Porphyrinyl triazine framework loaded nano-silver catalyst as well as preparation method and application thereof

Abstract

The invention discloses a porphyrinyl triazine framework loaded nano-silver catalyst and a preparation method and application thereof.The preparation method comprises the steps that 5, 10, 15, 20-tetra (4-aminophenyl) porphyrin and cyanuric chloride serve as raw materials, a reflux stirring reaction is conducted for 72 h under the alkaline condition, and a porphyrinyl triazine framework is synthesized; and then stirring the porphyrinyl triazine framework with a tetrahydrofuran solution of tetrafluoroborate at room temperature in darkness for 1 hour, heating to 80 DEG C, stirring for 24 hours, filtering, washing with a solvent for multiple times, and carrying out vacuum drying to obtain the porphyrinyl triazine framework loaded nano-silver catalyst. The preparation process is simple, the yield and purity of the catalyst are high, the obtained porphyrin porous polymer supported nano-silver catalyst efficiently and highly selectively catalyzes CO2 and propargyl alcohol derivatives to be converted into alpha-alkylene cyclic carbonate under the solvent-free condition by taking 1, 8-diazacyclo [5, 4, 0] undecylene-7 as a cocatalyst, and the method has the advantages of high efficiency and high selectivity. The catalyst recovery and regeneration process is simple, and the reusability is good; belongs to the technical field of heterogeneous catalysts.

Description

Technical Field

[0001] The invention belongs to the technical field of multiphase catalysts, and in particular relates to a preparation method of a porphyrinyl triazine framework-supported nanosilver catalyst and an application of the catalyst in catalyzing carbon dioxide and propargyl alcohol compounds to synthesize alpha-alkylene cyclic carbonates. Background Art

[0002] The continuous consumption of fossil energy has led to an increase in the content of carbon dioxide (CO2) in the air, triggering a series of ecological and environmental crises. At present, carbon capture, utilization and storage (CCUS) is an important means to effectively alleviate environmental and energy shortage problems. From the perspective of green and sustainable development, the rational design of process technology can catalytically convert CO2 to prepare high-value-added chemicals, and also obtain high-value-added chemical raw materials and energy resources. Among the many reactions involving CO2, the reaction of CO2 with propargyl alcohol derivatives to synthesize α-alkylene cyclic carbonates is an environmentally friendly and more carbon-balanced method with 100% atom economy (Green Chem., 2021, 23, 9334). More importantly, α-alkylene cyclic carbonates have broad application prospects in new materials and fine chemicals, and can be used as polar aprotic solvents, monomers for the synthesis of polycarbonates and polyurethanes, and intermediates for organic synthesis (Catalysts, 2022, 12, 73; Angew. Chem. Int. Ed. 2022, e202114817).

[0003] For the carboxyl cyclization reaction of CO2 and propargyl alcohol derivatives, researchers have developed many catalysts, including metal (Cu, Co, Zn, Ag, Ru)-based catalysts, ionic liquid catalysts, and organic catalysts (ChemSusChem, 2021, 14, 2367; ACS Appl. Mater. Interfaces, 2021, 13, 45558). In general, silver-based catalysts have been widely studied in the past few years and have shown good catalytic performance. For example, Wang and colleagues reported an alkaline ionic liquid / AgOAc system to synthesize α-alkylene cyclic carbonates from CO2 at normal pressure. Since the alkaline ionic liquid has the dual role of absorbent and activator, excellent yields were obtained (Chem. Commun., 2016, 52, 7830). However, most of these existing catalytic systems are homogeneous catalytic systems. Obviously, from the perspective of separation and recovery, silver-based heterogeneous catalysts have greater industrial application value. It is generally believed that the mechanism of nanosilver catalysis of this reaction is similar to that of Ag. +The catalytic mechanism is similar. Therefore, heterogeneous catalytic systems based on nanosilver have attracted widespread research interest in recent years (Inorg.Chem., 2020, 59, 9765; ACSSustainable Chem.Eng., 2020, 8, 7051-7058). However, due to its high surface energy, nanosilver usually has inherent insufficient thermodynamic stability, which makes it easy to aggregate and then lose activity in the catalytic reaction. At this time, a suitable carrier not only plays an important role in enhancing the stability of the catalyst and improving the catalytic performance, but also facilitates the recovery of the catalyst.

