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

Abstract

This disclosure relates to a eutectic titanium-silicon molecular sieve, its preparation method, and its applications. The XRD pattern of this eutectic titanium-silicon molecular sieve exhibits characteristic diffraction peaks of MFI-type molecular sieves in the range of 22°–25°, and diffraction peaks exist in the ranges of 15.47±0.2° and 15.87±0.2°, with a diffraction peak intensity I... 15.87 / I 15.47 The diffraction intensity ranges from 1.30 to 2.60; two adjacent diffraction peaks, at 23.91±0.2° and 23.68±0.2°, exist within the range of 22.5° to 23.5°, and their peak intensities I... 23.91 / I 23.68 The diffraction intensity ranges from 1.5 to 2.3; within the range of 29.5° to 30.5°, there are two adjacent diffraction peaks at 29.90±0.2° and 30.31±0.2°, and their diffraction peak intensities I are... 29.90 / I 30.31 The value ranges from 2.5 to 4.0. This eutectic titanium-silicon molecular sieve possesses a TS-1 / TS-2 eutectic molecular sieve structure and exhibits excellent catalytic performance.

Description

Technical Field

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

[0002] Ti-containing heteroatom molecular sieves refer to heteroatom molecular sieves with isolated tetracoordinated titanium in their framework. They have excellent selective catalytic oxidation performance of hydrocarbons, especially in reactions using hydrogen peroxide as an oxidant. They exhibit many advantages such as mild reaction conditions, high atom utilization, and environmentally friendly and pollution-free processes, and have great potential for industrial applications.

[0003] The successful development of the Ti-containing heteroatom-containing TS-1 with an MFI structure is considered a milestone in the field of molecular sieve catalysis. Currently, Ti-containing heteroatom-containing molecular sieves, represented by TS-1, have been successfully applied in industrial production processes such as propylene epoxidation, phenol hydroxylation, and cyclohexanone ammoxidation. However, the widely used Ti-containing heteroatom-containing molecular sieve, TS-1, is a ten-membered ring mesoporous molecular sieve with an MFI structure, but its pore size of approximately 5.5 nm limits its application in the selective oxidation reactions of macromolecular hydrocarbons.

[0004] The TS-1 molecular sieve framework contains two types of pore systems: a ten-membered ring cylindrical pore system with an elliptical cross-section parallel to the y-axis (pore size 0.54 nm × 0.56 nm) and a Z-shaped pore system with an approximately circular cross-section parallel to the x-axis (pore size 0.52 nm × 0.58 nm). These two types of pores intersect each other, with the intersection size reaching 0.9 nm. For some macromolecules, due to the pore restriction, it is difficult to contact the active center through the pores, thus greatly affecting the activity and lifetime of the catalyst.

[0005] TS-2, like TS-1, belongs to the Pentasil series. TS-2 also features characteristic structural units similar to those in the MFI configuration, consisting of eight pentagonal rings. These structural units are interconnected by shared edges to form chains, which are then linked by oxygen bridges to form sheet-like structures with ten-membered rings. These sheets are further connected by mirror interactions to form a three-dimensional framework structure. Unlike TS-1, TS-2 contains only one type of channel system: approximately circular ten-membered ring cylindrical channels (channel dimensions approximately 0.54 nm × 0.53 nm) with cross-sections parallel to the x and y axes.

[0006] Therefore, TS-1 / TS-2 eutectic molecular sieves, while possessing both MFI and MEL configurations, can better leverage the synergistic effect of TS-1 and TS-2 molecular sieves, and have broad research prospects. Summary of the Invention

[0007] The purpose of this disclosure is to provide a eutectic titanium-silicon molecular sieve, its preparation method and application, wherein the eutectic titanium-silicon molecular sieve has a TS-1 / TS-2 eutectic molecular sieve structure and good catalytic performance.

[0008] To achieve the above objectives, the first aspect of this disclosure provides a eutectic titanium-silicon molecular sieve, which has the following XRD characteristics:

[0009] The peak intensity of the diffraction peak at position 15.47±0.2° in the XRD pattern of the eutectic titanium-silicon molecular sieve is I. 15.47 The peak-intensity of the diffraction peak at position 15.87±0.2° is denoted as I. 15.87 ;

[0010] The peak intensity of the diffraction peak at position 23.68±0.2° in the XRD pattern of the eutectic titanium-silicon molecular sieve is denoted as I. 23.68 The peak intensity of the diffraction peak at position 23.91±0.2° is denoted as I. 23.91 ;

[0011] The peak intensity of the diffraction peak at position 29.90±0.2° in the XRD pattern of the eutectic titanium-silicon molecular sieve is denoted as I. 29.90 The peak intensity of the diffraction peak at position 30.31±0.2° is denoted as I. 30.31 ;

[0012] As defined in equation (1), X1 is any value within the range of 1.30 to 2.65:

[0013] X1 = I 15.87 / I 15.47 Equation (1); and,

[0014] As defined in equation (2), X2 is any value within the range of 1.5 to 2.45:

[0015] X2 = I 23.91 / I 23.68 Equation (2);

[0016] As defined in equation (3), X3 is any value within the range of 2.1 to 4.0:

[0017] X3 = I 29.90 / I 30.31 Equation (3).

[0018] Optionally, X1 is any value in the range of 1.5 to 2.3, X2 is any value in the range of 1.6 to 2.0, and X3 is any value in the range of 2.8 to 3.6.

[0019] Preferably, the XRD pattern of the eutectic titanium-silicon molecular sieve has diffraction peaks at positions 8.78±0.2° and 8.82±0.2° within the range of 8.5° to 9.5°.

[0020] Optionally, the eutectic titanium-silicon molecular sieve has the following UV-Vis characteristics:

[0021] The peak area of ​​the peak at position 270±10nm in the UV-Vis spectrum of the eutectic titanium-silicon molecular sieve is denoted as Q1, and the peak area of ​​the peak at position 330±10nm is denoted as Q2.

[0022] As defined in equation (4), X4 is any value within the range of 2.0 to 4.5:

[0023] X4 = Q1 / Q2 (Equation 4);

[0024] Preferably, X4 is any value in the range of 2.5 to 4.3; more preferably, X4 is any value in the range of 2.7 to 4.0.

[0025] Optionally, the molar ratio of titanium to silicon in the eutectic titanium-silicon molecular sieve is 1:2 to 1000, preferably 1:24 to 67;

[0026] Preferably, the eutectic titanium-silicon molecular sieve has a TS-1 / TS-2 eutectic molecular sieve structure;

[0027] Optionally, the average particle size of the eutectic titanium-silicon molecular sieve particles is 0.05–0.80 nm, preferably 0.20–0.35 nm; the BET specific surface area is 420–500 m². 2 / g, preferably 430-445m 2 / g; Microporous specific surface area is 370-450m² 2 / g, preferably 380-395m 2 / g; total pore volume is 0.1–0.30 cm³. 3 / g, preferably 0.23~0.28cm 3 / g; mesopore volume is 0.05~0.15cm³ 3 / g, preferably 0.07~0.13cm 3 / g.

[0028] A second aspect of this disclosure provides a method for preparing eutectic titanium-silicon molecular sieves, comprising the following steps:

[0029] S1. A silicon source, a titanium source, a template agent, and water are mixed to obtain a raw material mixture; the template agent is selected from one or more organic ammonium hydroxide compounds; and the template agent contains at least one selected from alkyl groups with 3 carbon atoms and alkenyl groups with 3 carbon atoms, and contains at least one selected from alkyl groups with 4 carbon atoms and alkenyl groups with 4 carbon atoms.

[0030] S2. The raw material mixture is subjected to a first hydrothermal crystallization treatment.

[0031] Optionally, the template agent is selected from one or more of the first template agents, or the template agent includes a second template agent and a third template agent;

[0032] The first template agent is selected from one or more compounds having the structure shown in formula (M-1):

[0033] R1, R2, R3 and R4 are each independently selected from alkyl groups having 3 to 4 carbon atoms and alkenyl groups having 3 to 4 carbon atoms, and R1, R2, R3 and R4 contain at least one alkyl or alkenyl group having 3 carbon atoms and at least one alkyl or alkenyl group having 4 carbon atoms.

[0034] The second template agent is selected from one or more compounds having the structure shown in formula (M-2):

[0035] R5, R6, R7 and R8 are each independently selected from alkyl groups with 3 carbon atoms and alkenyl groups with 3 carbon atoms;

[0036] The third template agent is selected from one or more compounds having the structure shown in formula (M-3):

[0037] Among them, R9, R 10 R 11 and R 12 Each is independently selected from alkyl groups with 4 carbon atoms and alkenyl groups with 4 carbon atoms.

[0038] Optionally, in the structural formula (M-1) of the first template agent, any three groups of R1, R2, R3 and R4 are selected from alkyl groups with 3 carbon atoms and alkenyl groups with 3 carbon atoms, and the other group is selected from alkyl groups with 4 carbon atoms and alkenyl groups with 4 carbon atoms.

[0039] Optionally, the alkyl group having 3 carbon atoms is selected from n-propyl and isopropyl, and the alkenyl group having 3 carbon atoms is selected from propenyl and allyl; the alkyl group having 4 carbon atoms is selected from n-butyl, isobutyl, sec-butyl and tert-butyl, and the alkenyl group having 4 carbon atoms is selected from n-butenyl and isobutylenyl.

[0040] Preferably, the first template agent is selected from tripropylbutylammonium hydroxide, tributylpropylammonium hydroxide, dipropyldibutylammonium hydroxide, 1-butenyltripropylammonium hydroxide, 2-butenyltripropylammonium hydroxide, 3-butenyltripropylammonium hydroxide, 1-butenylallyldipropylammonium hydroxide, 2-butenylallyldipropylammonium hydroxide, 3-butenylallyldipropylammonium hydroxide, 1-butenylpropenyldipropylammonium hydroxide, 2-butenylpropenyldipropylammonium hydroxide, 3-butenylpropenyldipropylammonium hydroxide, 1-butenylpropenylallyldipropylammonium hydroxide, 2-butenylpropenylallyldipropylammonium hydroxide, 3-butenylprop ... One or more of the following: propylpropylammonium hydroxide, allyltributylammonium hydroxide, propenyltributylammonium hydroxide, diallyl dibutylammonium hydroxide, allylpropenyl dibutylammonium hydroxide, triallyl butylammonium hydroxide, tripropenyl butylammonium hydroxide, diallyl propylbutylammonium hydroxide, diallyl propylbutylammonium hydroxide, allylpropenyl propylbutylammonium hydroxide, diallyl propenyl butylammonium hydroxide, allyl diallyl ammonium hydroxide, allyl dipropylbutylammonium hydroxide, propenyl dipropylbutylammonium hydroxide, 1-butenyl butyl dipropylammonium hydroxide, 2-butenyl butyl dipropylammonium hydroxide, and 3-butenyl butyl dipropylammonium hydroxide;

[0041] More preferably, the molar number of groups with 3 carbon atoms and the molar number of groups with 4 carbon atoms in the first template agent are calculated as follows: the ratio of the molar number of groups with 4 carbon atoms in the first template agent to the molar number of groups with 3 carbon atoms plus the molar number of groups with 4 carbon atoms is 5% to 95%.

