Inorganic-organic composite metal silicate catalyst as well as preparation method and application thereof

Abstract

The invention discloses an inorganic-organic composite metal silicate catalyst as well as a preparation method and application thereof, and is characterized in that the composition of the catalyst is xMOn / 2. Y R.1.0 SiO2, M is one or more than two metals of aluminum, iron, titanium and tin; n is the valence state of the metal M; x is the molar ratio of metal M to Si; r is cyclic organic amine with the ring number of 5-7; y is the molar ratio of the cyclic organic amine to Si; the catalyst is obtained by taking a zeolite molecular sieve as a raw material and carrying out hydrothermal reaction on the zeolite molecular sieve and a cyclic organic amine aqueous solution under high-temperature and high-pressure conditions; the catalyst is used for catalyzing a deacetalization-Kirschner condensation bifunctional cascade reaction of benzaldehyde dimethyl acetal and malononitrile and an epoxidation catalytic reaction of olefin to synthesize corresponding epoxide. Compared with the prior art, the preparation method disclosed by the invention is simple and convenient, and has the characteristics of mild reaction conditions, high target product yield and few byproducts in a deacetalization-Kirschner condensation acid-base bifunctional catalytic reaction and an olefin epoxidation catalytic reaction, and has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst preparation and application, and specifically to an inorganic-organic composite metal silicate catalyst, a preparation method thereof, a dual-functional acid-base catalysis reaction of acetal deprotection-Knoevenagel condensation, and an application in an olefin epoxidation catalytic reaction. Background Art

[0002] Crystalline metal silicate porous materials represented by zeolite materials, whether prepared from pure inorganic raw materials or hydrothermally synthesized through organic structure-directing agents, have a crystal framework composed of pure inorganic elements. They are mainly composed of tetrahedral units of silicon and other metals (aluminum, titanium, iron, tin, etc.) connected by sharing oxygen atoms to form a three-dimensional network porous crystal structure. Even for zeolite materials synthesized using organic structure-directing agents, after the directing agent completes its crystallization mission, it is necessary to remove the residual organic matter filled and blocked in the zeolite pores by calcination to open the pores to meet the requirements of adsorption, separation, and catalytic applications. Therefore, conventional crystalline metal silicate porous materials are composed of pure inorganic elements.

[0003] Heteroatom metals such as aluminum, titanium, iron, and tin other than silicon introduced into zeolite-based metal silicate crystalline materials can endow these materials with unique catalytic functions. Among them, aluminosilicate shows solid acid properties. For example, ZSM-5 zeolite with MFI structure, Beta zeolite, MCM-22 zeolite with MWW structure, and mordenite with MOR structure are all crystalline aluminosilicate inorganic materials, and they have been widely used in the fields of petroleum refining, energy chemistry, and fine chemicals; while titanium, iron, or tin-containing metal silicates have unique selective oxidation catalytic functions. In particular, titanium-containing inorganic silicate zeolite molecular sieves such as TS-1, Ti-MWW, Ti-Beta, and Ti-MOR have shown important practical application values in the liquid-phase selective oxidation reaction of hydrocarbons and have been gradually promoted and applied industrially. Due to the characteristics of these metal silicates composed of pure inorganic elements, their functions are relatively single, resulting in bottlenecks in the expansion and exploration of their catalytic applications and other functions.

[0004] In summary, based on the material design concept of function coupling and integrated strengthening, making full use of commercially available zeolite materials that can be prepared on a large scale as raw materials, introducing organic functional groups through a simple route, and constructing inorganic-organic composite metal silicate materials, it is expected to create dual (multi)-functional porous materials that better meet the concepts and requirements of "green chemistry" and "atom economy", and form new catalytic reaction technologies. Summary of the Invention

[0005] The object of the present invention is to provide an inorganic-organic composite metal silicate catalyst, its preparation method and application in view of the deficiencies of the prior art. By means of a hydrothermal reaction of zeolite molecular sieve and cyclic organic amine under high temperature and high pressure conditions, an inorganic-organic composite metal silicate porous material is prepared. Its main chemical elements are silicon oxide, metal oxide and organic amine, and the element composition can be expressed as xMOn / 2·y R·1.0SiO2, where M is one or more metals among aluminum, iron, titanium and tin, n is the valence state of metal M, x is the molar ratio of metal M to Si, and R is a cyclic organic amine with a ring number of 5-7. This catalyst has a unique crystal structure. When used as an acid-base bifunctional catalytic reaction and an olefin epoxidation catalytic reaction, in the catalytic deacetalization-Knoevenagel condensation bifunctional tandem reaction of benzaldehyde dimethyl acetal and malononitrile and the olefin epoxidation catalytic reaction to synthesize the corresponding epoxide, it shows a high product yield. The preparation method of the inorganic-organic composite metal silicate of the present invention is simple. In the deacetalization-Knoevenagel condensation acid-base bifunctional catalytic reaction and the olefin epoxidation catalytic reaction, it shows the characteristics of mild reaction conditions, high target product yield and few by-products, providing an efficient catalyst for important energy chemical reactions and a new catalytic process technology for the green production of chemicals, and having good application prospects and commercial development value.

