High-efficiency catalyst for cyclic carbonate, preparation method and application thereof

Abstract

The application provides a high-efficiency catalyst for cyclic carbonates, a preparation method and application thereof, and compared with the prior art, the catalyst is prepared from a monoamine-based polyether, a polyamine, a phenolic monomer and formaldehyde, an aminated intermediate is synthesized through a chemical grafting reaction, and then is reacted with an epoxy group quaternary ammonium salt to obtain a supported quaternary ammonium salt catalyst. The catalyst molecular structure comprises a quaternary ammonium salt group, a tertiary amine group, a hydroxyl group and an ether bond structure, can not only play a catalytic effect of the quaternary ammonium salt, but also has a certain complexing effect of oxygen atoms in the tertiary amine group, the hydroxyl group and the ether bond structure, can stabilize the ion pair of the quaternary ammonium salt catalyst, and ensure the catalytic effect of the catalyst. Moreover, the catalyst prepared in the application can be independently used for catalyzing preparation of cyclic carbonates, does not need a cocatalyst, and has high catalytic efficiency and good stability.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of cyclic carbonate catalysts, and particularly relates to a high-efficiency catalyst for cyclic carbonates and a preparation method and application thereof. BACKGROUND

[0002] The emission of greenhouse gases dominated by carbon dioxide (CO2) is one of the key factors leading to global climate and ecosystem changes. At present, the annual CO2 emission in the world has reached tens of billions of tons. How to effectively control CO2 emission, and recycle, fix, utilize and re-source it, has become an important problem to be solved by the world.

[0003] Cyclic carbonates, especially ethylene carbonate and propylene carbonate, are important basic chemical raw materials and main components of lithium battery electrolytes, and the direct cycloaddition synthesis of alkylene oxides and CO2 is the main method for industrial production at present.

[0004] There are two reaction paths of ring-opening polymerization and intramolecular addition for the chemical reaction of CO2 and alkylene oxides. Since the reaction belongs to gas-liquid interface reaction, the catalyst plays a key role in improving the selectivity and efficiency of the synthesis reaction of cyclic carbonates. At present, the catalysts for synthesizing cyclic carbonates from CO2 and alkylene oxides are mainly divided into two categories of homogeneous catalysts and heterogeneous catalysts. The homogeneous catalysts have the characteristics of small amount, high catalytic efficiency and mild reaction conditions, including quaternary phosphonium salts, quaternary ammonium salts, ionic liquids, alkali metal salts and organic metal salts.

[0005] The patent with the publication number CN 118179598 A disclosed on June 14, 2024 discloses a catalyst for preparing cyclic carbonates and a preparation method of cyclic carbonates. The disclosed main catalyst needs to be used together with a cocatalyst metal halide to achieve catalytic effect.

[0006] It is necessary to provide a cyclic carbonate catalyst that can be used alone. SUMMARY

[0007] The purpose of the present application is to provide a high-efficiency catalyst for cyclic carbonates and a preparation method thereof. The amine intermediate is synthesized by chemical grafting reaction from monoamine-based polyether, polyamine, phenolic monomer and formaldehyde, and then reacted with epoxy quaternary ammonium salt to obtain a supported quaternary ammonium salt catalyst. The preparation method is simple and efficient.

[0008] The application also aims to provide the application of the high-efficiency catalyst for cyclic carbonates, and the prepared catalyst can be independently used for catalyzing the preparation of cyclic carbonates without a cocatalyst, and has high catalytic efficiency and good stability.

[0009] The specific technical scheme of the application is as follows.

[0010] A high-efficiency catalyst for cyclic carbonates has the structural formula of:

[0011]

[0012] wherein R is a linear or branched alkyl group with ≤6 carbon atoms, preferably any one of methyl, ethyl, isopropyl or cyclohexyl; a is a positive integer between 4 and 40; and b is an integer between 0 and 20.

[0013] The application provides a preparation method of the high-efficiency catalyst for cyclic carbonates, which comprises the following steps.

[0014] 1) a phenolic monomer and a monoamine-based polyether are used as a base solution, formaldehyde is added dropwise, and after heat preservation and reaction, a polyamine is added, stirred and uniformly mixed, then formaldehyde is continuously added dropwise, and after heat preservation and reaction, an aminated intermediate is obtained;

[0015] 2) the catalyst and the aminated intermediate are used as a base solution, an epoxy-based quaternary ammonium salt is added dropwise, and after heat preservation and reaction, a supported quaternary ammonium salt catalyst is obtained.