[0042] Optionally, in the structural formula (M-2) of the second template agent, the alkyl group having 3 carbon atoms is selected from n-propyl and isopropyl, and the alkenyl group having 3 carbon atoms is selected from propenyl and allyl; preferably, the second template agent is selected from one or more of tetrapropylammonium hydroxide, allyltripropylammonium hydroxide, propenyltripropylammonium hydroxide, diallyldipropylammonium hydroxide, diallyldipropylammonium hydroxide, allylpropenyldipropylammonium hydroxide, triallylpropylammonium hydroxide, tripropenylpropylammonium hydroxide, allyldipropenylpropylammonium hydroxide, diallylpropenylpropylammonium hydroxide, diallylpropylisopropylammonium hydroxide, diallyldiisopropylammonium hydroxide, allylpropenyldiisopropylammonium hydroxide, triallylisopropylammonium hydroxide, tripropenylisopropylammonium hydroxide, allyldipropenylisopropylammonium hydroxide, and diallylpropenylisopropylammonium hydroxide;

[0043] Preferably, in the structural formula (M-3) of the third template agent, the alkyl group having 4 carbon atoms is selected from n-butyl, isobutyl, sec-butyl, and tert-butyl, and the alkenyl group having 4 carbon atoms is selected from n-butenyl and isobutylenyl; preferably, the third template agent is selected from one or more of tetrabutylammonium hydroxide, 1-butenyltributylammonium hydroxide, 2-butenyltributylammonium hydroxide, 3-butenyltributylammonium hydroxide, n-butyltri-n-butylammonium hydroxide, diisobutyltri-n-butylammonium hydroxide, tri-n-butylisobutylammonium hydroxide, sec-butyltri-n-butylammonium hydroxide, tert-butyltri-n-butylammonium hydroxide, and tri-n-butylisobutylammonium hydroxide;

[0044] More preferably, based on the total number of moles of groups with 3 carbon atoms in the second template agent and the total number of moles of groups with 4 carbon atoms in the third template agent, the ratio of the number of moles of groups with 4 carbon atoms in the second template agent to the number of moles of groups with 3 carbon atoms plus the number of moles of groups with 4 carbon atoms is 5% to 95%.

[0045] Optionally, 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.

[0046] Optionally, the silicone grease is selected from one or more compounds with the structure shown in formula (A):

[0047]

[0048] 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.

[0049] Optionally, the titanium source is selected from one or more of organic titanium sources and inorganic titanium sources;

[0050] Preferably, the organic titanium source is a titanium-containing organic ester, selected from at least one structure of the following formula (B):

[0051]

[0052] 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.

[0053] Preferably, the inorganic titanium source is selected from one or more of titanium chloride, nitrate or sulfate;

[0054] 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.

[0055] Optionally, in step S1, the molar ratio of silicon source (based on SiO2): titanium source (based on TiO2): template agent: water is 1:(0.001~0.050):(0.05~0.30):(5~40), preferably 1:(0.010~0.045):(0.08~0.24):(8~35), more preferably 1:(0.020~0.040):(0.12~0.20):(10~30), wherein the template agent is calculated based on the total molar number of the template agent;

[0056] Optionally, when the template agent includes a second template agent and a third template agent, the molar ratio of the second template agent to the third template agent is 1:0.20 to 20, preferably 1:0.75 to 7.5.

[0057] Optionally, the conditions for the first hydrothermal crystallization treatment in step S2 include: a hydrothermal crystallization temperature of 150–200°C, a hydrothermal crystallization time of 2–168 h, and a hydrothermal crystallization pressure of autogenous pressure; preferably, the hydrothermal crystallization temperature is 160–190°C, and the hydrothermal crystallization time is 12–144 h.

[0058] Optionally, before performing the first hydrothermal crystallization treatment, the method further includes: performing a hydrolysis and alcohol removal treatment on the raw material mixture; optionally, the conditions for the hydrolysis and alcohol removal treatment include: treatment at 5-120°C for 0.5-48 hours; preferably treatment at 40-100°C for 2-24 hours.

[0059] Optionally, after the first hydrothermal crystallization treatment in step S2, the method further includes the following steps:

[0060] S3. The product obtained from the first hydrothermal crystallization treatment is subjected to solid-liquid separation to obtain a solid product; the solid product is then subjected to drying and / or calcination treatment.

[0061] Optionally, the drying conditions include: a drying temperature of 100–200°C and a drying time of 2–10 hours;

[0062] The conditions for the calcination treatment include: a calcination temperature of 350–650°C and a calcination time of 2–10 h; preferably, the calcination temperature is 450–550°C and the calcination time is 3–8 h.

[0063] Optionally, after step S3, the method further includes the following steps:

[0064] S4. The product obtained from the roasting treatment is contacted with acid solution for acid treatment, and then a pH adjuster is added for neutralization treatment to obtain an intermediate product.

[0065] Optionally, in step S4, the acid solution used in the acid treatment is selected from one or more of hydrochloric acid, nitric acid, phosphoric acid, carbonic acid, sulfuric acid, and acetic acid; the concentration of the acid solution used is 0.1–1.0 mol / L, and the mass of the solid product used relative to 1 L of the acid solution is 80–150 g; optionally, the conditions for the acid treatment include: a contact temperature of 50–150°C, preferably 60–100°C, and a contact time of 0.5–5.0 h, preferably 1.0–3.5 h.

[0066] Optionally, the pH adjuster is selected from one or more alkaline solutions; the alkaline solution is selected from one or more of ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and sodium bicarbonate, and the neutralization treatment adjusts the pH of the solution to 5-7.

[0067] Optionally, after step S4, the method further includes the following steps:

[0068] S5. The intermediate product is brought into contact with an alkaline solution to undergo a second hydrothermal crystallization treatment.

[0069] Preferably, the weight ratio of the intermediate product to the effective alkali in the alkaline solution is 1:0.05 to 0.50, more preferably 1:0.10 to 0.40; optionally, the alkali in the alkaline solution is selected from one or more inorganic and organic alkalis.

[0070] Optionally, the inorganic base is selected from one or more of sodium hydroxide, sodium carbonate, and sodium bicarbonate; the organic base is selected from tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, allyltripropylammonium hydroxide, butyltripropylammonium hydroxide, 1-butenyltripropylammonium hydroxide, propyltributylammonium hydroxide, diallyldipropylammonium hydroxide, diallyldipropylammonium hydroxide, alllylpropenyldipropylammonium hydroxide, triallylpropylammonium hydroxide, alllyldipropenylpropylammonium hydroxide, diallylpropenylpropylammonium hydroxide, diallylpropylisopropylammonium hydroxide. Ammonium hydroxide, diallyl diisopropyl ammonium hydroxide, allyl propenyl diisopropyl ammonium hydroxide, triallyl isopropyl ammonium hydroxide, allyl diallyl isopropyl ammonium hydroxide, diallyl propenyl isopropyl ammonium hydroxide, 2-butenyl tributyl ammonium hydroxide, 3-butenyl tributyl ammonium hydroxide, n-butyl tri-n-butyl ammonium hydroxide, diisobutyl tri-n-butyl ammonium hydroxide, tri-n-butyl isobutyl ammonium hydroxide, sec-butyl tri-n-butyl ammonium hydroxide, tert-butyl tri-n-butyl ammonium hydroxide, and tri-n-butyl isobutyl ammonium hydroxide, one or more of these.

[0071] The conditions for the second hydrothermal crystallization treatment include: a hydrothermal crystallization temperature of 150–200°C, a hydrothermal crystallization time of 10–40 h, and a hydrothermal crystallization pressure of self-generated pressure; preferably, the hydrothermal crystallization temperature is 160–180°C and the hydrothermal crystallization time is 20–30 h.

[0072] The third aspect of this disclosure provides a eutectic titanium-silicon molecular sieve prepared according to the method described in the second aspect of this disclosure.

[0073] This fourth aspect of the disclosure provides the application of the eutectic titanium-silicon molecular sieves described in the first and third aspects of the disclosure in catalytic organic reactions and / or adsorption separation processes.

[0074] Optionally, the catalytic organic reaction includes propylene epoxidation to prepare propylene oxide, chloropropene catalytic chlorohydrin reaction to prepare dichloropropanol, and cyclohexanone oxime reaction to prepare cyclohexanone oxime;

[0075] Optionally, the preparation of cyclohexanone oxime by cyclohexanone oximation includes the following steps: under oximation reaction conditions, cyclohexanone, an oxidant, ammonia and a catalyst are contacted to carry out an oxidation reaction; the catalyst comprises the eutectic titanium-silicon molecular sieve;

[0076] 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;

[0077] 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.

[0078] Through the above technical solution, this disclosure provides a eutectic titanium-silicon molecular sieve, its preparation method, and its application. The XRD pattern of this eutectic titanium-silicon molecular sieve exhibits characteristic diffraction peaks of MFI-type and MEL-type molecular sieves in the 22°–25° range, respectively, yielding a TS-1 / TS-2 eutectic molecular sieve, which can leverage the synergistic effect of TS-1 and TS-2 molecular sieves. Furthermore, the XRD pattern of this eutectic titanium-silicon molecular sieve shows diffraction peaks in the 15.47±0.2° and 15.87±0.2° ranges, and its diffraction peak intensity I... 15.87 / I 15.47 The diffraction intensity ranges from 1.35 to 2.60; two adjacent diffraction peaks, at 23.68 ± 0.2° and 23.91 ± 0.2°, exist within the range of 22.5° to 23.5°, and their peak intensities I... 23.91 / I 23.68 The diffraction intensity ranges from 1.5 to 2.3; within the range of 29.5° to 30.5°, there are two adjacent diffraction peaks at 29.90±0.2° and 30.31±0.2°, and their diffraction peak intensities I are... 29.90 / I 30.31 With a pH of 2.5–4.0, this eutectic titanium-silicon molecular sieve exhibits excellent performance in catalytic oxidation reactions. When used for the amination of cyclohexanone to prepare cyclohexanone oxime, it demonstrates high catalytic activity, high feed conversion rate, and high selectivity for cyclohexanone oxime.

[0079] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0080] 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:

[0081] Figure 1 These are the XRD patterns of the titanium-silicon molecular sieves obtained in Example 1, Comparative Example 1, and Comparative Example 2;

[0082] Figure 2 These are the XRD patterns of the titanium-silicon molecular sieves obtained in Example 1, Comparative Example 1, and Comparative Example 2;

[0083] Figure 3 These are the XRD patterns of the titanium-silicon molecular sieves obtained in Example 1, Comparative Example 1, and Comparative Example 2;

[0084] Figure 4 These are the XRD patterns of the titanium-silicon molecular sieves obtained in Example 1, Comparative Example 1, and Comparative Example 2;

[0085] Figure 5 This is the UV-Vis spectrum of the eutectic titanium-silicon molecular sieve obtained in Example 1. Detailed Implementation

[0086] 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.

