Preparation and application of a metalloporphyrin-based porous polyionic liquid

Abstract

The application discloses a kind of preparation and application of metal porphyrin-based porous polyionic liquid.The general formula of the metal porphyrin-based porous polyionic liquid is: [M-R1-(R)4] n ;M is metal atom;R1 is porphyrin compound;R is selected from one of halogen-containing compounds.The metal porphyrin-based porous polyionic liquid is constructed by metal porphyrin and halogen-containing compound as organic unit, so that the metal porphyrin-based porous polyionic liquid has three-dimensional structure, the porous polyionic liquid has good chemical stability and controllable pore size, has high specific surface area, improves catalytic performance, realizes efficient and high-selectivity catalytic reaction.The metal porphyrin-based porous polyionic liquid prepared by the application is especially suitable for catalyzing the cycloaddition reaction of carbon dioxide and epoxide, has high selectivity and strong adsorption force for carbon dioxide, and can efficiently and high-selectively catalyze to generate cyclic carbonate.

Description

Technical Field

[0001] This invention relates to the field of organic polymer catalysis, specifically to the preparation and application of a metalloporphyrin-based porous polyionic liquid. Background Technology

[0002] Various catalytic systems have been developed for the cycloaddition reaction of epoxides with carbon dioxide. Porous organic polymers (POPs) have advantages such as structural designability, functional diversity, high thermal and chemical stability, and the ability to accelerate chemical reaction rates.

[0003] Porphyrins are typical units of porous organic polymers, possessing a π-conjugated system and an 18-electron structure, making them highly conjugated. Due to the high coordination activity of the four nitrogen atoms at the ring center, porphyrins readily complex with metal ions to form metalloporphyrins. Furthermore, numerous metalloporphyrin-based substances have achieved good results as heterogeneous catalysts in CO2 absorption and conversion. However, existing catalysts suffer from problems such as: demanding reaction conditions, often requiring high temperature and pressure; and poor catalyst recyclability, making recovery impossible. Summary of the Invention

[0004] To overcome the problems of existing technologies, this invention provides a method for preparing a metalloporphyrin-based porous polyionic liquid and its application in catalyzing the conversion of carbon dioxide into cyclic carbonates. Porphyrin is a macrocyclic compound with 26 π electrons, forming a highly conjugated system. Because the four nitrogen atoms at the ring center have high coordination activity, porphyrin readily complexes with metal ions to form metalloporphyrins. Further polymerization with different halogen-containing compounds can introduce halide ions, synthesizing multifunctional catalysts. This invention has advantages such as simple synthesis steps, low synthesis cost, simple purification, and immediate use after synthesis without the need for multi-step modification. Furthermore, the reaction with carbon dioxide does not require stringent reaction conditions or additional co-catalysts and solvents. The reaction exhibits high conversion rate and selectivity, and the catalyst is easy to recover, aligning with the concept of green and sustainable development and possessing broad application prospects.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The first aspect of this invention provides a metalloporphyrin-based porous polyionic liquid, wherein the general formula of the metalloporphyrin-based porous polyionic liquid is: [M-R1-(R)4] n ;

[0007] M is a metal atom;

[0008] R1 is a porphyrin compound;

[0009] R is selected from one of the halogenated compounds.

[0010] Porphyrins and their derivatives, due to their nitrogen-rich conjugated macrocyclic structure, not only enhance the affinity between polymers and CO2 but also promote coordination with metal ions, acting as linking ligands in the reaction process and improving the efficiency of carbon dioxide cycloaddition reactions. Further quaternization reactions can yield highly cross-linked polymers and introduce halide ions as nucleophiles, thus making the catalyst multifunctional. As a highly stable heterogeneous catalyst, this catalyst possesses a polymer framework structure with adjustable porous topology, offering advantages such as lowering reaction energy barriers, ease of operation, high conversion rate of target products, and reusability in heterogeneous catalytic reactions, aligning with the concept of green, low-carbon, and sustainable development. Furthermore, this metalloporphyrin-based porous polyionic liquid also shows application potential in adsorption and separation.

