Cyclotriphosphazene-derived silicon-based solid amine materials and their application in catalyzing the coupling of carbon dioxide and epoxides to prepare cyclic carbonates

Abstract

The present invention belongs to the field of material synthesis and catalysis technology and proposes a cyclotriphosphazene-derived silicon-based solid amine material and its application in catalyzing the coupling of carbon dioxide and epoxide to prepare cyclic carbonates. The present invention uses hexachlorotripolyphosphazene as a raw material to synthesize a silicon source precursor (CPF), then uses a hydrothermal co-condensation method to construct a cyclotriphosphazene-derived mesoporous organosilicon. The cyclotriphosphazene-derived silicon-based solid amine material is then synthesized with polyethyleneimine via an impregnation method. The entire synthesis process is simple, environmentally friendly, and mild. The present invention achieves highly selective catalytic synthesis of cyclic carbonates under solvent-free and co-catalyst-free conditions, while also enabling simple separation and regeneration of the catalyst.

Description

Technical Field

[0001] The present invention belongs to the technical field of material synthesis catalysis, and specifically relates to a cyclotriphosphazene-derived silicon-based solid amine material and its application in catalyzing the coupling of carbon dioxide and epoxide to prepare cyclic carbonates. Background Art

[0002] CO2 is a major greenhouse gas. As atmospheric CO2 levels increase annually, it can easily trigger ecological and environmental problems such as glacial melting and global warming. Furthermore, CO2 is an abundant, inexpensive, low-toxic, and renewable carbon resource. Consequently, CO2 capture and resource utilization technologies have garnered widespread attention. Using CO2 as a raw material, the development of efficient catalytic technologies can convert CO2 into high-value-added chemical products. This not only reduces CO2 emissions but also reduces the consumption of non-renewable fossil energy, offering significant benefits for environmental protection and sustainable development. However, currently, only a few processes for producing organic chemicals using CO2 as a raw material have been industrialized worldwide. According to statistics, industrial CO2 consumption accounts for only 0.36% of total global emissions. Therefore, there is still significant room for development in the resource utilization of CO2.

[0003] Among numerous reactions, the cycloaddition reaction of CO2 coupled with epoxides to prepare cyclic carbonates has attracted widespread attention from scientists. On the one hand, CO2 cycloaddition reactions are atom-economical, replacing the traditional hazardous production process of highly toxic phosgene, meeting the requirements of green chemistry and safe production. On the other hand, cyclic carbonate products have excellent physical and chemical properties (such as high boiling point, high polarity, and low volatility) and good biodegradability, and are widely used in the chemical, pharmaceutical, and polymer fields. However, carbon dioxide itself is thermodynamically stable and kinetically inert, making it unfavorable for participating in chemical reactions. In addition, chemical reactions involving CO2 require the introduction of highly active reaction substrates and the use of new catalysts to reduce the activation energy of the reaction.

[0004] A range of catalysts have been reported for CO2 cycloaddition reactions, including metal oxides, metal-salen complexes, metal-organic frameworks (MOFs), porous organic polymers (POPs), conjugated organic frameworks (COFs), and functional ionic liquids (TSILs). However, most metal catalysts are expensive, complex to synthesize, and pose potential environmental risks due to long-term metal use. Therefore, the development and design of non-metallic, inexpensive, environmentally friendly catalysts that effectively avoid the use of co-catalysts and can efficiently catalyze CO2 cycloaddition reactions under mild, solvent-free conditions is a major trend.