[0006] The object of the present invention is achieved as follows: An inorganic-organic composite metal silicate catalyst, characterized in that the metal silicate catalyst is composed of silicon oxide, metal oxide and organic amine, and its element composition can be expressed as: xMOn / 2·y R·1.0SiO2. Among them, M is one or more metals among aluminum, iron, titanium and tin, n is the valence state of metal M, and its value is +3 or +4; x is the molar ratio of metal M to Si, and its value range is 0.005-0.1; R is a cyclic organic amine with a ring number of 5-7; y is the molar ratio of cyclic organic amine to Si, and its value range is 0.01-0.2.

[0007] The metal silicate catalytic material has the X-ray diffraction data of the diffraction peaks shown in Table 1 below, Cu-Kα,

[0008] Table 1. X-ray diffraction data of inorganic-organic composite metal silicate materials

[0009]

[0010]

[0011] Among them, (a)The intensity of the strongest diffraction peak in the powder X-ray diffraction pattern is designated as 100, and the relative intensity levels of other diffraction peaks with respect to the strongest peak are as follows: W is less than 25 (weak); M is 25 to 50 (medium); S is 50 to 75 (strong); VS is 75 to 100 (very strong).

[0012] The second object of the present invention is to provide a preparation method of the above-mentioned inorganic-organic composite metal silicate catalyst, which is characterized in that the preparation method specifically includes the following steps:

[0013] Step 1: Mix commercially available zeolite molecular sieves (calculated according to the total molar amount of SiO2 and MO n / 2 with organic amines in a molar ratio of 1.0: (0.05 to 1.5) and with water in a molar ratio of 1.0: (5 to 50), and stir at room temperature for 2 to 5 hours to obtain a uniformly mixed gel. The commercially available zeolite molecular sieves have MFI, Beta, MWW, and MOR topological structures, and in addition to silicon and oxygen, the zeolite framework elements also contain one or more metals among aluminum, iron, titanium, and tin; the organic amines are cyclic organic amines with a ring number of 5-7.

[0014] Step 2: Treat the gel obtained in Step 1 at 120 to 170 °C for 5 to 20 hours, then filter and repeatedly wash with deionized water until the pH of the filtrate is <7.5, and dry at 80 to 120 °C for 5 to 10 hours to finally obtain the catalyst of the inorganic-organic composite metal silicate material.

[0015] The third object of the present invention is to provide an application of the above-mentioned inorganic-organic composite metal silicate catalyst, which is characterized in that the specific operation of using the catalyst in the deacetalization-Knoevenagel condensation tandem reaction is as follows:

[0016] Mix benzaldehyde dimethyl acetal with the catalyst, solvent, water, and malononitrile in a weight ratio of 1.0: 0.01 to 0.4: 5 to 10: 0.00002 to 0.1: 0.2 to 1.0, heat to 60 to 80 °C, and react for 5 to 20 hours. After the reaction is completed, cool it in an ice-water bath, centrifuge to remove the catalyst, and the liquid-phase product obtained is benzylidenemalononitrile. Analyze the reaction solution by gas chromatography to determine the product yield and selectivity. The solvent is one or a mixture of two or more of acetonitrile, methanol, acetone, and benzene.

