A titanium-silicon molecular sieve material, its preparation method and application

Abstract

This disclosure relates to a titanium-silicon molecular sieve material, its preparation method, and its application. The titanium-silicon molecular sieve has the following UV-Vis characteristics: the UV-Vis spectrum of the titanium-silicon molecular sieve has peaks at positions of 210±10 nm, 260±10 nm, and 330±10 nm, respectively; the peak area of ​​the peak at position 210±10 nm in the UV-Vis spectrum of the titanium-silicon molecular sieve is denoted as I. 210 Let the peak area of ​​the spectral peak at position 260±10nm be denoted as I. 260 Let the peak area at the position of 330±10nm be denoted as I. 330 , where I 260 >I 210 >I 330 It can effectively increase the active centers of titanium-silicon molecular sieves, improve the titanium content of the molecular sieve framework, and exhibit good catalytic performance.

Description

Technical Field

[0001] This application relates to the field of inorganic material preparation technology, specifically to a titanium-silicon molecular sieve material, its preparation method, and its application. Background Technology

[0002] Molecular sieves, due to their unique pore structure and active centers, exhibit high activity and product selectivity in many reactions. Inserting titanium into the molecular sieve framework opens up new pathways for activating hydrogen peroxide and catalyzing organic matter conversion under mild conditions. In particular, the discovery of TS-1 molecular sieve has laid the foundation for the development of new technologies for many hydrogen peroxide-involved oxidation reactions, such as propylene epoxidation, cyclohexanone ammoniation, phenol hydroxylation, and thioether oxidation.

[0003] Based on the different titanium atom distributions in TS-1, titanium species can be classified into tetracoordinate titanium species, pentacoordinate and hexacoordinate titanium species, anatase TiO2, and amorphous titanium species. Tetracoordinate framework titanium species, due to their superior catalytic oxidation performance, have become the most studied and widely recognized active species. A research paper (Chemical Engineering Journal 253(2014)464–471) points out that pentacoordinate and hexacoordinate titanium species in titanium-silicon molecular sieves, like tetracoordinate framework titanium, possess strong catalytic oxidation performance, while anatase TiO2 will cause H2O2 to self-decompose, which is detrimental to the catalytic oxidation reaction of TS-1. However, there is an upper limit to the amount of tetracoordinate titanium in TS-1 (Si / Ti = 39). Therefore, improving the catalytic oxidation activity of titanium-silicon molecular sieves by increasing the content of tetracoordinate framework titanium and pentacoordinate and hexacoordinate titanium in TS-1 while minimizing the occurrence of anatase species will be the focus of research.

[0004] Titanium silicate molecular sieves are zeolite materials with an MFI-type framework structure, and their synthesis typically uses quaternary ammonium compounds as organic structure-directing agents. Specifically, for example, US3702886 relates to ZSM-5 and its synthetic method using tetrapropylammonium as a structure-directing agent. On the other hand, US4410501 relates to TS-1 zeolite and its synthetic method; regarding ZSM-5, it can be achieved using compounds containing tetrapropylammonium.

[0005] However, the titanium-silicon molecular sieves prepared by existing processes still have problems such as insufficient active centers and low titanium content in the framework, which prevents them from achieving ideal results in catalytic oxidation reactions. Summary of the Invention

[0006] The purpose of this disclosure is to provide a titanium-silicon molecular sieve material, its preparation method, and its application, which can effectively increase the active centers of the titanium-silicon molecular sieve, improve the titanium content of the molecular sieve framework, and have good catalytic performance.

[0007] To achieve the above objectives, the first aspect of this disclosure provides a titanium-silicon molecular sieve, which has the following UV-Vis characteristics:

[0008] The UV-Vis spectrum of the titanium-silicon molecular sieve exhibits peaks at positions of 210±10 nm, 260±10 nm, and 330±10 nm, respectively; the peak area of ​​the peak at position 210±10 nm in the UV-Vis spectrum of the titanium-silicon molecular sieve is denoted as I. 210 Let I denote the peak area of ​​the spectral peak at position 260±10nm. 260 Let the peak area at the position of 330±10nm be denoted as I. 330 , where I 260 >I 210 >I 330 .

[0009] Optionally, X1, as defined in equation (1), can be any value within the range of 1.1 to 2.0:

[0010] X1 = I 260 / I 210 Equation (1);

[0011] Optionally, X2, as defined in equation (2), can be any value within the range of 1.6 to 3.3:

[0012] X2 = I 210 / I 330 Equation (2);

[0013] Optionally, X3, as defined in equation (3) below, can be any value within the range of 2.7 to 3.8:

[0014] X2 = I 260 / I 330 Equation (3);

[0015] Preferably, X1 is any value in the range of 1.3 to 1.6, X2 is any value in the range of 2.0 to 2.8, and X3 is any value in the range of 2.9 to 3.5.

[0016] Optionally, the molar ratio of silicon to titanium in the titanium-silicon molecular sieve is 1:10 to 100, preferably 1:16 to 34;

[0017] Preferably, the titanium-silicon molecular sieve contains at least one cavity structure within its crystals; preferably, the size of a single cavity structure is 15 nm to 40 nm; more preferably, the total volume of the cavity structure accounts for 20% to 80% of the total volume of the titanium-silicon molecular sieve, and more preferably 50% to 70%.

[0018] Optionally, the average particle size of the titanium-silicon molecular sieve particles is 250 nm to 400 nm, preferably 310 nm to 380 nm; the BET specific surface area is 440 m². 2 / g~450m 2 / g, preferably 443m 2 / g~447m 2 / g; micropore volume is 0.16cm³ 3 / g~0.20cm 3 / g, preferably 0.17cm 3 / g~0.19cm 3 / g; mesopore volume is 0.08cm³ 3 / g~0.14cm 3 / g, preferably 0.10cm 3 / g~0.12cm 3 / g;

[0019] Optionally, the relative crystallinity of the titanium-silicon molecular sieve is 80% or more, preferably 82% or more;

[0020] Preferably, a hysteresis loop exists between the adsorption isotherm and desorption isotherm of the low-temperature nitrogen adsorption of the titanium-silicon molecular sieve; preferably, the initial relative pressure (P / P0) at which the hysteresis loop appears is 0.4 to 0.5.

[0021] A second aspect of this disclosure provides a method for preparing titanium-silicon molecular sieves, comprising the following steps:

[0022] S1. Mix silicon source, titanium source, first template agent and water, and perform first hydrothermal treatment to obtain molecular sieve intermediate product;

[0023] S2. Mix the molecular sieve intermediate product, the second template agent, and water, and perform a second hydrothermal treatment.

[0024] The first template agent is selected from one or more compounds having the structure shown in formula (M-1):

[0025] R1, R2, R3 and R4 are each independently selected from one of alkyl groups having 2 to 4 carbon atoms and alkenyl groups having 2 to 4 carbon atoms;

[0026] The second template agent is selected from one or more compounds having the structure shown in formula (M-2):

[0027] R5, R6, R7 and R8 are each independently selected from one of alkyl groups having 2 to 4 carbon atoms and alkenyl groups having 2 to 4 carbon atoms; and at least one alkenyl group is present in R5, R6, R7 and R8.

[0028] Optionally, in the formula (M-1) of the first template agent, R1, R2, R3 and R4 are each independently selected from one of an alkyl group having 3 carbon atoms and an alkenyl group having 3 carbon atoms;

[0029] In the second template agent of formula (M-2), R5, R6, R7 and R8 are each independently selected from one of an alkyl group having 3 carbon atoms and an alkenyl group having 3 carbon atoms;

[0030] Preferably, the first template agent is selected from one or more of tetrapropylammonium hydroxide, allyl tripropylammonium hydroxide, propenyl tripropylammonium hydroxide, diallyl dipropylammonium hydroxide, diallyl dipropylammonium hydroxide, allyl propenyl dipropylammonium hydroxide, diallyl propenyl propylammonium hydroxide, diallyl allyl propylammonium hydroxide, triallyl propylammonium hydroxide, triallyl propylammonium hydroxide, tetraallyl ammonium hydroxide, and tetraallyl ammonium hydroxide; more preferably, it is selected from one or more of tetrapropylammonium hydroxide, allyl tripropylammonium hydroxide, propenyl tripropylammonium hydroxide, allyl propenyl dipropylammonium hydroxide, triallyl propylammonium hydroxide, and tetraallyl ammonium hydroxide; and even more preferably, it is selected from one or more of tetrapropylammonium hydroxide, allyl tripropylammonium hydroxide, and propenyl tripropylammonium hydroxide.

[0031] The second template agent is selected from one or more of allyl tripropylammonium hydroxide, propenyl tripropylammonium hydroxide, diallyl dipropylammonium hydroxide, diallyl dipropylammonium hydroxide, allyl propenyl dipropylammonium hydroxide, diallyl propenyl propylammonium hydroxide, diallyl allyl propylammonium hydroxide, triallyl propylammonium hydroxide, triallyl propylammonium hydroxide, tetraallyl ammonium hydroxide, and tetraallyl ammonium hydroxide; preferably selected from allyl tripropylammonium hydroxide, propenyl tripropylammonium hydroxide, allyl propenyl dipropylammonium hydroxide, triallyl propylammonium hydroxide, and tetraallyl ammonium hydroxide; more preferably selected from one or more of allyl tripropylammonium hydroxide, propenyl tripropylammonium hydroxide, allyl propenyl dipropylammonium hydroxide, triallyl propylammonium hydroxide, and tetraallyl ammonium hydroxide; and more preferably selected from one or more of allyl tripropylammonium hydroxide and propenyl tripropylammonium hydroxide.

[0032] Optionally, in step S1, the silicon source is selected from at least one of silicone grease, solid silica gel, fumed silica, and silica sol; preferably, it is selected from at least one of silicone grease, solid silica gel, and fumed silica.

[0033] Optionally, the silicone grease is selected from one or more compounds with the structure shown in formula (A):

[0034]

[0035] R a R b R c and R d Each is independently selected from alkyl groups having 1 to 4 carbon atoms, wherein the alkyl group is branched or straight-chain alkyl; preferably, the R a R b R c and R d Each of the following is independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, or tert-butyl; more preferably, the organosilicon is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, and dimethyl diethyl silyl ester; even more preferably, it is selected from one or more of tetramethyl silicate, tetraethyl silicate, and dimethyl diethyl silyl ester.

