Metal covalent polymer catalyst, preparation method and application of metal covalent polymer catalyst in propylene epoxidation reaction

Abstract

The invention discloses a metal covalent polymer catalyst, a preparation method and application of the metal covalent polymer catalyst in propylene epoxidation reaction. The structural formula is shown as a general formula (I): # imgabs0 #, wherein M in the formula (I) is selected from one of metal atoms Ru, Rt, Pa, Ir, Au, Ag, Cu, Fe, Co, Ni and Zn; according to the method, propylene is taken as a raw material, air or oxygen is taken as an oxidizing agent, the prepared metal covalent polymer is taken as a catalyst, a solvent and a sacrificial agent are added, a catalytic reaction is carried out under the conditions that the reaction temperature is 80-160 DEG C and the reaction pressure is 0.1-5.0 MPa, and epoxypropane can be prepared with high selectivity; the method has the advantages of safe reaction conditions, good catalytic effect, high selectivity, simple process and the like; belongs to the technical field of heterogeneous catalysis.

Description

Technical Field

[0001] The present invention relates to a preparation method of a metal covalent polymer catalyst and its application in catalytic in-situ dehydrogenation of cumene for epoxidation of propylene. Specifically, it relates to a preparation method of a metal covalent polymer catalyst. Using the synthesized metal covalent polymer as a catalyst, air as an oxidant, and cumene as a sacrificial agent, the dehydrogenation of cumene is enhanced in the reaction system, and low-concentration cumene hydroperoxide is in-situ generated for the epoxidation of propylene to prepare propylene oxide; it belongs to the field of heterogeneous catalysis. Background Art

[0002] Propylene oxide (PO) is an important organic compound and reactive intermediate, playing a fundamental role in supporting diverse industrial applications. Its high reactivity and diverse chemical structure enable it to be converted into high-value-added products. In the polyurethane manufacturing field, PO becomes the main monomer for producing polyether polyols through ring-opening polymerization reactions, forming the core framework of soft and hard foams in automotive interiors, building insulation materials, and furniture. The surfactant industry relies on PO to synthesize non-ionic surfactants through alkoxylation reactions, producing household cleaners, as well as emulsifiers and detergents indispensable in the oil recovery process. In addition to traditional fields, emerging uses include lithium-ion battery electrolytes and biofuel additives, highlighting its expanding role in sustainable technologies. Its large-scale application and huge profits have attracted extensive attention from researchers. Therefore, the propylene epoxidation reaction has both academic significance and industrial value.

[0003] At present, the main production processes of epoxides include the chlorohydrin method, the direct oxidation method, and the co-oxidation method. Although the traditional chlorohydrin method has the advantages of mature technology, strong raw material adaptability, and low investment cost, it faces prominent problems such as high chlorine consumption, high pollution, and equipment corrosion. The treatment cost of the chlorine-containing wastewater generated accounts for 15%-20% of the total cost. As a new generation of clean process, the direct oxidation method achieves a propylene conversion rate and selectivity of over 95% by using hydrogen peroxide as the oxidant, and the wastewater volume is reduced by 70% compared with the traditional process. However, the safety requirements for the storage and transportation of hydrogen peroxide and the relatively high raw material cost restrict its large-scale promotion. The co-oxidation method effectively avoids the environmental risks of the chlorohydrin method by introducing ethylbenzene or isobutane as the co-oxidant. However, the characteristics of co-producing styrene or tert-butanol limit the process flexibility, and the economy can only be manifested when the market demand for the co-products matches. Alkyl hydroperoxides, including tert-butyl hydroperoxide (TBHP), ethylbenzene hydroperoxide (EBHP), and cumene hydroperoxide (CHP), have attracted increasing attention due to their environmental protection characteristics and the high economic value of the by-products of the epoxidation reaction. However, the processes for producing alkyl hydroperoxides from isobutane, ethylbenzene, or cumene still face problems such as many by-products, equipment corrosion, complex processes, and harsh operating conditions. Moreover, the storage and transportation of high-concentration alkyl hydroperoxides are difficult and unsafe, and there are limitations in the self-decomposition characteristics under high temperature and high pressure. Therefore, in-situ generation of low-concentration alkyl peroxides in the reaction system for propylene epoxidation has important strategic significance.

[0004] Therefore, it is of great practical significance and application prospect to develop a propylene epoxidation process with mild reaction conditions, high efficiency, and simple operation for the preparation of propylene oxide.

