An aromatic ring-containing organic imine salt compound catalyst, a preparation method thereof, and a method for preparing a cyclic carbonate by catalyzing carbon dioxide

Abstract

The application provides an aromatic ring-containing organic imine salt compound catalyst, a preparation method thereof and a method for preparing a cyclic carbonate by catalyzing carbon dioxide. The preparation method of the aromatic ring-containing organic imine salt compound catalyst comprises the following steps: adding an organic imine salt dye, a halide salt and a solvent into a container, stirring until the reaction is completed, cooling in an ice water bath, and then performing suction filtration and drying to obtain a modified aromatic ring-containing organic imine salt dye catalyst. The application further discloses a method for preparing a cyclic carbonate by catalyzing carbon dioxide by using the aromatic ring-containing organic imine salt compound catalyst. The aromatic ring-containing organic imine salt compound catalyst can significantly improve the yield of the cyclic carbonate prepared from carbon dioxide, the reaction condition is mild, no metal and solvent are needed, and the catalyst can be recycled and used after a nanofiltration process.

Description

TECHNICAL FIELD

[0001] The present application relates to dye catalyst synthesis and catalytic carbon dioxide technology, and particularly relates to an organic imine salt compound catalyst containing an aromatic ring, a preparation method thereof and a method for preparing cyclic carbonate by catalyzing carbon dioxide. BACKGROUND

[0002] The reaction of CO2 and epoxide for cycloaddition to generate cyclic carbonate is one of important ways to realize carbon cycle. The cycloaddition reaction can not only convert carbon dioxide into chemical products with high added value, but also has very good atom economy and meets the requirements of green chemistry. Although the current organic dye catalysts have good catalytic activity after structural modification, addition of solvents and addition of HBDs groups, the following problems still exist:

[0003] (1) The solubility is generally low, and organic solvents are needed to participate in the reaction to accelerate the dissolution and further improve the reaction rate.

[0004] (2) Although the regeneration effect is good and the catalytic activity can be maintained well, the recovery process is complicated and needs to be optimized. SUMMARY

[0005] The present application aims at the problems of low solubility, complex recovery process, poor selectivity, low yield and complicated operation of the current organic dye catalysts for converting carbon dioxide into chemical products with high added value, and provides a preparation method of an organic imine salt compound catalyst containing an aromatic ring. The preparation method is simple, easy to implement and has high yield. The organic imine salt compound catalyst containing an aromatic ring prepared by the method can significantly improve the yield of cyclic carbonate prepared from carbon dioxide, and the reaction conditions are mild and do not need metal and solvent. Meanwhile, the catalyst can be recovered and recycled by nanofiltration.

[0006] It should be noted that in the present application, unless otherwise specified, the specific meaning of "including" involved in the composition limitation and description includes both open "including", "containing" and the like and closed "consisting of", "consisting essentially of" and the like.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows: a preparation method of an organic imine salt compound catalyst containing an aromatic ring, comprising the following steps:

[0008] An organic imine salt dye, a halide salt and a solvent are added to a container, and after stirring and reaction, the mixture is cooled in an ice water bath, filtered and dried to obtain a modified organic imine salt dye catalyst containing an aromatic ring.

[0009] Further, the organic imine salt dye is a mixture of one or more of Victoria blue B, safranin T, crystal violet, basic red 9, rhodamine B, rhodamine 6G and betaine. The organic imine salt dye is preferably a mixture of one or more of safranin T, crystal violet and basic red 9.

[0010] Further, the solvent is a mixture of one or more of distilled water, methanol, ethanol, acetonitrile, acetone, tetrahydrofuran, dichloromethane and N,N-dimethylformamide. The solvent is preferably a mixture of one or more of distilled water, acetonitrile and dichloromethane.

[0011] Further, the halide salt is a mixture of one or more of potassium bromide, potassium iodide, sodium bromide, sodium iodide, ammonium bromide, ammonium iodide, copper bromide, copper iodide, magnesium bromide and magnesium iodide; the halide salt is preferably a mixture of one or more of potassium bromide, potassium iodide, sodium bromide and sodium iodide.

[0012] Further, the molar ratio of the organic imine salt dye and the halide salt is 1:1-1:200, preferably 1:1-1:20. The solvent can dissolve all the organic imine salt dye and the halide salt.

[0013] Further, the reaction temperature is 20-80℃, and the reaction time is 0.5-24h, preferably the reaction temperature is 40-80℃, and the reaction time is 6-18h.