[0036] Optionally, the titanium source is selected from one or more of organic titanium sources and inorganic titanium sources;

[0037] Preferably, the organic titanium source is a titanium-containing organic ester, selected from at least one structure of the following formula (B):

[0038]

[0039] Where R e R f R g and R h Each is selected from alkyl groups having 1 to 6 carbon atoms, preferably straight-chain alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms, and more preferably R. e R f R g and R h Each is selected from straight-chain alkyl groups having 2 to 4 carbon atoms and branched alkyl groups having 2 to 4 carbon atoms; optionally, R e R f R g and R h Each of the following is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, isopentyl, hexyl, or isohexyl; preferably, each of the following is independently selected from ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, or tert-butyl.

[0040] Preferably, the inorganic titanium source is selected from one or more of titanium chloride, nitrate or sulfate;

[0041] More preferably, the titanium source is selected from one or more of titanium tetrachloride, titanium sulfate, titanium nitrate, tetraethyl titanate, tetrapropyl titanate, and tetrabutyl titanate.

[0042] Optionally, in step S1, the molar ratio of silicon source (as SiO2): titanium source (as TiO2): first template agent: water is 1:(0.01~0.10):(0.05~0.30):(15~30), preferably 1:(0.03~0.06):(0.10~0.25):(18~25).

[0043] Optionally, in step S1, the conditions for the first hydrothermal treatment include: a hydrothermal temperature of 150℃~200℃, a hydrothermal time of 2h~100h, and a hydrothermal crystallization pressure of autogenous pressure; preferably, the hydrothermal temperature is 160℃~190℃, and the hydrothermal crystallization time is 4h~80h; more preferably, the hydrothermal temperature is 165℃~188℃, and the hydrothermal crystallization time is 5h~40h.

[0044] Optionally, before performing the first hydrothermal treatment, the method further includes: performing a hydrolysis and alcohol removal treatment on the raw material mixture obtained by mixing the silicon source, titanium source, first template agent and water; optionally, the conditions for the hydrolysis and alcohol removal treatment include: treatment at 5℃ to 120℃ for 0.5h to 48h; preferably treatment at 50℃ to 100℃ for 1h to 24h.

[0045] Optionally, the method further includes:

[0046] The solid product obtained from the hydrothermal treatment in step S1 is dried and calcined to obtain the first intermediate product.

[0047] Preferably, the method further includes: contacting the first intermediate product with a peroxide for mixing treatment to obtain the molecular sieve intermediate product.

[0048] Optionally, the peroxide is selected from one or more of inorganic peroxides and organic peroxides; optionally, the inorganic peroxide is selected from one or more of hydrogen peroxide, potassium peroxide, and sodium peroxide; the organic peroxide is selected from one or more of tert-butyl peroxide, cumene hydroperoxide, and m-chloroperoxybenzoic acid.

[0049] Optionally, the peroxide is used in solution form, wherein the solvent of the peroxide solution is selected from one or more of water, alcohols having 1 to 10 carbon atoms, esters having 2 to 10 carbon atoms, and ketones having 3 to 10 carbon atoms. Preferably, the solvent is selected from one or more of water, n-butanol, tert-butanol, ethanol, methanol, and cyclohexanol.

[0050] The peroxide concentration in the solution is 0.1% to 10% by weight, preferably 0.3% to 7% by weight; the pH value is 2.0 to 6.5, preferably 3.0 to 6.0, more preferably 3.7 to 5.0; the weight ratio of the peroxide solution to the first intermediate product is (0.5 to 50):1, preferably (1 to 40):1, more preferably (1.5 to 25):1.

[0051] Optionally, the calcination conditions include: a calcination temperature of 350℃ to 650℃ and a calcination time of 2h to 10h; preferably, the calcination temperature is 450℃ to 600℃ and the calcination time is 4h to 8h.

[0052] The conditions for mixing the second intermediate product with the peroxide include: a treatment temperature of 25°C to 100°C, preferably 50°C to 95°C, more preferably 75°C to 85°C; a treatment time of 5 min to 1440 min, preferably 60 min to 1200 min, more preferably 75 min to 1000 min; and a pressure of 0 MPa to 5 MPa, preferably 0.2 MPa to 2.0 MPa.

[0053] Optionally, in step S2, the weight ratio of the molecular sieve intermediate product: the second template agent: water is 1:(0.05-0.50):(1-10), preferably 1:(0.15-0.45):(2-6);

[0054] Optionally, the conditions for the second hydrothermal treatment include: a temperature of 150℃ to 200℃, a time of 2 hours to 72 hours, and an autogenous pressure; preferably, the temperature is 160℃ to 180℃, and the time is 12 hours to 48 hours.

[0055] The third aspect of this disclosure provides a titanium-silicon molecular sieve prepared according to the method described in the second aspect of this disclosure.

[0056] This fourth aspect of the disclosure provides the application of the titanium-silicon molecular sieves described in the first and third aspects of the disclosure in catalyzing organic reactions.

[0057] Optionally, the catalytic organic reaction includes propylene epoxidation to prepare propylene oxide, chloropropene catalytic chlorohydrination to prepare dichloropropanol, and cyclohexanone oximation to prepare cyclohexanone oxime; optionally, the cyclohexanone oximation to prepare cyclohexanone oxime includes the following steps:

[0058] Under oxime reaction conditions, cyclohexanone, an oxidant, ammonia, and a catalyst are brought into contact to carry out an oxidation reaction; the catalyst comprises the titanium-silicon molecular sieve.

[0059] Optionally, the oxidant is selected from one or more of hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, and m-chloroperoxybenzoic acid; preferably, the reaction is carried out in the presence of a solvent; the solvent is selected from one or more of n-butanol, tert-butanol, ethanol, methanol, and cyclohexanol;

[0060] Preferably, the oxime reaction conditions include: a molar ratio of oxidant to cyclohexanone of 1.2–2.0:1, a molar ratio of solvent to cyclohexanone of 0.5–5:1, a molar ratio of ammonia to cyclohexanone of 1.0–3.0:1, a weight ratio of catalyst to cyclohexanone of 0.05–0.2:1; a reaction temperature of 60–90°C, and a reaction time of 0.3–1.0 h.

[0061] Through the above technical solution, this disclosure provides a titanium-silicon molecular sieve material, its preparation method and application. The signal peak area at 260±10nm in the UV-Vis spectrum of this titanium-silicon molecular sieve is higher than that at other positions (210±10nm and 330±10nm). The titanium-silicon molecular sieve provided by this disclosure contains a higher content of multi-coordinated Ti species. This titanium-silicon molecular sieve has good effect in catalytic oxidation reaction. When used for the amination of cyclohexanone to prepare cyclohexanone oxime, it has high catalytic activity, high raw material conversion rate and high cyclohexanone oxime selectivity.

[0062] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0063] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0064] Figure 1 This is the UV-Vis spectrum of the titanium-silicon molecular sieve prepared in Example 1;

[0065] Figure 2(a) is a nitrogen adsorption-desorption curve of the titanium-silicon molecular sieve prepared in Example 1;

[0066] Figure 2(b) is a pore distribution diagram of the titanium-silicon molecular sieve prepared in Example 1;

[0067] Figure 3 This is a TEM image of the titanium-silicon molecular sieve prepared in Example 1;

[0068] Figure 4 This is the XRD pattern of the titanium-silicon molecular sieve prepared in Example 1. Detailed Implementation

[0069] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure.

[0070] The first aspect of this disclosure provides a titanium-silicon molecular sieve, which has the following UV-Vis characteristics:

[0071] The UV-Vis spectrum of the titanium-silicon molecular sieve exhibits peaks at positions of 210±10 nm, 260±10 nm, and 330±10 nm, respectively; the peak area of ​​the peak at position 210±10 nm in the UV-Vis spectrum of the titanium-silicon molecular sieve is denoted as I. 210 Let I denote the peak area of ​​the spectral peak at position 260±10nm. 260 Let the peak area at the position of 330±10nm be denoted as I. 330 , where I 260 >I 210 >I 330 .

[0072] This disclosure provides a titanium-silicon molecular sieve. In this disclosure, the spectral peak at 210±10 nm in the UV-Vis spectrum represents the framework four-coordinate titanium species, the spectral peak at 260±10 nm represents the isolated six-coordinate titanium species, and the spectral peak at 330±10 nm represents anatase. The peak area of ​​the signal peak at 260±10 nm in the UV-Vis spectrum of this titanium-silicon molecular sieve is higher than that of the signal peaks at other positions (210±10 nm and 330±10 nm), indicating that the titanium-silicon molecular sieve provided in this disclosure contains a higher content of multi-coordinate Ti species. This titanium-silicon molecular sieve has good performance in catalytic oxidation reactions. When used for the amination of cyclohexanone to prepare cyclohexanone oxime, it has high catalytic activity, high feed conversion rate, and high selectivity for cyclohexanone oxime.

[0073] Through experimental research, the inventors of this disclosure discovered that there is a certain proportional relationship between the peak area of ​​the spectral peak at position 260±10nm and the peak area of ​​the spectral peak at position 210±10nm in the UV-Vis spectrum of the titanium-silicon molecular sieve, and the catalytic effect of the titanium-silicon molecular sieve is better within this proportional range.

[0074] In one implementation, X1, as defined in equation (1), is any value within the range of 1.4 to 2.0:

[0075] X1 = I 260 / I 210 Equation (1);

[0076] Optionally, X2, as defined in equation (2), can be any value within the range of 1.6 to 3.3:

[0077] X2 = I210 / I 330 Equation (2);

[0078] Optionally, X3, as defined in equation (3) below, can be any value within the range of 2.7 to 3.8:

[0079] X2 = I 260 / I 330 Equation (3).

[0080] In a preferred embodiment, X1 is any value within the range of 1.3 to 1.6, X2 is any value within the range of 2.0 to 2.8, and X3 is any value within the range of 2.9 to 3.5. When X1, X2, and X3 of the titanium-silicon molecular sieve are within the range of this embodiment, the titanium-silicon molecular sieve exhibits better catalytic performance in catalytic oxidation reactions.