[0004] As an ideal heterogeneous catalytic platform, porous organic polymers (POPs) have attracted much attention due to their unique advantages in structure and function (Green Chem. Eng., 2022, 3, 96). Importantly, the abundant nanopores and CO2-philic heteroatoms in the polymer network can promote the enrichment of CO2, playing a key role in promoting its activation and conversion under mild conditions (Curr. Opin. Green Sustain. Chem., 2020, 26, 100365).

[0005] In addition, the micro-mesoporous structure is conducive to promoting the diffusion of reactants in the internal pores. For example, Han et al. reported a biomass-based porous organic polymer (GA-azo-POP) supported AgNPs catalyst (Ag / GA-azo-POP, as shown in the figure below). When 1,8-diazabicyclo[5.4.0]undec-7-ene was used as a co-catalyst, the use of Ag was very low (0.14 mol%). It can effectively catalyze the carboxylation of CO2 (Green Chem., 2018, 20, 4655). Li reported a bifunctional urea conjugated porous polymer (UCPP) supported nanosilver catalyst, which can smoothly catalyze the reaction of CO2 with propargyl alcohol to synthesize the corresponding cyclic carbonate at room temperature (Dalton. Trans., 2020, 49, 13052). Recently, our research group has also developed a nanosilver-loaded tubular porous porphyrin network catalyst (Ag@NT-PPN). It has been proven that porphyrin has good chelation and stabilization effects on nanosilver, and also exhibits good catalytic activity, product selectivity, substrate extensibility and reusability in the reaction of CO2 and propargyl alcohol to prepare α-alkylene cyclic carbonates (Asian J.Org.Chem., 2022, 11, e202200194). However, the synthesis process of Ag@NT-PPN is relatively complicated, and the porphyrin-based polymer carrier cannot be synthesized in one step. At the same time, a large amount of anhydrous ferric chloride is required as a catalyst in the preparation of porphyrin-based polymer carriers, and strong acid is required in the demetallization process. The above research results provide a reference for the subsequent development of heterogeneous catalytic materials with similar structural and functional characteristics.

[0006] Therefore, developing a greener and simpler synthetic strategy to prepare porphyrin porous polymer-supported nanosilver catalysts that can be used to efficiently and stably catalyze CO2 carboxylation reactions still has great basic research significance and application value. Summary of the invention

[0007] The first object of the present invention is to provide a porphyrin-based triazine framework-loaded nanosilver catalyst, which has porphyrin, secondary amine and triazine structures, can play a good chelating and stabilizing role on nanosilver, can play a good selective adsorption and enrichment role on CO2 during the catalytic process, and improve the catalytic efficiency.

[0008] The second object of the present invention is to provide a method for preparing the above catalyst, which has a simple preparation process, readily available raw materials, high yield and purity, and all reaction solvents can be recovered.

[0009] The third object of the present invention is to provide the above-mentioned catalyst for catalyzing CO2 and propargyl alcohol to prepare α-alkylene cyclic carbonate, and the reaction does not require the addition of solvent and can be carried out efficiently and selectively at normal temperature and pressure.

[0010] To this end, the first technical solution provided by the present invention is as follows:

[0011] A porphyrinyl triazine framework-supported nanosilver catalyst, the structural formula of which is shown in formula (I):

[0012]

[0013] The second technical solution provided by the present invention is a preparation method of a porphyrin-based triazine framework-supported nano-silver catalyst. The method uses 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and cyanuric chloride as raw materials, synthesizes a porphyrin-based triazine framework under alkaline conditions, reacts with a tetrahydrofuran solution of silver tetrafluoroborate under dark conditions, and then filters, washes with a solvent for multiple times, and vacuum-dries to obtain the porphyrin-based triazine framework-supported nano-silver catalyst.