[0011] In the catalytic conversion of carbon dioxide into cyclic carbonates, the metalloporphyrin-based porous polyionic liquid contains alkali metals and halide ions, which act as nucleophiles in the ring-opening reaction. The metal ions coordinate with the oxygen sites of the epoxide, forming metal coordination, thereby reducing the electron density of the oxygen sites and making them more susceptible to attack and ring-opening. Secondly, the imidazole or pyridine functional groups on the porphyrin ring have activation sites that interact with carbon dioxide, increasing the adsorption capacity of carbon dioxide. This enriches and activates CO2 on the catalyst surface, promoting contact with the epoxide. This triple activation effectively promotes the cycloaddition reaction of cyclic carbonates, significantly improving the yield of cyclic carbonates. This approach aligns with the concept of green and sustainable development and has broad application prospects.

[0012] Preferably, R1 is Where M is Al, Co, Zn or Cu.

[0013] Preferably, R is selected from... One of them, where X is Br or Cl.

[0014] More preferably, the chemical structural formula of the metalloporphyrin-based porous polyionic liquid is:

[0015]

[0016] One of them.

[0017] As a preferred embodiment, the metalloporphyrin-based porous polyionic liquid is 5,10,15,20-tetra(4'-imidazolylphenyl)aluminum porphyrin and... It is obtained by polymerization via quaternization reaction, and its structural formula is:

[0018]

[0019] As a preferred embodiment, the metalloporphyrin-based porous polyionic liquid is 5,10,15,20-tetra(4'-imidazolylphenyl)aluminum porphyrin and... It is obtained by polymerization via quaternization reaction, and its structural formula is:

[0020]

[0021] As a preferred embodiment, the metalloporphyrin-based porous polyionic liquid is 5,10,15,20-tetra(4'-imidazolylphenyl)aluminum porphyrin and... It is obtained by polymerization via quaternization reaction, and its structural formula is:

[0022]

[0023] As a preferred embodiment, the metalloporphyrin-based porous polyionic liquid is 5,10,15,20-tetra(4'-imidazolylphenyl)zinc porphyrin and It is obtained by polymerization via quaternization reaction, and its structural formula is:

[0024]

[0025] By employing the above-described scheme, using porphyrin compounds and halogenated compounds as organic units and Lewis acid metal salts as catalysts, a metalloporphyrin-based porous polyionic liquid is obtained by polymerizing porphyrin compounds and halogenated compounds through a quaternization reaction. Metalloporphyrin compounds possess extremely high nitrogen content and strong electron-withdrawing properties, making them more advantageous in the cycloaddition reaction of epoxides. The introduction of halogenated compounds endows the catalyst with both electron-withdrawing and extremely strong ring-opening capabilities. The quaternization reaction endows the catalyst with extremely high stability, excellent tolerance, abundant exposed active sites, and diverse pore structures. These characteristics enable the metalloporphyrin-based porous polyionic liquid to perform carbon dioxide cycloaddition reactions without requiring stringent reaction conditions or additional co-catalysts and solvents, and the reaction exhibits high conversion and selectivity, with easy catalyst recovery.

[0026] A second aspect of the present invention provides a method for preparing the aforementioned metalloporphyrin-based porous polyionic liquid, comprising the following steps:

[0027] R1 and R were refluxed in a solvent under an inert gas atmosphere. After the reaction was completed, the mixture was cooled to room temperature, and purified after solid-liquid separation to obtain the metalloporphyrin-based porous polyionic liquid.

[0028] Using porphyrin-based and halogen-containing compounds as organic units, metalloporphyrin-based porous polyionic liquids are obtained by polymerizing porphyrin-based and halogen-containing compounds through a quaternization reaction. Alkali metal ions, as active sites in the polymer, can also activate carbon dioxide molecules. In ring-opening reactions, halide ions, as nucleophilic attack reagents, have a stronger activating ability on epoxides, and have an excellent promoting effect on accelerating catalytic reactions and promoting the cycloaddition reactions of epoxides.

[0029] Preferably, the reflux reaction is carried out at a temperature of 80-180°C for a time of 12-36 hours.

[0030] Preferably, the molar mass ratio of R1 and R is R1:R = 1:(1~4).

[0031] Preferably, the organic solvent includes at least one of N,N-dimethylformamide and dichloroethane.

[0032] In some specific embodiments of the present invention, the purification step after solid-liquid separation includes: washing with N,N-dimethylformamide, methanol and dichloromethane, performing Soxhlet extraction with methanol and drying to obtain a metalloporphyrin-based porous polyionic liquid.