[0005] Solid-state amines are polymers with a large specific surface area and numerous micro- and mesopores, enabling CO2 diffusion within these micro- and mesoporous structures. By modifying a carrier material with amine groups, active sites for CO2 adsorption can be created, offering advantages such as high adsorption efficiency and ease of desorption, while also making the adsorbent more recyclable during the desorption process. Currently, solid-state amine CO2 adsorbents are being used as a post-combustion CO2 capture technology, offering advantages such as low energy consumption, low corrosiveness, high thermal stability, and easy recyclability. In 2017, Chen's group developed a DVB-co-EGDMA polymer loaded with 30% PEI, capable of adsorbing 3.28 mmol / g CO2 at 25°C. Later, in 2021, Zhang's group synthesized a 40%-PEI@SiO2-6% adsorbent that adsorbed 131 mg / g CO2 in a simulated biogas environment. However, the silicon-based solid amine material synthesized in the report only serves as an adsorbent and cannot reconvert the adsorbed CO2. Therefore, from the perspective of economy and sustainability, it is still a great challenge to explore and develop a new type of heterogeneous catalyst that is stable, highly active, easily recyclable, and has a high adsorption capacity, so that it can achieve efficient catalysis of CO2 to synthesize cyclic carbonates under mild (or normal temperature and pressure) conditions. Based on this, we proposed this invention research. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects in the prior art and provide a stable, highly active, easily recyclable and reusable cyclotriphosphazene-derived silicon-based solid amine material and its preparation method, and provide its use as a catalyst for the cycloaddition reaction of carbon dioxide and epoxides, and at the same time provide a method for catalyzing the coupling of CO2 and epoxides to prepare cyclic carbonates.

[0007] The technical solution of the present invention is achieved as follows:

[0008] In one aspect, the present invention provides a method for preparing a cyclotriphosphazene-derived silicon-based solid amine material, comprising the following steps:

[0009] A. Hexachlorotriphosphazene and 3-aminopropyltriethoxysilane are subjected to a coupling reaction in a solvent to synthesize a silicon source precursor;

[0010] B. Using a hydrothermal-cocondensation method, a silicon source precursor is mixed with tetraethyl orthosilicate, and hexadecyltrimethylammonium bromide is used as a template to prepare cyclotriphosphazene-derived mesoporous organosilicon under alkaline conditions;

[0011] C. Dissolve polyethyleneimine in methanol, stir and mix at room temperature, then add cyclotriphosphazene-derived mesoporous organosilicon, stir at room temperature until the methanol is completely evaporated, and vacuum dry to obtain a cyclotriphosphazene-derived silicon-based solid amine material.

[0012] As some preferred embodiments of the present invention, the molar ratio of hexachlorotriphosphazene to 3-aminopropyltriethoxysilane in step A is 1:6;

[0013] In step B, the molar ratio of the silicon source precursor to the silicon in tetraethyl orthosilicate is 1:10-30;

[0014] The molar ratio of hexadecyltrimethylammonium bromide to silicon source precursor is 1.44-2.88:0.2;

[0015] In step C, the mass ratio of polyethyleneimine to cyclotriphosphazene-derived mesoporous organosilicon is 0.21-1.17:0.5.

[0016] As some preferred embodiments of the present invention, in step A, hexachlorotriphosphazene and anhydrous tetrahydrofuran are first mixed under a nitrogen atmosphere at 45-55° C., and then 3-aminopropyltriethoxysilane pre-dissolved in anhydrous tetrahydrofuran is added dropwise over 0.5-1 hour under stirring. After the coupling reaction is completed, the solvent is removed under vacuum to obtain a silicon source precursor.

[0017] As some preferred embodiments of the present invention, in step B, 0.525-1.05 g of hexadecyltrimethylammonium bromide is first suspended in a solution of 1.8-3.6 ml of NH 3 ·H 2 O and 24.6-49.2 ml of deionized water, and stirred at 30-60° C. until the hexadecyltrimethylammonium bromide is dissolved to obtain a mixed solution;

[0018] A silicon source precursor, tetraethyl orthosilicate and ethanol are mixed to form a premixed solution; the premixed solution of silicon source precursor and tetraethyl orthosilicate is added dropwise to the mixed solution, and then stirred at 35-45° C. to form a uniform emulsion system, and then heated at 85-95° C. for 90-100 hours, followed by filtration, extraction and vacuum drying to finally obtain cyclotriphosphazene-derived mesoporous organosilicon.

[0019] In another aspect, the present invention provides the use of the cyclotriphosphazene-derived silicon-based solid amine material prepared by the aforementioned method as a catalyst for the cycloaddition reaction of carbon dioxide and epoxide.