[0016] In step 1), the molar ratio of the monoamine-based polyether, the polyamine, the phenolic monomer and the formaldehyde is (0.8-1.1):(1.5-2.2):1:(2.4-3.3).

[0017] In step 1), the grafting reaction of the monoamine-based polyether and the phenolic monomer in the first stage is carried out, the dropping temperature of the formaldehyde is between 60-80 DEG C, the dropping time of the formaldehyde in the first stage is between 1-2h, and after the dropping is completed, heat preservation and reaction are carried out for 2h; the grafting reaction of the polyamine and the phenolic monomer in the second stage is carried out, the dropping temperature of the formaldehyde is between 60-80 DEG C, the dropping time of the formaldehyde in the second stage is between 1-3h, and after the dropping is completed, heat preservation and reaction are carried out for 2h.

[0018] In step 1), the monoamine-based polyether is a commercially available product, the number average molecular weight (M n ) is between 200-2000, and the molecular structure formula is shown in the following formula (3).

[0019]

[0020] wherein R is a linear or branched alkyl group with ≤6 carbon atoms, preferably any one of methyl, ethyl, isopropyl or cyclohexyl; a is a positive integer between 4 and 40; and b is an integer between 0 and 20.

[0021] In step 1), the formaldehyde is added in two stages, and the first-stage formaldehyde dropwise adding amount is 30%-40% of the total formaldehyde amount.

[0022] In step 1), the formaldehyde is added in the form of a formaldehyde solution, a trioxane solution or a polyoxymethylene solution; considering the dropwise adding mode and the convenience of reaction operation, the formaldehyde solution containing a methanol stabilizer is preferably used.

[0023] In step 1), the polyamine is a commercially available product, including ethylenediamine, propylenediamine, butylenediamine, cyclohexyldiamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, polyethylenepolyamine (M w The molecular weight of the polyamine is smaller than that of the monoamine-based polyether, and the number of N-H is significantly more than that of the monoamine-based polyether. On the one hand, the reactivity with formaldehyde and phenolic monomers is significantly higher than that of the monoamine-based polyether; on the other hand, more N-H active sites are provided for subsequent reactions.

[0024] In step 1), the phenolic monomer is any one of phenol, 2-methylphenol, 3-methylphenol, 4-methylphenol, 2-sec-butylphenol, 4-sec-butylphenol, 2-tert-butylphenol, 4-tert-butylphenol, 4-nonylphenol, 2-methoxyphenol, 3-methoxyphenol, 4-methoxyphenol, 2-ethoxyphenol, 3-ethoxyphenol, 4-ethoxyphenol, 2-isopropoxyphenol, 2-(2-hydroxyethoxy)phenol, p-benzenediol, o-benzenediol, m-benzenediol, 1-naphthol and 2-naphthol. Considering the number of reaction sites on the aromatic ring and the convenience of reaction control, the phenolic monomer is preferably phenol as the reaction monomer.

[0025] In step 1), the structure of the prepared aminated intermediate is as follows:

[0026]

[0027] wherein R is a linear or branched alkyl group with ≤6 carbon atoms, and is preferably any one of methyl, ethyl, isopropyl or cyclohexyl; a is a positive integer between 4 and 40; and b is a positive integer between 0 and 20.

[0028] In step 1), the grafting reaction of the monoamine-based polyether and the polyamine with the phenolic monomer needs to be carried out under alkaline conditions, and since the monoamine-based polyether and the polyamine themselves have strong alkalinity, they are both reactants and alkaline catalysts in the present application.

[0029] In step 2), the molar ratio of the aminated intermediate to the epoxy-based quaternary ammonium salt is 1:X, wherein X is the number of moles of N-H bonds in the aminated intermediate.

[0030] In step 2), the amount of the catalyst is 1%-5% of the mass of the amination intermediate.