[0014] Further, the cooling time in the ice water bath is 0.5-18h, preferably 1-5h.

[0015] Taking the basic red 9 modified catalyst as an example, the reaction equation is as follows:

[0016] Another object of the present application also discloses an aromatic ring-containing organic imine salt compound catalyst prepared by the above method.

[0017] Another object of the present application also discloses a method for preparing cyclic carbonate from carbon dioxide by using an aromatic ring-containing organic imine salt compound catalyst, comprising the following steps:

[0018] The aromatic ring-containing organic imine salt compound catalyst and propylene oxide are added to a reaction kettle with a stirring device, a temperature sensor and a pressure sensor, and after sealing, carbon dioxide gas is introduced into the reaction kettle, and the reaction is heated; after the reaction kettle is cooled to room temperature, the remaining carbon dioxide is released; the reaction product is filtered, the obtained solid catalyst is washed with a solvent and dried for cyclic use, and the obtained liquid is separated by reduced pressure distillation to obtain cyclic carbonate.

[0019] Further, the filtration is nanofiltration.

[0020] Further, the content of the aromatic ring-containing organic imine salt compound catalyst is 0.05% to 30% of the content of propylene oxide, preferably 0.5% to 5%.

[0021] Further, the pressure of carbon dioxide in the reaction kettle is 0.5 to 10 MPa, preferably 1 to 5 MPa.

[0022] Further, the reaction temperature is 20 to 200°C, and the reaction time is 0.5 to 24 hours, preferably the reaction temperature is 80 to 150°C, and the reaction time is 6 to 18 hours.

[0023] Taking the basic red 9 modified organic imine salt dye catalyst as an example, the reaction equation is as follows:

[0024]

[0025] The application discloses an aromatic ring-containing organic imine salt compound catalyst, a preparation method thereof and a method for preparing cyclic carbonate by catalyzing carbon dioxide, and has the following advantages compared with the prior art:

[0026] 1) The preparation method of the aromatic ring-containing organic imine salt compound catalyst is simple, easy to operate and high in yield, and can be applied to the preparation of cyclic carbonate from carbon dioxide.

[0027] 2) Compared with traditional catalysts, the aromatic ring-containing organic imine salt compound catalyst realizes high-selectivity catalysis of cyclic carbonate under mild, metal-free and solvent-free conditions, exhibits excellent adsorption and conversion dual-functionality to carbon dioxide, and has a strong market prospect.

[0028] 3) The aromatic ring-containing organic imine salt compound catalyst is convenient to recycle, is conducive to the recycling of the catalyst, and reduces production cost. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a scanning electron microscope graph of the safranin T modified catalyst in Example 1.

[0030] Figure 2 It is an infrared spectrum graph of the safranin T modified catalyst in Example 1.

[0031] Figure 3 It is a nuclear magnetic resonance spectrum graph of propylene carbonate in Example 1.

[0032] Figure 4 It is a scanning electron microscope graph of the basic red 9 modified catalyst in Example 2.

[0033] Figure 5 It is an infrared spectrum graph of the basic red 9 modified catalyst in Example 2. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to embodiments. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0035] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0036] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0037] In this specification, the numerical range indicated by "above" or "below" refers to the numerical range that includes the stated number.

[0038] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0039] In this specification, the terms "optional" or "optional" are used to indicate the use or omission of certain substances, components, procedures, application conditions, etc.

[0040] In this instruction manual, when "room temperature" or "room temperature" is used, the temperature can be 15-25℃.

[0041] Unless otherwise specified, all reagents or instruments used in this instruction manual are commercially available products.

[0042] Example 1

[0043] This embodiment discloses an aromatic ring-containing organic imine salt compound catalyst, and a method for catalyzing the preparation of cyclic carbonates from carbon dioxide using this catalyst, as follows:

[0044] Synthesis method of saffron T modified catalyst: 2 mmol (0.702 g) of saffron T and 2.2 mmol (0.365 g) of KI (1.1 eq.) were added to a 100 mL round-bottom flask, along with 50 mL of deionized water. The mixture was stirred and refluxed at 60 °C for 1 h at a speed of 600 r / min. The flask was then placed in an ice-water bath for 1 h, followed by filtration using a Buchner funnel. A large amount of solid was obtained, which was washed repeatedly with deionized water and dried in an oven to obtain the organic dye catalyst saffron TI. The solid was then stored in a desiccator for later use.