[0014] The specific steps include:

[0015] (1) 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and cyanuric chloride in a molar ratio of 1:1 to 3 are added to a round-bottom flask containing a solvent, and the solvent and acid binding agent are continuously added. After stirring and mixing at room temperature for 0.5 h, the mixture is continuously heated to reflux and reacted for 72 h. After filtering and washing the obtained precipitate, the precipitate is vacuum dried at 100° C. for 12 h to obtain a porphyrin triazine framework containing a secondary amine group.

[0016] (2) Add tetrahydrofuran of silver tetrafluoroborate to a round-bottom flask, stir evenly at room temperature to obtain a tetrahydrofuran solution containing silver nitrate, then add the porphyrinyl triazine framework containing a secondary amine group obtained in step 1) to the round-bottom flask, stir for 1 hour in the dark at room temperature, continue to heat to 80° C., react for 24 hours, filter, wash with solvent several times, and vacuum dry at 100° C. for 12 hours to obtain a porphyrinyl triazine framework-supported nanosilver catalyst.

[0017] Furthermore, the solvent in step 1) is any one of tetrahydrofuran, 1,2-dioxane, N,N-dimethylformamide, and dimethyl sulfoxide;

[0018] Furthermore, the acid-binding agent in step 1) is intended to provide alkaline reaction conditions to remove HCl generated during the reaction, thereby promoting the polymerization reaction, and is any one of potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, and N,N-diisopropylethylamine;

[0019] Furthermore, the amount of the acid binding agent in step 1) is 2.5 to 7.5 times the amount of cyanuric chloride;

[0020] Furthermore, in step 1), the washing is performed by combining suction filtration and Soxhlet extraction, the suction filtration and washing solvents are 50 to 150 mL of methanol, N,N-dimethylformamide, tetrahydrofuran and dichloromethane, respectively, the Soxhlet extraction uses 300 mL of tetrahydrofuran as solvent, and the extraction time is 24 hours;

[0021] Furthermore, in step 2), the mass ratio of the porphyrinyl triazine framework to silver tetrafluoroborate is 100:2-10;

[0022] Furthermore, the concentration of the silver nitrate tetrahydrofuran solution in step 2) is 1 to 5 mg / 10 mL;

[0023] The third technical solution of the present invention is the use of a porphyrinyl triazine framework-supported nanosilver catalyst in the catalytic synthesis of α-alkylene cyclic carbonates from CO2 and propargyl alcohol compounds.

[0024] The method for synthesizing α-alkylene cyclic carbonate by catalyzing CO2 and propargyl alcohol compound using porphyrinyl triazine framework-supported nanosilver catalyst comprises the following steps in sequence: without adding any solvent, CO2 of a certain volume concentration and 1 mmol of propargyl alcohol of the structural formula described in formula (II) are reacted under constant temperature and pressure for 5 to 48 hours in the presence of porphyrinyl triazine framework-supported nanosilver catalyst and a certain amount of 1,8-diazacyclo[5,4,0]undecene-7 as a co-catalyst, to obtain α-alkylene cyclic carbonate of the structural formula described in formula (III) after constant temperature stirring reaction for 5 to 48 hours;

[0025] In the above steps, the CO2 with a certain volume concentration is 15 to 100% CO2, and the CO2 with a concentration lower than 100% is obtained by mixing any inert gas of nitrogen, helium, neon or argon into the CO2 gas;

[0026] The epoxide in the above steps has a structural formula as shown in formula (II):

[0027]

[0028] The α-alkylene cyclic carbonate described in the above steps has a structural formula as shown in formula (III):