[0087] The first aspect of this disclosure provides a eutectic titanium-silicon molecular sieve, which has the following XRD characteristics:

[0088] The peak intensity of the diffraction peak at position 15.47±0.2° in the XRD pattern of the eutectic titanium-silicon molecular sieve is I. 15.47 The peak-intensity of the diffraction peak at position 15.87±0.2° is denoted as I. 15.87 ;

[0089] The peak intensity of the diffraction peak at position 23.68±0.2° in the XRD pattern of the eutectic titanium-silicon molecular sieve is denoted as I. 23.68 The peak intensity of the diffraction peak at position 23.91±0.2° is denoted as I. 23.91 ;

[0090] The peak intensity of the diffraction peak at position 29.90±0.2° in the XRD pattern of the eutectic titanium-silicon molecular sieve is denoted as I. 29.90 The peak intensity of the diffraction peak at position 30.31±0.2° is denoted as I. 30.31 ;

[0091] As defined in equation (1), X1 is any value within the range of 1.30 to 2.65:

[0092] X1 = I 15.87 / I 15.47 Equation (1); and,

[0093] As defined in equation (2), X2 is any value within the range of 1.5 to 2.45:

[0094] X2 = I 23.91 / I 23.68 Equation (2);

[0095] As defined in equation (3), X3 is any value within the range of 2.1 to 4.0:

[0096] X3 = I 29.90 / I 30.31 Equation (3).

[0097] This disclosure provides a eutectic titanium-silicon molecular sieve. In the XRD pattern of the eutectic titanium-silicon molecular sieve, there are characteristic diffraction peaks of MFI type molecular sieve (2θ is 23.06°, 23.25°, 23.68°, 23.91°, 24.39°) and MEL type molecular sieve (2θ is 23.12° and 23.93°) in the range of 22° to 25°, respectively, to obtain TS-1 / TS-2 eutectic molecular sieve, which can exert the synergistic effect of TS-1 molecular sieve and TS-2 molecular sieve. In addition, the intensity of the diffraction peaks in the XRD pattern of the eutectic titanium-silicon molecular sieve meets the numerical range of X1 to X3 defined by formula (1) to (3). The eutectic titanium-silicon molecular sieve has good effect in catalytic oxidation reaction. When used for the preparation of cyclohexanone oxime by ammonification of cyclohexanone, it has high catalytic activity, high raw material conversion rate and high cyclohexanone oxime selectivity.

[0098] In this disclosure, the diffraction peaks at various positions in the XRD pattern of the eutectic titanium-silicon molecular sieve represent different diffraction crystal planes, where the diffraction peaks near 2θ of 7.91°, 8.78°, 23.05°, 23.92° and 24.38° represent the diffraction of the (101), (200), (501), (033) and (133) crystal planes, respectively.

[0099] In a preferred embodiment, X1 is any value within the range of 1.5 to 2.3, X2 is any value within the range of 1.6 to 2.0, and X3 is any value within the range of 2.8 to 3.6. Through extensive experiments, the inventors of this disclosure have discovered that when the values ​​of X1 to X3 obtained from formulas (1) to (3) of the eutectic titanium-silicon molecular sieve are within the range of this embodiment, the eutectic titanium-silicon molecular sieve exhibits better catalytic performance in catalytic oxidation reactions.

[0100] In one embodiment, the XRD pattern of the eutectic titanium-silicon molecular sieve exhibits diffraction peaks at positions 8.78±0.2° and 8.82±0.2° within the range of 8.5° to 9.5°, and diffraction peaks at positions 17.60±0.1°, 17.66±0.1°, and 17.75±0.1° within the range of 17.4° to 18.0°. When the eutectic titanium-silicon molecular sieve meets the positions of the diffraction peaks in this embodiment, it can exert the synergistic effect of TS-1 and TS-2 molecular sieves, exhibiting good performance in catalytic oxidation reactions. When used for the amination of cyclohexanone to prepare cyclohexanone oxime, it demonstrates high catalytic activity, high feed conversion rate, and high selectivity for cyclohexanone oxime.

[0101] Through experimental research, the inventors of this disclosure also discovered that the UV-Vis spectrum of the eutectic titanium-silicon molecular sieve provided in this disclosure has signal peaks at positions of 270±10nm and 330±10nm, respectively. The signal peak at position 270±10nm represents an isolated six-coordinated titanium species, and the signal peak at position 330±10nm represents anatase. Furthermore, the peak intensities of the signal peaks of these two species satisfy a certain ratio.

[0102] In a preferred embodiment, the eutectic titanium-silicon molecular sieve has the following UV-Vis characteristics:

[0103] The peak intensity of the peak at position 270±10nm in the UV-Vis spectrum of the eutectic titanium-silicon molecular sieve is denoted as Q1, and the peak intensity of the peak at position 330±10nm is denoted as Q2.

[0104] As defined in equation (4), X4 is any value within the range of 1.6 to 4.5:

[0105] X4 = Q1 / Q2 (Equation 4);

[0106] Preferably, X4 is any value within the range of 2.5 to 4.3; more preferably, X4 is any value within the range of 2.7 to 4.0. The X4 value of the eutectic titanium-silicon molecular sieve provided in this disclosure is within the optimized range provided in this embodiment, and the eutectic titanium-silicon molecular sieve exhibits higher catalytic activity.

[0107] In one specific embodiment, the molar ratio of titanium to silicon in the eutectic titanium-silicon molecular sieve is 1:2 to 1000, preferably 1:24 to 67.

[0108] In one specific embodiment, the average particle size of the eutectic titanium-silicon molecular sieve particles is 0.05–0.80 nm, preferably 0.20–0.35 nm; the BET specific surface area is 420–500 m². 2 / g, preferably 430-445m 2 / g; Microporous specific surface area is 370-450m² 2 / g, preferably 380-395m 2 / g; total pore volume is 0.1–0.30 cm³. 3 / g, preferably 0.23~0.28cm 3 / g; mesopore volume is 0.05~0.15cm³ 3 / g, preferably 0.07~0.13cm 3 / g.

[0109] Optionally, the eutectic titanium-silicon molecular sieve has an MFI structure and a MEL structure.

[0110] In one specific embodiment, the eutectic titanium-silicon molecular sieve provided in this disclosure can be used as the catalytically active component. Utilizing its unique framework elements, or by using it as a support to further load active centers, or by combining it with other catalysts, co-catalysts, structural additives, electronic additives, binders, inert supports, etc., through mechanical mixing, kneading molding, tableting, extrusion molding, spray molding, spheroidizing, oil column molding, or other methods, a catalyst can be prepared. The reagents and preparation processes used can all be conventional reagents or processes in the art.

[0111] A second aspect of this disclosure provides a method for preparing eutectic titanium-silicon molecular sieves, comprising the following steps:

[0112] S1. A silicon source, a titanium source, a template agent, and water are mixed to obtain a raw material mixture; the template agent is selected from one or more organic ammonium hydroxide compounds; and the structural formula of the template agent contains at least one selected from alkyl and alkenyl groups with 3 carbon atoms, and the structural formula of the template agent contains at least one selected from alkyl and alkenyl groups with 4 carbon atoms.

[0113] S2. The raw material mixture is subjected to a first hydrothermal crystallization treatment.

[0114] The method for preparing eutectic titanium-silicon molecular sieves disclosed herein uses an organic ammonium hydroxide compound as a template agent, and the template agent contains at least one group with 3 carbon atoms and at least one group with 4 carbon atoms, that is, it cannot be all groups with 3 carbon atoms or all groups with 4 carbon atoms, so as to achieve the effect of preparing eutectic titanium-silicon molecular sieves containing both MFI and MEL configurations.

[0115] In one embodiment, the template agent is selected from one or more of the first template agents, or the template agent includes one or more of the second template agents and one or more of the third template agents;

[0116] The first template agent is selected from one or more compounds having the structure shown in formula (M-1):

[0117] R1, R2, R3 and R4 are each independently selected from alkyl groups having 3 to 4 carbon atoms and alkenyl groups having 3 to 4 carbon atoms, and R1, R2, R3 and R4 contain at least one alkyl or alkenyl group having 3 carbon atoms and at least one alkyl or alkenyl group having 4 carbon atoms.

[0118] The second template agent is selected from one or more compounds having the structure shown in formula (M-2):

[0119] R5, R6, R7 and R8 are each independently selected from alkyl groups with 3 carbon atoms and alkenyl groups with 3 carbon atoms;

[0120] The third template agent is selected from one or more compounds having the structure shown in formula (M-3):

[0121] Among them, R9, R 10 R 11 and R 12 Each is independently selected from alkyl groups with 4 carbon atoms and alkenyl groups with 4 carbon atoms.

[0122] In one embodiment, in the structural formula (M-1) of the first template agent, any three groups of R1, R2, R3 and R4 are selected from alkyl groups with 3 carbon atoms and alkenyl groups with 3 carbon atoms, and the other group is selected from alkyl groups with 4 carbon atoms and alkenyl groups with 4 carbon atoms.

[0123] Optionally, the alkyl group having 3 carbon atoms is selected from n-propyl and isopropyl, and the alkenyl group having 3 carbon atoms is selected from propenyl and allyl; the alkyl group having 4 carbon atoms is selected from n-butyl, isobutyl, sec-butyl, and tert-butyl, and the alkenyl group having 4 carbon atoms is selected from n-butenyl and isobutylenyl. In a preferred embodiment, the first template agent is selected from tripropylbutylammonium hydroxide, tributylpropylammonium hydroxide, dipropyldibutylammonium hydroxide, 1-butenyltripropylammonium hydroxide, 2-butenyltripropylammonium hydroxide, 3-butenyltripropylammonium hydroxide, 1-butenylallyldipropylammonium hydroxide, 2-butenylallyldipropylammonium hydroxide, 3-butenylallyldipropylammonium hydroxide, 1-butenylpropenyldipropylammonium hydroxide, 2-butenylpropenyldipropylammonium hydroxide, 3-butenylpropenyldipropylammonium hydroxide, 1-butenylpropenylallyldipropylammonium hydroxide, 2-butenylpropenyldipropylammonium hydroxide, 3-butenylpropenyldipropylammonium hydroxide, 1-butenylpropenylallyldipropylammonium hydroxide Ammonium, 2-Butenylpropenylallylpropylammonium hydroxide, 3-Butenylpropenylallylpropylammonium hydroxide, allyltributylammonium hydroxide, propenyltributylammonium hydroxide, diallyl dibutylammonium hydroxide, allylpropenyl dibutylammonium hydroxide, triallyl butylammonium hydroxide, tripropenyl butylammonium hydroxide, diallyl propyl butylammonium hydroxide, diallyl propyl butylammonium hydroxide, allylpropenyl propyl butylammonium hydroxide, diallyl propenyl butylammonium hydroxide, allyl diallyl ammonium hydroxide, allyl dipropyl butylammonium hydroxide, propenyl dipropyl butylammonium hydroxide, 1 -Butenylbutyldipropylammonium hydroxide, 2-butenylbutyldipropylammonium hydroxide, and 3-butenylbutyldipropylammonium hydroxide; preferably selected from tripropylbutylammonium hydroxide, tributylpropylammonium hydroxide, dipropyldibutylammonium hydroxide, 1-butenyltripropylammonium hydroxide, 2-butenyltripropylammonium hydroxide, 3-butenyltripropylammonium hydroxide, tripropylbutylammonium hydroxide, and tributylpropylammonium hydroxide, dipropyldibutylammonium hydroxide, 1-butenyltripropylammonium hydroxide, 2-butenyltripropylammonium hydroxide, 3-butenyltripropylammonium hydroxide, allyldipropylammonium hydroxide, etc. Propylbutylammonium hydroxide, propenyl dipropylbutylammonium hydroxide, 1-butenyl butyl dipropylammonium hydroxide, 2-butenyl butyl dipropylammonium hydroxide, 3-butenyl butyl dipropylammonium hydroxide; more preferably, it is selected from one or more of tripropylbutylammonium hydroxide, tributylpropylammonium hydroxide, dipropyl dibutylammonium hydroxide, allyl dipropylbutylammonium hydroxide, propenyl dipropylbutylammonium hydroxide, 1-butenyl tripropylammonium hydroxide, 1-butenyl butyl dipropylammonium hydroxide, 2-butenyl butyl dipropylammonium hydroxide, 3-butenyl butyl dipropylammonium hydroxide.