[0045] Characterization of the catalyst: by transmission electron microscopy (TEM) Figure 1 It can be observed that the prepared catalyst has a porous structure with a specific surface area of ​​10.2 m².2 / g, while the rough surface, the advantage of the surface functional groups of naked, accelerate the catalytic speed. By infrared spectrogram can qualitative analysis of the structure of the catalyst Figure 2 , a is safranin T, b is modified safranin T).

[0046] The safranin T modified catalyst catalyzed carbon dioxide to prepare cyclic carbonate: respectively, safranin T-I (0.2mmol) and propylene oxide (20mmol) were added to the reaction kettle with magnetic, temperature sensor and pressure sensor, quickly sealed high pressure reaction kettle. Then open the inlet valve, 1.5MPa of carbon dioxide gas was added to the reaction kettle, heated to 80℃ for 6h, the reaction was as shown in formula 1. After the reaction, the reaction kettle was cooled to room temperature, the exhaust valve was opened gently, and the remaining carbon dioxide was slowly released. The solution sample was filtered, the solid catalyst was washed with solvent for several times and dried for recycling, and the liquid was separated by vacuum distillation to obtain the product propylene carbonate (yield 58%), the spectrum was as shown in Figure 3 , it can be seen that the new synthesized modified organic imine salt dye catalyst can efficiently catalyze carbon dioxide to prepare cyclic carbonate.

[0047]

[0048] Example 2

[0049] The present embodiment discloses an organic imine salt compound catalyst containing aromatic ring, and a method for catalyzing carbon dioxide to prepare cyclic carbonate by using the catalyst, the method is as follows:

[0050] Synthesis of modified catalyst of basic red 9: 2mmol (0.6476g) of basic red 9 and 2mmol (0.189g) of 3-chloropropanol were dissolved in 25mL of anhydrous ethanol. And 2mmol (0.08g) of NaOH was added to absorb the generated hydrogen chloride and promote the reaction. Stirring was carried out at 70℃ under the condition of refluxing with condensed water for 24h. Then the obtained dark red mixed solution was heated to 35℃ by using a rotary evaporator to remove the ethanol solvent. Then it was washed with deionized water for several times to dissolve the residual 3-chloropropanol on the surface of the solid. Then it was suction filtered and washed with solvent, and finally the solid was dried in an oven, recrystallized with acetonitrile, suction filtered to obtain the intermediate compound in the form of black powder, which was dried in an oven for standby.

[0051] A black powdery solid and 2.2 mmol (0.365 g) of KI (1.1 eq) were added to a 100 mL round-bottom flask, followed by 50 mL of deionized water. The mixture was heated to 60 °C and refluxed with stirring for 1 h at a speed of 600 rpm. The flask was then placed in an ice-water bath for 1 h, followed by filtration using a Buchner funnel. A large amount of solid was obtained, which was washed repeatedly with deionized water and dried in an oven to obtain the organic dye catalyst Basic Red 9-n-propanol-I. This was then stored in a desiccator for later use. The synthetic route for Basic Red 9-n-propanol-I is shown in Formula 2.

[0052]

[0053] Characterization of the catalyst: by transmission electron microscopy (TEM) Figure 4 It can be observed that the prepared catalyst has a plate-like, porous structure with a specific surface area of ​​11.9 m². 2 / g, and the rough surface of the lamellar structure facilitates the exposure of surface functional groups, accelerating the catalytic rate. The structure of the catalyst can be qualitatively analyzed using infrared spectroscopy. Figure 5 ).

[0054] Cyclic carbonates were prepared from carbon dioxide using Basic Red 9-n-propanol-I as an organic dye catalyst. Basic Red 9-n-propanol-I catalyst (0.4 mmol) and propylene oxide (20 mmol) were added to a reactor equipped with a magnetic induction device, temperature sensor, and pressure sensor, and the high-pressure reactor was quickly sealed. Then, the inlet valve was opened, and carbon dioxide gas at 3 MPa was added to the reactor. The reactor was heated to 120°C and reacted for 12 h, as shown in Formula 1. After the reaction, the reactor was allowed to cool naturally to room temperature, and the exhaust valve was gently opened to slowly release the remaining carbon dioxide. The solution sample was filtered. The solid catalyst was repeatedly washed and dried with solvent for reuse. The liquid was separated into propylene carbonate (77% yield) by vacuum distillation. The chromatogram is shown below. Figure 3 As shown, the newly synthesized modified organic imine salt dye catalyst can efficiently catalyze the preparation of cyclic carbonates from carbon dioxide.