[0029]

[0030] The amount of 1,8-diazacyclo[5,4,0]undecene-7 in the above step is 0.5 to 2.5 mmol, preferably, the amount of 1,8-diazacyclo[5,4,0]undecene-7 is 1 mmol;

[0031] In the above steps, the amount of the porphyrinyl triazine framework-supported nanosilver catalyst is 5 to 50 mg, and preferably, the amount of the catalyst c is 20 mg;

[0032] The pressure in the above steps is 0.1-5.0 MPa, and preferably, the reaction pressure is 1.0 MPa;

[0033] The reaction temperature in the above steps is 25-80°C, preferably 40°C;

[0034] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0035] 1. The preparation method of the porphyrin-based triazine framework-supported nanosilver catalyst provided by the present invention is simple, the raw materials are readily available, the yield and purity are high, all the reaction solvents can be recovered, and the obtained catalyst is stable to air and water.

[0036] 2. The porphyrin-based triazine framework-loaded nanosilver catalyst prepared by the present invention has porphyrin, triazine and secondary amine structures, which can play a good chelating and stabilizing role on nanosilver, and can play a good selective adsorption and enrichment role on CO2 during the catalytic process, thereby improving the catalytic efficiency; in particular, when low-concentration CO2 is used as a raw material, it can smoothly convert it into cyclic carbonate, which can effectively reduce the energy consumption generated in the process of obtaining pure CO2, and realize the coupling of CO2 selective capture and catalytic conversion.

[0037] 3. The porphyrin-based triazine framework-supported nanosilver catalyst provided by the present invention is used to catalyze CO2 and propargyl alcohol to prepare α-alkylene cyclic carbonate. The reaction does not require the addition of solvent and can be carried out efficiently and selectively at normal temperature and pressure. The catalyst recovery and regeneration process is simple and has good reusability. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 TEM image of the porphyrin-based triazine framework-supported nanosilver catalyst provided in Example 1;

[0039] Figure 2 XPS image of the porphyrin-based triazine framework-supported nanosilver catalyst provided in Example 1

[0040] Figure 3 α-Alkylene cyclic carbonate (2a) synthesized in Example 2 1 HNMR spectra;

[0041] Figure 4 α-Alkylene cyclic carbonate (2b) synthesized in Example 3 1 H NMR spectra;

[0042] Figure 5 α-Alkylene cyclic carbonate (2c) synthesized in Example 4 1 HNMR spectra;

[0043] Figure 6 α-Alkylene cyclic carbonate (2d) synthesized in Example 5 1 H NMR spectra;

[0044] Figure 7 α-Alkylene cyclic carbonate (2e) synthesized in Example 6 1 HNMR spectra;

[0045] Figure 8 α-Alkylene cyclic carbonate (2f) synthesized in Example 7 1 H NMR spectra;

[0046] Fig. 9 α-Alkylene cyclic carbonate synthesized in Example 8 (2 g) 1 H NMR spectra. DETAILED DESCRIPTION

[0047] The present invention is further described in detail below by way of examples, but these examples are for illustrative purposes only and should not be construed as any limitation to the present invention.

[0048] Example 1

[0049] This embodiment provides a porphyrinyl triazine framework-supported nanosilver catalyst, which is prepared by the following steps:

[0050] 1) Synthesis of porphyrin-based triazine framework

[0051] 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (1mmol, 0.674g) and cyanuric chloride (2mmol, 0.369g), 60mL tetrahydrofuran and potassium carbonate (4mmol, 0.553g) were added to a 150mL round-bottom flask, stirred at room temperature for 0.5h, and then placed in a 70°C reaction bath and refluxed for 72h. The precipitate was washed three times with methanol (60mL), N,N-dimethylformamide ethyl acetate (100mL), tetrahydrofuran (60mL) and dichloromethane (60mL), and then further purified by Soxhlet extraction, using 300mL tetrahydrofuran as solvent, and the extraction time was 24h. The solid was vacuum dried at 100°C for 24h to obtain 0.866g of porphyrinyl triazine framework.