[0005] Chinese invention patent CN11338523A discloses a method for propylene epoxidation by oxidizing propylene with tert-butyl hydroperoxide (TBHP) using a coordinated molybdenum oxacycle as a catalyst at a relatively high temperature. Although this method overcomes the disadvantages such as pollution and high production cost, the catalytic effect is not ideal. Using TBHP as the oxygen source for propylene epoxidation, the production and transportation of TBHP require relatively high costs, and there are certain safety production risks in the reaction system with high-concentration peroxides.

[0006] Chinese invention patent CN 202111131048.2 discloses a reaction process for the preparation of propylene oxide by gas-phase direct epoxidation of propylene. In this method, propylene, hydrogen, oxygen, and a stabilizer gas are pre-mixed to form a feed gas, and then the feed gas is introduced into a reactor to produce propylene oxide. The reaction can be carried out under the conditions of controlling the reaction temperature at 80-320 °C and the reaction pressure at 0.05-2.0 MPa to obtain propylene oxide. This method uses a mixed gas, the operation is dangerous, and the selectivity of the product propylene oxide is not high. Summary of the Invention

[0007] In order to overcome the defects existing in the above-mentioned prior art, the object of the present invention is to provide a metal covalent polymer catalyst with high reaction efficiency and high product selectivity.

[0008] The second object of the present invention is to provide a preparation method of the metal covalent polymer catalyst, which has simple synthesis and low production cost.

[0009] The third object of the present invention is to provide the application of the catalyst in the propylene epoxidation reaction.

[0010] To achieve the above object, the first technical solution of the present invention is to provide a metal covalent polymer catalyst, the structural formula of which is shown in general formula (I):

[0011]

[0012] M in formula (I) is selected from one of the metal atoms Ru, Rt, Pa, Ir, Au, Ag, Cu, Fe, Co, Ni, Zn.

[0013] The second technical solution of the present invention is the preparation method of the above metal covalent polymer catalyst, which successively includes the following steps:

[0014] 1) Add pyrrole, terephthalaldehyde, catalyst, and solvent 1 into a reaction flask, react at 70-90 °C for 9-15 h, cool to room temperature, filter the reaction solution, wash the filter cake, and dry it in a vacuum drying oven to obtain a solid powder;

[0015] 2) Add the solid powder prepared in step 1) into a reaction tube, then add a metal compound and solvent 2, react at 170-190 °C for 9-15 h, cool to room temperature, filter, wash the filter cake, and dry it to obtain a solid product of general formula (I).

[0016] The molar ratio of the pyrrole to the terephthalaldehyde is 2.0:0.25;

[0017] The mass ratio of the solid powder to the metal compound is: 50:20.

[0018] Furthermore, in the above preparation method of the metal covalent polymer catalyst, the metal compound is one of Ru3CO1, PtCl3, PdCl2, IrCl3, AuCl3, AgCl, CuCl2, FeCl2, CoCl2, NiCl2, ZnCl2.

[0019] Furthermore, in the above preparation method of the metal covalent polymer catalyst, the catalyst is trifluoroacetic acid.

[0020] Furthermore, in the above-mentioned method for preparing the metal covalent polymer catalyst, the solvent 1 is acetic acid; and the solvent 2 is decalin.

[0021] Another technical solution of the present invention is to use the metal covalent polymer catalyst to catalyze the in-situ dehydrogenation and epoxidation of propylene by isopropylbenzene.

[0022] Another technical solution of the invention is a method for propylene epoxidation, which uses propylene as a raw material, adds an organic solvent and a sacrificial agent, uses air as an oxidant, and uses a prepared metal covalent polymer having the general formula (I) as a catalyst. The catalytic reaction is carried out under conditions of a reaction temperature of 80 to 160° C. and a reaction pressure of 0.1 to 6.0 MPa to produce propylene oxide. The amount of the catalyst used is 0.2 to 20 wt% of the raw material; the amount of the sacrificial agent used is 0.1 to 5.0 eq. of the raw material.

[0023] Furthermore, in the above-mentioned method for catalyzing propylene epoxidation, the sacrificial agent is one of isobutane, cumene, ethylbenzene, toluene, cyclohexylbenzene, and adamantane.

[0024] Furthermore, in the above-mentioned method for catalyzing propylene epoxidation, the organic solvent is one of acetonitrile, benzonitrile, ethanol, isopropanol, hexafluoroisopropanol, N,N-dimethylformamide, tetrahydrofuran, ethyl acetate, and methyl benzoate.