[0020] The present invention also provides a method for preparing cyclic carbonates by catalyzing the coupling of carbon dioxide and epoxide using the cyclotriphosphazene-derived silicon-based solid amine material prepared by the aforementioned method. The cyclotriphosphazene-derived silicon-based solid amine material is used as a catalyst to synthesize cyclic carbonates by a cycloaddition reaction of epoxide and carbon dioxide.

[0021] As some preferred embodiments of the present invention, cyclic carbonates are synthesized by cycloaddition reaction of epoxide and low-concentration carbon dioxide using cyclotriphosphazene-derived silicon-based solid amine materials as catalysts, wherein the low-concentration carbon dioxide refers to 15% CO2 and 85% N2.

[0022] As some preferred embodiments of the present invention, the structural formula of the epoxide is as follows:

[0023]

[0024] As some preferred embodiments of the present invention, the amount of the cyclotriphosphazene-derived silicon-based solid amine material catalyst is 7wt%-16wt% of the reaction system, which refers to 7wt%-16wt% of the total mass of the epoxide and the catalyst.

[0025] As some preferred embodiments of the present invention, the cycloaddition reaction temperature is 80-120° C., the reaction pressure is 0.5-1.5 MPa, and the reaction time is 5-9 h.

[0026] As some preferred embodiments of the present invention, the cycloaddition reaction temperature is 100° C., the reaction pressure is 1.0 MPa, and the reaction time is 7 h.

[0027] The working principle and beneficial effects of the present invention are:

[0028] 1. The cyclotriphosphazene-derived silicon-based solid amine material provided by the present invention has the advantages of high catalytic performance, good selectivity, easy recovery, reusability and high carbon dioxide capture performance.

[0029] 2. The preparation method of the cyclotriphosphazene-derived silicon-based solid amine material provided by the present invention has few steps, high yield, stable output, and great industrial application potential.

[0030] 3. The cyclotriphosphazene-derived silicon-based solid amine material provided by the present invention has a carrier silicon source precursor with a double hydrogen bond donor, which simultaneously activates carbon dioxide and epoxides. Combined with the adsorption of carbon dioxide by polyethyleneimine (amine polymer), it exhibits excellent catalytic activity and selectivity in the catalytic conversion of carbon dioxide to synthesize cyclic carbonates under mild, metal / solvent-free and catalyst-free conditions. The catalyst is easy to recover and has excellent catalytic recycling performance. By catalyzing the cycloaddition reaction of epoxides with different substituents with CO2, it was found that the catalyst exhibited good universality. Compared with the reported silicon-based solid amine adsorbents, it not only achieves selective adsorption of carbon dioxide, but also converts the adsorbed carbon dioxide into the high-value-added chemical propylene carbonate, and has good potential for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Figure 1 is the reaction scheme of the present invention;

[0033] Figure 2 IR spectra of hexachlorotriphosphazene (HCCP) and silicon source precursor (CPF) in Example 1 of the present invention;

[0034] Figure 3 is the infrared spectrum of PMO-CPF-X in the present invention;

[0035] Figure 4 The infrared spectra of PEI, PMO-CPF-20, PMO-CPF-20@30%, PMO-CPF-20@50% and PMO-CPF-20@70% of the present invention are shown;

[0036] Figure 5 XRD spectra of PMO-CPF-20, PMO-CPF-20@30%, PMO-CPF-20@50%, and PMO-CPF-20@70% of the present invention;

[0037] in, Figure 1 (A) indicates step A; (B) indicates step B; (C) indicates step C;

[0038] Figure 2 HCCP represents hexachlorotriphosphazene; CPF represents the silicon source precursor prepared in Example;

[0039] Figure 3 Wherein PMO-CPF-10, PMO-CPF-15 and PMO-CPF-20 represent the cyclotriphosphazene-derived mesoporous organosilicon prepared in Example 3, Example 4 and Example 2, respectively;

