple times, and then dry it under vacuum for 12 h to obtain o-benzenesulfonylimide (saccharin) tetrabutylphosphonium azide ionic liquid. Then mix tetrabutylphosphonium bromide and the above-prepared ionic liquid in equimolar amounts and dissolve them in ethanol. After stirring at room temperature, perform rotary evaporation for separation, washing, and drying to obtain a double-positive and double-negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium cation, o-benzenesulfonylimide (saccharin) IMD-4 azide anion, and bromide ion.

[0042] Example 6

[0043] [PBu4]2[N containing tetrabutylphosphonium salt cation, IMD-5 azide anion, and bromide ion IMD-5 Preparation of

[0044] Add aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) into a 100 mL single-necked round-bottom flask, then add 1,8-naphthalenedicarboximide IMD-5 (4 mmol). Place the flask in a water bath and stir the reaction mixture at room temperature for 24 h. After the reaction is completed, perform rotary evaporation for 2 h, then wash with ether / ethyl acetate multiple times, and then dry in vacuum for 12 h to obtain 1,8-naphthalenedicarboximide tetrabutylphosphonium azide ionic liquid. Then mix tetrabutylphosphonium bromide with the above-prepared ionic liquid in an equimolar amount and dissolve it in ethanol. After stirring at room temperature, perform rotary evaporation for separation, washing, and drying to obtain a double-positive and double-negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium cation, 1,8-naphthalenedicarboximide IMD-5 azide anion, and bromide ion.

[0045] Example 7

[0046] Preparation of double-positive and double-negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium cation, IMD-6 azide anion, and bromide ion [PBu4]2[N IMD-6 Br

[0047] Add aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) into a 100 mL single-necked round-bottom flask, then add 4-aminophthalimide IMD-6 (4 mmol). Place the flask in a water bath and stir the reaction mixture at room temperature for 24 h. After the reaction is completed, perform rotary evaporation for 2 h, then wash with ether / ethyl acetate multiple times, and then dry in vacuum for 12 h to obtain 4-aminophthalimide tetrabutylphosphonium azide ionic liquid. Then mix tetrabutylphosphonium bromide with the above-prepared ionic liquid in an equimolar amount and dissolve it in ethanol. After stirring at room temperature, perform rotary evaporation for separation, washing, and drying to obtain a double-positive and double-negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium cation, 4-aminophthalimide IMD-6 azide anion, and bromide ion.

[0048] Example 8

[0049] Preparation of double-positive and double-negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium cation, CyPr-1 azide anion, and bromide ion [PBu4]2[N CyPr-1 Br

[0050] Add aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) to a 100 mL single-necked round-bottom flask, then add 3-cyanopyrrole CyPr-1 (4 mmol). Place the flask in a water bath and stir the reaction mixture at room temperature for 24 h. After the reaction is completed, perform rotary evaporation for 2 h, then wash with ether / ethyl acetate multiple times, and then dry in vacuum for 12 h to obtain 3-cyanopyrrole CyPr-1 nitrogen negative tetrabutylphosphonium salt ionic liquid. Then mix tetrabutylphosphonium bromide with the ionic liquid prepared above in an equimolar amount and dissolve it in ethanol. After stirring at room temperature, perform rotary evaporation for separation, washing, and drying to obtain a double positive and double negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium positive ion, 3-cyanopyrrole CyPr-1 nitrogen negative ion, and bromide ion.

[0051] Example 9

[0052] Preparation of ionic liquid containing tetrabutylphosphonium salt positive ion, CyPr-2 nitrogen negative ion, and bromide ion [PBu4]2[N CyPr-2 Br

[0053] Add aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) to a 100 mL single-necked round-bottom flask, then add ethyl 3-cyanopyrrole-2-carboxylate CyPr-2 (4 mmol). Place the flask in a water bath and stir the reaction mixture at room temperature for 24 h. After the reaction is completed, perform rotary evaporation for 2 h, then wash with ether / ethyl acetate multiple times, and then dry in vacuum for 12 h to obtain ethyl 3-cyanopyrrole-2-carboxylate CyPr-2 nitrogen negative tetrabutylphosphonium salt ionic liquid. Then mix tetrabutylphosphonium bromide with the ionic liquid prepared above in an equimolar amount and dissolve it in ethanol. After stirring at room temperature, perform rotary evaporation for separation, washing, and drying to obtain a double positive and double negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium positive ion, ethyl 3-cyanopyrrole-2-carboxylate CyPr-2 nitrogen negative ion, and bromide ion.