[0025] Furthermore, in the above-mentioned method for catalyzing propylene epoxidation, the amount of the catalyst used is 0.2-20 wt% of the raw material; and the amount of the sacrificial agent used is 0.1-5.0 eq of the raw material.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The catalyst of the present invention has high catalytic efficiency, high product selectivity, simple process and low production cost.

[0028] 2. The technical solution provided by the present invention uses air as an oxidant in the propylene epoxidation reaction, avoiding the serious equipment corrosion, environmental pollution and safety problems caused by peroxyacids and peroxides, and has good industrial application prospects.

[0029] 3. The technical solution provided by the present invention adds a catalyst to a solvent and a sacrificial agent, so that propylene and air undergo an epoxidation reaction to produce propylene oxide under the action of the catalyst; the sacrificial agent is added to capture the hydrogen atoms of the sacrificial agent to generate C free radicals, thereby activating oxygen and generating a low concentration of peroxide in situ, which further epoxidizes propylene to produce propylene oxide; and the metal in the catalyst also has a good activation effect on molecular oxygen, thereby producing a high-valent metal oxide, which assists the epoxidation reaction.

[0030] 4. The technical solution provided by the present invention has a high conversion rate of propylene under various reaction systems, relatively high selectivity, a small amount of catalyst used, the catalyst can be reused by centrifugation or filtration, and the operation is simple and the production is safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the infrared spectrum of the metal covalent polymer catalyst;

[0032] Figure 2 is the XRD spectrum of the metal covalent polymer catalyst. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The present invention will be further described below in conjunction with embodiments, but the protection scope of the present invention is not limited to the scope shown in the embodiments.

[0034] Example 1

[0035] This example provides a catalyst having a structure as shown in the general formula (I):

[0036]

[0037] Synthesis steps of the structural catalyst described by the general formula (I):

[0038] 1) Add 134 mg of pyrrole (2.0 mmol), 134 mg of terephthalaldehyde (0.25 mmol), 1 mL of trifluoroacetic acid, and 200 mL of acetic acid to a 200 mL round-bottom flask in sequence, react at 80 °C for 12 h, cool to room temperature, filter the reaction solution, wash the filter cake with deionized water (100 mL × 3), then wash with ethanol (100 mL × 3), and dry in a vacuum drying oven at 80 °C for 12 h to obtain a black solid powder.

[0039] 2) Take 50 mg of the black solid powder obtained in the previous step into a 25 mL Schlenk tube, then add 20 mg of dodecacarbonyltriruthenium and 50 mL of decalin, react at 180 °C for 12 h, cool to room temperature, filter, wash the filter cake three times with 20 mL of deionized water and ethanol respectively, and dry to obtain the solid product of the general formula (I).

[0040] The infrared spectrum of the metal covalent polymer catalyst prepared in Example 1 is referred to Figure 1 , it can be seen that there is an obvious peak in the infrared spectrum at around 1670 cm -1 , attributed to the C=N stretching vibration, and the characteristic peak at 3425 m -1 belongs to the characteristic stretching frequency of N-H. The aromatic C=C stretching vibration at 1606 cm -1 , and 795 cm -lThe peak at [location] belongs to the bending vibration of C-H on the benzene ring. These observations confirm the successful synthesis of this catalyst. See the XRD pattern Figure 2 ; It can be seen from the XRD pattern that there is a broad diffraction peak at 22°, corresponding to the characteristic signal peak of the polymer.

[0041] Example 2

[0042] This example provides a catalyst with a structure as shown in general formula (I):

[0043]

[0044] Synthesis steps of the catalyst with the structure described in general formula (I):

[0045] 1) Add 134 mg of pyrrole (2.0 mmol), 134 mg of terephthalaldehyde (0.25 mmol), 1 mL of trifluoroacetic acid, and 200 mL of acetic acid to a 200 mL round-bottom flask in sequence. React at 80 °C for 12 h, cool to room temperature, filter the reaction solution, wash the filter cake with deionized water (100 mL × 3), then wash with ethanol (100 mL × 3), and dry in a vacuum drying oven at 80 °C for 12 h to obtain a black solid powder.