[0033] By combining porphyrin compounds with halogen-containing compounds using the above scheme, an extremely stable, highly cross-linked compound is formed. The pyrrole inner ring of the metal porphyrin can tightly chelate the metal within it. The nitrogen-rich porphyrin compound and the nitrogen-containing imidazole functional group significantly improve the ring-opening ability of the catalyst in the reaction. When applied to catalyze the conversion of carbon dioxide, it helps to improve the yield of cyclic carbonates.

[0034] The metalloporphyrin-based porous polyionic liquid of this invention possesses a polymer framework structure with adjustable porous topology. In heterogeneous catalytic reactions, it offers advantages such as lowering reaction energy barriers, ease of operation, high conversion rate of target products, and reusability. During catalytic reactions, it has a large contact area with reactants, which facilitates reactant adsorption and results in high catalytic efficiency. Furthermore, the metalloporphyrin-based porous polyionic liquid catalyst is a highly stable heterogeneous catalyst that does not require the addition of any solvent during catalytic reactions. It exhibits characteristics of fast reaction rates, high yield of target products, and complete catalytic reaction in heterogeneous catalytic reactions. The obtained products are easily separated, enabling effective reuse of the catalyst.

[0035] A third aspect of the present invention provides the application of the aforementioned metalloporphyrin-based porous polyionic liquid in the catalytic synthesis of cyclic carbonates from carbon dioxide and epoxides.

[0036] A fourth aspect of the present invention provides a method for synthesizing cyclic carbonates from carbon dioxide and epoxides, using the aforementioned metalloporphyrin-based porous polyionic liquid as a catalyst, comprising the following steps:

[0037] The catalyst and epoxide are added to a container, and then carbon dioxide is introduced to carry out the reaction. After the reaction is completed, the mixture is cooled and filtered to obtain the filtrate, which is the cyclic carbonate.

[0038] Preferably, the amount of catalyst used is 0.01-2.50 mol% of the epoxide; more preferably, the amount of catalyst used is 0.15-2.50 mol% of the epoxide.

[0039] Preferably, the pressure introduced after the carbon dioxide is discharged from the air in the reaction vessel is 0.1-3 MPa; more preferably, the pressure introduced after the carbon dioxide is discharged from the air in the reaction vessel is 0.1-1.5 MPa.

[0040] Preferably, the reaction time is 4-48 hours, the reaction temperature is 50-90°C, and the reaction is carried out under stirring.

[0041] Preferably, the epoxide comprises In one of the following, R2 is one of hydrogen, halogen, alkyl, unsaturated ether bond, phenyl, and phenoxy; in some preferred embodiments of the present invention, the epoxide is one of epichlorohydrin, propylene oxide, 1,2-epoxybutane, epibromopropane, allyl glycidyl ether, and styrene oxide; more preferably, the epoxide is epichlorohydrin.

[0042] In the process of catalyzing the conversion of carbon dioxide and epoxides into cyclic carbonates, the metalloporphyrin-based porous polyionic liquid of this invention, with its nitrogen-rich and imidazole functional group, has a good promoting effect on the capture and utilization of carbon dioxide. Furthermore, the metalloporphyrin-based porous polyionic liquid contains a metal center and a halide ion as a nucleophilic attack reagent for the ring-opening reaction. The metal center, as an active site, can activate carbon dioxide, while the halide ion has the ability to activate epoxides in the ring-opening reaction. Through the triple activation of the metal center, nitrogen element, and halide ion, the cycloaddition reaction of carbon dioxide and epoxides is effectively promoted, improving the selectivity for carbon dioxide and the yield of cyclic carbonates.

[0043] Compared with the prior art, the beneficial effects of the present invention are:

[0044] The metalloporphyrin-based porous polyionic liquid of this invention features metalloporphyrin compounds with extremely high nitrogen content and strong electron-withdrawing properties, making them more advantageous in the cycloaddition reaction of epoxides. The introduction of halogen-containing compounds endows the catalyst with both electron-withdrawing and extremely strong ring-opening capabilities. Quaternization reaction gives the catalyst structure extremely high stability, excellent tolerance, abundant exposed active sites, and diverse pore structures. These characteristics enable the metalloporphyrin-based porous polyionic liquid to perform carbon dioxide cycloaddition reactions without requiring stringent reaction conditions or additional co-catalysts and solvents. The reaction also exhibits high conversion and selectivity, and the catalyst is easy to recover, aligning with the concept of green and sustainable development and possessing broad application prospects. The metalloporphyrin-based porous polyionic liquid of this invention can achieve highly efficient and selective catalysis of the cycloaddition reaction of carbon dioxide and epoxides, achieving a 99.9% yield of cyclic carbonates after 6 hours of reaction. Attached Figure Description

[0045] Figure 1 The infrared spectrum of the metalloporphyrin-based porous polyionic liquid in Example 1 is shown below.