[0017] The specific operation of using the catalyst in the epoxidation of olefins is as follows:

[0018] Mix a solvent, a catalyst, an oxidant, and an olefin reactant, where the molar ratio of olefin / oxidant is 0.5 - 28, the mass ratio of olefin / catalyst is 2 - 400, and the mass ratio of solvent / olefin is 0.5 - 20. Heat to 30 - 90 °C and react for 0.5 - 4 hours. After the reaction, cool it in an ice-water bath, centrifuge to remove the catalyst, and the liquid-phase product obtained is an epoxide. Analyze the reaction solution by gas chromatography to determine the product yield and selectivity. The solvent is one or a mixture of two or more of the protic solvents methanol, ethanol, tert-butanol, water, and the aprotic solvents acetone, acetonitrile, cyclohexane; the oxidant is an aqueous solution or an organic solvent solution of hydrogen peroxide, tert-butyl hydroperoxide, ethylbenzene hydroperoxide, and cumene hydroperoxide; the olefin is one of straight-chain olefins with 2 - 6 carbon atoms and cyclic olefins with 5 - 8 carbon atoms.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects and remarkable technical progress:

[0020] 1) The organic-inorganic composite metal silicate of the present invention has a novel structure and the characteristics of dual (multiple) catalytic functions;

[0021] 2) The required raw materials are widely available and easy to obtain, and the preparation process is simple and easy for industrial production;

[0022] 3) It has high catalytic activity and few by-products in the bifunctional deacetalization and Knoevenagel condensation coupling reaction, as well as the olefin epoxidation reaction, and the reaction process is environmentally friendly. Description of the Drawings

[0023] Figure 1 X-ray diffraction pattern of the inorganic-organic composite aluminum silicate catalyst prepared in Example 1

[0024] Figure 2 Scanning electron microscope photograph of the inorganic-organic composite aluminum silicate catalyst prepared in Example 1;

[0025] Figure 3 Thermogravimetric test (TG) curve of the organic-inorganic composite aluminum silicate catalyst prepared in Example 1;

[0026] Figure 4 X-ray diffraction pattern of the inorganic-organic composite titanium silicate catalyst prepared in Example 2;

[0027] Figure 5 Scanning electron microscope photograph of the inorganic-organic composite titanium silicate catalyst prepared in Example 2;

[0028] Figure 6 Thermogravimetric test (TG) curve of the inorganic-organic composite titanium silicate material prepared in Example 2. Detailed Description of the Invention

[0029] The materials, preparation methods, and catalytic applications of the present invention are further described in detail below through specific examples. Only the technical data of the key steps are listed to simplify the description. The specific examples provided are all operated according to the operation steps of the technical solution. Any simple modifications and decorations in any form to the embodiments of the present invention fall within the protection scope of the technical solution of the present invention. Any fine-tuning of other operations and conditions such as the raw materials, feeding ratios, temperatures, and synthesis processes of the present invention is considered to infringe the rights and interests of the present invention.

[0030] Example 1

[0031] Step 1: Mix commercially available MWW-structured H-MCM-22 silicoaluminophosphate zeolite (Si / Al molar ratio = 15, where silicon is calculated as SiO2 and Al is calculated as AlO 3 / 2 ), hexamethyleneimine (HMI), and water in a molar ratio of 1.0SiO2:0.066AlO 3 / 2 :1.0HMI:15H2O, and stir at room temperature for 3 hours to obtain a uniformly mixed gel.

[0032] Step 2: Transfer the prepared gel to a pressure-resistant reactor, perform dynamic hydrothermal treatment at 140 °C for 15 hours. After completion, filter and wash repeatedly with deionized water until the pH of the filtrate is 7.2, and dry in an oven at 85 °C for 7 hours to prepare an inorganic-organic composite aluminosilicate material. The Si / Al molar ratio is determined to be 14.9 by inductively coupled plasma (ICP) elemental analysis.

[0033] Refer to Figure 1 , the above-prepared inorganic-organic composite aluminosilicate material is characterized by X-ray diffraction (Cu-Kα, ), and has good crystallinity and a novel crystal structure.

[0034] Refer to Figure 2 , the inorganic-organic composite aluminosilicate material prepared in Example 1 is characterized by scanning electron microscopy, and its crystal morphology shows the stacking of nanosheet crystals.

[0035] Refer to Figure 3 , the inorganic-organic composite aluminosilicate material prepared in Example 1 is tested by thermogravimetry (TG), and 9.8% of the organic matter is contained in its structure.

[0036] Example 2

[0037] Step 1: Mix MOR-structured titanium silicalite Ti-MOR (Si / Ti molar ratio = 40, where silicon is calculated as SiO2 and Ti is calculated as TiO2), piperidine (PI), and water in a molar ratio of 1.0SiO2:0.025TiO2:0.5PI:10H2O, and stir at room temperature for 4 hours to obtain a uniformly mixed gel.