[0124] In a preferred embodiment, the ratio of the total number of moles of groups with three carbon atoms and the total number of moles of groups with four carbon atoms in the first template agent to the number of moles of groups with four carbon atoms is 5% to 95%. When the number of moles of C3 and C4 groups in the first template agent is within the range defined in this embodiment, the prepared eutectic titanium silicate molecular sieve can exert the synergistic effect of TS-1 and TS-2 molecular sieves, exhibiting good performance in catalytic oxidation reactions. When used for the amination of cyclohexanone to prepare cyclohexanone oxime, it exhibits high catalytic activity, high feed conversion rate, and high selectivity for cyclohexanone oxime.

[0125] In one embodiment, in the structural formula (M-2) of the second template agent, the alkyl group having 3 carbon atoms is selected from n-propyl and isopropyl, and the alkenyl group having 3 carbon atoms is selected from propenyl and allyl.

[0126] In the structural formula (M-3) of the third template agent, the alkyl group having 4 carbon atoms is selected from n-butyl, isobutyl, sec-butyl, and tert-butyl, and the alkenyl group having 4 carbon atoms is selected from n-butenyl and isobutylenyl.

[0127] In a preferred embodiment, the second template agent is selected from tetrapropylammonium hydroxide, allyltripropylammonium hydroxide, propenyltripropylammonium hydroxide, diallyldipropylammonium hydroxide, diallyldipropylammonium hydroxide, allylpropenyldipropylammonium hydroxide, triallylpropylammonium hydroxide, allyldipropenylpropylammonium hydroxide, diallylpropenylpropylammonium hydroxide, diallylpropylisopropylammonium hydroxide, diallyldiisopropylammonium hydroxide, allylpropenyldiisopropylammonium hydroxide, and triallylisopropylammonium hydroxide. The third template agent is selected from one or more of the following: tripropenylisopropylammonium hydroxide, allyldipropenylisopropylammonium hydroxide, and diallylpropenylisopropylammonium hydroxide;

[0128] In a preferred embodiment, based on the total molar number of groups with 3 carbon atoms in the second template agent and the total molar number of groups with 4 carbon atoms in the third template agent, the ratio of the molar number of groups with 4 carbon atoms in the second and third template agents to the molar number of groups with 3 carbon atoms plus the molar number of groups with 4 carbon atoms is 5-95%. When the molar number of the three carbon groups in the second template agent and the four carbon groups in the third template agent is within the range defined in this embodiment, the prepared eutectic titanium silicate molecular sieve can exert the synergistic effect of TS-1 and TS-2 molecular sieves, exhibiting good performance in catalytic oxidation reactions. When used for the amination of cyclohexanone to prepare cyclohexanone oxime, it exhibits high catalytic activity, high feed conversion rate, and high selectivity for cyclohexanone oxime.

[0129] 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.

[0130] In a preferred embodiment, the silicone grease is selected from one or more compounds with the structure shown in formula (A):

[0131]

[0132] 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 Rc 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.

[0133] In one embodiment, the titanium source is selected from one or more of organic titanium sources and inorganic titanium sources;

[0134] Preferably, the organic titanium source is a titanium-containing organic ester, selected from at least one structure of the following formula (B):

[0135]

[0136] 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.

[0137] Preferably, the inorganic titanium source is selected from one or more of titanium chloride, nitrate or sulfate;

[0138] 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.

[0139] 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.

[0140] In one embodiment, in step S1, the molar ratio of silicon source (based on SiO2): titanium source (based on TiO2): template agent: water is 1:(0.001~0.050):(0.05~0.30):(5~40), preferably 1:(0.010~0.045):(0.08~0.24):(8~35), more preferably 1:(0.020~0.040):(0.12~0.20):(10~30), wherein the template agent is calculated based on the total molar number of template agents. Preparing eutectic titanium-silicon molecular sieves according to the optimized raw material molar ratio in this embodiment can further improve the catalytic performance of the eutectic titanium-silicon molecular sieves.

[0141] In a preferred embodiment, when the second template agent and the third template agent are used in combination, the molar ratio of the second template agent to the third template agent is 1:0.20 to 20, preferably 1:0.75 to 7.5.

[0142] In one specific embodiment, before performing the first hydrothermal crystallization treatment, the method further includes: performing a hydrolysis and alcohol removal treatment on the raw material mixture; optionally, the conditions for the hydrolysis and alcohol removal treatment include: treatment at 5-120°C for 0.5-48 hours; preferably treatment at 40-100°C for 2-24 hours.

[0143] In one embodiment, the conditions for the first hydrothermal crystallization treatment in step S2 include: a hydrothermal crystallization temperature of 150–200°C, a hydrothermal crystallization time of 2–168 h, and a self-generated pressure.

[0144] In a preferred embodiment, the conditions for the first hydrothermal crystallization treatment in step S2 include: a hydrothermal crystallization temperature of 160–190°C and a hydrothermal crystallization time of 12–144 h. The optimized first hydrothermal crystallization treatment conditions according to this embodiment can further improve the catalytic performance of the molecular sieve.

[0145] In one embodiment, after the first hydrothermal crystallization treatment in step S2, the method further includes the following steps:

[0146] S3. The product obtained from the first hydrothermal crystallization treatment is subjected to solid-liquid separation to obtain a solid product; the solid product is then subjected to drying and / or calcination treatment.

[0147] In this disclosure, the solid-liquid separation includes one or more of centrifugation, filtration, evaporation, sedimentation, and membrane separation, and the solid-liquid separation can be performed according to conventional operations and conditions in the art. It also includes returning the liquid product after separating the solid product to the first step for preparing the silicon-titanium gel. The liquid product includes eutectic titanium-silicon molecular sieve nanocrystals, amorphous silicon, amorphous titanium, and a template agent. The specific liquid recycling process is a conventional operation for those skilled in the art.

[0148] In this disclosure, most of the moisture in the molecular sieve can be removed by drying, thereby reducing the amount of moisture evaporation from the solid during calcination; the purpose of calcination is to remove the template agent from the molecular sieve.

[0149] In one embodiment, the drying conditions include: a drying temperature of 100–200°C and a drying time of 2–10 hours;

[0150] The conditions for the calcination treatment include: a calcination temperature of 350–650°C and a calcination time of 2–10 h; preferably, the calcination temperature is 450–550°C and the calcination time is 3–8 h.

[0151] In one embodiment, after step S3, the method further includes the following steps:

[0152] S4. The product obtained from the roasting treatment is contacted with acid solution for acid treatment, and then a pH adjuster is added for neutralization treatment to obtain an intermediate product.

[0153] Optionally, in step S4, the acid solution used in the acid treatment is selected from one or more of hydrochloric acid, nitric acid, phosphoric acid, carbonic acid, sulfuric acid, and acetic acid; the concentration of the acid solution used is 0.1–1.0 mol / L, and the mass of the solid product used relative to 1 L of the acid solution is 80–150 g; optionally, the conditions for the acid treatment include: a contact temperature of 50–150°C, preferably 60–100°C, and a contact time of 0.5–5.0 h, preferably 1.0–3.5 h.

[0154] Optionally, the pH adjuster is selected from one or more alkaline solutions; the alkaline solution is selected from one or more of ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and sodium bicarbonate, and the neutralization treatment adjusts the pH of the solution to 5-7.

[0155] In one embodiment, after step S4, the method further includes the following steps:

[0156] S5. The intermediate product is brought into contact with an alkaline solution to undergo a second hydrothermal crystallization treatment.

[0157] Preferably, the weight ratio of the intermediate product to the effective alkali in the alkaline solution is 1:0.05 to 0.50, more preferably 1:0.10 to 0.40; optionally, the alkali in the alkaline solution is selected from one or more inorganic and organic alkalis.

[0158] Optionally, the inorganic base is selected from one or more of sodium hydroxide, sodium carbonate, and sodium bicarbonate; the organic base is selected from tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, allyltripropylammonium hydroxide, butyltripropylammonium hydroxide, 1-butenyltripropylammonium hydroxide, propyltributylammonium hydroxide, diallyldipropylammonium hydroxide, diallyldipropylammonium hydroxide, alllylpropenyldipropylammonium hydroxide, triallylpropylammonium hydroxide, alllyldipropenylpropylammonium hydroxide, diallylpropenylpropylammonium hydroxide, diallylpropylisopropylammonium hydroxide, diallyldiisopropylammonium hydroxide, etc. One or more of allylpropenyl diisopropyl ammonium hydroxide, triallyl isopropyl ammonium hydroxide, tripropenyl isopropyl ammonium hydroxide, allyl diallyl isopropyl ammonium hydroxide, diallyl propenyl isopropyl ammonium hydroxide, 2-butenyl tributyl ammonium hydroxide, 3-butenyl tributyl ammonium hydroxide, n-butyltri-n-butyl ammonium hydroxide, diisobutyltri-n-butyl ammonium hydroxide, tri-n-butyl isobutyl ammonium hydroxide, sec-butyltri-n-butyl ammonium hydroxide, tert-butyltri-n-butyl ammonium hydroxide, and tri-n-butyl isobutyl ammonium hydroxide; preferably, the contact conditions include: a temperature of 160–180°C and a time of 20–30 h;

[0159] Preferably, the conditions for the second hydrothermal crystallization treatment include: a hydrothermal crystallization temperature of 150–200°C, a hydrothermal crystallization time of 10–40 h, and a hydrothermal crystallization pressure of self-generated pressure; preferably, the hydrothermal crystallization temperature is 160–180°C, and the hydrothermal crystallization time is 20–30 h. By subjecting the intermediate product after acid treatment to a second hydrothermal crystallization treatment, a hierarchical porous structure can be prepared inside the molecular sieve, improving diffusion performance.

[0160] The third aspect of this disclosure provides a eutectic titanium-silicon molecular sieve prepared according to the method described in the second aspect of this disclosure.