[0054] Example 10

[0055] Preparation of ionic liquid containing tetrabutylphosphonium salt positive ion, CyPr-3 nitrogen negative ion, and bromide ion [PBu4]2[N CyPr-3 Br

[0056] An aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) were added to a 100 mL single-necked round-bottom flask, and then ethyl 4-cyanopyrrole-2-carboxylate CyPr-3 (4 mmol) was added. The flask was placed in a water bath, and the reaction mixture was stirred at room temperature for 24 h. After the reaction was completed, rotary evaporation was carried out for 2 h, followed by repeated washing with ether / ethyl acetate, and then vacuum drying for 12 h to obtain an ethyl 4-cyanopyrrole-2-carboxylate CyPr-3 nitrogen negative tetrabutylphosphonium salt ionic liquid. Then, tetrabutylphosphonium bromide and the ionic liquid prepared above were mixed in an equimolar amount and dissolved in ethanol. After stirring at room temperature, rotary evaporation separation, washing, and drying were carried out to obtain a double positive and double negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium positive ions, ethyl 4-cyanopyrrole-2-carboxylate CyPr-3 nitrogen negative ions, and bromide ions.

[0057] Example 11

[0058] Preparation of [PBu4]2[N CyPr-4 Br] containing tetrabutylphosphonium salt positive ions, CyPr-4 nitrogen negative ions, and bromide ions

[0059] An aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) were added to a 100 mL single-necked round-bottom flask, and then ethyl 4-cyanopyrrole-2-carboxylate CyPr-4 (4 mmol) was added. The flask was placed in a water bath, and the reaction mixture was stirred at room temperature for 24 h. After the reaction was completed, rotary evaporation was carried out for 2 h, followed by repeated washing with ether / ethyl acetate, and then vacuum drying for 12 h to obtain an ethyl 4-cyanopyrrole-2-carboxylate CyPr-4 nitrogen negative tetrabutylphosphonium salt ionic liquid. Then, tetrabutylphosphonium bromide and the ionic liquid prepared above were mixed in an equimolar amount and dissolved in ethanol. After stirring at room temperature, rotary evaporation separation, washing, and drying were carried out to obtain a double positive and double negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium positive ions, ethyl 4-cyanopyrrole-2-carboxylate CyPr-4 nitrogen negative ions, and bromide ions.

[0060] Example 12

[0061] Preparation of [PBu4]2[N CyPr-5 Br] containing tetrabutylphosphonium salt positive ions, CyPr-5 nitrogen negative ions, and bromide ions

[0062] An aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) were added to a 100 mL single-necked round-bottom flask, and then ethyl 4-cyanopyrrole-2-carboxylate CyPr-5 (4 mmol) was added. The flask was placed in a water bath, and the reaction mixture was stirred at room temperature for 24 h. After the reaction was completed, rotary evaporation was carried out for 2 h, followed by repeated washing with ether / ethyl acetate, and then vacuum drying for 12 h to obtain an ethyl 4-cyanopyrrole-2-carboxylate CyPr-5 nitrogen negative tetrabutylphosphonium salt ionic liquid. Then, tetrabutylphosphonium bromide and the ionic liquid prepared above were mixed in an equimolar amount and dissolved in ethanol. After stirring at room temperature, rotary evaporation separation, washing, and drying were carried out to obtain a double positive and double negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium positive ions, ethyl 4-cyanopyrrole-2-carboxylate CyPr-5 nitrogen negative ions, and bromide ions.