[0081] In one specific embodiment, the molar ratio of silicon to titanium is 1:10 to 100, preferably 1:16 to 34.

[0082] In a preferred embodiment, the titanium-silicon molecular sieve crystal contains at least one cavity structure; preferably, the size of a single cavity structure is 15 nm to 40 nm. The titanium-silicon molecular sieve crystal provided in this disclosure has one or more cavity structures, which is beneficial for improving the diffusion performance of the molecular sieve, accelerating the reaction rate, and extending the catalyst lifetime. In this disclosure, the cavity structure and its size are obtained through transmission electron microscopy (TEM). In this disclosure, the size of the cavity structure refers to the length between two positions on the cavity wall passing through the center of the cavity structure in the TEM image of the molecular sieve; for example, "the size of a single cavity structure is 15 nm to 40 nm" means that the length between two positions on the cavity wall passing through the center of any cavity structure in the molecular sieve is within the range of 15 nm to 40 nm.

[0083] In one embodiment, the total volume of the cavity structure accounts for 30% to 80% of the total volume of the titanium-silicon molecular sieve, preferably 50% to 70%.

[0084] In one specific embodiment, the titanium-silicon molecular sieve comprises molecular sieve particles composed of multiple aggregates of crystals with approximately right-angled sides, and the molecular sieve particles have a right-angled side morphology; the right-angled side angle ranges from 90° to 10°.

[0085] In one embodiment, the average particle size of the titanium-silicon molecular sieve particles is 250 nm to 400 nm, preferably 310 nm to 380 nm; the BET specific surface area is 440 m². 2 / g~450m 2 / g, preferably 443m 2 / g~447m 2 / g; micropore volume is 0.16cm³ 3 / g~0.20cm 3 / g, preferably 0.17cm 3 / g~0.19cm 3 / g; mesopore volume is 0.08cm³ 3 / g~0.14cm 3 / g, preferably 0.10cm 3 / g~0.12cm 3 / g.

[0086] In a preferred embodiment, a hysteresis loop exists between the adsorption isotherm and desorption isotherm of the low-temperature nitrogen adsorption of the titanium-silicon molecular sieve; preferably, the initial relative pressure (P / P0) at which the hysteresis loop appears is 0.4 to 0.5, more preferably 0.42 to 0.48.

[0087] In one specific embodiment, the relative crystallinity of the titanium-silicon molecular sieve is 80% or higher, preferably 82% or higher. For example, using XRD to characterize an MFI structure, with MFI-type all-silicon molecular sieve S-1 as a reference sample, its relative crystallinity is greater than 80%, preferably greater than 82%. The titanium-silicon molecular sieve provided in this disclosure has a high relative crystallinity.

[0088] In one specific embodiment, the titanium-silicon molecular sieve may have a two-dimensional hexagonal phase structure with AEL, AFI, AFN, BEC, CFI, CHA, CON, EUO, FAU, FER, IMF, LTA, MER, MFI, MEL, MOR, MWW, RHO, TON, *BEA, *EWT, and preferably an MFI structure.

[0089] In one specific embodiment, the titanium-silicon molecular sieve provided in this disclosure can be used as the catalytically active component, utilizing its unique framework elements, or it can be used as a support to further load active centers, or it can be prepared by mechanical mixing, kneading, pressing, extrusion, spray molding, spheroidizing, oil column molding, or other methods with other catalysts, co-catalysts, structural additives, electronic additives, binders, inert supports, etc. The reagents and preparation processes used can all be conventional reagents or processes in the art.

[0090] The second aspect of this disclosure provides a method for preparing titanium-silicon molecular sieves, comprising the following steps:

[0091] S1. Mix silicon source, titanium source, first template agent and water, and perform first hydrothermal treatment to obtain molecular sieve intermediate product;

[0092] S2. Mix the molecular sieve intermediate product, the second template agent, and water, and perform a second hydrothermal treatment.

[0093] The first template agent is selected from one or more compounds having the structure shown in formula (M-1):

[0094] R1, R2, R3 and R4 are each independently selected from one of alkyl groups having 2 to 4 carbon atoms and alkenyl groups having 2 to 4 carbon atoms;

[0095] The second template agent is selected from one or more compounds having the structure shown in formula (M-2):

[0096] R5, R6, R7 and R8 are each independently selected from one of alkyl groups having 2 to 4 carbon atoms and alkenyl groups having 2 to 4 carbon atoms; and at least one alkenyl group is present in R5, R6, R7 and R8.

[0097] This disclosure provides a method for preparing titanium-silicon molecular sieves, using an organic ammonium hydroxide compound having the above formulas (M-1) and (M-2) as a first template agent and a second template agent, wherein the first template agent and the second template agent contain alkenyl groups, especially the second template agent contains at least one alkenyl group, which can interact with titanium species to promote titanium insertion into the framework, thereby preparing a molecular sieve with a high content of isolated six-coordinated titanium species.

[0098] In one embodiment, in the formula (M-1) of the first template agent, R1, R2, R3 and R4 are each independently selected from one of an alkyl group having 3 carbon atoms and an alkenyl group having 3 carbon atoms;

[0099] In the second template agent of formula (M-2), R5, R6, R7 and R8 are each independently selected from one of an alkyl group having 3 carbon atoms and an alkenyl group having 3 carbon atoms.

[0100] In one specific embodiment, the first template agent is selected from one or more of tetrapropylammonium hydroxide, allyl tripropylammonium hydroxide, propenyl tripropylammonium hydroxide, diallyl dipropylammonium hydroxide, diallyl dipropylammonium hydroxide, allyl propenyl dipropylammonium hydroxide, diallyl propenyl propylammonium hydroxide, diallyl allyl propylammonium hydroxide, triallyl propylammonium hydroxide, triallyl propylammonium hydroxide, tetraallyl ammonium hydroxide, and tetraallyl ammonium hydroxide; preferably selected from one or more of tetrapropylammonium hydroxide, allyl tripropylammonium hydroxide, propenyl tripropylammonium hydroxide, allyl propenyl dipropylammonium hydroxide, triallyl propylammonium hydroxide, and tetraallyl ammonium hydroxide; more preferably selected from one or more of tetrapropylammonium hydroxide, allyl tripropylammonium hydroxide, and propenyl tripropylammonium hydroxide.

[0101] The second template agent is selected from one or more of allyl tripropylammonium hydroxide, propenyl tripropylammonium hydroxide, diallyl dipropylammonium hydroxide, diallyl dipropylammonium hydroxide, allyl propenyl dipropylammonium hydroxide, diallyl propenyl propylammonium hydroxide, diallyl allyl propylammonium hydroxide, triallyl propylammonium hydroxide, triallyl propylammonium hydroxide, tetraallyl ammonium hydroxide, and tetraallyl ammonium hydroxide; preferably selected from allyl tripropylammonium hydroxide, propenyl tripropylammonium hydroxide, allyl propenyl dipropylammonium hydroxide, triallyl propylammonium hydroxide, and tetraallyl ammonium hydroxide; more preferably selected from one or more of allyl tripropylammonium hydroxide, propenyl tripropylammonium hydroxide, allyl propenyl dipropylammonium hydroxide, triallyl propylammonium hydroxide, and tetraallyl ammonium hydroxide; and more preferably selected from one or more of allyl tripropylammonium hydroxide and propenyl tripropylammonium hydroxide.

[0102] In one embodiment, the silicon source is selected from at least one of silicone grease, solid silica gel, fumed silica, and silica sol; preferably, it is selected from at least one of silicone grease, solid silica gel, and fumed silica. Preferably, the solid silicon source (solid silica gel, fumed silica, and silica sol) has a SiO2 content of not less than 99.99% by weight on a dry basis, and the total mass content of Fe, Al, and Na impurities is less than 10 ppm; for example, the SiO2 content is 99.99–100% by weight, typically greater than 99.99% and less than 100% by weight. The solid silicon source can be high-purity silica gel and / or fumed silica, preferably fumed silica; wherein the high-purity silica gel preferably has a SiO2 content greater than or equal to 99.99% by weight, for example, greater than 99.99% by weight and less than 100% by weight, and the total mass content of Fe, Al, and Na impurities is less than 10 ppm. Based on the dry weight of the silica, the SiO2 content in the silica is preferably greater than or equal to 99.99% by weight, for example, 99.99% to 100% by weight, for example, greater than 99.99% by weight and less than 100% by weight; the total mass content of Fe, Al, and Na impurities in the silica is less than 10 ppm on an atomic basis; and the specific surface area of ​​the silica is between 20 and 1000 m². 2 Between / g, preferably 50-400m 2 / g.

[0103] In a preferred embodiment, the silicone grease is selected from one or more compounds with the structure shown in formula (A):

[0104]

[0105] R a R b R cand R d Each is independently selected from alkyl groups having 1 to 4 carbon atoms, wherein the alkyl group is branched or straight-chain alkyl; preferably, the R a R b R c and R d Each of the following is independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, or tert-butyl; more preferably, the organosilicon grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, and dimethyl diethyl silyl ester; even more preferably, it is selected from one or more of tetramethyl silicate, tetraethyl silicate, and dimethyl diethyl silyl ester.

[0106] In one embodiment, the titanium source is selected from one or more of organic titanium sources and inorganic titanium sources;

[0107] Preferably, the organic titanium source is a titanium-containing organic ester, selected from at least one structure of the following formula (B):

[0108]

[0109] Where R e R f R g and R h Each is selected from alkyl groups having 1 to 6 carbon atoms, preferably straight-chain alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms, and more preferably R. e R f R g and R h Each is selected from straight-chain alkyl groups having 2 to 4 carbon atoms and branched alkyl groups having 2 to 4 carbon atoms; optionally, R e R f R g and R h Each of the following is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, isopentyl, hexyl, or isohexyl; preferably, each of the following is independently selected from ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, or tert-butyl.