[0040] Figure 4 Wherein PEI, PMO-CPF-20, PMO-CPF-20@30%, PMO-CPF-20@50% and PMO-CPF-20@70% represent polyethyleneimine, cyclotriphosphazene-derived mesoporous organosilicon prepared in Example 2, and cyclotriphosphazene-derived silicon-based solid amine materials prepared in Example 6, Example 7 and Example 5, respectively;

[0041] Figure 5 PMO-CPF-20, PMO-CPF-20@30%, PMO-CPF-20@50%, and PMO-CPF-20@70% respectively represent the cyclotriphosphazene-derived mesoporous organosilicon prepared in Example 2, and the cyclotriphosphazene-derived silicon-based solid amine materials prepared in Example 6, Example 7, and Example 5. DETAILED DESCRIPTION

[0042] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In the following examples, polyethyleneimine was purchased from Aladdin Reagent, model: MW60099%; NH3·H2O model: Shanghai Test, AR content (NH3) 25.0-28.0%.

[0043] Example 1 Preparation of silicon source precursor (CPF)

[0044] Hexachlorotriphosphazene (HCCP, 0.073 g, 0.21 mmol) was first mixed with anhydrous tetrahydrofuran (THF, 7 mL) at 50°C under a nitrogen atmosphere. 6.0 equivalents of 3-aminopropyltriethoxysilane (APTES, 0.28 g, 1.26 mmol) pre-dissolved in anhydrous tetrahydrofuran (3 mL) were added dropwise to the solution with stirring over 0.5 h. After the coupling reaction was completed, the solvent was removed under vacuum to obtain CPF as a viscous liquid with a yield of 95%.

[0045] Example 2 Preparation of Cyclotriphosphazene-derived Mesoporous Organosilicon (PMO-CPF-X)

[0046] Hexadecyltrimethylammonium bromide (CTAB, 1.05 g, 2.88 mmol) was first suspended in a solution of NH3·H2O (3.6 mL) and deionized water (49.2 mL), and then stirred at 40°C for 0.5 h, during which CTAB was completely dissolved to obtain a mixed solution; a silicon source precursor (0.29 g, 0.20 mmol) and tetraethyl orthosilicate (TEOS, 5 g, 24 mmol) were mixed with ethanol (16.4 mL) to form a premixed solution; and 1% ethanol was added to the mixed solution. The premixed solution was added; then vigorously stirred at 40°C for 24 hours at a stirring rate of 420 rpm to form a uniform emulsion system, which was then transferred to a Teflon-lined autoclave and statically heated at 90°C for 96 hours; thereafter, the white solid was separated by filtration and extracted with ethanolic hydrochloric acid solution (0.5 M) at 60°C for 2 hours to remove CTAB; and finally PMO-CPF-20 was obtained by filtration and vacuum drying; wherein the molar ratio of silicon in CPF and TEOS was 1:20.

[0047] Example 3

[0048] Hexadecyltrimethylammonium bromide (CTAB, 0.525 g, 1.44 mmol) was first suspended in a solution of NH3·H2O (1.8 mL) and deionized water (24.6 mL), and then stirred at 40°C for 0.5 h, during which CTAB was completely dissolved to obtain a mixed solution; a silicon source precursor (0.29 g, 0.20 mmol) and tetraethyl orthosilicate (TEOS, 2.5 g, 12 mmol) were mixed with ethanol (8.2 mL) to form a premixed solution; and the mixed solution was added to the mixture. The premixed solution was added dropwise; then vigorously stirred at 40°C for 24 hours at a stirring rate of 420 rpm to form a uniform emulsion system, which was then transferred to a Teflon-lined autoclave and statically heated at 90°C for 96 hours; thereafter, the white solid was separated by filtration and extracted with ethanolic hydrochloric acid solution (0.5 M) at 60°C for 2 hours to remove CTAB; and finally PMO-CPF-10 was obtained by filtration and vacuum drying; wherein the molar ratio of silicon in CPF and TEOS was 1:10.