[0046] Figure 2 This is a solid-state NMR spectrum of the metalloporphyrin-based porous polyionic liquid of Example 1;

[0047] Figure 3 The X-ray photoelectron diffraction energy spectrum narrow-spectrum scan of the metal porphyrin-based porous polyionic liquid in Example 1 is shown.

[0048] Figure 4 The infrared spectrum of the metalloporphyrin-based porous polyionic liquid in Example 2;

[0049] Figure 5 The X-ray photoelectron diffraction energy spectrum narrow-spectrum scan of the metal porphyrin-based porous polyionic liquid in Example 2 is shown below.

[0050] Figure 6 Specific surface area diagrams of the metalloporphyrin-based porous polyionic liquids of Examples 1 and 2;

[0051] Figure 7 The gas chromatogram of the cyclic carbonate solution obtained by the carbon dioxide cycloaddition reaction catalyzed by the metalloporphyrin-based porous polyionic liquid in Example 1 is shown.

[0052] Figure 8 This is a gas chromatogram of the cyclic carbonate solution obtained by catalyzing carbon dioxide and cyclohexene oxidation with a metalloporphyrin-based porous polyionic liquid in Example 1. Detailed Implementation

[0053] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0054] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0055] In their research on the synthesis of cyclic carbonates using carbon dioxide and epoxides, the inventors discovered that porphyrins, due to their macrocyclic structure and ease of metal complexation, form stable complexes with alkali metal ions. The presence of π-metal orbitals between the metal and the porphyrin macrocycle enhances the stability of the catalyst's metal active sites. Simultaneously, the imidazole functional groups on the porphyrin ring selectively absorb carbon dioxide molecules, efficiently catalyzing the formation of cyclic carbonates. Furthermore, the introduction of nucleophilic halide ions during the polymerization of porphyrins and halogen-containing compounds further enhances the catalytic activity of this bifunctional metalloporphyrin-based porous polyionic liquid. This catalyst's multiple activation mechanisms effectively promote the synthesis of cyclic carbonates.

[0056] Example 1

[0057] A metalloporphyrin-based porous polyionic liquid, wherein R1 is selected from... M is an Al atom, and R is selected from... The structure of the metalloporphyrin-based porous polyionic liquid is as follows, denoted as POP1: Where X is Br.

[0058] The above-mentioned metalloporphyrin-based porous polyionic liquid can be prepared by the following method:

[0059] S01, will The reaction was carried out under a nitrogen atmosphere in N,N-dimethylformamide at a temperature of 165°C for 24 hours to allow the reactants to react fully and form a network structure.

[0060] S02. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with N,N-dimethylformamide, methanol and dichloromethane, extracted with methanol using a Soxhlet extract and dried to obtain a metalloporphyrin-based porous organic polymer.

[0061] Among them, S01 described The molar mass ratio is R1:R = 1:4.

[0062] Figure 1The image shows the infrared spectrum of the metalloporphyrin-based porous polyionic liquid of Example 1. As can be seen from the image, POP1 has a wavelength of 2835 cm⁻¹. -1 and at 1608cm -1 There are two absorption peaks at 2835 cm⁻¹, one of which is at 2835 cm� -1 The peak is for the CH bond in 1,4-di(bromomethyl)benzene, at 1608 cm⁻¹. -1 The peaks are from the C-C bonds on the porphyrin ring, indicating that the metalloporphyrin-based porous polyionic liquid with the corresponding structure was successfully obtained.

[0063] Figure 2 The solid-state NMR spectrum of the metalloporphyrin-based porous polyionic liquid of Example 1 shows resonance peaks at 134, 130, and 120 ppm, corresponding to carbon atoms on the porphyrin macrocycle and aromatic ring, respectively; the peaks at 31 ppm and 50 ppm correspond to methyl (-CH4) groups, respectively. 3) The presence of methylene (-CH2-) groups demonstrates that a halogenated compound has been introduced into the metal porphyrin-based porous polyionic liquid of the present invention, and proves that the metal porphyrin-based porous polyionic liquid of Example 1 of the present invention has the structure shown in Example 1.