[0161] This fourth aspect of the disclosure provides the application of the eutectic titanium-silicon molecular sieves described in the first and third aspects of the disclosure in catalytic organic reactions and / or adsorption separation processes.

[0162] 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).

[0163] In one specific embodiment, the organic catalytic reaction includes propylene epoxidation to prepare propylene oxide, chloropropene catalytic chlorohydrin reaction to prepare dichloropropanol, and cyclohexanone oxime reaction to prepare cyclohexanone oxime.

[0164] In one specific embodiment, the preparation of cyclohexanone oxime by cyclohexanone oxime includes the following steps:

[0165] 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 eutectic titanium-silicon molecular sieve.

[0166] 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;

[0167] 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.

[0168] In the application of the eutectic titanium-silicon molecular sieve provided in this disclosure, the eutectic titanium-silicon molecular sieve or the catalyst containing the eutectic 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 application 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.

[0169] 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.

[0170] The present disclosure is further described in detail below through examples. All raw materials used in the examples are commercially available.

[0171] In the following embodiments and comparative examples:

[0172] 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 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.

[0173] The chemical composition of the molecular sieve was determined by XRF analysis.

[0174] 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 RIPP 151-90 in "Analytical Methods for Petrochemical Industry" (published by Science Press in September 1990, first edition) compiled by Yang Cuiding et al.

[0175] 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.

[0176] The state of titanium species was determined by ultraviolet-visible spectroscopy analysis using a JASCO UV-visible 550 ultraviolet spectrophotometer. The testing method included pellet pressing, with a scanning range of 190–800 nm.

[0177] Unless otherwise specified, all raw materials used in the examples and comparative examples are analytical grade reagents.

[0178] Example 1

[0179] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:0.03:0.20:25, a sol was obtained by stirring a solution of butyltripropylammonium hydroxide (20 wt%, first template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4] and deionized water at 65°C for about 12 hours. The molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 25%. Then, crystallization was carried out at 185℃ for 34 hours (first hydrothermal crystallization treatment). The solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and then calcined at 550℃ for 6 hours. Next, it was mixed with a 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: a mass-to-volume ratio of acid to the solid product of 100 g solid product / 1 L acid, a contact temperature of 75℃, a contact time of 2 hours, and neutralization with a suitable amount of ammonia water to a pH of approximately 6.5 after hydrochloric acid treatment. The intermediate product obtained after acid treatment was then mixed with a tetrapropylammonium hydroxide aqueous solution (alkali solution, 25% by weight), with a mass ratio of intermediate product to alkali solution (effective mass of alkali) of 1:0.20, and hydrothermally treated at 173℃ for 17 hours (second hydrothermal crystallization treatment) to obtain a molecular sieve solid, designated TS-1-A.

[0180] The XRD characterization results of molecular sieve TS-1-A are as follows: Figures 1-4 As shown, by Figures 1-4 It can be seen that the molecular sieve exhibits diffraction peaks at positions of 15.47±0.2° and 15.87±0.2°. Figure 3 Diffraction peaks are present at positions of 23.06±0.2° and 23.22±0.2°. Figure 1 , Figure 4 The diffraction peaks at positions 29.90±0.2° and 30.31±0.2° were calculated based on the XRD spectrum data and are listed in Table 1.

[0181] And by Figure 2 It can be seen that the molecular sieve TS-1-A has two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°. Figure 4 It can be seen that the molecular sieve TS-1-A has diffraction peaks (MEL configuration) at the 23.12° position, indicating that the sample is a eutectic titanium-silicon molecular sieve with both MFI and MEL configurations.

[0182] The UV-Vis characterization results of molecular sieve TS-1-A are as follows: Figure 5 As shown, by Figure 5 It can be seen that the molecular sieve has spectral peaks at 270 nm and 330 nm. The calculated X4 is listed in Table 1.

[0183] Example 2

[0184] A sol was prepared by mixing 1-butenyltripropylammonium hydroxide (25 wt%, first template agent) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water at 76 °C for approximately 14 hours according to a molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:0.04:0.15:22. The molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 25%. Then, crystallization was carried out at 167℃ for 19 hours (first hydrothermal crystallization treatment). Afterwards, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and calcined at 550℃ for 6 hours. Next, it was mixed with a 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: a mass-to-volume ratio of acid to the solid product of 110 g solid product / 1 L acid, a contact temperature of 70℃, a contact time of 3 hours, and neutralization with an appropriate amount of ammonia water after hydrochloric acid treatment. Then, it was mixed with a tetrabutylammonium hydroxide aqueous solution (alkali solution, 30 wt%), with a mass ratio of intermediate product to alkali solution (effective mass of alkali) of 1:0.35, and hydrothermally treated at 166℃ for 25 hours (second hydrothermal crystallization treatment) to obtain a molecular sieve solid, designated TS-1-B.

[0185] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0186] Example 3

[0187] A sol was prepared by stirring a 25% by weight solution of butylallyl dipropylammonium hydroxide (first template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water at 63°C for about 6 hours according to a molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:0.04:0.15:27. The molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 25%. Then, crystallization was carried out at 178℃ for 10 hours (first hydrothermal crystallization treatment). Afterwards, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and calcined at 550℃ for 6 hours. Next, it was mixed with a 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: a mass-to-volume ratio of acid to the solid product of 130 g solid product / 1 L acid, a contact temperature of 100℃, a contact time of 1.0 h, and neutralization with an appropriate amount of ammonia water after hydrochloric acid treatment. Then, it was mixed with an allyltripropylammonium hydroxide aqueous solution (alkali solution, 25 wt%), with a mass ratio of intermediate product to alkali solution (effective mass of alkali) of 1:0.10, and hydrothermally treated at 166℃ for 25 hours (second hydrothermal crystallization treatment) to obtain a molecular sieve solid, designated TS-1-C.

[0188] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0189] Example 4

[0190] A sol was prepared by stirring dibutyldipropylammonium hydroxide solution (25 wt%, first template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water at 85°C for about 14 hours according to the molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water as 1:0.04:0.20:26. The molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 50%. Then, crystallization was carried out at 182℃ for 26 hours (first hydrothermal crystallization treatment). Afterwards, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and calcined at 550℃ for 6 hours. Next, it was mixed with a 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: a mass-to-volume ratio of acid to the solid product of 80 g solid product / 1 L acid, a contact temperature of 60℃, a contact time of 3.5 hours, and neutralization with an appropriate amount of ammonia water after hydrochloric acid treatment. Then, it was mixed with an aqueous solution of butyltripropylammonium hydroxide (alkali solution, 26 wt%), with a mass ratio of intermediate product to alkali solution (effective mass of alkali) of 1:0.40, and hydrothermally treated at 172℃ for 32 hours (second hydrothermal crystallization treatment) to obtain a molecular sieve solid, designated TS-1-D.

[0191] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0192] Example 5

[0193] Tributylpropylammonium hydroxide solution (25 wt%, first template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water were stirred at 76°C for about 8 hours according to the molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:0.04:0.20:23 to obtain a sol. The molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 75%. Then, crystallization was carried out at 153℃ for 40 hours (first hydrothermal crystallization treatment). Afterwards, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and calcined at 550℃ for 6 hours. Next, it was mixed with 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: the mass-to-volume ratio of acid solution to the solid product was 150 g solid product / 1 L acid solution, the contact temperature was 85℃, the contact time was 2 hours, and an appropriate amount of ammonia water was added to neutralize after hydrochloric acid treatment. Then, it was mixed with an aqueous solution of 1-butenyltripropylammonium hydroxide (alkali solution, 23 wt%), the mass ratio of intermediate product to alkali solution (effective mass of alkali) was 1:0.15, and hydrothermally treated at 167℃ for 23 hours (second hydrothermal crystallization treatment) to obtain molecular sieve solid, numbered TS-1-E.

[0194] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0195] Example 6

[0196] A sol was prepared by stirring 2-butenylbutyldipropylammonium hydroxide solution (25 wt%, first template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water at 63°C for approximately 19 hours according to the molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water as 1:0.04:0.20:20. The molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 50%. Then, crystallization was carried out at 167℃ for 20 hours (first hydrothermal crystallization treatment). Afterwards, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and calcined at 550℃ for 6 hours. Next, it was mixed with a 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: a mass-to-volume ratio of acid to the solid product of 90 g solid product / 1 L acid, a contact temperature of 87℃, a contact time of 0.5 hours, and neutralization with an appropriate amount of ammonia water after hydrochloric acid treatment. Then, it was mixed with an aqueous solution of propyltributylammonium hydroxide (alkali solution, 35 wt%), with a mass ratio of intermediate product to alkali solution (effective mass of alkali) of 1:0.25, and hydrothermally treated at 166℃ for 16 hours (second hydrothermal crystallization treatment) to obtain a molecular sieve solid, designated TS-1-F.

[0197] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0198] Example 7

[0199] A sol was prepared by stirring tetrapropylammonium hydroxide solution (25 wt%, second template agent), tetrabutylammonium hydroxide solution (40 wt%, third template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water at 82°C for approximately 17 hours, according to a molar ratio of silicon source (SiO2): titanium source (TiO2): template agent (total molar number of template agents): water of 1:0.04:0.20:20. Then, crystallization was carried out at 185℃ for 33 hours (first hydrothermal crystallization treatment). Afterwards, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and calcined at 550℃ for 6 hours. Next, it was mixed with a 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: a mass-to-volume ratio of acid to the solid product of 126 g solid product / 1 L acid, a contact temperature of 100℃, a contact time of 0.5 hours, and neutralization with an appropriate amount of ammonia water after hydrochloric acid treatment. Then, it was mixed with a tetrapropylammonium hydroxide aqueous solution (alkali solution, 25 wt%), with a mass ratio of intermediate product to alkali solution (effective mass of alkali) of 1:0.38, and hydrothermally treated at 173℃ for 22 hours (second hydrothermal crystallization treatment) to obtain a molecular sieve solid, designated TS-1-G.

[0200] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0201] Example 8

[0202] A sol was prepared by stirring allyl tripropylammonium hydroxide (25 wt%, second template agent), tetrabutylammonium hydroxide (40 wt%, third template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water at 68°C for approximately 13 hours, according to a molar ratio of silicon source (SiO2): titanium source (TiO2): template agent (total molar number of template agents): water of 1:0.04:0.20:20. Then, crystallization was carried out at 178℃ for 8 hours (first hydrothermal crystallization treatment). Afterwards, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and calcined at 550℃ for 6 hours. Next, it was mixed with 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: the mass-to-volume ratio of acid solution to the solid product was 96 g solid product / 1 L acid solution, the contact temperature was 95℃, the contact time was 0.8 hours, and an appropriate amount of ammonia water was added to neutralize after hydrochloric acid treatment. Then, it was mixed with tetrabutylammonium hydroxide aqueous solution (alkali solution, 40 wt%), the mass ratio of intermediate product to alkali solution (effective mass of alkali) was 1:0.33, and hydrothermally treated at 162℃ for 35 hours (second hydrothermal crystallization treatment) to obtain molecular sieve solid, numbered TS-1-H.