[0038] Step 2: Transfer the gel prepared in Step 1 to a pressure-resistant reactor, dynamically process it at 165 °C for 10 hours. After completion, filter and repeatedly wash with deionized water until the pH of the filtrate is 7.3, and dry at 90 °C for 8 hours to prepare an organic-inorganic composite titanium silicate material. The Si / Ti molar ratio is determined to be 39 by inductively coupled plasma (ICP) elemental analysis.

[0039] Refer to Figure 4 , the inorganic-organic composite titanium silicate material prepared in Example 2 is characterized by X-ray diffraction (Cu-Kα, ), with good crystallinity, similar to Figure 1 , and has a novel crystal structure.

[0040] Refer to Figure 5 , the inorganic-organic composite titanium silicate material prepared in Example 2 is characterized by scanning electron microscopy, and its crystal morphology shows the stacking of nanosheet crystals.

[0041] Refer to Figure 6 , the inorganic-organic composite titanium silicate material prepared in Example 2 is tested by thermogravimetry (TG), and 14.5% of organic matter is contained in its structure.

[0042] The following uses the inorganic-organic composite aluminosilicate material prepared in Example 1 as a catalyst for the one-pot deacetalization-Knoevenagel condensation bifunctional reaction of benzaldehyde dimethyl acetal and malononitrile. The reaction product is analyzed by gas chromatography, and it is found that this material indeed has excellent acid-base bifunctional catalytic performance.

[0043] Example 3

[0044] The deacetalization-Knoevenagel condensation bifunctional reaction of benzaldehyde dimethyl acetal and malononitrile is as follows:

[0045] Add 0.2 g of the inorganic-organic composite aluminosilicate catalyst prepared in Example 1, 5 mmol of benzaldehyde dimethyl acetal, 5 mmol of malononitrile, 5 g of acetonitrile, and 20 micrograms of water, stir and react at 75 °C for 6 hours. After cooling with ice water, centrifuge to remove the solid catalyst, and the liquid-phase product is benzylidene malononitrile.

[0046] Add 0.5 mmol of n-dodecane internal standard to the liquid-phase product, and analyze and calculate the conversion rate of benzaldehyde dimethyl acetal and the selectivity of the condensation product benzylidene malononitrile by gas chromatography (Shimadzu 2014, FID detector). The comparison of the results of the inorganic-organic composite aluminosilicate material prepared in Example 1 and Comparative Example 1 using H-MCM-22 zeolite as a catalyst is shown in Table 2 below.

[0047] Table 2. Comparison of the catalytic performance of inorganic-organic composite aluminosilicate and H-MCM-22 inorganic zeolite in the dual-functional reaction of acetal deprotection-Knoevenagel condensation

[0048] Conversion rate of benzaldehyde dimethyl acetal (%) Selectivity of benzylidene malononitrile (%) Example 3 92.2 91.7 Comparative Example 1 5.6 65.1

[0049] The H-MCM-22 pure inorganic zeolite catalyst used in Comparative Example 1 was the same as the raw materials used in Example 1, and its Si / Al molar ratio was 15. The conditions for the dual-functional reaction of benzaldehyde dimethyl acetal and malononitrile were the same as those in Example 3, and the products were analyzed by gas chromatography. The measured data proved that the inorganic-organic composite aluminosilicate used in Example 3 had better catalytic activity than the H-MCM-22 inorganic catalyst used in Comparative Example 1 in the acetal deprotection-Knoevenagel condensation reaction of benzaldehyde dimethyl acetal and malononitrile.

[0050] The following uses the inorganic-organic composite titanium silicate material prepared in Example 2 as a catalyst for the epoxidation of olefins, and it is found that it exhibits excellent catalytic activity.

[0051] Example 4

[0052] The catalyst prepared in Example 2 was applied to the liquid-phase epoxidation reaction of ethylene and hydrogen peroxide in a closed high-pressure resistant reaction kettle. The main operation steps were as follows: 10 mL of methanol, 0.2 g of catalyst, 20 mmol of ethylene, and 22 mmol of hydrogen peroxide (30% aqueous solution by mass) were successively added to the high-pressure resistant reaction kettle. Then, the reaction was stirred at 40 °C for 2 hours. The reaction kettle was taken out and cooled with an ice-water bath, and the solid catalyst was removed by centrifugation to obtain the liquid-phase product, which was ethylene oxide.

[0053] The liquid-phase product was analyzed by gas chromatography (Shimadzu 2014, FID detector). The conversion rate of ethylene was 90.3%, and the selectivity of the target product ethylene oxide (EO) was 99.7%. For the comparison of the performance of the organic-inorganic composite titanium silicate material prepared in Example 2 and the TS-1 and Ti-MWW titanium silicate molecular sieves in the epoxidation of ethylene, see Table 3 below.