[0110] Preferably, the inorganic titanium source is selected from one or more of titanium chloride, nitrate or sulfate;

[0111] More preferably, the titanium source is selected from one or more of titanium tetrachloride, titanium sulfate, titanium nitrate, tetraethyl titanate, tetrapropyl titanate, and tetrabutyl titanate.

[0112] In this disclosure, the silicon source, titanium source, first template agent, second template agent, and third template agent can be purchased through ordinary commercial channels or prepared by known methods.

[0113] In one embodiment, in step S1, the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water is 1:(0.01~0.10):(0.05~0.30):(15~30), preferably 1:(0.03~0.06):(0.10~0.25):(18~25). The titanium-silicon molecular sieve prepared according to the optimized raw material molar ratio in this embodiment can further improve the catalytic performance of the titanium-silicon molecular sieve.

[0114] In one embodiment, in step S1, the conditions for the first hydrothermal treatment include: a hydrothermal temperature of 150℃ to 200℃, a hydrothermal time of 2h to 100h, and a hydrothermal crystallization pressure of autogenous pressure; preferably, the hydrothermal temperature is 160℃ to 190℃, and the hydrothermal crystallization time is 4h to 80h; more preferably, the hydrothermal temperature is 165℃ to 188℃, and the hydrothermal crystallization time is 5h to 40h. The optimized hydrothermal crystallization treatment conditions according to this embodiment can further improve the catalytic performance of the molecular sieve.

[0115] In one specific embodiment, before performing the first hydrothermal treatment, the method further includes: performing a hydrolysis and alcohol removal treatment on the raw material mixture obtained by mixing the silicon source, titanium source, first template agent and water; optionally, the conditions for the hydrolysis and alcohol removal treatment include: treatment at 5℃~120℃ for 0.5h~48h; preferably treatment at 50℃~100℃ for 1h~24h.

[0116] In a preferred embodiment, the method further includes:

[0117] The solid product obtained from the hydrothermal treatment in step S1 is dried and calcined to obtain a first intermediate product. The first intermediate product is then mixed with a peroxide to obtain the molecular sieve intermediate product. In this disclosure, the drying process removes most of the moisture from the molecular sieve, reducing the amount of moisture evaporation during calcination. The drying temperature can be 100–200°C. The calcination process removes the template agent from the molecular sieve, obtaining a template agent-free titanium-silicon molecular sieve. This disclosure uses peroxide to treat the titanium-silicon molecular sieve intermediate product, which is beneficial for the formation of a hierarchical porous structure and improves the molecular sieve performance. Furthermore, compared to traditional hydrochloric acid treatment, peroxide treatment of the titanium-silicon molecular sieve avoids the acid corrosion of the equipment and chlorine corrosion of the catalyst caused by hydrochloric acid in industrial applications. Hydrochloric acid treatment of the molecular sieve requires the introduction of ammonia water for neutralization, generating a large amount of nitrogen-containing wastewater. This disclosure effectively avoids the generation of nitrogen-containing wastewater by using peroxide treatment.

[0118] In one specific embodiment, the peroxide is selected from one or more of inorganic peroxides and organic peroxides; optionally, the inorganic peroxide is selected from one or more of hydrogen peroxide, potassium peroxide, and sodium peroxide; and the organic peroxide is selected from one or more of tert-butyl peroxide, cumene hydroperoxide, and m-chloroperoxybenzoic acid.

[0119] Optionally, the peroxide is used in solution form, wherein the solvent of the peroxide solution is selected from one or more of water, alcohols having 1 to 10 carbon atoms, esters having 2 to 10 carbon atoms, and ketones having 3 to 10 carbon atoms. Preferably, the solvent is selected from one or more of water, n-butanol, tert-butanol, ethanol, methanol, and cyclohexanol.

[0120] The peroxide concentration in the solution is 0.1% to 10% by weight, preferably 0.3% to 7% by weight; the pH value is 2.0 to 6.5, preferably 3.0 to 6.0, more preferably 3.7 to 5.0; the weight ratio of the peroxide solution to the first intermediate product is (0.5 to 50):1, preferably (1 to 40):1, more preferably (1.5 to 25):1.

[0121] In a preferred embodiment, the calcination conditions include: a calcination temperature of 350℃ to 650℃ and a calcination time of 2h to 10h; preferably, the calcination temperature is 450℃ to 600℃ and the calcination time is 4h to 8h.

[0122] The conditions for mixing the second intermediate product with the peroxide include: a treatment temperature of 25℃ to 100℃, preferably 50℃ to 95℃, more preferably 75℃ to 85℃; a treatment time of 5 min to 1440 min, preferably 60 min to 1200 min, more preferably 75 min to 1000 min; and a pressure (gauge pressure) of 0 MPa to 5 MPa, preferably 0.2 MPa to 2 MPa.

[0123] In this disclosure, before drying the solid product obtained by hydrothermal treatment in step S1, the product obtained by hydrothermal treatment is further filtered and washed. Filtration is to separate the crystallized titanium silicon molecular sieve from the crystallization mother liquor. The purpose of washing is to remove the template agent adsorbed on the surface of the molecular sieve particles. For example, the washing or rinsing can be carried out at a temperature of room temperature to 50°C and a weight ratio of molecular sieve to water of 1:1 to 20, for example, a mixing ratio of 1:(1 to 15).

[0124] In one embodiment, in step S2, the weight ratio of the molecular sieve intermediate product: the second template agent: water is 1:(0.05-0.50):(1-10), preferably 1:(0.15-0.45):(2-6).

[0125] In one embodiment, the conditions for the second hydrothermal treatment include: a temperature of 150°C to 200°C, a time of 2 hours to 72 hours, and a pressure of autogenous pressure; preferably, the temperature is 160°C to 180°C and the time is 12 hours to 48 hours.

[0126] The third aspect of this disclosure provides a titanium-silicon molecular sieve prepared according to the method described in the second aspect of this disclosure.

[0127] This fourth aspect of the disclosure provides the application of the titanium-silicon molecular sieves described in the first and third aspects of the disclosure in catalytic organic reactions and / or adsorption separation processes.

[0128] In this disclosure, the organic reactions include: catalytic oxidation reactions (olefin oxidation / epoxidation to prepare aldehydes, ketones, acids, epoxides, and vicinal diols; alkane oxidation to prepare alcohols, aldehydes, and acids; alcohol oxidation to prepare ketones and acids; aldehyde oxidation to prepare acids; aromatic hydrocarbon oxidation to prepare phenols; thioether oxidation to prepare sulfoxides and sulfones), reduction reactions, oxime reactions (aldehyde / ketone aminooxime to prepare amides and lactams), aldol condensation reactions, substitution / halogenation reactions, elimination reactions, transesterification reactions, dehydration reactions, etherification reactions, esterification reactions, double / triple bond addition reactions, diene addition reactions, Beckmann rearrangement reactions (cyclohexanone oxime gas-phase rearrangement to caprolactam), hydrogen transfer reactions, etc. The adsorption separation processes include: adsorption separation of hydrocarbons (such as ethane, ethylene, butene, and dibutene), gases (such as helium separation), and inorganic substances (such as cesium ion separation).

[0129] In one specific embodiment, the organic catalytic reaction includes the oximation of cyclohexanone to prepare cyclohexanone oxime; optionally, it includes the following steps:

[0130] Under oxime reaction conditions, cyclohexanone, an oxidant, ammonia, and a catalyst are brought into contact to carry out an oxidation reaction; the catalyst comprises the titanium-silicon molecular sieve.

[0131] Optionally, the oxidant is selected from one or more of hydrogen peroxide, tert-butylhydrogen peroxide, cumene hydroperoxide, and m-chloroperoxybenzoic acid; preferably, the reaction is carried out in the presence of a solvent; the solvent is selected from one or more of n-butanol, tert-butanol, ethanol, methanol, and cyclohexanol;

[0132] Preferably, the oxime reaction conditions include: a molar ratio of oxidant to cyclohexanone of 1.2–2.0:1, a molar ratio of solvent to cyclohexanone of 0.5–5:1, a molar ratio of ammonia to cyclohexanone of 1.0–3.0:1, a weight ratio of catalyst to cyclohexanone of 0.05–0.2:1; a reaction temperature of 60–90°C, and a reaction time of 0.3–1.0 h.

[0133] In the applications of the titanium-silicon molecular sieve provided in this disclosure, the titanium-silicon molecular sieve or the catalyst containing the titanium-silicon molecular sieve can be used in powder form or in the form of shaped spheres, strips, cakes, granules, etc., and can be mixed with other catalysts; the applications can be carried out in various reactors such as batch reactors, slurry bed reactors, fixed bed reactors, fluidized bed reactors, moving bed reactors, and microchannel reactors; the reaction raw materials and catalysts can be fed at once, intermittently, or continuously.

[0134] Those skilled in the art will understand that the separation of products from catalysts can be achieved in various ways. For example, when using raw powdered molecular sieves as catalysts, the separation of products and the recycling and reuse of catalysts can be achieved through sedimentation, filtration, centrifugation, evaporation, membrane separation, etc. Alternatively, the catalyst can be shaped and loaded into a fixed-bed reactor, and the catalyst can be recovered after the reaction is completed. Various methods for separating and recovering catalysts are known methods.

[0135] The present disclosure is further described in detail below through examples. All raw materials used in the examples are commercially available.

[0136] In the following embodiments and comparative examples:

[0137] The structure of the molecular sieve was determined by XRD analysis using a Siemens D5005 X-ray diffractometer. The testing methods included: Cu target, Kα radiation, Ni filter, tube point voltage of 40 kV, tube current of 250 mA, scintillation counter, and a step size of 0.02°. The scanning range was 2θ = 5°–35°, and the scanning rate was 0.4° / min.

[0138] The chemical composition of the molecular sieve was determined by XRF analysis.

[0139] The specific surface area of ​​the molecular sieve was measured by nitrogen low-temperature adsorption-desorption method and the micropore specific surface area was calculated by BET method; the pore volume and pore distribution were determined according to the method described in RIPP151-90 of "Analytical Methods for Petrochemical Industry" (published by Science Press in September 1990, first edition) compiled by Yang Cuiding et al.