[0031] In step 2), the epoxy group quaternary ammonium salt includes a three-membered oxygen heterocycle and a quaternary ammonium salt group in the molecular structure, and is generally synthesized by reacting epichlorohydrin with trimethylamine, triethylamine, tetramethyl ethylenediamine, N,N,N,N-tetramethyl-1,6 hexanediamine, etc. Based on the use cost and the cross-linking reaction problem of the double three-membered oxygen heterocycle, the present application mainly refers to the commercially available glycidyl trimethyl ammonium chloride product. The molecular structure formula of the epoxy group quaternary ammonium salt is as follows:

[0032]

[0033] In step 2), the catalyst is a Lewis acid, and the present application mainly refers to a metal halide salt. Preferably, the halogen is one of bromine and iodine. The catalyst is selected from one of soluble metal halide salts such as sodium bromide, potassium bromide, aluminum bromide, zinc bromide, iron bromide, copper bromide, chromium bromide, tin bromide, cobalt bromide, sodium iodide, potassium iodide, aluminum iodide, zinc iodide, iron iodide, copper iodide, chromium iodide, tin iodide, and cobalt iodide.

[0034] The Lewis acid is added in this step to fully catalyze the ring-opening reaction of the epoxy group quaternary ammonium salt, and to perform complexation and ion exchange with the quaternary ammonium salt group as much as possible.

[0035] In step 2), the reaction temperature is 50-100℃ under a nitrogen atmosphere, the dropping time of the epoxy group quaternary ammonium salt is 1-3h, and the holding reaction time after the dropping is completed is 2h.

[0036] In step 2), the ring-opening polymerization reaction of the amination intermediate and the epoxy group quaternary ammonium salt is carried out at a normal pressure and a reaction temperature of 50-100℃, the dropping time of the epoxy group quaternary ammonium salt is 1-3h, and the holding reaction time after the dropping is completed is 2h, to obtain the supported quaternary ammonium salt catalyst. In the present application, the metal halide salt not only catalyzes the ring-opening polymerization reaction of the amination intermediate and the epoxy group quaternary ammonium salt, but also has an auxiliary catalytic effect in the subsequent cyclic carbonate synthesis process due to the catalyst metal halide salt of the ring-opening polymerization reaction, which can further improve the catalytic activity of the supported quaternary ammonium salt catalyst. Therefore, further purification and separation operations of the supported quaternary ammonium salt catalyst are not required, which reduces the production cost and saves the process.

[0037] The present application provides an application of a high-efficiency catalyst for cyclic carbonates, and the specific application method is as follows: the high-efficiency catalyst for cyclic carbonates and cyclic carbonates are added into a reaction kettle, the reaction kettle is sealed and replaced with nitrogen, after warming, the alkylene oxide and carbon dioxide are simultaneously introduced into the reaction kettle under a certain pressure, after the feeding is completed, the reaction is continuously held, after the reaction is completed, the temperature is lowered to 50℃ to discharge the material, and the reaction liquid of the cyclic carbonates is obtained, and the sample is taken for GC testing.

[0038] The cyclic carbonate is selected from ethylene carbonate (EC) or propylene carbonate (PC);

[0039] The carbon dioxide is food grade, with purity ≥99.9%;

[0040] The alkylene oxide has water content ≤1000 ppm, gas phase purity ≥99%, and aldehyde content ≤100 ppm, and is selected from one of ethylene oxide (EO) or propylene oxide (PO);

[0041] The mass ratio of the alkylene oxide to carbon dioxide (CO2) is 1:(1.1-2.0);

[0042] The amount of the high-efficiency catalyst for the cyclic carbonate is 0.2%-5% of the mass of the alkylene oxide;

[0043] In the application reaction, the reaction temperature is 110-150℃, the reaction pressure is 0.1-2.0 MPa, and after the dropping is completed, the holding reaction time is 1.0 h.

[0044] The reaction of CO2 and alkylene oxide involved in the application is a gas-liquid phase interface chemical reaction. The cyclic carbonate added in the reaction kettle is an excellent solvent for carbon dioxide and alkylene oxide, which can significantly improve the solubility of CO2 and alkylene oxide in the liquid phase, and further improve their contact probability and reaction efficiency. The cyclic carbonate used is consistent with the type of the target synthesis product: for example, when synthesizing ethylene carbonate (EC), EC is used as the bottom liquid; when synthesizing propylene carbonate (PC), PC is used as the bottom liquid. The amount of the cyclic carbonate is 10%-20% of the amount of the alkylene oxide.

[0045] The cyclic carbonate prepared by using the high-efficiency catalyst for the cyclic carbonate synthesis has a yield of more than 99.50%.