[0049] Example 4

[0050] Hexadecyltrimethylammonium bromide (CTAB, 0.788 g, 2.16 mmol) was first suspended in a solution of NH3·H2O (2.7 mL) and deionized water (36.9 mL), and then stirred at 40°C for 0.5 h, during which CTAB was completely dissolved to obtain a mixed solution; a silicon source precursor (0.29 g, 0.20 mmol) and tetraethyl orthosilicate (TEOS, 3.75 g, 18 mmol) were mixed with ethanol (12.3 mL) to form a premixed solution; and the mixed solution was added to the mixture. The premixed solution was added dropwise to the precipitate; the mixture was then vigorously stirred at 40°C for 24 hours at a stirring rate of 420 rpm to form a uniform emulsion system, which was then transferred to a Teflon-lined autoclave and statically heated at 90°C for 96 hours; thereafter, the white solid was separated by filtration and extracted with ethanolic hydrochloric acid solution (0.5 M) at 60°C for 2 hours to remove CTAB; and finally PMO-CPF-15 was obtained by filtration and vacuum drying; wherein the molar ratio of silicon in CPF and TEOS was 1:15.

[0051] Example 5 Preparation of Cyclotriphosphazene-derived Silicon-based Solid Amine Material (PMO-CPF-20@70%)

[0052] In a 50 ml beaker, polyethyleneimine (PEI, 1.17 g) was dissolved in anhydrous methanol (8 ml) and stirred at room temperature (25°C) for 0.5 h. Then, PMO-CPF-20 (0.5 g) prepared in Example 2 was added and stirred at room temperature (25°C) for 8 h for immersion until the solution became viscous. The mixture was then placed in an oven for drying to obtain a cyclotriphosphazene-derived silicon-based solid amine material (PMO-CPF-20@70%).

[0053] Example 6

[0054] In a 50 ml beaker, polyethyleneimine (PEI, 0.21 g) was dissolved in anhydrous methanol (8 ml) and stirred at room temperature (25°C) for 0.5 h. Then, PMO-CPF-20 (0.5 g) prepared in Example 2 was added and stirred at room temperature (25°C) for 8 h for immersion until the solution became viscous. The mixture was then placed in an oven for drying to obtain a cyclotriphosphazene-derived silicon-based solid amine material (PMO-CPF-20@30%).

[0055] Example 7

[0056] In a 50 ml beaker, polyethyleneimine (PEI, 0.5 g) was dissolved in anhydrous methanol (8 ml) and stirred at room temperature (25°C) for 0.5 h. Then, PMO-CPF-20 (0.5 g) prepared in Example 2 was added and stirred at room temperature (25°C) for 8 h for immersion until the solution became viscous. The mixture was then placed in an oven for drying to obtain a cyclotriphosphazene-derived silicon-based solid amine material (PMO-CPF-20@50%).

[0057] from Figure 4 As can be seen in Figure 2, the more PEI is loaded, the more obvious the -NH2 peak is; Figure 5 It can be seen that even if PEI is loaded, the catalyst still has a periodic mesoporous structure.

[0058] Application Example 1

[0059] The reactant propylene oxide and the catalyst PMO-CPF-20@70% prepared in Example 5 were added sequentially to a 25 mL stainless steel autoclave with a polytetrafluoroethylene liner, wherein 34.5 mmol of propylene oxide and 0.22 g of PMO-CPF-20@70% were added. Low concentration CO2 gas (15% CO2 and 85% N2) was slowly introduced into the reactor to remove residual air inside. Afterwards, the reactor was heated to 120° C. in an oil bath, CO2 gas was introduced to maintain a constant pressure of 1.5 MPa, and the reaction was continued for 8 hours. After the reaction was completed, the reactor was cooled to room temperature in an ice-water bath. The product was quantitatively analyzed by gas chromatography, and the yield of propylene carbonate was 93% and the selectivity was ≥99%.