[0052] 2) Preparation of porphyrin-based triazine framework-supported nanosilver catalyst

[0053] Add 15 mg of silver tetrafluoroborate to a 100 mL volumetric flask, add tetrahydrofuran to make up to the mark, and prepare a tetrahydrofuran solution with a silver tetrafluoroborate concentration of 1.5 mg / 10 mL for later use. Add the porphyrinyl triazine framework (500 mg) prepared in Example 1 to a 100 mL round-bottom flask, and dropwise add the silver tetrafluoroborate tetrahydrofuran solution within 1 h in the dark at room temperature, continue heating to 80 ° C, react for 24 h, filter, wash with solvent several times, and vacuum dry at 100 ° C for 24 h to obtain 0.479 g of porphyrinyl triazine framework-supported nanosilver catalyst. TEM image see Figure 1 ; XPS spectrum reference Figure 2 .

[0054] Example 2 Catalyst catalyzes the carboxyl cyclization reaction of CO2 and propargyl alcohol 1a

[0055] At room temperature, 20 mg of porphyrin triazine framework-loaded nanosilver catalyst, 1 mmol of 1,8-diazacyclo[5,4,0]undecene-7 and 1 mmol of propargyl alcohol 1a were added to a 10 mL stainless steel reactor. After the reactor was sealed, CO2 gas was repeatedly and slowly filled and discharged 3 times. Then CO2 was charged to stabilize the pressure at 1.0 MPa. The reactor was placed in a 40°C constant temperature stirrer and stirred for 12 hours. After the reaction was completed, the unreacted CO2 was slowly released. Subsequently, 5 mL of ethyl acetate was added to the reactor and the solid catalyst was separated by centrifugation. An appropriate amount of supernatant was taken for gas chromatography analysis, and the conversion rate was calculated to be 96.9%, the selectivity was 98.1%, and the α-alkylene cyclic carbonate 2a was 98.1%. 1 HNMR Reference Figure 3 .

[0056] Example 3 Catalyst catalyzes the carboxyl cyclization reaction of CO2 and propargyl alcohol 1b

[0057] At room temperature, 20 mg of porphyrin triazine framework-loaded nanosilver catalyst, 1 mmol of 1,8-diazacyclo[5,4,0]undecene-7 and 1 mmol of propargyl alcohol 1b were added to a 10 mL stainless steel reactor. After the reactor was sealed, CO2 gas was repeatedly and slowly filled and discharged 3 times. Then CO2 was charged to stabilize the pressure at 1.0 MPa. The reactor was placed in a 40°C constant temperature stirrer and stirred for 16 hours. After the reaction was completed, the unreacted CO2 was slowly released. Subsequently, 5 mL of ethyl acetate was added to the reactor and the solid catalyst was separated by centrifugation. An appropriate amount of supernatant was taken for gas chromatography analysis, and the conversion rate was calculated to be 96.7%, the selectivity was 97.8%, and the α-alkylene cyclic carbonate 2b was 97.8%. 1 HNMR Reference Figure 4 .

[0058] Example 4 Catalyst catalyzes the carboxyl cyclization reaction of CO2 and propargyl alcohol 1c

[0059] At room temperature, 20 mg of porphyrin triazine framework-loaded nanosilver catalyst, 1 mmol of 1,8-diazacyclo[5,4,0]undecene-7 and 1 mmol of propargyl alcohol 1c were added to a 10 mL stainless steel reactor. After the reactor was sealed, CO2 gas was repeatedly and slowly filled and discharged 3 times. Then CO2 was charged to stabilize the pressure at 1.0 MPa. The reactor was placed in a 40°C constant temperature stirrer and stirred for 24 hours. After the reaction was completed, the unreacted CO2 was slowly released. Subsequently, 5 mL of ethyl acetate was added to the reactor and the solid catalyst was separated by centrifugation. An appropriate amount of supernatant was taken for gas chromatography analysis, and the conversion rate was calculated to be 95.6%, the selectivity was 98.5%, and the α-alkylene cyclic carbonate 2c was 98.5%. 1 HNMR Reference Figure 5 .