[0046] The catalyst of the present application loads the quaternary ammonium salt group on the polyether side chain by chemical synthesis method, and the catalyst molecular structure contains quaternary ammonium salt group, tertiary amine group, hydroxyl group and ether bond structure, which not only can play the catalytic effect of quaternary ammonium salt, but also the oxygen atoms in the tertiary amine group, the hydroxyl group and the ether bond structure have certain complexing effect, which can stabilize the ion pair of quaternary ammonium salt catalyst and ensure the catalytic effect of the catalyst. The catalyst structure of the present application contains basic tertiary amine group, which has good adsorption effect on acidic carbon dioxide gas, promotes the contact and reaction probability of ethylene oxide and carbon dioxide in liquid phase, and improves the reaction efficiency of cyclic carbonate. In the preparation of the present application, the amine intermediate is synthesized with epoxy quaternary ammonium salt using metal halide salt as catalyst, which not only plays the Lewis acidity and complexing ability of metal halide salt to improve the ring-opening polymerization activity of ternary epoxy heterocycle, but also the metal halide salt is rich in halogen ions with large ionic radius such as bromine and iodine, which exchanges ions with chloride ions in quaternary ammonium salt to form quaternary ammonium salt with higher catalytic activity. The supported quaternary ammonium salt catalyst prepared in the present application realizes high selectivity and yield of cyclic carbonate in the simplest and most economical way.

[0047] Compared with the prior art, the present application is prepared from monoamine-based polyether, polyamine, phenolic monomer and formaldehyde to synthesize amine intermediate by chemical grafting reaction, and then reacts with epoxy quaternary ammonium salt to obtain supported quaternary ammonium salt catalyst. The preparation method is simple and efficient. Moreover, the catalyst prepared in the present application can be independently used for catalytic preparation of cyclic carbonate without cocatalyst, and has high catalytic efficiency and good stability. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 GC test spectrum of Example 3;

[0049] Figure 2 GC test spectrum of Example 9. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0051] The test materials and reagents used in the following examples, etc. can be obtained from commercial channels if not otherwise specified.

[0052] If the specific technology or condition is not specified in the examples, it can be carried out according to the technology or condition described in the literature in the art or according to the product instruction.

[0053] The application provides a high-efficiency catalyst for cyclic carbonates, which is prepared by the following method.

[0054] (1) first, an aminated intermediate is synthesized by chemical grafting reaction of a monoamine-based polyether, a polyamine, a phenolic monomer, formaldehyde and the like, and the synthesis steps are as follows: the phenolic monomer and the monoamine-based polyether are weighed and laid as a base, formaldehyde is weighed and continuously added dropwise to the reaction system in a titration manner, and the reaction is kept at a certain temperature for a certain time; after the reaction is completed, the polyamine is weighed and added to the above reaction system, and the mixture is fully stirred and mixed; then, the formaldehyde is weighed and continuously added dropwise to the reaction system in a titration manner, and the reaction is kept at a certain temperature for a certain time. After the reaction is completed, the aminated intermediate in brown yellow is obtained;

[0055] (2) the aminated intermediate and an epoxy-based quaternary ammonium salt are used as raw materials to generate ring-opening polymerization under the action of a catalyst to obtain a supported quaternary ammonium salt catalyst. The synthesis steps are as follows: the catalyst and the aminated intermediate in step (1) are weighed and sequentially added to a reaction base, the epoxy-based quaternary ammonium salt is weighed and continuously added dropwise to the reaction system in a titration manner, and the reaction is kept at a certain temperature for a certain time. After the reaction is completed, the supported quaternary ammonium salt catalyst in brown yellow is obtained.

[0056] Unless otherwise specified, the parts in the application refer to mass parts.

[0057] The aminated intermediate and the supported quaternary ammonium salt catalyst are tested by using a high-performance liquid chromatograph. According to the principle that the residence time of different compounds in a liquid chromatograph column is different due to different polarities, the separation of raw material peaks and product peaks is realized, and the reaction conversion rate is calculated according to the area ratio of each peak. The column type used is Bioband GP120-C18 5μm 120Λ250mm×4.6mm id reversed-phase column, the mobile phase is acetonitrile and tetrahydrofuran, the volume ratio is 9:1, and the flow rate is 0.6ml / min.