[0060] Application Example 2

[0061] The reactants propylene oxide and the catalyst PMO-CPF-20@70% prepared in Example 5 were added sequentially into a 25 mL stainless steel autoclave with a polytetrafluoroethylene liner, wherein 34.5 mmol of propylene oxide and 0.26 g of PMO-CPF-20@70% were added. Low-concentration CO2 gas (15% CO2 and 85% N2) was slowly introduced into the reactor to remove residual air inside. Afterwards, the reactor was heated to 100° C. in an oil bath, CO2 gas was introduced to maintain a constant pressure of 1.5 MPa, and the reaction was continued for 8 hours. After the reaction was completed, the reactor was cooled to room temperature in an ice-water bath. The product was quantitatively analyzed by gas chromatography, and the yield of propylene carbonate was 97% and the selectivity was ≥99%.

[0062] Application Example 3

[0063] The reactant propylene oxide and the catalyst PMO-CPF-20@70% prepared in Example 5 were added sequentially to a 25 mL stainless steel autoclave with a polytetrafluoroethylene liner, wherein 34.5 mmol of propylene oxide and 0.3 g of PMO-CPF-20@70% were added. Low concentration CO2 gas (15% CO2 and 85% N2) was slowly introduced into the reactor to remove residual air inside. Afterwards, the reactor was heated to 120° C. in an oil bath, CO2 gas was introduced to maintain a constant pressure of 0.5 MPa, and the reaction was continued for 9 hours. After the reaction was completed, the reactor was cooled to room temperature in an ice-water bath. The product was quantitatively analyzed by gas chromatography, and the yield of propylene carbonate was 94% and the selectivity was ≥99%.

[0064] Application Example 4

[0065] The reactant propylene oxide and the catalyst PMO-CPF-20@70% prepared in Example 5 were added sequentially to a 25 mL stainless steel autoclave with a polytetrafluoroethylene liner, wherein 34.5 mmol of propylene oxide and 0.26 g of PMO-CPF-20@70% were added. Low concentration CO2 gas (15% CO2 and 85% N2) was slowly introduced into the reactor to remove residual air inside. Afterwards, the reactor was heated to 120° C. in an oil bath, CO2 gas was introduced to maintain a constant pressure of 1.5 MPa, and the reaction was continued for 2 hours. After the reaction was completed, the reactor was cooled to room temperature in an ice-water bath. The product was quantitatively analyzed by gas chromatography, and the yield of propylene carbonate was 78% and the selectivity was ≥99%.

[0066] Application Example 5

[0067] The reactant propylene oxide and the catalyst PMO-CPF-20@70% prepared in Example 5 were added sequentially to a 25 mL stainless steel autoclave with a polytetrafluoroethylene liner, wherein 34.5 mmol of propylene oxide and 0.34 g of PMO-CPF-20@70% were added. Low concentration CO2 gas (15% CO2 and 85% N2) was slowly introduced into the reactor to remove residual air inside. Afterwards, the reactor was heated to 90° C. in an oil bath, CO2 gas was introduced to maintain a constant pressure of 1.0 MPa, and the reaction was continued for 6 hours. After the reaction was completed, the reactor was cooled to room temperature in an ice-water bath. The product was quantitatively analyzed by gas chromatography, and the yield of propylene carbonate was 64% and the selectivity was ≥99%.

[0068] Application Example 6

[0069] The specific experimental process and detection method are the same as those in Application Example 1, except that propylene oxide is replaced with other epoxides with different substituents, and cycloaddition reactions are carried out with carbon dioxide respectively. The results are shown in Table 1.

[0070] Table 1 Cycloaddition reaction results of different epoxides with carbon dioxide catalyzed by PMO-CPF-20@70%

[0071]

[0072] Application Examples 7-11

[0073] The specific experimental conditions and steps were the same as those in Application Example 3, except that the catalyst PMO-CPF-20@70% was replaced with the PMO-CPF-20@70% recovered in Application Example 3. Five cycle experiments were performed under the same conditions. The results are shown in Table 2.