[0046] 2) Take 50 mg of the black solid powder prepared in step 1) and place it in a 25 mL Schlenk tube. Then add 20 mg of IrCl3 and 50 mL of decalin. React at 180 °C for 12 h. After cooling to room temperature, filter, and wash the filter cake three times with 20 mL of deionized water and ethanol respectively, and then dry to obtain the solid product of general formula (I).

[0047] Example 3

[0048] In a high-pressure reactor, add 5 mg of the covalent polymer catalyst with the structure of general formula (I) (M = Ru) prepared in Example 1, add 20 mmol of the sacrificial agent cumene, 20 mL of acetonitrile solution, charge 10 mmol of propylene and 2 MPa of air, stir at a temperature of 130 °C for 3 h. After gas chromatography detection, the propylene conversion rate is 60%, and the selectivity of propylene oxide is 96%.

[0049] Example 4

[0050] In a high-pressure reactor, add 50 mg of the covalent polymer catalyst with the structure of general formula (I) (M = Ru) prepared in Example 1, add 20 mmol of the sacrificial agent cumene, 20 mL of acetonitrile solution, charge 10 mmol of propylene and 2 MPa of air, stir at 130 °C for 3 h. After gas chromatography detection, the propylene conversion rate is 60%, and the selectivity of propylene oxide is 98%.

[0051] Example 5

[0052] In a high-pressure reactor, 100 mg of the covalent polymer catalyst (M = Ru) with the general formula (I) structure prepared in Example 1 was added successively, 20 mmol of the sacrificial agent cumene was added, 20 mL of acetonitrile solution was added, 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 130 °C for 3 h. By gas chromatography detection, the conversion rate of propylene was 65%, and the selectivity of propylene oxide was 98%.

[0053] Example 6

[0054] In a high-pressure reactor, 5 mg of the covalent polymer catalyst (M = Ru) with the general formula (I) structure prepared in Example 1 was added successively, 1 mmol of the sacrificial agent cumene was added, 20 mL of acetonitrile solution was added, 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 130 °C for 3 h. By gas chromatography detection, the conversion rate of propylene was 15%, and the selectivity of propylene oxide was 95%.

[0055] Example 5

[0056] In a high-pressure reactor, 5 mg of the covalent polymer catalyst (M = Ru) with the general formula (I) structure prepared in Example 1 was added successively, 40 mmol of the sacrificial agent cumene was added, 20 mL of acetonitrile solution was added, 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 130 °C for 2 h. By gas chromatography detection, the conversion rate of propylene was 65%, and the selectivity of propylene oxide was 98%.

[0057] Example 6

[0058] In a high-pressure reactor, 5 mg of the covalent polymer catalyst (M = Ru) with the general formula (I) structure prepared in Example 1 was added successively, 20 mmol of the sacrificial agent cumene was added, 20 mL of acetonitrile solution was added, 20 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 130 °C for 2 h. By gas chromatography detection, the conversion rate of propylene was 35%, and the selectivity of propylene oxide was 97%.

[0059] Example 7

[0060] In a high-pressure reactor, 5 mg of the covalent polymer catalyst (M = Ru) with the general formula (I) structure prepared in Example 1 was added successively, 20 mmol of the sacrificial agent cumene was added, 20 mL of acetonitrile solution was added, 5 mmol of propylene and 4 MPa of air were charged, and the mixture was stirred at 130 °C for 2 h. By gas chromatography detection, the conversion rate of propylene was 75%, and the selectivity of propylene oxide was 98%.

[0061] Example 8

[0062] In a high-pressure reactor, 5 mg of the covalent polymer catalyst (M = Ru) with the general formula (I) structure prepared in Example 1 was added successively. Then, 20 mmol of the sacrificial agent ethylbenzene and 20 mL of acetonitrile solution were added. 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 110 °C for 2 h. After gas chromatography detection, the propylene conversion rate was 55%, and the selectivity for propylene oxide was 96%.

[0063] Example 9

[0064] In a high-pressure reactor, 5 mg of the covalent polymer catalyst (M = Ru) with the general formula (I) structure prepared in Example 1 was added successively. Then, 20 mmol of the sacrificial agent cyclohexylbenzene and 20 mL of acetonitrile solution were added. 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 130 °C for 3 h. After gas chromatography detection, the propylene conversion rate was 65%, and the selectivity for propylene oxide was 94%.

[0065] Example 10

[0066] In a high-pressure reactor, 5 mg of the covalent polymer catalyst (M = Ru) with the general formula (I) structure prepared in Example 1 was added successively. Then, 20 mmol of the sacrificial agent cumene and 20 mL of acetonitrile solution were added. 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 110 °C for 3 h. After gas chromatography detection, the propylene conversion rate was 25%, and the selectivity for propylene oxide was 98%.