[0203] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0204] Example 9

[0205] A sol was prepared by mixing butyltripropylammonium hydroxide (20 wt%, first template agent) solution, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water at 74 °C for approximately 19 hours, with a molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:0.03:0.20:25. The sol was obtained by stirring at 74 °C for approximately 19 hours, wherein the molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 25%. The sol was then crystallized at 178 °C for 39 hours (first hydrothermal crystallization treatment). Afterwards, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100 °C for 3 hours, and calcined at 550 °C for 6 hours to obtain a molecular sieve solid, designated TS-1-I.

[0206] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0207] Example 10

[0208] A solution of 1-butenyltripropylammonium hydroxide (25 wt%, first template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water were stirred at 61 °C for approximately 9 hours to obtain a sol, wherein the molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 25%. The sol was then crystallized at 174 °C for 19 hours (first hydrothermal crystallization treatment). The solid obtained by centrifugation was filtered, washed with distilled water, dried at 100 °C for 3 hours, and calcined at 550 °C for 6 hours to obtain a molecular sieve solid, designated TS-1-J.

[0209] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0210] Example 11

[0211] A solution of 2-butenylbutyldipropylammonium hydroxide (25 wt%, first template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water were stirred at 76 °C for about 10 hours to obtain a sol, wherein the molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 50%. The sol was then crystallized at 183 °C for 17 hours (first hydrothermal crystallization treatment). The solid obtained by centrifugation was then filtered, washed with distilled water, dried at 100 °C for 3 hours, and calcined at 550 °C for 6 hours to obtain a molecular sieve solid, designated TS-1-K.

[0212] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0213] Example 12

[0214] A sol was prepared by stirring tetrapropylammonium hydroxide (25 wt%, second template agent), tetrabutylammonium hydroxide (40 wt%, third template agent), tetrabutyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water at 81 °C for approximately 16 hours, according to a molar ratio of silicon source (SiO2): titanium source (TiO2): template agent (total molar number of template agents): water of 1:0.04:0.20:20. The mixture was obtained by stirring at 81 °C for approximately 16 hours, with the molar ratio of the second template agent to the third template agent being 53:47. The total molar ratio of C4 groups in the two template agents (C4 / (C3+C4)) was 47%. The mixture was then crystallized at 174 °C for 25 hours (first hydrothermal crystallization treatment). Afterward, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100 °C for 3 hours, and calcined at 550 °C for 6 hours to obtain a molecular sieve solid, designated TS-1-L.

[0215] XRD characterization revealed two adjacent diffraction peaks (MFI configuration) at 8.78±0.2° and 8.82±0.2°, and a diffraction peak (MEL configuration) at 23.12°, indicating that the sample is a eutectic titanium silicate molecular sieve with both MFI and MEL configurations.

[0216] Example 13

[0217] This embodiment refers to the preparation method of Example 1, but differs from Example 1 in that:

[0218] A butyltripropylammonium hydroxide solution (20% by weight, first template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water were mixed according to a molar ratio of silicon source (SiO2): titanium source (TiO2): template agent (total molar amount of template agent): water of 1:0.001:0.05:40. The remaining process was the same as in Example 1 to obtain a molecular sieve solid, designated TS-1-M.

[0219] Comparative Example 1

[0220] This embodiment refers to the preparation method of Example 13, but differs from Example 13 in that:

[0221] A butyltripropylammonium hydroxide solution (20% by weight, first template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water were mixed according to a molar ratio of silicon source (SiO2): titanium source (TiO2): template agent (total molar amount of template agent): water of 1:0.1:0.02:60. The remaining process was the same as in Example 13, and a molecular sieve solid was obtained, designated TS-1-N.

[0222] Comparative Example 2

[0223] This embodiment refers to the preparation method of Example 7, but differs from Example 7 in that:

[0224] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): template agent (total molar amount of template agent): water of 1:0.001:0.05:40, tetrapropylammonium hydroxide solution (25 wt%, second template agent), tetrabutylammonium hydroxide solution (40 wt%, third template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4] and deionized water were mixed, wherein the molar ratio of the second template agent and the third template agent was 7:3, and the molar ratio of the total C4 groups in the two template agents (C4 / (C3+C4)) was 30%; the rest of the process was the same as in Example 7, and a molecular sieve solid was obtained, numbered TS-1-O.

[0225] Comparative Example 3

[0226] According to the molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:0.03:0.20:25, a sol was obtained by stirring a solution of butyltripropylammonium hydroxide (20 wt%, first template agent), tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4] and deionized water at 65°C for about 12 hours. The molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 25%. Then, crystallization was carried out at 150℃ for 10 hours (first hydrothermal crystallization treatment). The solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and calcined at 350℃ for 3 hours. Next, it was mixed with a 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: a mass-to-volume ratio of acid to the solid product of 80 g solid product / 1 L acid, a contact temperature of 50℃, a contact time of 0.5 hours, and neutralization with a suitable amount of ammonia water to approximately pH 6.5 after hydrochloric acid treatment. The intermediate product obtained after acid treatment was then mixed with a tetrapropylammonium hydroxide aqueous solution (alkali solution, 25 wt%), with a mass ratio of intermediate product to alkali solution (effective mass of alkali) of 1:0.29, and hydrothermally treated at 150℃ for 10 hours (second hydrothermal crystallization treatment) to obtain a molecular sieve solid, designated TS-1-P.

[0227] Comparative Example 1

[0228] This comparative example illustrates the titanium-silicon molecular sieve prepared using a template agent containing only groups with 3 carbon atoms.

[0229] A sol was prepared by stirring a 25% by weight solution of tetrapropylammonium hydroxide, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water at 81°C for about 13 hours according to a molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:0.04:0.15:20. The molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 0%. Then, crystallization was carried out at 179℃ for 38 hours (first hydrothermal crystallization treatment). Afterwards, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and calcined at 550℃ for 6 hours. Next, it was mixed with a 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: a mass-to-volume ratio of acid to the solid product of 86 g solid product / 1 L acid, a contact temperature of 66℃, a contact time of 2 hours, and neutralization with an appropriate amount of ammonia water after hydrochloric acid treatment. Then, it was mixed with a tetrapropylammonium hydroxide aqueous solution (alkali solution, 25 wt%), with a mass ratio of intermediate product to alkali solution (effective mass of alkali) of 1:0.30, and hydrothermally treated at 173℃ for 22 hours (second hydrothermal crystallization treatment) to obtain a molecular sieve solid, designated D-1.

[0230] The XRD pattern of the molecular sieve is as follows: Figures 1-4 As shown, the molecular sieve exhibits a five-finger peak at 22°–25° (2θ values ​​are 23.06°, 23.25°, 23.68°, 23.91°, and 24.39°), indicating that the molecular sieve possesses an MFI topology and is classified as TS-1 molecular sieve.

[0231] Comparative Example 2

[0232] This comparative example illustrates the titanium-silicon molecular sieve prepared using a template agent containing only groups with 4 carbon atoms.

[0233] A sol was prepared by stirring a 25% by weight solution of tetrabutylammonium hydroxide, tetraethyl orthosilicate (TEOS), tetrabutyl titanate [Ti(OBu)4], and deionized water at 68°C for about 11 hours according to a molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:0.04:0.15:20. The molar ratio of C4 groups in the template agent (C4 / (C3+C4)) was 100%. Then, crystallization was carried out at 167℃ for 26 hours (first hydrothermal crystallization treatment). Afterwards, the solid obtained by centrifugation was filtered, washed with distilled water, dried at 100℃ for 3 hours, and calcined at 550℃ for 6 hours. Next, it was mixed with a 0.2 mol / L hydrochloric acid solution for acid treatment. The acid treatment conditions included: a mass-to-volume ratio of acid to the solid product of 100 g solid product / 1 L acid, a contact temperature of 80℃, a contact time of 2 hours, and neutralization with an appropriate amount of ammonia water after hydrochloric acid treatment. Then, it was mixed with a tetrabutylammonium hydroxide aqueous solution (alkali solution, 40 wt%), with a mass ratio of intermediate product to alkali solution (effective mass of alkali) of 1:0.20, and hydrothermally treated at 173℃ for 22 hours (second hydrothermal crystallization treatment) to obtain the molecular sieve solid, designated D-2. The XRD pattern of this molecular sieve is shown below. Figures 1-4 As shown, the molecular sieve has MEL topological characteristic peaks at positions of 22° to 25° (2θ is 23.12° and 23.93°), indicating that the molecular sieve is TS-2 molecular sieve.

[0234] Comparative Example 3

[0235] Eutectic titanium-silicon molecular sieves were prepared according to the methods of Comparative Example 1 and Comparative Example 2. The eutectic titanium-silicon molecular sieves prepared by Comparative Example 1 and Comparative Example 2 were mechanically mixed at a mass ratio of 3 to obtain a solid molecular sieve, which was numbered D-3.

[0236] The XRD patterns and UV-Vis characteristics 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.

[0237] Table 1

[0238]

[0239]

[0240] In Table 1, taking the catalyst TS-1-A prepared in Example 1 as an example, the peak intensity I of the diffraction peak at position 15.47±0.2° in its XRD spectrum is... 15.47 The peak intensity of the diffraction peak at position 502, 15.87±0.2° is denoted as I. 15.87 It is 1026, by I 15.87 / I 15.47 The calculated X1 is 2.04; the peak intensity I of the diffraction peak at position 23.91±0.2° is... 23.91 The peak intensity I of the diffraction peak at position 3553, 23.68 ± 0.2° is 23.68 For 1919, by I 23.91 / I 23.68 The calculated X² is 1.85; the peak intensity I of the diffraction peak at position 29.90±0.2° is... 29.90 The peak intensity I of the diffraction peak at position 864, 30.31 ± 0.2° is 30.31 It is 287, by I 29.90 / I 30.31 The calculated X3 is 3.01; in its UV-Vis spectrum, the peak area Q1 of the peak at 270±10nm is 52.40, the peak area Q2 of the peak at 330±10nm is 19.05, and the calculated X4 from Q1 / Q2 is 2.75.

[0241] Table 2

[0242]

[0243]

[0244] Application test cases

[0245] This test example is used to evaluate the performance of the eutectic 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:

[0246] 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.

[0247] 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.

[0248] Cyclohexanone conversion rate (%) = (moles of cyclohexanone in the feed - moles of cyclohexanone in the product) / moles of cyclohexanone in the feed × 100%;

[0249] Cyclohexanone oxime selectivity (%) = number of moles of cyclohexanone oxime generated in the product / number of moles of cyclohexanone consumed to generate all products × 100%;

[0250] Cyclohexanone conversion rate reduction (%) = (0.5h cyclohexanone conversion rate - 120h cyclohexanone conversion rate) / 0.5h cyclohexanone conversion rate × 100%;

[0251] Cyclohexanone oxime selectivity reduction rate (%) = (0.5h cyclohexanone oxime selectivity - 120h cyclohexanone oxime selectivity) / 0.5h cyclohexanone oxime selectivity × 100%.

[0252] 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℃.