[0064] The metalloporphyrin-based porous polyionic liquid of Example 1 was subjected to X-ray photoelectron diffraction to verify the elemental composition of the product. The results are as follows: Figure 3 As shown, the narrow-spectrum X-ray photoelectron diffraction energy spectrum shows that it contains abundant C, N, Al and Br elements. The binding energies corresponding to the orbital energy levels are consistent with their valence states, proving that the metal porphyrin-based porous polyionic liquid in Example 1 is rich in nitrogen, has an active metal center and halide ions.

[0065] Example 2

[0066] A metalloporphyrin-based porous polyionic liquid, wherein R1 is selected from... M is an Al atom, and R is selected from... The structure of the metalloporphyrin-based porous polyionic liquid is as follows, denoted as POP2: Where X is Cl.

[0067] The above-mentioned metalloporphyrin-based porous polyionic liquid can be prepared by the following method:

[0068] S01, will The reaction was carried out under a nitrogen atmosphere in N,N-dimethylformamide at a temperature of 160°C for 24 hours to allow the reactants to react fully and form a network structure.

[0069] S02. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with N,N-dimethylformamide, methanol and dichloromethane, extracted with methanol using a Soxhlet extract and dried to obtain a metalloporphyrin-based porous organic polymer.

[0070] Among them, S01 described The molar mass ratio is R1:R = 1:4.

[0071] Figure 4 The infrared spectrum of the metalloporphyrin-based porous polyionic liquid of Example 2 is shown in the figure. POP2 is at 3617 cm⁻¹. -1 1121cm -1 and 641cm -1 There are three absorption peaks, including one at 3617 cm⁻¹. -1 The peak value for the Si-OH bond in chloromethylsilsesquioxane (Cl-poss) is 1121 cm⁻¹. -1 The peak value for the Si-O-Si bond in chloromethylsilsesquioxane (Cl-poss) is 641 cm⁻¹. -1 The peak elution of imidazole on the porphyrin ring indicates that the metalloporphyrin-based porous polyionic liquid with the corresponding structure was successfully obtained.

[0072] The metalloporphyrin-based porous polyionic liquid of Example 2 was subjected to X-ray photoelectron diffraction to verify the elemental composition of the product. The results are as follows: Figure 5 As shown, the narrow-spectrum X-ray photoelectron diffraction pattern reveals that it contains abundant C, N, Si, Al, and Cl elements. The binding energies corresponding to the orbital energy levels are consistent with their valence states, proving that the metal porphyrin in Example 2 introduced chloromethylsilsesquioxane (Cl-poss) structural units, indicating that the metal porphyrin-based porous polyionic liquid with the corresponding structure was successfully obtained.

[0073] Figure 6 The figure shows the specific surface area diagrams of the metal porphyrin-based porous polyionic liquids of Examples 1 and 2. As the pressure increases, the adsorption amount gradually increases, and a hysteresis loop appears. This type of isothermal adsorption curve is a typical type I curve. It can be clearly seen that the specific surface area of ​​the metal porphyrin-based porous polyionic liquid obtained in Example 1 is 28 m². 2 ·g -1 ,

[0074] The metalloporphyrin-based porous polyionic liquid obtained in Example 2 has a specific surface area of ​​388 m². 2 ·g -1 This confirms that the metalloporphyrin-based porous polyionic liquid described in this invention has a large specific surface area.

[0075] Example 3

[0076] A metalloporphyrin-based porous polyionic liquid, wherein R1 is selected from... M is an Al atom, and R is selected from... The structure of the metalloporphyrin-based porous polyionic liquid is as follows, denoted as POP3: Where X is Br.

[0077] The above-mentioned metalloporphyrin-based porous polyionic liquid can be prepared by the following method:

[0078] S01, will The reaction was carried out under a nitrogen atmosphere in N,N-dimethylformamide at a temperature of 160°C for 24 hours to allow the reactants to react fully and form a network structure.

[0079] S02. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with N,N-dimethylformamide, methanol and dichloromethane, extracted with methanol using a Soxhlet extract and dried to obtain a metalloporphyrin-based porous organic polymer.

[0080] Among them, S01 is described The molar mass ratio is 3:4.