[0063] Example 13

[0064] Preparation of ionic liquid containing tetrabutylphosphonium salt positive ions, CyPr-6 nitrogen negative ions, and bromide ions [PBu4]2[N CyPr-6 Br

[0065] An aqueous solution of tetrabutylphosphonium hydroxide (4 mmol) and absolute ethanol (15 mL) were added to a 100 mL single-necked round-bottom flask, and then 2-amino-3-cyano-4,5-dimethylpyrrole CyPr-6 (4 mmol) was added. The flask was placed in a water bath, and the reaction mixture was stirred at room temperature for 24 h. After the reaction was completed, rotary evaporation was carried out for 2 h, followed by repeated washing with ether / ethyl acetate, and then vacuum drying for 12 h to obtain a 2-amino-3-cyano-4,5-dimethylpyrrole CyPr-6 nitrogen negative tetrabutylphosphonium salt ionic liquid. Then, tetrabutylphosphonium bromide and the ionic liquid prepared above were mixed in an equimolar amount and dissolved in ethanol. After stirring at room temperature, rotary evaporation separation, washing, and drying were carried out to obtain a double positive and double negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium positive ions, 2-amino-3-cyano-4,5-dimethylpyrrole CyPr-6 nitrogen negative ions, and bromide ions.

[0066] Example 14

[0067] Preparation of ionic liquid containing tetrabutylammonium salt positive ions, IMD-1 nitrogen negative ions, and bromide ions [NBu4]2[N IMD-1 Br

[0068] Add aqueous solution of tetrabutylammonium hydroxide (4 mmol) and absolute ethanol (15 mL) into a 100 mL single-necked round-bottom flask, then add 1,2-cyclohexanedicarboximide IMD-1 (4 mmol). Place the flask in a water bath and stir the reaction mixture at room temperature for 24 h. After the reaction is completed, perform rotary evaporation for 2 h, then wash with ether / ethyl acetate multiple times, and then dry in vacuum for 12 h to obtain 1,2-cyclohexanedicarboximide nitrogen tetrabutyl quaternary ammonium salt ionic liquid. Then, mix tetrabutylammonium bromide and the above-prepared ionic liquid in equimolar amounts and dissolve them in ethanol. After stirring at room temperature, perform rotary evaporation for separation, washing, and drying to obtain a double positive and double negative halogen-non-halogen ionic liquid containing tetrabutyl quaternary ammonium cation, 1,2-cyclohexanedicarboximide IMD-1 nitrogen anion, and bromide ion.

[0069] Example 15

[0070] Containing tetrabutylphosphonium salt cation, IMD-1 nitrogen anion and chloride ion [PBu4]2[N IMD-1 Cl] Preparation

[0071] The difference from Example 1 is that after preparing 1,2-cyclohexanedicarboximide IMD-1 nitrogen tetrabutylphosphonium salt ionic liquid, mix tetrabutylphosphonium chloride and the above ionic liquid in equimolar amounts and dissolve them, with other conditions unchanged. Finally, a double positive and double negative halogen-non-halogen ionic liquid containing tetrabutylphosphonium cation, 1,2-cyclohexanedicarboximide IMD-1 nitrogen anion, and chloride ion is obtained.

[0072] The preparation of halogen-non-halogen ionic liquid composite aluminum-based double metal hydroxide intercalation material (A2NX) IL-(MAl)LDH includes Examples 16 - 19:

[0073] Example 16

[0074] Ionic liquid composite intercalation material [PBu4]2[N IMD-1 Br]-(ZnAl)LDH Preparation

[0075] Weigh 0.01 mol zinc nitrate (Zn(NO3)2·6H2O) and 0.005 mol aluminum nitrate (Al(NO3)3·9H2O), and dissolve them with deionized water to prepare a mixed salt solution with a Zn / Al molar ratio of 2:1. Pour the mixed salt solution into a round-bottom flask, then add 0.06 mol urea to the mixed salt solution and adjust the volume to 150 mL with deionized water. Under reflux conditions, place the round-bottom flask in an oil bath at 100 °C and stir vigorously for 24 h. Wash the obtained precipitate with ethanol and deionized water until the pH of the supernatant is 7, and then dry it in a vacuum drying oven at 50 °C for 6 h. The obtained white powder is ZnAl-LDH. The double positive and double negative halogen-non-halogen ionic liquid [PBu4]2[NIMD-1 Br (60 mg) and ZnAl-LDH (60 mg) were dissolved in 50 mL of deionized water and placed in a 100 mL round-bottom flask. Then the solution was sonicated to fully mix the components and stirred at room temperature for 24 h. Then the solution was rotary evaporated at 50 °C for 2 h and finally placed in a vacuum drying oven at 50 °C for vacuum drying for 24 h to obtain [PBu4]2[N IMD-1 Br]-ZnAl-LDH system.