[0054] Table 3. Comparison of the epoxidation performance of inorganic-organic composite titanium silicate, TS-1 and Ti-MWW inorganic titanium silicate molecular sieves

[0055] Conversion rate of ethylene (%) Selectivity of ethylene oxide EO (%) Example 4 90.3 99.7 Comparative Example 2 53.6 95.8 Comparative Example 3 30.5 92.3

[0056] For the TS-1 catalyst used in Comparative Example 2, its Si / Ti molar ratio was 38.6; for the Ti-MWW catalyst used in Comparative Example 3, its Si / Ti molar ratio was 40. The conditions for the ethylene epoxidation reaction were the same as those in Example 4, and the product was analyzed by gas chromatography. The measured data proved that the catalytic activity of the inorganic-organic composite titanium silicate used in Example 4 for the liquid-phase epoxidation reaction of ethylene and hydrogen peroxide was much higher than that of the two inorganic titanium silicate molecular sieve catalysts, namely TS-1 used in Comparative Example 2 and Ti-MWW used in Comparative Example 3.

[0057] Example 5

[0058] The catalyst prepared in Example 2 was applied to the liquid-phase epoxidation reaction of propylene and hydrogen peroxide in a closed high-pressure resistant reactor. The main operation steps were as follows: 10 mL of solvents (the solvents were acetonitrile, methanol, and water respectively), 0.1 g of catalyst, 30 mmol of propylene, and 28 mmol of hydrogen peroxide (30% aqueous solution by mass) were successively added to the high-pressure resistant reactor. Then, the reaction was stirred at 40 °C for 1 hour. The reactor was taken out and cooled in an ice-water bath, and the solid catalyst was removed by centrifugation to obtain the liquid-phase product of propylene oxide.

[0059] The liquid-phase product was analyzed by gas chromatography (Shimadzu 2014, FID detection) to obtain the propylene conversion rate and the selectivity of the target product propylene oxide (PO). The performance comparison of the organic-inorganic composite titanium silicate material prepared in Example 2 with the TS-1 in Comparative Example 4 and the Ti-MWW titanium silicate molecular sieve in Comparative Example 5 for the propylene epoxidation reaction in three different solvents, namely acetonitrile, methanol, and water, is shown in Table 4 below in detail.

[0060] Table 4. Performance comparison of the catalytic propylene epoxidation of the inorganic-organic composite titanium silicate with the TS-1 and Ti-MWW inorganic titanium silicate molecular sieves

[0061]

[0062] For the TS-1 catalyst used in Comparative Example 4, its Si / Ti molar ratio was 38.6; for the Ti-MWW catalyst used in Comparative Example 5, its Si / Ti molar ratio was 40. The conditions for the propylene epoxidation reaction were the same as those in Example 6, and the product was analyzed by gas chromatography. The measured data proved that the catalytic activity of the inorganic-organic composite titanium silicate used in Example 5 for the liquid-phase epoxidation reaction of propylene and hydrogen peroxide was better than that of the two pure inorganic titanium silicate molecular sieve catalysts, namely TS-1 used in Comparative Example 4 and Ti-MWW used in Comparative Example 5.

[0063] Example 6

[0064] The catalyst prepared in Example 2 was applied to the liquid-phase epoxidation reaction of allyl chloride and hydrogen peroxide, which was carried out in a closed high-pressure resistant reactor. The main operation steps were as follows: 10 mL of solvent (methanol, water or tert-butanol), 0.2 g of catalyst, 10 mmol of allyl chloride and 10 mmol of hydrogen peroxide (30% aqueous solution by mass) were successively added into the high-pressure resistant reactor. Then, the reaction was stirred at 60 °C for 2 hours. The reactor was taken out and cooled with an ice-water bath, and the solid catalyst was removed by centrifugation to obtain the liquid-phase product of epichlorohydrin.

[0065] The liquid-phase product was analyzed by gas chromatography (Shimadzu 2014, FID detector) to obtain the conversion rate of allyl chloride and the selectivity of the target product epichlorohydrin (ECH). The performance comparison of the organic-inorganic composite titanium silicate material prepared in Example 2, the TS-1 in Comparative Example 6 and the Ti-MWW titanium silicalite in Comparative Example 7 in the catalytic epoxidation reaction of allyl chloride in different solvents is shown in Table 5 below.