[0081] Example 4

[0082] A metalloporphyrin-based porous polyionic liquid, wherein R1 is selected from... M is an Al atom, and R is selected from... The structure of the metalloporphyrin-based porous polyionic liquid is as follows, denoted as POP4:

[0083] The above-mentioned metalloporphyrin-based porous polyionic liquid can be prepared by the following method:

[0084] S01, will The reaction was carried out under a nitrogen atmosphere in N,N-dimethylformamide at a temperature of 160°C for 24 hours to allow the reactants to react fully and form a network structure.

[0085] S02. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with N,N-dimethylformamide, methanol and dichloromethane, extracted with methanol using a Soxhlet extract and dried to obtain a metalloporphyrin-based porous organic polymer.

[0086] The The molar mass ratio is 1:4.

[0087] Example 5

[0088] A metalloporphyrin-based porous polyionic liquid, wherein R1 is selected from... M is a Zn atom, and R is selected from... The structure of the metalloporphyrin-based porous polyionic liquid is as follows, denoted as POP5: Where X is Br.

[0089] The above-mentioned metalloporphyrin-based porous polyionic liquid can be prepared by the following method:

[0090] S01, will The reaction was carried out under a nitrogen atmosphere in N,N-dimethylformamide at a temperature of 165°C for 24 hours to allow the reactants to react fully and form a network structure.

[0091] S02. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with N,N-dimethylformamide, methanol and dichloromethane, extracted with methanol using a Soxhlet extract and dried to obtain a metalloporphyrin-based porous organic polymer.

[0092] Among them, S01 described The molar mass ratio is R1:R = 1:1.

[0093] Example 6

[0094] A metalloporphyrin-based porous polyionic liquid, wherein R1 is selected from... M is a Zn atom, and R is selected from... The structure of the metalloporphyrin-based porous polyionic liquid is as follows, denoted as POP6: Where X is Br.

[0095] The above-mentioned metalloporphyrin-based porous polyionic liquid can be prepared by the following method:

[0096] S01, will The reaction was carried out under a nitrogen atmosphere in N,N-dimethylformamide at a temperature of 165°C for 24 hours to allow the reactants to react fully and form a network structure.

[0097] S02. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with N,N-dimethylformamide, methanol and dichloromethane, extracted with methanol using a Soxhlet extract and dried to obtain a metalloporphyrin-based porous organic polymer.

[0098] Among them, S01 described The molar mass ratio is R1:R = 1:1.

[0099] Result detection

[0100] 1. Cycloaddition reaction of carbon dioxide with epichlorohydrin:

[0101] (1) Take 0.21 mmol% (relative to the amount of epichlorohydrin) of each of the metal porphyrin-based porous polyionic liquids of Examples 1 to 6, and add them independently with 3.0 mmol of epichlorohydrin into a 10 mL stainless steel high-pressure reactor.

[0102] In Examples 1-6, carbon dioxide gas at 1 MPa is introduced.

[0103] Example 1 corresponds to a stirring reaction at 60°C for 6 hours; Example 2 corresponds to a stirring reaction at 80°C for 4 hours; Example 3 corresponds to a stirring reaction at 60°C for 8 hours; Example 4 corresponds to a stirring reaction at 80°C for 6 hours; Example 5 corresponds to a stirring reaction at 80°C for 5 hours; Example 6 corresponds to a stirring reaction at 80°C for 4 hours.

[0104] (2) After the reaction, the mixture was cooled to room temperature and filtered to separate the metal porphyrin-based porous polyionic liquid, resulting in a cyclic carbonate solution.

[0105] The test results are shown in Table 1.

[0106] 2. Cycloaddition reactions of carbon dioxide with propylene oxide, 1,2-epoxybutane, epibromopropane, allyl glycidyl ether, and styrene oxide:

[0107] (1) Take 0.03 mmol% of the metal porphyrin-based porous polyionic liquid of Example 1 and add it independently to 3.0 mmol of propylene oxide, 1,2-epoxybutane, epichlorohydrin, allyl glycidyl ether and styrene oxide into a 10 mL stainless steel high-pressure reactor, introduce carbon dioxide gas at 1 MPa and react at 60 °C.

[0108] The reaction was carried out with propylene oxide for 7 hours; with 1,2-epoxybutane for 20 hours; with epoxybromopropane for 6 hours; with allyl glycidyl ether for 36 hours; and with styrene oxide for 48 hours.