[0058] The reaction solution of the cyclic carbonate described in the application is tested by a Shimadzu 2030 gas chromatograph, the chromatographic column is an Agilent DB-1701 type chromatographic column (column length x column inner diameter x coating thickness: 30 m x 0.53 mm x 0.50 um), and the sample is prepared by using acetonitrile at a mass ratio of 1:1. The test conditions are as follows: the sample amount is 0.4 microliters, the split ratio is 20:1, the sample inlet temperature is set to 270 DEG C, the detector temperature is set to 290 DEG C, and the column oven is set to program temperature (initial 100 DEG C, keep for 2 min, 10 DEG C / min to 120 DEG C, 20 DEG C / min to 220 DEG C, keep for 5 min, 20 DEG C / min to 240 DEG C, keep for 20 min). The GC test only records the peak area percentage of key components such as alkylene oxide, ethylene / propylene glycol, diethylene / propylene glycol, cyclic carbonate, etc.

[0059] The monoamine polyether used in the application is purchased from Ningbo Hailuo New Material Technology Co., Ltd., and the monoamine polyether and code are shown in Table 1.

[0060] Table 1 Monoamine polyether raw materials and code

[0061]

[0062] Example 1

[0063] Synthesis of amination intermediate:

[0064] Monoamine polyether A-1 100 parts, phenol 46.81 parts are weighed in sequence and added to a reaction kettle, the reaction kettle is heated to 60 DEG C, formaldehyde solution 29.07 parts is weighed, and is added by dropwise addition, the dropwise addition time is 1.0 h, and the reaction temperature is controlled at 60±5 DEG C, after the dropwise addition is completed, the reaction is kept for 2.0 h; ethylenediamine 44.82 parts is weighed and added to the above reaction kettle at one time. The reaction kettle is heated to 80 DEG C. Formaldehyde solution 67.84 parts is weighed and added by dropwise addition, the dropwise addition time is 3.0 h, and the reaction temperature is controlled at 75±5 DEG C, after the dropwise addition is completed, the reaction is kept for 2.0 h, a brownish yellow liquid with certain viscosity is obtained, which is the amination intermediate, named AN-1, and the amination intermediate yield is 99.3% by HPLC test.

[0065] Similarly, the following amination intermediates are prepared according to the same reaction steps, and the amination intermediate synthesis formula and synthesis process parameters are shown in Table 2.

[0066] Table 2 Amination intermediate synthesis formula and process parameters (unit: parts)

[0067]

[0068] Example 2 Synthesis of high-efficiency catalyst for cyclic carbonate

[0069] Take 100 parts of amine intermediate AN-1 and 1.1 parts of catalyst sodium bromide in a reaction kettle, replace with nitrogen for 3 times, start stirring and heat exchange, and heat the reaction kettle to 50°C. Take 234.11 parts of epoxy propyl trimethyl ammonium chloride, and feed by dropwise addition, with a dropwise addition time of 1.0 h, and the reaction temperature is controlled at 50±5°C. After the dropwise addition is completed, heat for 2.0 h. A brownish yellow liquid with certain viscosity is obtained, which is a supported quaternary ammonium salt catalyst, named CAN-1, and the ring-opening reaction rate of the epoxy propyl quaternary ammonium salt monomer is 99.6% by HPLC test.

[0070] Similarly, the following supported quaternary ammonium salt catalysts are prepared according to the same reaction steps, and the synthesis formula and synthesis process parameters are shown in Table 3.

[0071] Table 3 Synthesis formula and process parameters of supported quaternary ammonium salt catalyst (unit: parts)

[0072]

[0073] Synthesis of cyclic carbonates

[0074] Take 10 parts of ethylene carbonate (abbreviated as EC) and 0.42 parts of cyclic carbonate high-efficiency catalyst CAN-1, and add them into the reaction kettle in sequence. Seal the reaction kettle and replace with nitrogen for 3 times. Heat the reaction kettle to 110°C. Take 100 parts of ethylene oxide (abbreviated as EO) and 110 parts of carbon dioxide (abbreviated as CO2) as the feed, set the mass feed rate of CO2 to be 1.1 times that of EO, control the reaction temperature to be 110±5°C, and control the reaction pressure to be 2.0 MPa (the insufficient part is supplemented by nitrogen). After the feeding is completed, continue to heat for 1.0 h, and obtain a light brownish yellow ethylene carbonate reaction liquid, which is sampled for GC test.

[0075] Similarly, according to the same reaction steps of Example 3, except for changing the raw material dosage ratio and conditions, the cyclic carbonates of Examples 4-9 are prepared, as shown in Tables 4 and 5.