[0066] Table 5. Performance comparison of inorganic-organic composite titanium silicate, TS-1 and Ti-MWW inorganic titanium silicalite in the catalytic epoxidation of allyl chloride

[0067]

[0068] The TS-1 catalyst used in Comparative Example 6 was provided by Zhejiang Taide New Materials Co., Ltd., and its Si / Ti molar ratio was 38.6; the Ti-MWW catalyst used in Comparative Example 7 was provided by Zhejiang Taide New Materials Co., Ltd., and its Si / Ti molar ratio was 40. The conditions used in the allyl chloride epoxidation reaction were the same as those in Example 6, and the products were analyzed by gas chromatography. The measured data proved that the catalytic activity of the inorganic-organic composite titanium silicate used in Example 6 in the liquid-phase epoxidation reaction of allyl chloride and hydrogen peroxide was superior to that of the two pure inorganic titanium silicalite catalysts, namely TS-1 in Comparative Example 6 and Ti-MWW in Comparative Example 7.

[0069] Example 7

[0070] The catalyst prepared in Example 2 was applied to the liquid-phase epoxidation reaction of 1-hexene and hydrogen peroxide, which was carried out in a closed high-pressure resistant reactor. The main operation steps were as follows: 10 mL of acetonitrile, 0.05 g of catalyst, 10 mmol of 1-hexene and 11 mmol of hydrogen peroxide (30% aqueous solution by mass) were successively added into the high-pressure resistant reactor. Then, the reaction was stirred at 65 °C for 2 hours. The reactor was taken out and cooled with an ice-water bath, and the solid catalyst was removed by centrifugation to obtain the liquid-phase product of epoxyhexane.

[0071] The liquid-phase product was analyzed by gas chromatography (Shimadzu 2014, FID detector) to obtain the conversion rate of 1-hexene and the selectivity of the target product cyclohexene oxide. The performance comparison of the organic-inorganic composite titanium silicate material prepared in Example 2, the TS-1 in Comparative Example 8, and the Ti-MWW titanium silicate molecular sieve in Comparative Example 9 for the epoxidation reaction of 1-hexene in different solvents is shown in Table 6 below.

[0072] Table 6. Performance comparison of inorganic-organic composite titanium silicate, TS-1, and Ti-MWW titanium silicate molecular sieves for the epoxidation of 1-hexene

[0073] Solvent Conversion rate of 1-hexene (%) Selectivity of cyclohexene oxide (%) Example 7 Acetonitrile 76.5 99.8 Comparative Example 8 Acetonitrile 15.3 98.3 Comparative Example 9 Acetonitrile 53.2 99.2

[0074] For the TS-1 catalyst used in Comparative Example 8, the Si / Ti molar ratio was 38.6; for the Ti-MWW catalyst used in Comparative Example 9, the Si / Ti molar ratio was 40. The conditions used for the epoxidation reaction of 1-hexene were the same as those in Example 8, and the product was analyzed by gas chromatography. The measured data demonstrated that the catalytic activity of the organic-inorganic composite titanium silicate used in Example 7 for the liquid-phase epoxidation reaction of 1-hexene and hydrogen peroxide was superior to that of the two pure inorganic titanium silicate molecular sieve catalysts, namely TS-1 in Comparative Example 8 and Ti-MWW in Comparative Example 9.

[0075] Example 8

[0076] The catalyst prepared in Example 2 was applied to the liquid-phase epoxidation reaction of cyclohexene and hydrogen peroxide in a closed high-pressure resistant reaction kettle. The main operation steps were as follows: 10 mL of acetonitrile, 0.05 g of the catalyst, 11 mmol of cyclohexene, and 12 mmol of hydrogen peroxide (30% aqueous solution by mass) were successively added to the high-pressure resistant reaction kettle. Then, the reaction was stirred at 70 °C for 2 hours. The reaction kettle was taken out and cooled with an ice-water bath, and the solid catalyst was removed by centrifugation to obtain the liquid-phase product cyclohexene oxide.

[0077] The liquid-phase product was analyzed by gas chromatography (Shimadzu 2014, FID detector) to obtain the conversion rate of cyclohexene and the selectivity of the target product cyclohexene oxide. The performance comparison of the organic-inorganic composite titanium silicate material prepared in Example 2, the TS-1 in Comparative Example 10, and the Ti-MWW titanium silicate molecular sieve in Comparative Example 11 for the epoxidation reaction of cyclohexene in different solvents is shown in Table 7.