[0074] Table 2 Experimental results of catalyst recycling in Examples 7-11

[0075]

[0076] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a cyclotriphosphazene-derived silicon-based solid amine material, characterized in that: The steps include: A. Hexachlorotriphosphazene and 3-aminopropyltriethoxysilane are subjected to a coupling reaction in a solvent to synthesize a silicon source precursor; B. Using a hydrothermal-cocondensation method, a silicon source precursor is mixed with tetraethyl orthosilicate, and hexadecyltrimethylammonium bromide is used as a template to prepare cyclotriphosphazene-derived mesoporous organosilicon under alkaline conditions; C. Dissolving polyethyleneimine in methanol, stirring at room temperature, then adding cyclotriphosphazene-derived mesoporous organosilicon, stirring at room temperature until the methanol is completely evaporated, and vacuum drying to obtain a cyclotriphosphazene-derived silicon-based solid amine material; In step A, the molar ratio of hexachlorotriphosphazene to 3-aminopropyltriethoxysilane is 1:6; In step B, the molar ratio of the silicon source precursor to the silicon in tetraethyl orthosilicate is 1:10-30; The molar ratio of hexadecyltrimethylammonium bromide to silicon source precursor is 1.44-2.88:0.2; In step C, the mass ratio of polyethyleneimine to cyclotriphosphazene-derived mesoporous organosilicon is 0.21-1.17:0.

5.

2. The method for preparing the cyclotriphosphazene-derived silicon-based solid amine material according to claim 1, characterized in that: In step A, hexachlorotriphosphazene and anhydrous tetrahydrofuran are first mixed under a nitrogen atmosphere at 45-55° C., and then 3-aminopropyltriethoxysilane pre-dissolved in anhydrous tetrahydrofuran is added dropwise over 0.5-1 hour under stirring. After the coupling reaction is completed, the solvent is removed under vacuum to obtain a silicon source precursor.

3. The method for preparing the cyclotriphosphazene-derived silicon-based solid amine material according to claim 1 or 2, characterized in that: In step B, 0.525-1.05 g of hexadecyltrimethylammonium bromide is first suspended in a solution of 1.8-3.6 ml of NH 3 · H 2 O and 24.6-49.2 ml of deionized water, and stirred at 30-60° C. until the hexadecyltrimethylammonium bromide is dissolved to obtain a mixed solution; A silicon source precursor, tetraethyl orthosilicate and ethanol are mixed to form a premixed solution; the premixed solution is added dropwise to the mixed solution, and then stirred at 35-45°C to form a uniform emulsion system, and then heated at 85-95°C for 90-100 hours, followed by filtration, extraction and vacuum drying to finally obtain cyclotriphosphazene-derived mesoporous organosilicon.

4. Use of a cyclotriphosphazene-derived silicon-based solid amine material prepared by the method according to claim 1 as a catalyst for the cycloaddition reaction of carbon dioxide and epoxide.

5. A method for preparing cyclic carbonates by coupling carbon dioxide with epoxides using a cyclotriphosphazene-derived silicon-based solid amine material prepared according to claim 1, characterized in that: Cyclic carbonates are synthesized by cycloaddition reaction of epoxide and carbon dioxide using cyclotriphosphazene-derived silicon-based solid amine materials as catalysts.

6. The method for preparing cyclic carbonate by coupling carbon dioxide with epoxide catalyzed by cyclotriphosphazene-derived silicon-based solid amine material according to claim 5, characterized in that: The structural formula of the epoxide is as follows: , , , , or .

7. The method for preparing cyclic carbonate by coupling carbon dioxide with epoxide catalyzed by cyclotriphosphazene-derived silicon-based solid amine material according to claim 5, characterized in that: The cyclotriphosphazene-derived silicon-based solid amine material catalyst is used in an amount of 7 wt% to 16 wt% of the reaction system.

8. The method for preparing cyclic carbonate by coupling carbon dioxide with epoxide catalyzed by cyclotriphosphazene-derived silicon-based solid amine material according to claim 5, characterized in that: The cycloaddition reaction temperature is 80-120° C., the reaction pressure is 0.5-1.5 MPa, and the reaction time is 5-9 h.

9. The method for preparing cyclic carbonate by coupling carbon dioxide with epoxide catalyzed by cyclotriphosphazene-derived silicon-based solid amine material according to claim 5, characterized in that: The cycloaddition reaction temperature is 100° C., the reaction pressure is 1.0 MPa, and the reaction time is 7 h.

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