[0076] Table 4 Material ratio for synthesis of cyclic carbonates (unit: parts)

[0077] Examples Host catalyst Cyclic carbonate Alkylene oxide Carbon dioxide Example 3 CAN-1 : 0.42 EC: 10 EO: 100 110 Example 4 CAN-2: 1.0 EC: 12 EO: 100 150 Example 5 CAN-3: 2.0 EC: 14 EO: 100 180 Example 6 CAN-4: 3.0 PC: 16 PO: 100 200 Example 7 CAN-5: 4.0 PC: 18 PO: 100 170 Example 8 CAN-6: 4.98 PC: 20 PO: 100 160 Example 9 CAN-7: 3.5 EC: 15 EO: 100 140

[0078] The synthesis process parameters and GC test results of each example are shown in Table 5.

[0079] Table 5 Synthesis process parameters and GC test of cyclic carbonates

[0080]

[0081]

[0082] Figure 1 GC test spectrum of Example 3, wherein the peak at 2.51 minutes is an ethylene oxide peak, the peak at 3.76 minutes is an ethylene glycol peak, the peak at 7.59 minutes is a diethylene glycol peak, and the peak at 10.99 minutes is an ethylene carbonate peak.

[0083] Figure 2 GC test spectrum of Example 9, wherein the peak at 2.51 minutes is an ethylene oxide peak, the peak at 3.77 minutes is an ethylene glycol peak, the peak at 7.59 minutes is a diethylene glycol peak, and the peak at 11.05 minutes is an ethylene carbonate peak.

[0084] Comparative Example 1

[0085] Take 20 parts of ethylene carbonate, 4.5 parts of polyethylene glycol (PEG2000), and 3.5 parts of catalyst KBr in a reaction kettle, close the reaction kettle and do 3 times of nitrogen replacement. The reaction kettle is heated to 170℃. Take 100 parts of ethylene oxide (EO) and 135 parts of carbon dioxide (CO2) as feed, set the mass feed rate of CO2 to be 1.35 times of EO, control the reaction temperature to be 170±5℃, and the reaction pressure to be 1.8 MPa (the insufficient part is supplemented by nitrogen). After the feeding is completed, continue to heat for 1.0 h to obtain a light brown yellow ethylene carbonate reaction liquid. The sample is tested by GC (peak area percentage / %): ethylene glycol 2.37%, diethylene glycol 3.15%, ethylene oxide 0.58%, and ethylene carbonate 93.90%.

[0086] Only polyethylene glycol is used in physical mixing with potassium bromide, there is no chemical synthesis of supported catalyst and no cocatalyst, the reaction temperature exceeds the control value (the reaction temperature is higher), and the propylene carbonate yield is lower.

[0087] Comparative Example 2

[0088] Take 15 parts of propylene carbonate and 2.5 parts of catalyst tetrabutylammonium bromide in a reaction kettle, close the reaction kettle and do 3 times of nitrogen replacement. The reaction kettle is heated to 135℃. Take 100 parts of propylene oxide (PO) and 115 parts of carbon dioxide (CO2) as feed, set the mass feed rate of CO2 to be 1.15 times of EO, and control the reaction pressure to be 2.5 MPa (the insufficient part is supplemented by nitrogen). After the feeding is completed, continue to heat for 1.0 h to obtain a light brown yellow propylene carbonate reaction liquid, the temperature is 135±5℃, and the reaction pressure is sampled for GC test (peak area percentage / %): propylene glycol 3.85%, dipropylene glycol 2.32%, ethylene oxide 0.45%, and propylene carbonate 93.38%.

[0089] There is no chemical synthesis of supported catalyst, the pressure exceeds the limit value (the pressure is higher), and the propylene carbonate yield is lower.

[0090] Comparative Example 3

[0091] Take 30 parts of propylene carbonate (PC for short), 2.4 parts of AN-1, 5.62 parts of epoxy propyl trimethyl ammonium chloride, and 0.1 part of potassium iodide, and add them into a reaction kettle in sequence. The reaction kettle is closed and subjected to three nitrogen replacements. The reaction kettle is heated to 140°C. Take 100 parts of propylene oxide (PO for short) and 90 parts of carbon dioxide (CO2 for short) as feedstocks. The mass feed rate of CO2 is set to be 0.9 times that of PO. The reaction temperature is controlled to be 140±5°C, and the reaction pressure is 1.7 MPa (the insufficient part is supplemented by nitrogen). After the feeding is completed, the reaction is continued for 1.0 h at constant temperature. A light brownish yellow propylene carbonate reaction liquid is obtained. The sample is tested by GC (peak area percentage / %) as follows: 9.2% of propylene glycol, 4.73% of dipropylene glycol, 0.47% of propylene oxide, and 85.6% of propylene carbonate.