[0253] Table 3

[0254]

[0255]

[0256] Based on the data in Tables 1-3 above, it can be seen that:

[0257] Compared with catalysts D-1 to D-3 prepared in Comparative Examples 1 to 3, the eutectic titanium-silicon molecular sieves prepared in Examples 1 to 13 using the method provided in this disclosure exhibit diffraction peaks at 8.78±0.2° and 8.82±0.2°, respectively, and a diffraction peak at 23.12°, indicating a TS-1 / TS-2 eutectic structure. Furthermore, the X1 ester of the eutectic molecular sieves prepared in Examples 1 to 13 has a stoichiometric ratio (X1) in the range of 1.30–2.60, and the X2 ester has a stoichiometric ratio (X2) in the range of 2.5–3.6. Within the range of X3 (1.9–2.8) and X4 (2.0–4.5) calculated from the UV-Vis spectrum, compared to the molecular sieve catalysts in Comparative Example 1 (MFI topology only), Comparative Example 2 (MEL topology), and Comparative Example 3 (mechanical mixing of molecular sieves with the two structures obtained from Comparative Example 1 and Comparative Example 2), the eutectic titanium silicate molecular sieves prepared in Examples 1–16 can achieve higher cyclohexanone conversion and cyclohexanone oxime selectivity in the cyclohexanone ammoniation reaction, and the catalyst has higher stability under long-term reaction conditions.

[0258] In Examples 1-13, the molecular sieves prepared in Examples 1-8 meet the preferred range of "X1 is 1.5-2.3, X2 is 1.6-2.0, and X3 is 2.8-3.6". The molecular sieves prepared in Examples 9-13 have X1-X3 that are not within this preferred range. Compared with the molecular sieves prepared in Examples 9-13, the molecular sieves prepared in Examples 1-8 can obtain higher cyclohexanone conversion and cyclohexanone oxime selectivity in the cyclohexanone amination reaction, and the catalyst has higher stability under long-term reaction conditions.

[0259] Example 13 was compared with Comparative Example 1. In Example 13, a eutectic titanium-silicon molecular sieve was prepared according to the molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:(0.001-0.050):(0.05-0.30):(5-40). The molar ratio of Comparative Example 1 was not within this range. Compared with Comparative Example 1, the molecular sieve prepared in Example 13 showed better catalytic effect in the cyclohexanone ammonium oxime reaction.

[0260] Comparing Example 1 with Example 13, Example 1 prepared eutectic titanium-silicon molecular sieves according to the preferred molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:(0.020~0.040):(0.12~0.20):(10~30) during the preparation process. The molar ratio of Example 13 is not within this preferred range. Compared with Example 13, the molecular sieve prepared in Example 1 can obtain higher cyclohexanone conversion and cyclohexanone oxime selectivity in the cyclohexanone amination oxime reaction, and the catalyst has higher stability under long-term reaction conditions.

[0261] Comparing Example 7 with Comparative Example 2, Example 7 prepared a eutectic titanium-silicon molecular sieve according to the preferred molar ratio of silicon source (SiO2): titanium source (TiO2): template agent: water of 1:(0.020-0.040):(0.12-0.20):(10-30) during the preparation process. The molar ratio of Comparative Example 2 is not within this preferred range. Compared with Comparative Example 2, the molecular sieve prepared in Example 7 has a better catalytic effect in the cyclohexanone ammonium oxime reaction.

[0262] Comparing Example 1 with Comparative Example 3, Example 1 prepared a eutectic titanium-silicon molecular sieve according to the optimized preparation conditions provided in this disclosure, while the conditions in Comparative Example 3 were not within the range of optimized preparation conditions. Compared with the catalyst prepared in Comparative Example 3, the molecular sieve prepared in Example 1 can obtain a higher cyclohexanone conversion and cyclohexanone oxime selectivity in the cyclohexanone amination reaction, and the catalyst has higher stability under long-term reaction conditions.

[0263] 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.

[0264] 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.

[0265] 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 eutectic titanium-silicon molecular sieve, characterized in that, The eutectic titanium-silicon molecular sieve has MFI-type and MEL-type molecular sieve structures; the eutectic titanium-silicon molecular sieve has the following XRD characteristics: The peak intensity of the diffraction peak at position 15.47±0.2° in the XRD pattern of the eutectic titanium-silicon molecular sieve is denoted as I. 15.47 The peak-intensity of the diffraction peak at position 15.87±0.2° is denoted as I. 15.87 ; The peak intensity of the diffraction peak at position 23.68±0.2° in the XRD pattern of the eutectic titanium-silicon molecular sieve is denoted as I. 23.68 The peak intensity of the diffraction peak at position 23.91±0.2° is denoted as I. 23.91 ; The peak intensity of the diffraction peak at position 29.90±0.2° in the XRD pattern of the eutectic titanium-silicon molecular sieve is denoted as I. 29.90 The peak intensity of the diffraction peak at position 30.31±0.2° is denoted as I. 30.31 ; As defined in equation (1), X1 is any value within the range of 1.30 to 2.60: X1=I 15.87 / I 15.47 Equation (1); and, As defined in equation (2), X2 is any value within the range of 1.5 to 2.3: X2=I 23.91 / I 23.68 Equation (2); As defined in equation (3), X3 is any value within the range of 2.5 to 4.0: X3 = I 29.90 / I 30.31 Equation (3); The eutectic titanium-silicon molecular sieve has the following UV-Vis characteristics: The peak area of ​​the peak at position 270±10nm in the UV-Vis spectrum of the eutectic titanium-silicon molecular sieve is denoted as Q1, and the peak area of ​​the peak at position 330±10nm is denoted as Q2. As defined in equation (4), X4 is any value within the range of 2.0 to 4.5: X4 = Q1 / Q2 (4).

2. The eutectic titanium-silicon molecular sieve according to claim 1, characterized in that, X1 is any value in the range of 1.5 to 2.3, X2 is any value in the range of 1.6 to 2.0, and X3 is any value in the range of 2.8 to 3.

6.

3. The eutectic titanium-silicon molecular sieve according to claim 2, characterized in that, The XRD pattern of the eutectic titanium-silicon molecular sieve shows diffraction peaks at positions 8.78±0.2° and 8.82±0.2° within the range of 8.5° to 9.5°.

4. The eutectic titanium-silicon molecular sieve according to claim 1, characterized in that, X4 can be any value within the range of 2.5 to 4.

3.

5. The eutectic titanium-silicon molecular sieve according to claim 4, characterized in that, X4 can be any value within the range of 2.7 to 4.

0.

6. The eutectic titanium-silicon molecular sieve according to claim 1, characterized in that, The molar ratio of titanium to silicon in the eutectic titanium-silicon molecular sieve is 1:2 to 1000.

7. The eutectic titanium-silicon molecular sieve according to claim 6, characterized in that, The molar ratio of titanium to silicon in the eutectic titanium-silicon molecular sieve is 1:24~67.

8. The eutectic titanium-silicon molecular sieve according to claim 1, characterized in that, The eutectic titanium-silicon molecular sieve has a TS-1 / TS-2 eutectic molecular sieve structure.

9. The eutectic titanium-silicon molecular sieve according to claim 1, characterized in that, The eutectic titanium-silicon molecular sieve has an average particle size of 0.05~0.80 nm and a BET specific surface area of ​​420~500 m². 2 / g; Microporous specific surface area is 370~450m² 2 / g; total pore volume is 0.1~0.30cm³. 3 / g; mesopore volume is 0.05~0.15cm³ 3 / g.

10. The eutectic titanium-silicon molecular sieve according to claim 9, characterized in that, The eutectic titanium-silicon molecular sieve has an average particle size of 0.20~0.35nm and a BET specific surface area of ​​430~445m². 2 / g; Microporous specific surface area is 380~395m² 2 / g; total pore volume is 0.23~0.28cm³. 3 / g; mesopore volume is 0.07~0.13cm³ 3 / g.

11. A method for preparing eutectic titanium-silicon molecular sieves, characterized in that, Includes the following steps: S1. A silicon source, a titanium source, a template agent, and water are mixed to obtain a raw material mixture; the template agent is selected from one or more organic ammonium hydroxide compounds; and the structural formula of the template agent contains at least one selected from alkyl and alkenyl groups with 3 carbon atoms, and the structural formula of the template agent contains at least one selected from alkyl and alkenyl groups with 4 carbon atoms. S2. The raw material mixture is subjected to a first hydrothermal crystallization treatment; The eutectic titanium-silicon molecular sieve has MFI-type molecular sieve and MEL-type molecular sieve structures; In step S1, the molar ratio of silicon source: titanium source: template agent: water is 1:(0.001~0.050):(0.05~0.30):(5~40), wherein the silicon source is calculated as SiO2, the titanium source as TiO2, and the template agent is calculated based on the total molar number of the template agent; the molar number of groups with 4 carbon atoms in the template agent / (molar number of groups with 3 carbon atoms + molar number of groups with 4 carbon atoms) is 5~95%; The conditions for the first hydrothermal crystallization treatment in step S2 include: hydrothermal crystallization temperature of 150~200℃, hydrothermal crystallization time of 2~168h, and hydrothermal crystallization pressure of self-generated pressure.

12. The method according to claim 11, characterized in that, The template agent is selected from one or more of the first template agents, or the template agent includes a second template agent and a third template agent; 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 alkyl groups having 3 to 4 carbon atoms and alkenyl groups having 3 to 4 carbon atoms, and at least one alkyl or alkenyl group having 3 carbon atoms and at least one alkyl or alkenyl group having 4 carbon atoms are present in R1, R2, R3 and R4. 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 alkyl groups having 3 carbon atoms and alkenyl groups having 3 carbon atoms; The third template agent is selected from one or more compounds having the structure shown in formula (M-3): Equation (M-3); where R9, R 10 R 11 and R 12 Each is independently selected from alkyl groups with 4 carbon atoms and alkenyl groups with 4 carbon atoms.

13. The method according to claim 12, characterized in that, In the structural formula (M-1) of the first template agent, any three groups of R1, R2, R3 and R4 are selected from alkyl groups with 3 carbon atoms and alkenyl groups with 3 carbon atoms, and the other group is selected from alkyl groups with 4 carbon atoms and alkenyl groups with 4 carbon atoms.

14. The method according to claim 13, characterized in that, The alkyl group having 3 carbon atoms is selected from n-propyl and isopropyl, and the alkenyl group having 3 carbon atoms is selected from propenyl and allyl; the alkyl group having 4 carbon atoms is selected from n-butyl, isobutyl, sec-butyl and tert-butyl, and the alkenyl group having 4 carbon atoms is selected from n-butenyl and isobutenyl.