[0140] High-resolution morphology analysis of the molecular sieves was performed using TEM (Transmission Electron Microscope). The instrument used was a FEI TECNAIG2F20 (200kV) transmission electron microscope. The testing method included sample preparation using the suspension method: 0.01g of HTS molecular sieve sample was placed in a 2ml sample vial; anhydrous ethanol was added for dispersion, and the sample was shaken thoroughly. A drop was placed on a 3mm sample grid, dried, and then inserted into the sample injector for observation under the electron microscope. The accelerating voltage was 20kV.

[0141] The instrument used for ultraviolet-visible spectroscopy analysis was a JASCOUV-visible550 ultraviolet spectrophotometer. The testing method included pellet pressing, and the scanning range was 190–800 nm.

[0142] Unless otherwise specified, all raw materials used in the examples and comparative examples are analytical grade reagents.

[0143] Example 1

[0144] A solution of allyl tripropylammonium hydroxide (first template agent, ATPAOH, 25 wt%), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 68 °C for about 20 hours to obtain a sol, which was then crystallized at 170 °C for 24 hours (first hydrothermal treatment). The solid obtained by centrifugation was then filtered, washed with deionized water, dried at 100 °C for 3 hours, and calcined at 550 °C for 6 hours to obtain a first intermediate product. This first intermediate product was then mixed with a hydrogen peroxide solution (solvent: tert-butanol, hydrogen peroxide concentration: 1 wt%, pH: 5.0) at a weight ratio of 5:1 (peroxide solution to first intermediate product), at 80 °C for 200 min, and at a pressure of 0.7 MPa to obtain a molecular sieve intermediate product. The molecular sieve intermediate was then mixed with ATPAOH (second template agent, 25% by weight) and water, with a weight ratio of molecular sieve intermediate: second template agent: water of 1:0.22:3. The mixture was then hydrothermally treated at 180°C for 38 hours (second hydrothermal treatment) to obtain a solid molecular sieve, designated TS-1-A.

[0145] The UV-Vis spectrum and peak fractionation results of the titanium-silicon molecular sieve TS-1-A are as follows: Figure 1 As shown, the UV-Vis spectrum of this titanium-silicon molecular sieve exhibits peaks at positions of 210±10 nm, 260±10 nm, and 330±10 nm, respectively. The peak area I of the peak at 210±10 nm is particularly significant. 210 The value is 33.9 (because the ultraviolet spectral scan starts at 190 nm). Figure 1 The peak area at 210±10nm is calculated by integrating from 190nm, and the peak area at 260±10nm is I. 260 The peak area I of the spectrum at positions 50.8 and 330±10 nm is 330 It is 15.4, I 260 >I 210 >I 330 X1 calculated by equation (1) is 1.5, X2 calculated by equation (2) is 2.2, and X3 calculated by equation (3) is 3.3.

[0146] The nitrogen adsorption-desorption curve of the titanium-silicon molecular sieve TS-1-A is shown in Figure 2(a), and the pore distribution diagram is shown in Figure 2(b). As can be seen from Figure 2(a), there is a hysteresis loop between the adsorption isotherm and the desorption isotherm of the low-temperature nitrogen adsorption of the titanium-silicon molecular sieve. The initial relative pressure (P / P0) at which the hysteresis loop appears is 0.45. As can be seen from Figure 2(b), there are abundant mesopores inside the molecular sieve.

[0147] TEM image of titanium-silicon molecular sieve TS-1-A is shown below Figure 3 As shown, by Figure 3 It can be seen that the particle size of the molecular sieve is 360 nm, and the molecular sieve crystals have a right-angled morphology formed by the aggregation and growth of multiple small crystals with approximately right angles. There are multiple cavity structures within the molecular sieve crystals, and the size of a single cavity structure is about 20-25 nm. The total volume of the cavity structure accounts for 55% of the total volume of the titanium silicon molecular sieve.

[0148] The XRD pattern of titanium-silicon molecular sieve TS-1-A is shown below. Figure 4 As shown, by Figure 4 It can be seen that this molecular sieve has an MFI structure ( Figure 4 (The diffraction peaks are shown in the dashed box).

[0149] Example 2

[0150] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.04:0.20:30, an allyltripropylammonium hydroxide (first template agent, ATPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 75°C for about 17 hours to obtain a sol. Then, it was crystallized at 186°C for 37 hours (first hydrothermal treatment). After that, the solid obtained by centrifugation was filtered, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain the first intermediate product. Then, it was mixed with hydrogen peroxide solution (solvent: tert-butanol, hydrogen peroxide concentration: 5 wt%, pH value: 4) at a weight ratio of 3:1 for the peroxide solution to the first intermediate product. The mixing temperature was 55°C, the treatment time was 800 min, and the pressure was 0.5 MPa to obtain the molecular sieve intermediate product. The molecular sieve intermediate was then mixed with ATPAOH (second template agent, 25% by weight) and water, with a weight ratio of molecular sieve intermediate: second template agent: water of 1:0.43:6. The mixture was then hydrothermally treated at 169℃ for 24 hours (second hydrothermal treatment) to obtain a solid molecular sieve, designated TS-1-B.

[0151] Example 3

[0152] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.03:0.15:20, an allyl tripropylammonium hydroxide (first template agent, ATPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 85°C for about 15 hours to obtain a sol. Then, crystallization was carried out at 168°C for 25 hours (first hydrothermal treatment). After that, the solid obtained by centrifugation was filtered, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain the first intermediate product. Then, it was mixed with tert-butyl hydrogen peroxide solution (solvent is tert-butanol, peroxide concentration is 6 wt%, pH value is 4.3) at a weight ratio of peroxide solution to first intermediate product of 10:1. The mixing treatment temperature was 83°C, the treatment time was 1000 min, and the pressure was 1 MPa to obtain the molecular sieve intermediate product. The molecular sieve intermediate was then mixed with ATPAOH (second template agent, 25% by weight) and water, with a weight ratio of molecular sieve intermediate: second template agent: water of 1:0.15:2. The mixture was then hydrothermally treated at 166℃ for 47 h (second hydrothermal treatment) to obtain a solid molecular sieve, designated TS-1-C.

[0153] Example 4

[0154] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.04:0.15:20, a solution of tetrapropylammonium hydroxide (first template agent, TPAOH, 25 wt%), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 76°C for about 19 hours to obtain a sol, which was then crystallized at 167°C for 35 hours (first hydrothermal treatment). After that, the solid obtained by centrifugation was filtered, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain a first intermediate product. Then, it was mixed with a hydrogen peroxide solution (solvent: tert-butanol, hydrogen peroxide concentration: 0.5 wt%, pH: 4.0) at a weight ratio of 15:1 for the peroxide solution to the first intermediate product, at a mixing temperature of 75°C for 900 min, and at a pressure of 0.9 MPa to obtain a molecular sieve intermediate product. The molecular sieve intermediate was then mixed with ATPAOH (second template agent, 25% by weight) and water, with a weight ratio of molecular sieve intermediate: second template agent: water of 1:0.35:2.5. The mixture was then hydrothermally treated at 178°C for 23 hours (second hydrothermal treatment) to obtain a solid molecular sieve, designated TS-1-D.

[0155] Example 5

[0156] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.04:0.20:20, tetrapropylammonium hydroxide (first template agent, TPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT] and deionized water were stirred at 65°C for about 20 hours to obtain a sol. Then, it was crystallized at 178°C for 40 hours (first hydrothermal treatment). After that, the solid obtained by centrifugation was filtered, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain the first intermediate product. Then, it was mixed with tert-butyl hydrogen peroxide solution (solvent is tert-butanol, peroxide concentration is 7 wt%, pH value is 3.7) at a weight ratio of peroxide solution to first intermediate product of 25:1. The mixing temperature was 85°C, the treatment time was 75 min, and the pressure was 1.5 MPa to obtain the molecular sieve intermediate product. The molecular sieve intermediate was then mixed with ATPAOH (second template agent, 25% by weight) and water, with a weight ratio of molecular sieve intermediate: second template agent: water of 1:0.40:5. The mixture was then hydrothermally treated at 168℃ for 33 hours (second hydrothermal treatment) to obtain a solid molecular sieve, designated TS-1-E.

[0157] Example 6

[0158] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.04:0.20:20, tetrapropylammonium hydroxide (first template agent, TPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 72°C for about 14 hours to obtain a sol; then crystallized at 169°C for 38 hours (first hydrothermal treatment); the solid obtained by centrifugation was filtered, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain the first intermediate product; then mixed with hydrogen peroxide solution (solvent: tert-butanol, peroxide concentration: 4 wt%, pH: 4.2), the weight ratio of peroxide solution to the first intermediate product was 1.5:1, the mixing temperature was 78°C, the treatment time was 400 min, and the pressure was 0.2 MPa to obtain the molecular sieve intermediate product. The molecular sieve intermediate was then mixed with propenyltripropylammonium hydroxide (second template agent, 20 wt%) and water. The weight ratio of molecular sieve intermediate to second template agent to water was 1:0.45:4. The mixture was then hydrothermally treated at 167 °C for 25 h (second hydrothermal treatment) to obtain a solid molecular sieve, designated TS-1-F.

[0159] Example 7

[0160] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.04:0.20:30, an allyltripropylammonium hydroxide (first template agent, ATPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 79°C for about 8 hours to obtain a sol. This sol was then crystallized at 170°C for 30 hours (first hydrothermal treatment). The solid obtained after centrifugation was filtered, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain a molecular sieve intermediate. This intermediate was then mixed with ATPAOH (second template agent, 25 wt%) and water at a weight ratio of 1:0.2:2.5 and hydrothermally treated at 172°C for 18 hours (second hydrothermal treatment) to obtain a molecular sieve solid, designated TS-1-G.

[0161] Example 8

[0162] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.03:0.20:30, an allyl tripropylammonium hydroxide (first template agent, ATPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT] and deionized water were stirred at 75°C for about 6 hours to obtain a sol. Then, it was crystallized at 182°C for 20 hours (first hydrothermal treatment). After that, the solid obtained by centrifugation was filtered, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain the molecular sieve intermediate product. It was then mixed with propenyltripropylammonium hydroxide (second template agent, 16 wt%) and water, with a molecular sieve intermediate: second template agent: water weight ratio of 1:0.4:4, and hydrothermally treated at 167℃ for 32 h (second hydrothermal treatment) to obtain molecular sieve solid, numbered TS-1-H.