[0092] Comparative Example 3 uses all catalyst synthesis raw materials without chemical synthesis of supported catalysts. The CO2 dosage is lower than that of propylene oxide, and the propylene carbonate yield is lower.

[0093] The above description of the embodiments is to facilitate the ordinary skilled person in the art to understand and use the application. Those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the application is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art according to the disclosure of the application without departing from the scope of the application should be within the protection scope of the application.

Claims

1. A highly efficient catalyst for cyclic carbonate, characterized by, The structure of the high-efficiency catalyst for the cyclic carbonate is as follows: wherein R is a linear or branched alkyl group having ≤ 6 carbon atoms; a is a positive integer between 4 and 40; and b is an integer between 0 and 20.

2. A process for the preparation of the efficient catalyst for cyclic carbonate according to claim 1, characterized by, The preparation method comprises the following steps: 1) a phenolic monomer and a monoamine polyether are used as a base solution, formaldehyde is added dropwise, and then reacted after heat preservation; a polyamine is added, stirred and uniformly mixed, then formaldehyde is continuously added dropwise, and reacted after heat preservation, to obtain an aminated intermediate; 2) the catalyst and the aminated intermediate are used as a base solution, an epoxy quaternary ammonium salt is added dropwise, and reacted after heat preservation, to obtain a supported quaternary ammonium salt catalyst.

3. The preparation method according to claim 2, characterized in that, The molar ratio of the monoamine polyether, the polyamine, the phenolic monomer and the formaldehyde is (0.8-1.1):(1.5-2.2):1:(2.4-3.3).

4. The production method according to claim 2 or 3, characterized by, In step 1), the grafting reaction of the monoamine polyether and the phenolic monomer in the first stage, the dropwise addition temperature of the formaldehyde is between 60-80 DEG C, the dropwise addition time of the formaldehyde in the first stage is between 1-2 h, and the reaction is preserved for 2 h after the dropwise addition is completed; the grafting reaction of the polyamine and the phenolic monomer in the second stage, the dropwise addition temperature of the formaldehyde is between 60-80 DEG C, the dropwise addition time of the formaldehyde in the second stage is between 1-3 h, and the reaction is preserved for 2 h after the dropwise addition is completed.

5. The preparation method according to claim 2, characterized in that, In step 1), the monoamine-based polyether is a commercially available product having a number average molecular weight (Mn) of between 200 and 2000, and a molecular structure represented by the following formula (3). n ) In step 1), the monoamine-based polyether is a commercially available product having a number average molecular weight (Mn) of between 200 and 2000, and a molecular structure represented by the following formula (3). R is a linear or branched alkyl group with ≤6 carbon atoms; a is a positive integer between 4-40; and b is a positive integer between 0-20.

6. The preparation method according to claim 2, characterized in that, In step 1), the structure of the prepared aminated intermediate is as follows: R is a linear or branched alkyl group with ≤6 carbon atoms; a is a positive integer between 4-40; and b is a positive integer between 0-20.

7. The production method according to claim 2 or 6, characterized by, In step 2), the molar ratio of the aminated intermediate and the epoxy quaternary ammonium salt is 1:X, wherein X is the number of moles of N-H bonds in the aminated intermediate.

8. The preparation method according to claim 2, characterized in that, In step 2), the molecular structure of the epoxy quaternary ammonium salt comprises a three-membered epoxy heterocycle and a quaternary ammonium salt group; and the catalyst is a Lewis acid.

9. The preparation method according to claim 2, in step 2), under a nitrogen atmosphere, the reaction temperature is between 50-100 DEG C, the dropwise addition time of the epoxy quaternary ammonium salt is between 1-3 h, and the reaction is preserved for 2 h after the dropwise addition is completed.

10. Use of a high-efficiency catalyst for cyclic carbonates according to claim 1, characterized in that, The application method is as follows: the high-efficiency catalyst for the cyclic carbonate and the cyclic carbonate are added into a reaction kettle, the reaction kettle is sealed and replaced with nitrogen, after heating, the alkylene oxide and the carbon dioxide are simultaneously introduced into the reaction kettle under certain pressure, after the feeding is completed, the reaction is continuously preserved, after the reaction is completed, the temperature is lowered to 50 DEG C to discharge, and the reaction liquid of the cyclic carbonate is obtained.

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