[0078] Table 7. Performance comparison of inorganic-organic composite titanium silicate, TS-1, and Ti-MWW titanium silicate molecular sieves for the epoxidation of cyclohexene

[0079] Solvent Conversion rate of cyclohexene (%) Selectivity of cyclohexene oxide (%) Example 8 Acetonitrile 45.5 93.5 Comparative Example 10 Acetonitrile 2.3 81.3 Comparative Example 11 Acetonitrile 8.3 86.5

[0080] For the TS-1 catalyst used in Comparative Example 10, the Si / Ti molar ratio was 38.6; for the Ti-MWW catalyst used in Comparative Example 11, the Si / Ti molar ratio was 40. The conditions for the epoxidation reaction of cyclohexene were the same as those in Example 8, and the products were analyzed by gas chromatography. The measured data proved that the catalytic activity of the organic-inorganic composite titanium silicate used in Example 8 for the liquid-phase epoxidation reaction of cyclohexene and hydrogen peroxide was superior to that of the two pure inorganic titanium silicate molecular sieve catalysts, namely TS-1 in Comparative Example 10 and Ti-MWW in Comparative Example 11.

[0081] Example 9

[0082] The catalyst prepared in Example 2 was applied to the liquid-phase epoxidation reaction of propylene and cumene hydroperoxide in a closed high-pressure resistant reactor. The main operating steps were as follows: 10 mL of cumene, 0.03 g of the catalyst, 7.6 g of propylene, and 10 mmol of cumene hydroperoxide (cumene solution with a mass fraction of 70%) were successively added to the high-pressure resistant reactor. Then, the reaction was stirred at 80 °C for 1 hour. The reactor was taken out and cooled in an ice-water bath, and the solid catalyst was removed by centrifugation to obtain the liquid-phase product, propylene oxide.

[0083] The liquid-phase product was analyzed by gas chromatography (Shimadzu 2014, FID detector) to obtain the yield and selectivity of the target product, propylene oxide (PO). The performance comparison of the organic-inorganic composite titanium silicate material prepared in Example 2 and the Ti-MWW titanium silicate molecular sieve in Comparative Example 13 for the propylene epoxidation reaction is shown in Table 8 below.

[0084] Table 8. Performance comparison of the catalytic propylene epoxidation of the inorganic-organic composite titanium silicate and the Ti-MWW inorganic titanium silicate molecular sieve

[0085] Yield of propylene oxide PO (%) Selectivity of propylene oxide PO (%) Example 9 65.3 99.8 Comparative Example 12 12.3 99.6

[0086] For the Ti-MWW catalyst used in Comparative Example 12, the Si / Ti molar ratio was 40. The conditions for the propylene epoxidation reaction were the same as those in Example 9, and the products were analyzed by gas chromatography. The measured data proved that the catalytic activity of the inorganic-organic composite titanium silicate used in Example 9 for the liquid-phase epoxidation reaction of propylene and cumene hydroperoxide was superior to that of the Ti-MWW inorganic titanium silicate molecular sieve catalyst in Comparative Example 12.

[0087] Example 10

[0088] The catalyst prepared in Example 2 was applied to the liquid-phase epoxidation reaction of propylene with tert-butyl hydroperoxide, which was carried out in a closed high-pressure resistant reactor. The main operation steps were as follows: 10 mL of acetonitrile, 0.1 g of the catalyst, 11 g of propylene, and 10 mmol of tert-butyl hydroperoxide (70% aqueous solution by mass) were successively added to the high-pressure resistant reactor. Then, the reaction was stirred at 100 °C for 2 hours. The reactor was taken out and cooled in an ice-water bath, and the solid catalyst was removed by centrifugation to obtain the liquid-phase product of propylene oxide.

[0089] The liquid-phase product was analyzed by gas chromatography (Shimadzu 2014, FID detector) to obtain the yield and selectivity of the target product propylene oxide (PO). The performance comparison of the organic-inorganic composite titanium silicate material prepared in Example 2 and the Ti-MWW titanium silicalite catalyst in Example 14 for the epoxidation reaction of propylene is shown in Table 9 below.