[0163] Example 9

[0164] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.03:0.15:30, an allyltripropylammonium hydroxide (first template agent, ATPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 63°C for about 18 hours to obtain a sol. Then, crystallization was carried out at 165°C for 10 hours (first hydrothermal treatment). The solid obtained by centrifugation was filtered, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain a molecular sieve intermediate. This intermediate was then mixed with ATPAOH (second template agent, 25 wt%) and water at a weight ratio of molecular sieve intermediate:second template agent:water of 1:0.45:6, and hydrothermally treated at 173°C for 16 hours (second hydrothermal treatment) to obtain a molecular sieve solid, designated TS-1-I.

[0165] Example 10

[0166] Following a molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.04:0.20:20, tetrapropylammonium hydroxide (TPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 79°C for approximately 10 hours to obtain a sol. This sol was then crystallized at 175°C for 6 hours (first hydrothermal treatment). The resulting solid was then filtered by centrifugation, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain a molecular sieve intermediate. This intermediate was then mixed with ATPAOH (second template agent, 25 wt%) and water at a weight ratio of 1:0.15:3.2, and hydrothermally treated at 184°C for 27 hours (second hydrothermal treatment) to obtain a solid molecular sieve, designated TS-1-J.

[0167] Example 11

[0168] Following a molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.03:0.15:30, an allyl tripropylammonium hydroxide (ATPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 69°C for approximately 17 hours to obtain a sol. This sol was then crystallized at 153°C for 8 hours (first hydrothermal treatment). The resulting solid was then filtered by centrifugation, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain a molecular sieve intermediate. This intermediate was then mixed with diallyl dipropylammonium hydroxide (second template agent, 30 wt%) and water at a weight ratio of molecular sieve intermediate:second template agent:water of 1:0.33:5, and hydrothermally treated at 188°C for 25 hours (second hydrothermal treatment) to obtain a molecular sieve solid, designated TS-1-K.

[0169] Example 12

[0170] This embodiment refers to the preparation method of Example 1, except that: the silicon source tetraethyl orthosilicate (TEOS) is replaced with silica, the titanium source tetrabutyl titanate [TBOT] is replaced with titanium tetrachloride, and the first template agent is replaced with diallyl dipropyl ammonium hydroxide. The rest of the process is the same as in Example 1, and a molecular sieve solid is obtained, which is numbered TS-1-L.

[0171] Example 13

[0172] This embodiment follows the preparation method of Example 1, but differs from Example 1 in that: allyl tripropylammonium hydroxide solution, tetraethyl orthosilicate, tetrabutyl titanate, and deionized water are added according to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.1:0.05:30; the weight ratio of molecular sieve intermediate product: second template agent: water is 1:0.1:10; the rest of the process is the same as in Example 1, and a molecular sieve solid is obtained, designated TS-1-M.

[0173] Example 14

[0174] A solution of allyl tripropylammonium hydroxide (first template agent, ATPAOH, 25 wt%), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 68 °C for about 20 hours to obtain a sol, which was then crystallized at 150 °C for 2 hours (first hydrothermal treatment). The solid obtained by centrifugation was then filtered, washed with deionized water, dried at 100 °C for 3 hours, and calcined at 350 °C for 10 hours to obtain a first intermediate product. This first intermediate product was then mixed with a hydrogen peroxide solution (solvent: tert-butanol, hydrogen peroxide concentration: 1 wt%, pH: 6.5) at a weight ratio of 50:1 (peroxide solution to first intermediate product), at 100 °C for 50 minutes, and at a pressure of 0.7 MPa to obtain a molecular sieve intermediate product. The molecular sieve intermediate was then mixed with ATPAOH (second template agent, 25% by weight) and water, with a weight ratio of molecular sieve intermediate: second template agent: water of 1:0.22:3. The mixture was then hydrothermally treated at 150°C for 8 hours (second hydrothermal treatment) to obtain a solid molecular sieve, designated TS-1-N.

[0175] Example 15

[0176] A solution of allyl tripropylammonium hydroxide (the first template agent, ATPAOH, 25 wt%), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 68°C for about 20 hours to obtain a sol, which was then crystallized at 250°C for 0.5 hours (first hydrothermal treatment). The solid obtained by centrifugation was then filtered, washed with deionized water, dried at 100°C for 3 hours, and calcined at 300°C for 10 hours to obtain a first intermediate product. This first intermediate product was then mixed with a hydrogen peroxide solution (solvent: tert-butanol, hydrogen peroxide concentration: 1 wt%, pH: 6.5), with a weight ratio of peroxide solution to the first intermediate product of 80:1. The mixing temperature was 120°C, the treatment time was 50 minutes, and the pressure was 0.7 MPa to obtain a molecular sieve intermediate product. The molecular sieve intermediate was then mixed with ATPAOH (second template agent, 25% by weight) and water in a weight ratio of 1:1:20 and hydrothermally treated at 300°C for 1 hour (second hydrothermal treatment) to obtain a solid molecular sieve, designated TS-1-O.

[0177] Comparative Example 1

[0178] Following a molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.04:0.15:20, a solution of tetrapropylammonium hydroxide (first template agent, TPAOH, 25 wt%), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT], and deionized water were stirred at 68°C for approximately 22 hours to obtain a sol. This sol was then crystallized at 182°C for 30 hours. The resulting solid was then filtered by centrifugation, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours. h, the first intermediate was obtained, and then mixed with hydrochloric acid solution (hydrochloric acid, concentration 2 wt%). The hydrochloric acid treatment conditions included: the weight ratio of the first intermediate to hydrochloric acid was 1:15, the treatment temperature was 75℃, and the treatment time was 3h. After hydrochloric acid treatment, an appropriate amount of ammonia water was added to neutralize it, and a molecular sieve intermediate was obtained. After filtration and drying, it was mixed with TPAOH (second template agent, 25 wt%) and water. The weight ratio of molecular sieve intermediate: second template agent: water was 1:0.3:3, and it was hydrothermally treated at 163℃ for 30h to obtain a molecular sieve solid, numbered D-1.

[0179] Comparative Example 2

[0180] Following a molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.04:0.15:20, a tetrapropylammonium hydroxide (TPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate (TBOT), and deionized water were stirred at 87°C for approximately 7 hours to obtain a sol. This sol was then crystallized at 163°C for 25 hours. The resulting solid was then filtered by centrifugation, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours. This solid was then mixed with TPAOH and water and hydrothermally treated at 185°C for 13 hours to obtain a molecular sieve solid, designated D-2.

[0181] Comparative Example 3

[0182] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.04:0.15:20, tetrapropylammonium hydroxide (TPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT] and deionized water were stirred at 65°C for about 12 hours to obtain a sol. N-phenyl-aminopropyl-trimethoxysilane was added to the sol, with a molar ratio of N-phenyl-aminopropyl-trimethoxysilane to SiO2 of 0.04. Then, crystallization was carried out at 175°C for 26 hours. After that, the solid obtained by centrifugation was filtered, washed with deionized water, dried at 100°C for 3 hours, calcined at 550°C for 6 hours, and then mixed with hydrochloric acid solution. The acid treatment conditions were the same as those of Comparative Example 1. After hydrochloric acid treatment, an appropriate amount of ammonia water was added for neutralization. It was then mixed with TPAOH and water and hydrothermally treated at 173°C for 17 hours to obtain a molecular sieve solid, designated as D-3.

[0183] Comparative Example 4

[0184] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): first template agent: water of 1:0.04:0.20:20, an allyl tripropylammonium hydroxide (first template agent, ATPAOH, 25 wt%) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [TBOT] and deionized water were stirred at 78°C for about 6 hours to obtain a sol. Then, it was crystallized at 188°C for 12 hours (first hydrothermal treatment). After that, the solid obtained by centrifugation was filtered, washed with deionized water, dried at 100°C for 3 hours, and calcined at 550°C for 6 hours to obtain the molecular sieve intermediate product. It was then mixed with tetrapropylammonium hydroxide (second template agent, TPAOH, without alkenyl group, 25% by weight) and water, with a molecular sieve intermediate: second template agent: water weight ratio of 1:0.35:5, and hydrothermally treated at 165℃ for 50h (second hydrothermal treatment) to obtain molecular sieve solid, numbered D-4.

[0185] The UV-Vis spectra, molecular sieve configurations, titanium-silicon molar ratios, and relative crystallinity of the molecular sieve products obtained in the above examples and comparative examples are listed in Table 1 below; the structural parameters and other data of the molecular sieve products obtained in the above examples and comparative examples are listed in Table 2 below.

[0186] Table 1

[0187]

[0188]

[0189] Table 2

[0190]

[0191] Application test cases

[0192] This test example is used to evaluate the performance of the titanium-silicon molecular sieves prepared in the comparative example and the embodiment as catalysts in the catalytic amination reaction of cyclohexanone. Specifically, the following process is included:

[0193] The cyclohexanone amination reaction was carried out in a 250 ml three-necked flask reaction apparatus equipped with an automatic temperature-controlled water bath, magnetic stirring, and reflux condenser. Samples prepared in the above examples and comparative examples were added to a three-necked flask at a ratio of 1.00 g of sample, 10 g (0.14 mol) of tert-butanol solvent, and 9.8 g (0.1 mol) of cyclohexanone (catalyst to cyclohexanone mass ratio of 0.1). The flask was then placed in a water bath at a preset reaction temperature of 80 °C. Using a peristaltic pump, 13.7 g (0.12 mol) of 30% hydrogen peroxide and 28.1 g (0.2 mol) of 25% ammonia solution were simultaneously added dropwise, with a molar ratio of cyclohexanone:ammonia:hydrogen peroxide:solvent of 1:2:1.2:1.35. The reaction was stopped after 0.5 h, rapidly cooled, and the liquid product was obtained by filtration and composition determination. The results are listed in Table 3 below.