[0109] (2) After the reaction, the mixture was cooled to room temperature and filtered to separate the metal porphyrin-based porous polyionic liquid, resulting in a cyclic carbonate solution.

[0110] The test results are shown in Table 2.

[0111] Cyclic carbonate yield calculation: Cyclic carbonate yield = Actual cyclic carbonate production ÷ Theoretical cyclic carbonate production × 100%

[0112] Table 1. Yields of cyclic carbonates in Examples 1-6 for catalytic carbon dioxide cycloaddition reactions

[0113] Cyclic carbonate yield (%) Example 1 99 Example 2 96 Example 3 95 Example 4 99 Example 5 99 Example 6 97

[0114] As can be seen from Table 1, the metalloporphyrin-based porous polyionic liquid of the present invention has high catalytic efficiency for the carbon dioxide cycloaddition reaction. It can achieve a cyclic carbonate yield of more than 95% within an 8-hour reaction time. In Example 1, the cyclic carbonate yield reached more than 99% after 6 hours of reaction at 60°C, and in Example 2, the cyclic carbonate yield reached 96% after 4 hours of reaction at 80°C. The catalytic efficiency is higher than that of other examples.

[0115] Table 2. Yield of cyclic carbonates in the cycloaddition reaction of carbon dioxide and epoxides in Example 1.

[0116] Types of epoxides Cyclic carbonate yield (%) epichlorohydrin 99 propylene oxide 99 1,2-Epoxybutane 98 Epichlorohydrin 99 Allyl glycidyl ether 96 Styrene oxide 97

[0117] As can be seen from Table 2, the metalloporphyrin-based porous polyionic liquid described in this invention has good catalytic effect on the cycloaddition reaction of carbon dioxide with different epoxides, and the yield of cyclic carbonates is above 95%.

[0118] Figure 7 and Figure 8 The gas chromatograms of the reaction solution of Example 1 with epichlorohydrin and 1,2-epoxybutane are shown respectively. As can be seen from the spectra, there are no other impurity peaks besides solvent, substrate and product, indicating that the metalloporphyrin-based porous polyionic liquid of the present invention has good selectivity for carbon dioxide. In addition, the corresponding gas chromatograms can further prove the yield of the corresponding cyclic carbonate.

[0119] It should be noted that although the other embodiments do not provide relevant explanations of their characterization spectrum results, their related properties are quite similar.

[0120] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A metalloporphyrin-based porous polyionic liquid, characterized in that, The chemical structural formula of the metal porphyrin-based porous polyionic liquid is: , , , , , one of the following: X is Br or Cl.

2. A process for the preparation of the metalloporphyrin-based porous polyionic liquid of claim 1, characterized by, The method comprises the following steps: The porphyrin compound and the halogen-containing compound are placed in a solvent under an inert gas atmosphere for reflux reaction, and after the reaction is completed, the temperature is cooled to room temperature, and after solid-liquid separation, purification is performed to obtain the metal porphyrin-based porous polyionic liquid. The porphyrin compound is or wherein M is Al, Co, Zn or Cu. The halogen-containing compound is selected from , , , , , wherein X is Br or Cl.

3. The method for preparing a metalloporphyrin-based porous polyionic liquid according to claim 2, characterized in that, The temperature of the reflux reaction is 80-180 DEG C, and the time is 12-36 h.

4. The metal porphyrin-based porous polyionic liquid of claim 1 is applied to catalyze carbon dioxide and an epoxide to synthesize a cyclic carbonate.

5. A method for synthesizing cyclic carbonates from carbon dioxide and an epoxide, characterized by, The metal porphyrin-based porous polyionic liquid of claim 1 is used as a catalyst, and the method comprises the following steps: The catalyst and the epoxide are added into a container, and then carbon dioxide is introduced to perform reaction, and after the reaction is completed, the temperature is cooled, and after filtration, a filtrate is obtained, which is a cyclic carbonate.

6. The method of synthesizing cyclic carbonates from carbon dioxide and an epoxide of claim 5, wherein, The amount of the catalyst is 0.01-2.50 mol% of the epoxide, and after the carbon dioxide is discharged from the reaction container, air is introduced at a pressure of 0.1-3 MPa.

7. The method of synthesizing cyclic carbonates from carbon dioxide and an epoxide of claim 5, wherein, The epoxide comprises , R2 is one of hydrogen, halogen, alkyl, unsaturated ether linkage, phenyl, phenoxy.

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