[0090] Table 9 Performance comparison of the catalytic epoxidation of propylene by inorganic-organic composite titanium silicate and Ti-MWW inorganic titanium silicalite

[0091] Yield of propylene oxide PO (%) Selectivity of propylene oxide PO (%) Example 10 85.3 99.3 Comparative Example 13 34.1 98.6

[0092] For the Ti-MWW catalyst used in Comparative Example 13, its Si / Ti molar ratio was 40. The conditions used for the epoxidation reaction of propylene were the same as those in Example 10, and the product was analyzed by gas chromatography. The measured data proved that the catalytic activity of the inorganic-organic composite titanium silicate used in Example 10 for the liquid-phase epoxidation reaction of propylene and tert-butyl hydroperoxide was superior to that of the Ti-MWW inorganic titanium silicalite catalyst in Comparative Example 13.

[0093] The above examples are only for further illustration of the present invention and are not intended to limit this patent. All equivalent implementations of the present invention should be included within the scope of the claims of this patent.

Claims

1. An inorganic-organic composite metal silicate catalyst, characterized in that: The metal silicate catalyst is composed of silicon oxide, metal oxide and organic amine, and its chemical formula is: xMO n / 2 · y R·1.0 SiO2, wherein M is one or more metals selected from aluminum, iron, titanium and tin; n is the valence state of the metal M, which is +3 or +4; x is the molar ratio of the metal M to Si, which is in the range of 0.005 to 0.1; R is a cyclic organic amine having 5 to 7 ring members; y is the molar ratio of the cyclic organic amine to Si, which is in the range of 0.01 to 0.2; the metal silicate catalytic material has X-ray diffraction data with diffraction peaks shown in Table 1 below, Cu-Kα, λ=1.5406 Å: Table 1. X-ray diffraction data of inorganic-organic composite metal silicate materials ； In the table: (a) is the relative intensity level of the diffraction peak in the powder X-ray diffraction spectrum; W is the weak diffraction peak; M is the medium diffraction peak; S is the strong diffraction peak; VS is the strongest diffraction peak.

2. A method for preparing the inorganic-organic composite metal silicate catalyst according to claim 1, characterized in that: The preparation of the metal silicate catalyst specifically comprises the following steps: Step 1: SiO2 and MO n / 2 The total molar amount of zeolite molecular sieve, organic amine and deionized water are mixed in a molar ratio of 1.0: 0.05-1.5: 5-50, and stirred at room temperature for 2-5 hours to obtain a uniformly mixed gel, wherein the zeolite molecular sieve has MFI, Beta, MWW and MOR topological structures, and its framework elements, in addition to silicon and oxygen, also contain one or more metals selected from aluminum, iron, titanium and tin; the organic amine is a cyclic organic amine with 5-7 ring members; Step 2: The gel prepared above is subjected to a hydrothermal reaction at a temperature of 120 to 170°C for 5 to 20 hours, the zeolite molecular sieve is filtered out and washed with deionized water until the pH is less than 7, and then dried at a temperature of 80 to 120°C for 5 to 10 hours to obtain an inorganic organic composite metal silicate agent.

3. An application of the inorganic-organic composite metal silicate catalyst according to claim 1, characterized in that: The metal silicate catalyst is used for a deacetalization-Krzfelter condensation coupling reaction and an olefin epoxidation reaction. The specific operation of the deacetalization-Krzfelter condensation coupling reaction is as follows: benzaldehyde dimethyl acetal is mixed with a catalyst, a solvent, water and malononitrile in a weight ratio of 1.0:0.01~0.4:5~10:0.00002~0.1:0.2~1.0, heated to a temperature of 60~80°C, reacted for 5~20 hours, cooled the reaction solution, filtered out the catalyst, and obtained a liquid product of benzylmalononitrile; the solvent is one or a mixture of two or more of acetonitrile, methanol, acetone and benzene; The specific operation of the olefin epoxidation reaction is: mixing a solvent, a catalyst, an oxidant and an olefin reactant, heating to 30-90°C, reacting for 0.5-4 hours, cooling the reaction solution, filtering out the catalyst, and obtaining a liquid product as an epoxide; the olefin / oxidant molar ratio is 0.5-28; the olefin / catalyst mass ratio is 2-400; the solvent / olefin mass ratio is 0.5-20; the solvent is one or a mixture of two or more of the protic solvents methanol, ethanol, tert-butyl alcohol, water, and the aprotic solvents acetone, acetonitrile, and cyclohexane; the oxidant is an aqueous solution or an organic solvent solution of hydrogen peroxide, tert-butyl hydroperoxide, ethylbenzene hydroperoxide and isopropylbenzene hydroperoxide; the olefin is one of a linear olefin with 2-6 carbon atoms and a cyclic olefin with 5-8 carbon atoms.

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