[0067] Example 11

[0068] In a high-pressure reactor, 5 mg of the covalent polymer catalyst (M = Ru) with the general formula (I) structure prepared in Example 1 was added successively. Then, 20 mmol of the sacrificial agent cumene and 20 mL of acetonitrile solution were added. 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 150 °C for 3 h. After gas chromatography detection, the propylene conversion rate was 75%, and the selectivity for propylene oxide was 78%.

[0069] Example 12

[0070] In a high-pressure reactor, 5 mg of the covalent polymer catalyst (M = Ru) with the general formula (I) structure prepared in Example 1 was added successively. Then, 20 mmol of the sacrificial agent cumene and 20 mL of acetonitrile solution were added. 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 130 °C for 1 h. After gas chromatography detection, the propylene conversion rate was 25%, and the selectivity for propylene oxide was 98%.

[0071] Example 13

[0072] In a high-pressure reactor, 5 mg of the covalent polymer catalyst with the structure of general formula (I) (M = Ru) prepared in Example 1 was added successively. Then, 20 mmol of the sacrificial agent cumene, 20 mL of acetonitrile solution were added. 10 mmol of propylene and 2 MPa of air were charged. The mixture was stirred at 130 °C for 5 h. After gas chromatography detection, the conversion rate of propylene was 63%, and the selectivity of propylene oxide was 98%.

[0073] Example 14

[0074] In a high-pressure reactor, 5 mg of the covalent polymer catalyst with the structure of general formula (I) (M = Ru) prepared in Example 1 was added successively. Then, 20 mmol of the sacrificial agent cumene, 20 mL of benzonitrile solution were added. 10 mmol of propylene and 2 MPa of air were charged. The mixture was stirred at 130 °C for 3 h. After gas chromatography detection, the conversion rate of propylene was 49%, and the selectivity of propylene oxide was 96%.

[0075] Example 15

[0076] In a high-pressure reactor, 5 mg of the covalent polymer catalyst with the structure of general formula (I) (M = Ru) prepared in Example 1 was added successively. Then, 20 mmol of the sacrificial agent cumene, 20 mL of ethyl acetate solution were added. 10 mmol of propylene and 2 MPa of air were charged. The mixture was stirred at 130 °C for 3 h. After gas chromatography detection, the conversion rate of propylene was 70%, and the selectivity of propylene oxide was 99%.

[0077] Example 16

[0078] In a high-pressure reactor, 5 mg of the covalent polymer catalyst with the structure of general formula (I) (M = Ru) prepared in Example 1 was added successively. Then, 20 mmol of the sacrificial agent cumene, 20 mL of methyl benzoate solution were added. 10 mmol of propylene and 2 MPa of air were charged. The mixture was stirred at 130 °C for 3 h. After gas chromatography detection, the conversion rate of propylene was 60%, and the selectivity of propylene oxide was 91%.

[0079] Example 17

[0080] In a high-pressure reactor, 5 mg of the covalent polymer catalyst with the structure of general formula (I) (M = Ru) prepared in Example 1 was added successively. Then, 20 mmol of the sacrificial agent cumene, 20 mL of ethyl acetate solution were added. 10 mmol of propylene and 0.1 MPa of air were charged. The mixture was stirred at 130 °C for 3 h. After gas chromatography detection, the conversion rate of propylene was 30%, and the selectivity of propylene oxide was 98%.

[0081] Example 18

[0082] In a high-pressure reactor, 5 mg of the covalent polymer catalyst with the general formula (I) structure (M = Ru) prepared in Example 1 was sequentially added, 20 mmol of the sacrificial agent cumene was added, 20 mL of ethyl acetate solution was added, 10 mmol of propylene and 4 MPa of air were charged, and the mixture was stirred at 130 °C for 3 h. After gas chromatography detection, the propylene conversion rate was 70%, and the selectivity for propylene oxide was 96%.

[0083] Example 19

[0084] In a high-pressure reactor, 5 mg of the covalent polymer catalyst with the general formula (1) structure (M = Ir) prepared in Example 2 was sequentially added, 20 mmol of the sacrificial agent cumene was added, 20 mL of ethyl acetate solution was added, 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 130 °C for 3 h. After gas chromatography detection, the propylene conversion rate was 57%, and the selectivity for propylene oxide was 98%.