[0194] For the long-cycle reaction, 1.00 g of the obtained sample was placed in a 100 mL slurry bed reactor equipped with continuous feed and membrane separation device. Under stirring, 30% hydrogen peroxide (mass fraction 30%) was added at a rate of 24.7 mL / h, 25% ammonia (mass fraction 25%) was added at a rate of 61.7 mL / h, and a mixture of cyclohexanone and tert-butanol (cyclohexanone to tert-butanol volume ratio 1:2) was added at a rate of 72.2 mL / h, while simultaneously being continuously discharged at the same rate. The reaction temperature was maintained at 80 °C for 120 h, and then samples were taken for analysis every 12 h. The data in the "Long-cycle Reaction Results" column of Table 3 are the average of the five sampling results after 120 h of reaction.

[0195] Cyclohexanone conversion rate (%) = (moles of cyclohexanone in the feed - moles of cyclohexanone in the product) / moles of cyclohexanone in the feed × 100%;

[0196] Cyclohexanone oxime selectivity (%) = number of moles of cyclohexanone oxime generated in the product / number of moles of cyclohexanone consumed to generate all products × 100%;

[0197] Cyclohexanone conversion rate reduction (%) = (0.5h cyclohexanone conversion rate - 120h cyclohexanone conversion rate) / 0.5h cyclohexanone conversion rate × 100%;

[0198] Cyclohexanone oxime selectivity reduction rate (%) = (0.5h cyclohexanone oxime selectivity - 120h cyclohexanone oxime selectivity) / 0.5h cyclohexanone oxime selectivity × 100%.

[0199] The reaction products were analyzed by gas chromatography, and the results were quantified using the external standard method. The chromatographic conditions were as follows: Agilent-6890 chromatograph, HP-5 capillary column, injection volume 0.5 μL, injection port temperature 280℃. Column temperature was held at 100℃ for 2 min, then increased to 250℃ at a rate of 15℃ / min and held for 10 min. An FID detector was used, with a detector temperature of 300℃.

[0200] Table 3

[0201]

[0202] Comparing Examples 1-12 with Comparative Examples 1-4, the titanium-silicon molecular sieves prepared by the method provided in this disclosure in Examples 1-12 satisfy the requirement that the peak areas of the spectral peaks at positions 210±10nm, 260±10nm, and 330±10nm in the UV-Vis spectrum meet the requirement of I. 260 >I 210 >I 330 Furthermore, the X1 calculated by equations (1) to (3) is in the range of 1.1 to 2.0, X2 is in the range of 1.6 to 3.3, and X3 is in the range of 2.7 to 3.8. Compared with the molecular sieves prepared in Comparative Examples 1 to 4, the titanium-silicon molecular sieves prepared in Examples 1 to 12 have higher cyclohexanone conversion rate and cyclohexanone oxime selectivity in the catalytic cyclohexanone amination oxime reaction. Moreover, under long-cycle reaction conditions, the cyclohexanone conversion rate reduction rate and cyclohexanone oxime selectivity reduction rate are lower, and the reaction stability is higher.

[0203] Comparing Examples 1-14 with Example 15, it can be seen that the amount of raw materials added and the preparation conditions in Example 15 are not within the range provided in this disclosure. For example, the amount of raw materials added in Example 15 is not within the range of "the molar ratio of silicon source: titanium source: first template agent: water is 1:(0.01-0.10):(0.05-0.30):(15-30); the weight ratio of molecular sieve intermediate product: second template agent: water is 1:(0.05-0.50):(1-10)". In the UV-Vis spectral characteristics of the titanium-silicon molecular sieves prepared in Example 15, X2 calculated by formulas (2) to (3) is not in the range of 1.6 to 3.3 and X3 is not in the range of 2.7 to 3.8. Compared with Example 15, the titanium-silicon molecular sieves prepared in Examples 1 to 14 have higher cyclohexanone conversion rate and cyclohexanone oxime selectivity in the catalytic cyclohexanone amination oxime reaction. Under long-cycle reaction conditions, the cyclohexanone conversion rate reduction rate and cyclohexanone oxime selectivity reduction rate are lower, and the reaction stability is higher.

[0204] Comparing Example 1 with Example 13, it can be seen that the amount of raw materials added in Example 1 meets the preferred range of "the molar ratio of silicon source: titanium source: first template agent: water is 1:(0.03~0.06):(0.10~0.25):(18~25)" and "the weight ratio of molecular sieve intermediate product: second template agent: water is 1:(0.15~0.45):(2~6)". Example 13 did not prepare titanium-silicon molecular sieves according to the molar ratio and weight ratio of raw materials within this range. Comparing Example 1 with Example 14, it can be seen that Example 1 synthesized titanium-silicon molecular sieves according to the preferred preparation conditions of this disclosure, while Example 14 did not synthesize titanium-silicon molecular sieves according to the preferred preparation conditions of this disclosure. Compared with Examples 13 and 14, the titanium-silicon molecular sieves prepared in Example 1 have higher cyclohexanone conversion rate and cyclohexanone oxime selectivity in the catalytic cyclohexanone amination oxime reaction, and under long-cycle reaction conditions, the cyclohexanone conversion rate reduction rate and cyclohexanone oxime selectivity reduction rate are lower, and the reaction stability is higher.

[0205] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0206] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0207] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A titanium-silicon molecular sieve, characterized in that, The titanium-silicon molecular sieve has the following UV-Vis characteristics: The UV-Vis spectrum of the titanium-silicon molecular sieve exhibits peaks at positions of 210±10 nm, 260±10 nm, and 330±10 nm, respectively; the peak area of ​​the peak at position 210±10 nm in the UV-Vis spectrum of the titanium-silicon molecular sieve is denoted as I. 210 Let I denote the peak area of ​​the spectral peak at position 260±10nm. 260 Let the peak area at the position of 330±10nm be denoted as I. 330 , where I 260 >I 210 >I 330 ; As defined in equation (1), X1 can be any value within the range of 1.3 to 1.6: X1 = I 260 / I 210 Formula (1); As defined in equation (2), X2 is any value within the range of 2.0 to 2.8: X2=I 210 / I 330 Equation (2); As defined in equation (3), X3 is any value within the range of 2.9 to 3.5: X2=I 260 / I 330 Equation (3); The titanium-silicon molecular sieve contains at least one cavity structure within its crystal structure, and the size of a single cavity structure is 15 nm to 40 nm.

2. The titanium-silicon molecular sieve according to claim 1, characterized in that, The molar ratio of silicon to titanium in the titanium-silicon molecular sieve is 10~100:

1.

3. The titanium-silicon molecular sieve according to claim 2, characterized in that, The molar ratio of silicon to titanium in the titanium-silicon molecular sieve is 16~34:

1.

4. The titanium-silicon molecular sieve according to claim 1, characterized in that, The total volume of the cavity structure accounts for 20% to 80% of the total volume of the titanium-silicon molecular sieve.

5. The titanium-silicon molecular sieve according to claim 4, characterized in that, The total volume of the cavity structure accounts for 50% to 70% of the total volume of the titanium-silicon molecular sieve.

6. The titanium-silicon molecular sieve according to claim 1, characterized in that, The average particle size of the titanium-silicon molecular sieve particles is 250 nm to 400 nm; the BET specific surface area is 440 m². 2 / g~450m 2 / g; micropore volume is 0.16cm³ 3 / g~0.20cm 3 / g; mesopore volume is 0.08cm³ 3 / g~0.14cm 3 / g.

7. The titanium-silicon molecular sieve according to claim 6, characterized in that, The average particle size of the titanium-silicon molecular sieve particles is 310 nm to 380 nm; the BET specific surface area is 443 m². 2 / g~447m 2 / g; micropore volume is 0.17cm³ 3 / g~0.19cm 3 / g; mesopore volume is 0.10cm³ 3 / g~0.12cm 3 / g.

8. The titanium-silicon molecular sieve according to claim 1, characterized in that, The relative crystallinity of the titanium-silicon molecular sieve is above 80%.

9. The titanium-silicon molecular sieve according to claim 8, characterized in that, The relative crystallinity of the titanium-silicon molecular sieve is above 82%.

10. The titanium-silicon molecular sieve according to claim 1, characterized in that, There is a hysteresis loop between the adsorption isotherm and desorption isotherm of the low-temperature nitrogen adsorption of the titanium-silicon molecular sieve.

11. The titanium-silicon molecular sieve according to claim 10, characterized in that, The initial relative pressure P / P0 of the hysteresis loop is 0.4~0.

5.

12. A method for preparing titanium-silicon molecular sieves, characterized in that, Includes the following steps: S1. Mix silicon source, titanium source, first template agent and water, and perform first hydrothermal treatment to obtain molecular sieve intermediate product; S2. Mix the molecular sieve intermediate product, the second template agent, and water, and perform a second hydrothermal treatment. The first template agent is selected from one or more compounds having the structure shown in formula (M-1): Formula (M-1); wherein R1, R2, R3 and R4 are each independently selected from one of alkyl groups having 2 to 4 carbon atoms and alkenyl groups having 2 to 4 carbon atoms; The second template agent is selected from one or more compounds having the structure shown in formula (M-2): Formula (M-2); wherein R5, R6, R7 and R8 are each independently selected from one of an alkyl group having 2 to 4 carbon atoms and an alkenyl group having 2 to 4 carbon atoms; and at least one alkenyl group is present among R5, R6, R7 and R8; In step S1, the molar ratio of silicon source: titanium source: first template agent: water is 1:(0.01~0.10):(0.05~0.30):(15~30), the silicon source is calculated as SiO2, and the titanium source is calculated as TiO2; the conditions of the first hydrothermal treatment include: hydrothermal temperature of 150℃~200℃, hydrothermal time of 2h~100h, and hydrothermal crystallization pressure of self-generated pressure; In step S2, the weight ratio of the molecular sieve intermediate product, the second template agent, and water is 1:(0.05~0.50):(1~10); the conditions for the second hydrothermal treatment include: a temperature of 150℃~200℃, a time of 2h~72h, and an autogenous pressure.

13. The method according to claim 12, characterized in that, In the first template agent of formula (M-1), R1, R2, R3 and R4 are each independently selected from one of an alkyl group having 3 carbon atoms and an alkenyl group having 3 carbon atoms; In the second template agent of formula (M-2), R5, R6, R7 and R8 are each independently selected from one of an alkyl group having 3 carbon atoms and an alkenyl group having 3 carbon atoms.