[0076] Example 17

[0077] Ionic liquid composite intercalation material [PBu4]2[N IMD-1 Br]-(MgAl)LDH preparation

[0078] The difference from Example 16 is that, with other conditions unchanged, magnesium nitrate (Mg(NO3)2·6H2O) was used as the raw material to prepare hydrotalcite, and the ionic liquid composite intercalation material [PBu4]2[N IMD-1 Br]-(MgAl)LDH was obtained.

[0079] Example 18

[0080] Ionic liquid composite intercalation material [POctyl4]2[N IMD-1 Br]-(MgAl)LDH preparation

[0081] The difference from Example 16 is that, with other conditions unchanged, magnesium nitrate (Mg(NO3)2·6H2O) was used as the raw material to prepare hydrotalcite, and [POctyl4]2[N IMD-1 Br] ionic liquid was used for composite, and the ionic liquid composite intercalation material [POctyl4]2[N IMD-1 Br]-(MgAl)LDH was obtained.

[0082] Example 19

[0083] Ionic liquid composite intercalation material [PBu4]2[N CyPr-1 Br]-(ZnAl)LDH preparation

[0084] The difference from Example 16 is that, with other conditions unchanged, [PBu4]2[N CyPr-1 Br] ionic liquid was used for composite, and the ionic liquid composite intercalation material [PBu4]2[N CyPr-1 Br]-(ZnAl)LDH was obtained.

[0085] The composite material (A2NX)IL-(MAl)LDH was used as a catalyst for the reaction of synthesizing carbonate from CO2, including Examples 20 - 43, and Examples 20 - 37 are summarized in the table:

[0086] Example 20

[0087] 2 g of propylene oxide and 60 mg of the halogen-non-halogen ionic liquid composite double metal hydroxide intercalation material [PBu4]2[N IMD-1 Br]-(ZnAl)LDH were added to a closed high-pressure reactor. Under the conditions of a temperature of 120 °C and a CO2 filling pressure in the reactor of 3 MPa, the reaction was carried out for 5 h. After the reaction ended, the reactor was placed in a cold water bath and cooled to room temperature, and the gas phase part and the reaction solution were collected. A certain amount of the gas phase part and the reaction solution were analyzed by gas chromatography. The conversion rate of propylene oxide was 95.2%, the yield of the product propylene carbonate was 93.1%, the yield of the by-product bromopropanol was 0%, and the yield of 1,2-propanediol was 2.1%.

[0088] The differences between Examples 21 to 37 and Example 20 are shown in the table. Under the condition of the same reaction time of 5 h, the differences are that different (A2NX)IL-(MAl)LDH composite material catalyst types, reaction temperatures and reaction pressures were respectively screened.

[0089]

[0090]

[0091] Example 38

[0092] The difference from Example 20 is that the epoxy compound used is ethylene oxide and other conditions remain unchanged.

[0093] The product obtained in Example 38 was ethylene carbonate, the conversion rate of ethylene oxide was 98.6%, the yield of the product ethylene carbonate was 97.4%, and the yield of the halogenated alcohol was 0%.

[0094] Example 39

[0095] The difference from Example 20 is that the epoxy compound used is epichlorohydrin and other conditions remain unchanged.

[0096] The product obtained in Example 39 was propylene chlorocarbonate, the conversion rate of epichlorohydrin was 89.2%, the yield of the product propylene chlorocarbonate was 87.4%, and the yield of the halogenated alcohol was 0%.

[0097] Example 40

[0098] The difference from Example 20 is that the epoxy compound used is 2,2-dimethyloxirane and other conditions remain unchanged.

[0099] The product obtained in Example 40 was 4,4-dimethylethylene carbonate, the conversion rate of 2,2-dimethyloxirane was 87.1%, the yield of the product 4,4-dimethylethylene carbonate was 83.9%, and the yield of the halogenated alcohol was 0%.

[0100] Example 41

[0101] The difference from Example 20 is that the epoxy compound used is 2-n-butoxymethylethylene oxide, and other conditions remain unchanged.

[0102] The product obtained in Example 41 is 4-n-butoxymethyl ethylene carbonate, the conversion rate of 2-n-butoxymethylethylene oxide is 76.5%, the yield of the product 4-n-butoxymethyl ethylene carbonate is 74.3%, and the yield of the halogenated alcohol is 0%.