[0085] Comparative Example 1

[0086] In a high-pressure reactor, 5 mg of the covalent polymer catalyst with the general formula (I) structure (M = Ru) prepared in Example 1, 20 mL of ethyl acetate solution were sequentially added, 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 130 °C for 3 h. After gas chromatography detection, the propylene conversion rate was 12%, and the selectivity for propylene oxide was 98%.

[0087] Comparative Example 2

[0088] In a high-pressure reactor, 20 mmol of the sacrificial agent cumene, 20 mL of ethyl acetate solution were sequentially added, 10 mmol of propylene and 2 MPa of air were charged, and the mixture was stirred at 130 °C for 3 h. After gas chromatography detection, the propylene conversion rate was 10%, and the selectivity for propylene oxide was 98%.

[0089] Comparative Example 3

[0090] In a high-pressure reactor, 5 mg of the covalent polymer catalyst with the general formula (I) structure (M = Ru) prepared in Example 1, 20 mmol of the sacrificial agent cumene, 20 mL of ethyl acetate solution were sequentially added, 10 mmol of propylene was charged, and the mixture was stirred at 130 °C and atmospheric pressure for 3 h. After gas chromatography detection, the propylene conversion rate was 27%, and the selectivity for propylene oxide was 98%.

Claims

1. A metal covalent polymer catalyst, characterized in that, The structural formula is as shown in the general formula (I): M in the formula (I) is selected from one of the metal atoms Ru, Rt, Pa, Ir, Au, Ag, Cu, Fe, Co, Ni, Zn.

2. The preparation method of the metal covalent polymer catalyst according to claim 1, characterized in that, It successively includes the following steps: 1) Add pyrrole, terephthalaldehyde, a catalyst, and solvent 1 into a reaction flask, react at 70 - 90 °C for 9 - 15 h, cool to room temperature, filter the reaction solution, wash the filter cake, and dry it in a vacuum drying oven to obtain a solid powder; 2) Add the solid powder prepared in step 1) into a reaction tube, then add a metal compound and solvent 2, react at 170 - 190 °C for 9 - 15 h, cool to room temperature, filter, wash the filter cake, and dry it to obtain the solid product of the general formula (I). The molar ratio of the pyrrole to the terephthalaldehyde is 2.0:0.25; The mass ratio of the solid powder to the metal compound is: 50:

20.

3. The preparation method of the metal covalent polymer catalyst according to claim 2, wherein, The metal compound is Ru3CO 12 or one of PtCl3, PdCl2, IrCl3, AuCl3, AgCl, CuCl2, FeCl2, CoCl2, NiCl2, ZnCl2.

4. The preparation method of the metal covalent polymer catalyst according to claim 2, wherein, The catalyst is trifluoroacetic acid.

5. The preparation method of the metal covalent polymer catalyst according to claim 2, wherein, The solvent 1 is acetic acid; the solvent 2 is decalin.

6. The metal covalent polymer catalyst described in claim 1 is used for the reaction of catalytic in-situ dehydrogenation epoxidation of cumene to propylene oxide.

7. A method for propylene epoxidation reaction, characterized in that, Using propylene as a raw material, adding an organic solvent and a sacrificial agent, using air as an oxidant, using the prepared metal covalent polymer with the general formula (I) as a catalyst, controlling the catalytic reaction to be carried out under the conditions of a reaction temperature of 80 - 160 °C and a reaction pressure of 0.1 - 6.0 MPa to obtain propylene oxide, the catalyst dosage is 0.2 - 20 wt% of the raw material, and the sacrificial agent dosage is 0.5 - 5.0 eq. of the raw material.

8. The method for catalytic propylene epoxidation reaction according to claim 1, wherein The sacrificial agent is one of isobutane, cumene, ethylbenzene, toluene, cyclohexylbenzene, adamantane.

9. The method for catalytic epoxidation of propylene according to claim 1, wherein The organic solvent is one of acetonitrile, benzonitrile, ethanol, isopropanol, hexafluoroisopropanol, N,N-dimethylformamide, tetrahydrofuran, ethyl acetate, methyl benzoate.

10. The method for catalytic epoxidation of propylene according to claim 1, wherein The catalyst dosage is 0.2 - 20 wt% of the raw material; the sacrificial agent dosage is 0.1 - 5.0 eq. of the raw material.

Images