14. The method according to claim 13, characterized in that, The first template agent is selected from one or more of tetrapropylammonium hydroxide, allyltripropylammonium hydroxide, propenyltripropylammonium hydroxide, diallyldipropylammonium hydroxide, diallyldipropylammonium hydroxide, allylpropenyldipropylammonium hydroxide, diallylpropenylpropylammonium hydroxide, diallylallylpropylammonium hydroxide, triallylpropylammonium hydroxide, triallylpropylammonium hydroxide, tetraallylammonium hydroxide, and tetrapropenylammonium hydroxide; The second template agent is selected from one or more of allyltripropylammonium hydroxide, propenyltripropylammonium hydroxide, diallyldipropylammonium hydroxide, diallyldipropylammonium hydroxide, allylpropenyldipropylammonium hydroxide, diallylpropenylpropylammonium hydroxide, diallylallylpropylammonium hydroxide, triallylpropylammonium hydroxide, tripropenylpropylammonium hydroxide, tetraallylammonium hydroxide, and tetrapropenylammonium hydroxide.

15. The method according to claim 14, characterized in that, The first template agent is selected from one or more of tetrapropylammonium hydroxide, allyltripropylammonium hydroxide, propenyltripropylammonium hydroxide, allylpropenyldipropylammonium hydroxide, triallylpropylammonium hydroxide, and tetraallylammonium hydroxide; The second template agent is selected from allyltripropylammonium hydroxide, propenyltripropylammonium hydroxide, allylpropenyldipropylammonium hydroxide, triallylpropylammonium hydroxide, and tetraallylammonium hydroxide.

16. The method according to claim 15, characterized in that, The first template agent is selected from one or more of tetrapropylammonium hydroxide, allyltripropylammonium hydroxide, and propenyltripropylammonium hydroxide; The second template agent is selected from one or more of allyltripropylammonium hydroxide, propenyltripropylammonium hydroxide, allylpropenyldipropylammonium hydroxide, triallylpropylammonium hydroxide, and tetraallylammonium hydroxide.

17. The method according to claim 16, characterized in that, The second template agent is selected from one or more of allyltripropylammonium hydroxide and propenyltripropylammonium hydroxide.

18. The method according to claim 12, characterized in that, In step S1, the silicon source is selected from at least one of organosilicon grease, solid silica gel, fumed silica, and silica sol.

19. The method according to claim 18, characterized in that, The silicon source is selected from at least one of organosilicon grease, solid silica gel, and precipitated silica.

20. The method according to claim 19, characterized in that, The silicone grease is selected from one or more compounds with the structure shown in formula (A) below: （A）； R a R b R c and R d Each is independently selected from alkyl groups having 1 to 4 carbon atoms, wherein the alkyl group is a branched or straight-chain alkyl group.

21. The method according to claim 20, characterized in that, The R a R b R c and R d Each is independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, or tert-butyl.

22. The method according to claim 21, characterized in that, The silicone grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, and dimethyl diethyl silicate.

23. The method according to claim 22, characterized in that, The silicone grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, and dimethyl diethyl silicate.

24. The method according to claim 12, characterized in that, The titanium source is selected from one or more of organic and inorganic titanium sources.

25. The method according to claim 24, characterized in that, The organotitanium source is a titanium-containing organic ester, selected from at least one of the structures shown in formula (B) below: （B）； Where R e R f R g and R h Each is selected from alkyl groups having 1 to 6 carbon atoms.

26. The method according to claim 25, characterized in that, R e R f R g and R h Each is selected from straight-chain alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms.

27. The method according to claim 26, characterized in that, R e R f R g and R h Each is selected from straight-chain alkyl groups having 2 to 4 carbon atoms and branched alkyl groups having 2 to 4 carbon atoms.

28. The method according to claim 26, characterized in that, R e R f R g and R h Each of the following is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, isopentyl, hexyl, or isohexyl.

29. The method according to claim 28, characterized in that, R e R f R g and R h Each is independently selected from one of ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, or tert-butyl.

30. The method according to claim 24, characterized in that, The inorganic titanium source is selected from one or more of titanium chloride, nitrate or sulfate.

31. The method according to claim 24, characterized in that, The titanium source is selected from one or more of titanium tetrachloride, titanium sulfate, titanium nitrate, tetraethyl titanate, tetrapropyl titanate, and tetrabutyl titanate.

32. The method according to claim 12, characterized in that, In step S1, the molar ratio of silicon source: titanium source: first template agent: water is 1: (0.03~0.06): (0.10~0.25): (18~25).

33. The method according to claim 12, characterized in that, In step S1, the conditions for the first hydrothermal treatment include: a hydrothermal temperature of 160℃~190℃ and a hydrothermal crystallization time of 4h~80h.

34. The method according to claim 33, characterized in that, In step S1, the conditions for the first hydrothermal treatment include: a hydrothermal temperature of 165℃~188℃ and a hydrothermal crystallization time of 5h~40h.

35. The method according to claim 12, characterized in that, Prior to the first hydrothermal treatment, the method further includes: performing a hydrolysis and alcohol removal treatment on the raw material mixture obtained by mixing the silicon source, titanium source, first template agent and water.

36. The method according to claim 35, characterized in that, The conditions for the hydrolysis and alcohol removal treatment include: treatment at 5℃~120℃ for 0.5h~48h.

37. The method according to claim 36, characterized in that... The conditions for the hydrolysis and alcohol removal treatment include: treatment at 50℃~100℃ for 1h~24h.

38. The method according to claim 12, characterized in that, The method also includes: The solid product obtained from the hydrothermal treatment in step S1 is dried and calcined to obtain the first intermediate product.

39. The method according to claim 38, characterized in that, The method further includes: contacting the first intermediate product with a peroxide for mixing treatment to obtain the molecular sieve intermediate product.

40. The method according to claim 39, characterized in that, The peroxide is selected from one or more of inorganic peroxides and organic peroxides.

41. The method according to claim 40, characterized in that, The inorganic peroxide is selected from one or more of hydrogen peroxide, potassium peroxide, and sodium peroxide; the organic peroxide is selected from one or more of tert-butyl peroxide, cumene hydroperoxide, and m-chloroperoxybenzoic acid.

42. The method according to claim 41, characterized in that, The peroxide is used in solution form, and the solvent of the peroxide solution is selected from one or more of water, alcohols with 1 to 10 carbon atoms, esters with 2 to 10 carbon atoms, and ketones with 3 to 10 carbon atoms.

43. The method according to claim 42, characterized in that, The solvent is selected from one or more of water, n-butanol, tert-butanol, ethanol, methanol, and cyclohexanol; The peroxide concentration in the solution is 0.1% to 10% by weight. The pH value is 2.0~6.5; the weight ratio of the peroxide solution to the first intermediate product is (0.5~50):

1.

44. The method according to claim 43, characterized in that, The peroxide concentration in the solution is 0.3% to 7% by weight; the pH value is 3.0 to 6.0; the weight ratio of the peroxide solution to the first intermediate product is (1 to 40):

1.

45. The method according to claim 44, characterized in that, pH value is 3.7~5.0; The weight ratio of the peroxide solution to the first intermediate product is (1.5~25):

1.

46. ​​The method according to claim 39, characterized in that, The conditions for the calcination treatment include: a calcination temperature of 350℃~650℃ and a calcination time of 2h~10h; The conditions for mixing the second intermediate product with peroxide include: a treatment temperature of 25℃ to 100℃; a treatment time of 5 min to 1440 min; and a pressure of 0 MPa to 5 MPa.

47. The method according to claim 46, characterized in that, The conditions for the calcination treatment include: a calcination temperature of 450℃~600℃ and a calcination time of 4h~8h; The conditions for mixing the second intermediate product with peroxide include: a treatment temperature of 50℃ to 95℃; a treatment time of 60 min to 1200 min; and a pressure of 0.2 MPa to 2.0 MPa.

48. The method according to claim 47, characterized in that, The conditions for mixing the second intermediate product with the peroxide include: a treatment temperature of 75℃~85℃ and a treatment time of 75min~1000min.

49. The method according to claim 12, characterized in that, In step S2, the weight ratio of the molecular sieve intermediate product, the second template agent, and water is 1:(0.15~0.45):(2~6).

50. The method according to claim 12, characterized in that, The conditions for the second hydrothermal treatment include: a temperature of 160℃~180℃ and a time of 12h~48h.

51. The titanium-silicon molecular sieve prepared by the method according to any one of claims 12 to 50.

52. The use of the titanium-silicon molecular sieve according to any one of claims 1 to 11 and 51 in catalytic organic reaction and / or adsorption separation processes.

53. The application according to claim 52, characterized in that, The catalytic organic reactions include propylene epoxidation to prepare propylene oxide, chloropropene catalytic chlorohydrin reaction to prepare dichloropropanol, and cyclohexanone oxime reaction to prepare cyclohexanone oxime.

54. The application according to claim 53, characterized in that, The preparation of cyclohexanone oxime by cyclohexanone oximation includes the following steps: Under oxime reaction conditions, cyclohexanone, an oxidant, ammonia, and a catalyst are brought into contact to carry out an oxidation reaction; The catalyst comprises the titanium-silicon molecular sieve.

55. The application according to claim 54, characterized in that, The oxidant is selected from one or more of hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, and m-chloroperoxybenzoic acid.

56. The application according to claim 54, characterized in that, The oxidation reaction is carried out in the presence of a solvent; the solvent is selected from one or more of n-butanol, tert-butanol, ethanol, methanol and cyclohexanol.

57. The application according to claim 54, characterized in that, The oxime reaction conditions include: a molar ratio of oxidant to cyclohexanone of 1.2 to 2.0:1, a molar ratio of solvent to cyclohexanone of 0.5 to 5:1, a molar ratio of ammonia to cyclohexanone of 1.0 to 3.0:1, and a weight ratio of catalyst to cyclohexanone of 0.05 to 0.2:1; a reaction temperature of 60 to 90°C, and a reaction time of 0.3 to 1.0 h.

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