[0055] Compare with Example 1

[0056] Comparative Example 1 uses unmodified dye to catalyze carbon dioxide to prepare cyclic carbonate. Crocein T (0.2 mmol) and propylene oxide (20 mmol) are added to a reaction kettle with a magnetic stirrer, temperature sensor and pressure sensor, and the high-pressure reaction kettle is quickly sealed. Then the gas inlet valve is opened, 1.5 MPa of carbon dioxide gas is added to the reaction kettle, heated to 80°C for 6 hours, and the reaction is as shown in Formula 1. After the reaction is completed, the reaction kettle is naturally cooled to room temperature, the exhaust valve is gently opened, and the remaining carbon dioxide is slowly released. The solution sample is filtered, the solid catalyst is washed with solvent for multiple cycles and dried for reuse, and the liquid is separated by vacuum distillation to obtain the product propylene carbonate (yield 7%)

[0057] Comparative Example 1 and Comparative Example 1 show that the yield of propylene carbonate is increased from 7% to 58%. Thus, the modified organic imine salt dye catalyst has good application prospects in catalyzing the conversion of carbon dioxide.

[0058] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing examples, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a catalyst containing an aromatic ring organic imine salt compound, characterized in that, Includes the following steps: The aromatic ring-containing organic imine salt compound is catalyzed as a modified catalyst of Saffron T or Basic Red 9. The synthesis method of the saffron T modified catalyst is as follows: Saffron T and KI are added to a round-bottom flask, and deionized water is added. The mixture is stirred and refluxed at 60°C for 1 h with a speed of 600 r / min. Then, the round-bottom flask is placed in an ice-water bath for 1 h, and then filtered through a Buchner funnel. After obtaining a large amount of solid, it is washed with deionized water several times and dried in an oven to obtain the organic dye catalyst saffron TI. Synthesis of the modified catalyst of Basic Red 9: Basic Red 9 and 3-chloropropanol were dissolved in anhydrous ethanol, and NaOH was added to absorb the hydrogen chloride produced in the reaction and promote the reaction. The mixture was heated to 70 °C and stirred for 24 h under reflux with cooling water. Then, the mixture was heated to 35 °C using a rotary evaporator to remove the ethanol solvent from the resulting dark red mixed solution. Subsequently, the mixture was washed repeatedly with deionized water to dissolve the residual 3-chloropropanol on the surface of the solid. The solid was filtered and washed with solvent. Finally, the solid was dried in an oven and recrystallized with acetonitrile. The resulting black powdery intermediate compound was obtained by filtration and dried in an oven for later use. The black powdery solid and KI were added to a round-bottom flask, and deionized water was added. The mixture was heated to 60 °C and stirred under reflux for 1 h at a speed of 600 rpm. r / min; Place the round-bottom flask in an ice-water bath for 1 hour, then filter it using a Buchner funnel to obtain a large amount of solid. Wash it several times with deionized water, and dry it in an oven to obtain the organic dye catalyst Basic Red 9-n-propanol-I.

2. An aromatic ring-containing organic imine salt compound catalyst, prepared by the method described in the claims.

3. A method for preparing cyclic carbonates from carbon dioxide catalyzed by an aromatic ring-containing organic imine salt compound catalyst as described in claim 2, characterized in that, Includes the following steps: An aromatic ring-containing organic imine salt catalyst and propylene oxide were added to a reactor equipped with a stirrer, temperature sensor, and pressure sensor. After sealing, carbon dioxide gas was introduced into the reactor and the reaction was heated. After the reactor cooled to room temperature, the remaining carbon dioxide was released. The reactants were filtered, and the solid catalyst obtained by filtration was cleaned with a solvent, dried, and recycled. The liquid obtained by filtration was separated by vacuum distillation to obtain cyclic carbonates.

4. The method for preparing cyclic carbonates from carbon dioxide catalyzed by the aromatic ring-containing organic imine salt compound catalyst according to claim 3, characterized in that, The amount of the aromatic ring-containing organic imine salt compound catalyst is 0.05% to 30% of the amount of propylene oxide.

5. The method for preparing cyclic carbonates from carbon dioxide catalyzed by the aromatic ring-containing organic imine salt compound catalyst according to claim 3, characterized in that, The pressure of carbon dioxide inside the reactor is 0.5~10 MPa.

6. The method for preparing cyclic carbonates from carbon dioxide catalyzed by the aromatic ring-containing organic imine salt compound catalyst according to claim 3, characterized in that, The reaction temperature is 25~120℃, and the reaction time is 0.5~24h.

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