[0060] Example 5 Catalyst catalyzes the carboxyl cyclization reaction of CO2 and propargyl alcohol 1d

[0061] At room temperature, 20 mg of porphyrin triazine framework-loaded nanosilver catalyst, 1 mmol of 1,8-diazacyclo[5,4,0]undecene-7 and 1 mmol of propargyl alcohol 1d were added to a 10 mL stainless steel reactor. After the reactor was sealed, CO2 gas was repeatedly and slowly filled and discharged 3 times. Then CO2 was charged to stabilize the pressure at 1.0 MPa. The reactor was placed in a 40°C constant temperature stirrer and stirred for 16 hours. After the reaction was completed, the unreacted CO2 was slowly released. Subsequently, 5 mL of ethyl acetate was added to the reactor and the solid catalyst was separated by centrifugation. An appropriate amount of supernatant was taken for gas chromatography analysis, and the conversion rate was calculated to be 95.0%, the selectivity was 98.9%, and the α-alkylene cyclic carbonate 2d was 1 HNMR Reference Figure 6 .

[0062] Example 6 Catalyst catalyzes carboxyl cyclization reaction of CO2 with propargyl alcohol 1e

[0063] At room temperature, 20 mg of porphyrin-based triazine framework-loaded nanosilver catalyst, 1 mmol of 1,8-diazacyclo[5,4,0]undecene-7 and 1 mmol of propargyl alcohol 1e were added to a 10 mL stainless steel reactor. After the reactor was sealed, CO2 gas was repeatedly and slowly filled and discharged 3 times. Then CO2 was charged to stabilize the pressure at 1.0 MPa. The reactor was placed in a 40°C constant temperature stirrer and stirred for 24 hours. After the reaction was completed, the unreacted CO2 was slowly released. Subsequently, 5 mL of ethyl acetate was added to the reactor and the solid catalyst was separated by centrifugation. An appropriate amount of supernatant was taken for gas chromatography analysis, and the conversion rate was calculated to be 96.1%, the selectivity was 99.1%, and the α-alkylene cyclic carbonate 2e was 99.1%. 1 HNMR Reference Figure 7 .

[0064] Example 7 Catalyst catalyzes the carboxyl cyclization reaction of CO2 and propargyl alcohol 1f

[0065] At room temperature, 20 mg of porphyrin-based triazine framework-loaded nanosilver catalyst, 1 mmol of 1,8-diazacyclo[5,4,0]undecene-7 and 1 mmol of propargyl alcohol 1f were added to a 10 mL stainless steel reactor. After the reactor was sealed, CO2 gas was repeatedly and slowly filled and discharged for 3 times. Then CO2 was charged to stabilize the pressure at 1.0 MPa. The reactor was placed in a 40°C constant temperature stirrer and stirred for 24 hours. After the reaction was completed, the unreacted CO2 was slowly released. Subsequently, 5 mL of ethyl acetate was added to the reactor and the solid catalyst was separated by centrifugation. An appropriate amount of supernatant was taken for gas chromatography analysis, and the conversion rate was calculated to be 95.3%, the selectivity was 98.8%, and the α-alkylene cyclic carbonate 2f was 98.8%. 1 HNMR Reference Figure 8 .