15. The method according to claim 14, characterized in that, The first template agent is selected from tripropylbutylammonium hydroxide, tributylpropylammonium hydroxide, dipropyldibutylammonium hydroxide, 1-butenyltripropylammonium hydroxide, 2-butenyltripropylammonium hydroxide, 3-butenyltripropylammonium hydroxide, 1-butenylallyldipropylammonium hydroxide, 2-butenylallyldipropylammonium hydroxide, 3-butenylallyldipropylammonium hydroxide, 1-butenylpropenyldipropylammonium hydroxide, 2-butenylpropenyldipropylammonium hydroxide, 3-butenylpropenyldipropylammonium hydroxide, 1-butenylpropenylallyldipropylammonium hydroxide, 2-butenylpropenylallyldipropylammonium hydroxide, 3-butenylpropenylallyldipropylammonium hydroxide, 1-butenylpropenylallyldipropylammonium hydroxide, 2-butenylpropenylallyldipropylammonium hydroxide, 3-butenylpropenylallyldipropylammonium hydroxide. One or more of the following: propyl ammonium hydroxide, allyl tributyl ammonium hydroxide, propenyl tributyl ammonium hydroxide, diallyl dibutyl ammonium hydroxide, allyl propenyl dibutyl ammonium hydroxide, triallyl butyl ammonium hydroxide, tripropenyl butyl ammonium hydroxide, diallyl propyl butyl ammonium hydroxide, diallyl propyl butyl ammonium hydroxide, allyl propenyl propyl butyl ammonium hydroxide, diallyl propenyl butyl ammonium hydroxide, allyl diallyl ammonium hydroxide, allyl dipropyl butyl ammonium hydroxide, propenyl dipropyl butyl ammonium hydroxide, 1-butenyl butyl dipropyl ammonium hydroxide, 2-butenyl butyl dipropyl ammonium hydroxide, and 3-butenyl butyl dipropyl ammonium hydroxide.

16. The method according to claim 15, characterized in that, Based on the total number of moles of groups with 3 carbon atoms and the total number of moles of groups with 4 carbon atoms in the first template agent, the ratio of the number of moles of groups with 4 carbon atoms in the first template agent to (the number of moles of groups with 3 carbon atoms + the number of moles of groups with 4 carbon atoms) is 5~95%.

17. The method according to claim 12, characterized in that, In the structural formula (M-2) of the second template agent, the alkyl group with 3 carbon atoms is selected from n-propyl and isopropyl, and the alkenyl group with 3 carbon atoms is selected from propenyl and allyl.

18. The method according to claim 17, characterized in that, The second template agent is selected from one or more of tetrapropylammonium hydroxide, allyltripropylammonium hydroxide, propenyltripropylammonium hydroxide, diallyldipropylammonium hydroxide, diallyldipropylammonium hydroxide, allylpropenyldipropylammonium hydroxide, triallylpropylammonium hydroxide, tripropenylpropylammonium hydroxide, allyldipropenylpropylammonium hydroxide, diallylpropenylpropylammonium hydroxide, diallylpropylisopropylammonium hydroxide, diallyldiisopropylammonium hydroxide, allylpropenyldiisopropylammonium hydroxide, triallylisopropylammonium hydroxide, tripropenylisopropylammonium hydroxide, allyldipropenylisopropylammonium hydroxide, and diallylpropenylisopropylammonium hydroxide.

19. The method according to claim 12, characterized in that, In the structural formula (M-3) of the third template agent, the alkyl group having 4 carbon atoms is selected from n-butyl, isobutyl, sec-butyl, and tert-butyl, and the alkenyl group having 4 carbon atoms is selected from n-butenyl and isobutylenyl.

20. The method according to claim 19, characterized in that, The third template agent is selected from one or more of tetrabutylammonium hydroxide, 1-butenyltributylammonium hydroxide, 2-butenyltributylammonium hydroxide, 3-butenyltributylammonium hydroxide, n-butyltri-n-butylammonium hydroxide, diisobutyltri-n-butylammonium hydroxide, tri-n-butylisobutylammonium hydroxide, sec-butyltri-n-butylammonium hydroxide, tert-butyltri-n-butylammonium hydroxide, and tri-n-butylisobutylammonium hydroxide.

21. The method according to claim 20, characterized in that, Based on the total number of moles of groups with 3 carbon atoms in the second template agent and the total number of moles of groups with 4 carbon atoms in the third template agent, the ratio of the number of moles of groups with 4 carbon atoms in the second template agent to the number of moles of groups with 3 carbon atoms plus the number of moles of groups with 4 carbon atoms is 5-95%.

22. The method according to claim 11, characterized in that, The silicon source is selected from at least one of silicone grease, solid silica gel, fumed silica, and silica sol.

23. The method according to claim 22, characterized in that, The silicon source is selected from at least one of organosilicon grease, solid silica gel, and precipitated silica.

24. The method according to claim 22, 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.

25. The method according to claim 24, 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.

26. The method according to claim 25, characterized in that, The silicone grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, and dimethyl diethyl silicate.

27. The method according to claim 26, characterized in that, The silicone grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, and dimethyl diethyl silicate.

28. The method according to claim 11, characterized in that, The titanium source is selected from one or more of organic and inorganic titanium sources.

29. The method according to claim 28, 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.

30. The method according to claim 29, 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.

31. The method according to claim 30, 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.

32. The method according to claim 29, 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.

33. The method according to claim 32, 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.

34. The method according to claim 28, characterized in that, The inorganic titanium source is selected from one or more of titanium chloride, nitrate or sulfate.

35. The method according to claim 28, 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.

36. The method according to claim 11, characterized in that, In step S1, the molar ratio of silicon source: titanium source: template agent: water is 1: (0.010~0.045): (0.08~0.24): (8~35).

37. The method according to claim 36, characterized in that, In step S1, the molar ratio of silicon source: titanium source: template agent: water is 1: (0.020~0.040): (0.12~0.20): (10~30).

38. The method according to claim 12, characterized in that, When the template agent includes a second template agent and a third template agent, the molar ratio of the second template agent to the third template agent is 1:0.20~20.

39. The method according to claim 38, characterized in that, The molar ratio of the second template agent to the third template agent is 1:0.75~7.

5.

40. The method according to claim 11, characterized in that, The conditions for the first hydrothermal crystallization treatment in step S2 include: a hydrothermal crystallization temperature of 160~190℃ and a hydrothermal crystallization time of 12~144h.

41. The method according to claim 11, characterized in that, Prior to the first hydrothermal crystallization treatment, the method further includes: hydrolyzing and removing alcohol from the raw material mixture.

42. The method according to claim 41, characterized in that, The conditions for the hydrolysis and alcohol removal treatment include: treatment at 5~120℃ for 0.5~48h.

43. The method according to claim 42, characterized in that, The conditions for the hydrolysis and alcohol removal treatment include: treatment at 40~100℃ for 2~24h.

44. The method according to claim 11, characterized in that, Following the first hydrothermal crystallization treatment in step S2, the method further includes the following steps: S3. The product obtained from the first hydrothermal crystallization treatment is subjected to solid-liquid separation to obtain a solid product; the solid product is then subjected to drying and / or calcination treatment.

45. The method according to claim 44, characterized in that, The drying conditions include: a drying temperature of 100~200℃ and a drying time of 2~10h; The conditions for the calcination treatment include: a calcination temperature of 350~650℃ and a calcination time of 2~10h.

46. ​​The method according to claim 45, characterized in that, The roasting temperature is 450~550℃, and the roasting time is 3~8h.

47. The method according to claim 44, characterized in that, Following step S3, the method further includes the following steps: S4. The product obtained from the roasting treatment is contacted with acid solution for acid treatment, and then a pH adjuster is added for neutralization treatment to obtain an intermediate product.

48. The method according to claim 47, characterized in that, In step S4, the acid solution used in the acid treatment is selected from one or more of hydrochloric acid, nitric acid, phosphoric acid, carbonic acid, sulfuric acid, and acetic acid; the concentration of the acid solution used is 0.1~1.0 mol / L, and the mass of the solid product used relative to 1L of the acid solution is 80~150g. The conditions for acid treatment include: a contact temperature of 50~150℃ and a contact time of 0.5~5.0h.

49. The method according to claim 48, characterized in that, The conditions for acid treatment include: a contact temperature of 60~100℃ and a contact time of 1.0~3.5h.

50. The method according to claim 47, characterized in that, The pH adjuster is selected from one or more alkaline solutions; the alkaline solution is selected from one or more of ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and sodium bicarbonate; the neutralization treatment adjusts the pH of the solution to 5-7.

51. The method according to claim 47, characterized in that, Following step S4, the method further includes the following steps: S5. The intermediate product is brought into contact with an alkaline solution to undergo a second hydrothermal crystallization treatment.

52. The method according to claim 51, characterized in that, The weight ratio of the intermediate product to the effective alkali in the alkaline solution is 1:0.05~0.50; the alkali in the alkaline solution is selected from one or more inorganic and organic alkalis.

53. The method according to claim 52, characterized in that, The weight ratio of the intermediate product to the effective alkali in the alkaline solution is 1:0.10~0.

40.

54. The method according to claim 52, characterized in that, The inorganic base is selected from one or more of sodium hydroxide, sodium carbonate, and sodium bicarbonate; the organic base is selected from tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, allyltripropylammonium hydroxide, butyltripropylammonium hydroxide, 1-butenyltripropylammonium hydroxide, propyltributylammonium hydroxide, diallyldipropylammonium hydroxide, diallyldipropylammonium hydroxide, allylpropenyldipropylammonium hydroxide, triallylpropylammonium hydroxide, allyldipropenylpropylammonium hydroxide, diallylpropenylpropylammonium hydroxide, diallylpropylisopropylammonium hydroxide. Ammonium hydroxide, diallyl diisopropyl ammonium hydroxide, allyl propenyl diisopropyl ammonium hydroxide, triallyl isopropyl ammonium hydroxide, allyl diallyl isopropyl ammonium hydroxide, diallyl propenyl isopropyl ammonium hydroxide, 2-butenyl tributyl ammonium hydroxide, 3-butenyl tributyl ammonium hydroxide, n-butyl tri-n-butyl ammonium hydroxide, diisobutyl tri-n-butyl ammonium hydroxide, tri-n-butyl isobutyl ammonium hydroxide, sec-butyl tri-n-butyl ammonium hydroxide, tert-butyl tri-n-butyl ammonium hydroxide, and tri-n-butyl isobutyl ammonium hydroxide, one or more of these. The conditions for the second hydrothermal crystallization treatment include: a hydrothermal crystallization temperature of 150~200℃, a hydrothermal crystallization time of 10~40h, and a hydrothermal crystallization pressure of self-generated pressure.

55. The method according to claim 54, characterized in that, The conditions for the second hydrothermal crystallization treatment include: a hydrothermal crystallization temperature of 160~180℃ and a hydrothermal crystallization time of 20~30h.

56. The eutectic titanium-silicon molecular sieve prepared by the method according to any one of claims 11 to 55.

57. The use of the eutectic titanium-silicon molecular sieve according to any one of claims 1 to 10 and 56 in catalytic organic reaction and / or adsorption separation processes.

58. The application according to claim 57, 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.

59. The application according to claim 58, characterized in that, The preparation of cyclohexanone oxime by cyclohexanone oximation includes the following steps: under oximation reaction conditions, cyclohexanone, an oxidant, ammonia and a catalyst are brought into contact to carry out an oxidation reaction; the catalyst comprises the eutectic titanium-silicon molecular sieve.

60. The application according to claim 59, characterized in that, The oxidant is selected from one or more of hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, and m-chloroperoxybenzoic acid.

61. The application according to claim 60, 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.

62. The application according to claim 59, 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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