[0103] Example 42

[0104] The difference from Example 20 is that the epoxy compound used is 2-tert-butoxymethylethylene oxide, and other conditions remain unchanged.

[0105] The product obtained in Example 42 is 4-tert-butoxymethyl ethylene carbonate, the conversion rate of 2-tert-butoxymethylethylene oxide is 76.3%, the yield of the product 4-tert-butoxymethyl ethylene carbonate is 74.1%, and the yield of the halogenated alcohol is 0%.

[0106] Example 43

[0107] The difference from Example 20 is that the epoxy compound used is 2-phenylethylene oxide, and other conditions remain unchanged.

[0108] The product obtained in Example 43 is 4-phenyl ethylene carbonate, the conversion rate of 2-phenylethylene oxide is 86.9%, the yield of the product 4-phenyl ethylene carbonate is 85.3%, and the yield of the halogenated alcohol is 0%.

[0109] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any modification, equivalent replacement, improvement, etc. made by any person skilled in the art within the technical scope disclosed by the present invention shall be included in the protection scope of the present invention.

Claims

1. A halogen-non-halogen ionic liquid composite double metal hydroxide intercalation material for the reaction of synthesizing carbonates from CO2, characterized in that, The basic structural unit includes: layered aluminum-based double metal hydroxide, and the interlayer composite contains a halogen-non-halogen ionic liquid with the same kind of positive ions and two kinds of negative ions.

2. The structural formula of the halogen-non-halogen ionic liquid (IL) according to claim 1 is as follows: Among them, R 1 , R 2 , R 3 , R 4 are each independently selected from C1-C 10 alkyl groups, including: CH3, C2H5, C3H7, C4H9, C5H 11 , C6H 13 , C7H 15 , C8H 17 , C9H 19 , C 10 H 21 in one of them, the positive ion center A is P or N, that is, the positive ion is one of quaternary phosphonium salts or quaternary ammonium salts, and X in the two negative ions - is Cl - , Br - in one of them, and the other nitrogen negative ion is one of six imide nitrogen negative ions and six cyanopyrrole nitrogen negative ions.

3. The halogen-non-halogen ionic liquid (A2NX) IL composite double metal hydroxide intercalation material according to claim 1, characterized in that, The metal center of the double metal hydroxide intercalation material (LDH) is one of MgAl double metal or ZnAl double metal.

4. The preparation method of the halogen-non-halogen ionic liquid composite double metal hydroxide intercalation material according to claim 3 includes the following steps: Dissolve the halogen-non-halogen ionic liquid (A2NX) IL with double positive and double negative ions and the MgAl-LDH or ZnAl-LDH intercalation structure in equal mass in deionized water. Then, after ultrasonic dissolution of the solution, stir it at room temperature for 24 h, perform rotary evaporation at 45 °C for 1 h, and then vacuum dry it in a vacuum drying oven at 45 °C for 24 h to obtain the (A2NX) IL-(MAl) LDH material composite of the halogen-non-halogen ionic liquid and MgAl-LDH / ZnAl-LDH.

5. The halogen-non-halogen ionic liquid composite double metal hydroxide intercalation material (A2NX) IL-(MAl)LDH according to claim 4, characterized in that, It is applied to the synthesis of carbonate from CO2 and inhibits halogenated by-products.

6. For the application according to claim 5, the general reaction formula of the method is: Among them, R is one of a substituted or unsubstituted C1-C 18 linear or branched alkyl, a substituted or unsubstituted C3-C 18 cycloalkyl, a substituted or unsubstituted C3-C 18 heterocycloalkyl, a substituted or unsubstituted C6-C 18 aryl.

7. The method according to any one of claims 1 to 6, characterized in that, Add the epoxy compound and the halogen-non-halogen ionic liquid composite double metal hydroxide intercalation material (A2NX) IL-(MAl) LDH into a closed high-pressure reaction kettle. Under the conditions of a temperature of 90-150 °C and filling CO2 to make the pressure in the kettle 2-5 MPa, react for 2-6 h. After the reaction, while obtaining the product cyclic carbonate, the formation of haloalcohol is inhibited, and the selectivity of the target product is improved.

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