[0066] Example 8 Catalyst catalyzes the carboxyl cyclization reaction of CO2 and propargyl alcohol 1f

[0067] Under room temperature, add 20 mg of porphyrin triazine framework-loaded nanosilver catalyst, 1 mmol of 1,8-diazacyclo[5,4,0]undecene-7 and 1 mmol of 1 g of propargyl alcohol to a 10 mL stainless steel reactor. After sealing the reactor, slowly charge and discharge CO2 gas three times. Then charge CO2 to stabilize the pressure at 1.5 MPa. Place the reactor in a 40°C constant temperature stirrer and stir for 24 hours. After the reaction is completed, slowly release the unreacted CO2. Subsequently, add 5 mL of ethyl acetate to the reactor and separate the solid catalyst by centrifugation. Take an appropriate amount of supernatant for gas chromatography analysis, and the calculated conversion rate is 95.3%, the selectivity is 98.8%, and the α-alkylene cyclic carbonate 2g 1 HNMR Reference Fig. 9 .

[0068] Example 9 Catalyst catalyzes the carboxyl cyclization reaction of CO2 and propargyl alcohol 1a

[0069] At room temperature, 20 mg of porphyrinyl triazine framework-supported nanosilver catalyst, 0.5 mmol of 1,8-diazacyclo[5,4,0]undecene-7 and 1 mmol of propargyl alcohol 1a were added to a 10 mL stainless steel reactor. After the reactor was sealed, CO2 gas was repeatedly and slowly charged and discharged 3 times. Then CO2 was charged to stabilize the pressure at 1.0 MPa. The reactor was placed in a 40 ° C constant temperature stirrer and stirred for 12 hours. After the reaction was completed, the unreacted CO2 was slowly released. Subsequently, 5 mL of ethyl acetate was added to the reactor and the solid catalyst was separated by centrifugation. An appropriate amount of supernatant was taken for gas chromatography analysis, and the conversion rate was calculated to be 67.6%, and the selectivity of product 2a was 98.6%.

[0070] Example 10 Catalyst catalyzes carboxyl cyclization reaction of CO2 with propargyl alcohol 1a

[0071] At room temperature, 20 mg of porphyrinyl triazine framework-supported nanosilver catalyst, 1.0 mmol of 1,8-diazacyclo[5,4,0]undecene-7 and 1 mmol of propargyl alcohol 1a were added to a 10 mL stainless steel reactor. After the reactor was sealed, a mixed gas with a volume ratio of 15% CO2 + 85% N2 was repeatedly and slowly charged and discharged 3 times. Then the above mixed gas was filled to stabilize the pressure at 2.0 MPa. The reactor was placed in a 30 ° C constant temperature stirrer and stirred for 12 hours. After the reaction was completed, the unreacted CO2 was slowly released. Subsequently, 5 mL of ethyl acetate was added to the reactor and the solid catalyst was separated by centrifugation. An appropriate amount of supernatant was taken for gas chromatography analysis, and the conversion rate was calculated to be 87.2%, and the selectivity of product 2a was 95.2%.

[0072] Example 11 Catalyst catalyzes the carboxyl cyclization reaction of CO2 and propargyl alcohol 1a

[0073] At room temperature, 20 mg of porphyrinyl triazine framework-supported nanosilver catalyst, 1.0 mmol of 1,8-diazacyclo[5,4,0]undecene-7 and 1 mmol of propargyl alcohol 1a were added to a 10 mL stainless steel reactor. After the reactor was sealed, CO2 gas was repeatedly and slowly charged and discharged 3 times. Then CO2 was charged to stabilize the pressure at 0.5 MPa. The reactor was placed in a 30 ° C constant temperature stirrer and stirred for 12 hours. After the reaction was completed, the unreacted CO2 was slowly released. Subsequently, 5 mL of ethyl acetate was added to the reactor and the solid catalyst was separated by centrifugation. An appropriate amount of supernatant was taken for gas chromatography analysis, and the conversion rate was calculated to be 78.6%, and the selectivity of product 2a was 98.5%.

Claims

1. A porphyrinyl triazine framework-supported nanosilver catalyst, characterized in that: Its structural formula is shown in formula (I): Formula (I).

2. The method for preparing the porphyrinyl triazine framework-supported nanosilver catalyst according to claim 1, characterized in that: The steps are as follows: 1) Add 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and cyanuric chloride in a molar ratio of 1:1-2 into a round-bottom flask containing a solvent, continue to add the solvent and acid binding agent, stir and mix at room temperature for 0.5 h, continue to heat to reflux, and react for 72 h; after filtering and washing the obtained precipitate, vacuum drying at 100° C. for 12 h, a porphyrin triazine framework containing a secondary amine group is obtained; (2) adding tetrahydrofuran of silver tetrafluoroborate to a round-bottom flask, stirring evenly at room temperature to obtain a tetrahydrofuran solution containing silver nitrate, then adding the porphyrinyl triazine framework containing a secondary amine group obtained in step 1) to the round-bottom flask, stirring for 1 hour in the dark at room temperature, and then heating to 80° C., reacting for 24 hours, filtering, washing with solvent several times, and vacuum drying at 100° C. for 12 hours to obtain a porphyrinyl triazine framework-supported nanosilver catalyst; Step 2) The mass ratio of the porphyrin triazine framework to silver tetrafluoroborate is 100:2-10.

3. The method for preparing the porphyrinyl triazine framework-supported nano-silver catalyst according to claim 2, characterized in that: Step 1) The solvent is any one of tetrahydrofuran, 1,2-dioxane, N,N-dimethylformamide and dimethyl sulfoxide.

4. The method for preparing the porphyrinyl triazine framework-supported nano-silver catalyst according to claim 2, characterized in that: Step 1) The acid binding agent is any one of potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, triethylamine, and N,N-diisopropylethylamine.

5. The method for preparing the porphyrinyl triazine framework-supported nano-silver catalyst according to claim 2, characterized in that: The amount of the acid binding agent in step 1) is 2.5 to 7.5 times the amount of cyanuric chloride.

6. The method for preparing the porphyrinyl triazine framework-supported nano-silver catalyst according to claim 2, characterized in that: Step 1) The washing is carried out by combining suction filtration washing and Soxhlet extraction, the solvents for suction filtration washing are 50-150 mL of methanol, N,N-dimethylformamide, tetrahydrofuran and dichloromethane, respectively, and the Soxhlet extraction uses 300 mL of tetrahydrofuran as solvent, and the extraction time is 24 hours.

7. The method for preparing the porphyrinyl triazine framework-supported nano-silver catalyst according to claim 2, characterized in that: Step 2) The concentration of the silver nitrate tetrahydrofuran solution is 1-5 mg / mL.

8. The porphyrinyl triazine framework-supported nanosilver catalyst according to claim 1 is used to catalyze the cycloaddition reaction of propargyl alcohol compounds with CO2 to produce α-alkylene cyclic carbonate.

9. A method for preparing α-alkylene cyclic carbonate by catalyzing a cycloaddition reaction between a propargyl alcohol compound and CO2 using a porphyrinyl triazine framework-supported nanosilver catalyst, characterized in that: The method comprises the following steps in sequence: without adding any solvent, CO2 with a volume concentration of 15 to 100% and 1 mmol of epoxide 1a-1f of the structural formula as described in formula (II) are reacted in the presence of 20 mg of porphyrinyl triazine framework-supported nanosilver catalyst and 0.5 to 2.5 mmol of 1,8-diazacyclo[5,4,0]undecene-7 as a co-catalyst, at a pressure of 0.1 to 5.0 MPa and a reaction temperature of 25 to 80° C., followed by constant temperature stirring for 5 to 48 hours to obtain α-alkylene cyclic carbonate 2a-2f of the structural formula as shown in formula (III); Wherein: the epoxide has a structural formula as shown in formula (II): The α-alkylene cyclic carbonate has a structural formula as shown in formula (III):

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