Titanium silicalite molecular sieve catalyst, preparation method therefor, and use thereof

Abstract

The present invention relates to a titanium silicalite molecular sieve catalyst, a preparation method therefor, and a use thereof. The catalyst has a B value of 60%-96%, where B=B1 / B2, B1 represents the peak area of a characteristic peak at a chemical shift of 1.8 ppm in a 1H MAS NMR spectrum of the catalyst, and B2 represents the peak area of a characteristic peak at a chemical shift >2 ppm in the 1H MAS NMR spectrum of the catalyst; and / or the catalyst has a Q value ≥10, where Q=Q4 / Q3, Q4 represents the peak area of a characteristic peak at a chemical shift of -113 ppm in an 29Si MAS NMR spectrum of the catalyst, and Q3 represents the peak area of a characteristic peak at a chemical shift of -103 ppm in the 29Si MAS NMR spectrum of the catalyst.

Description

A titanium-silicon molecular sieve catalyst, its preparation method and applications Technical Field

[0001] This disclosure relates to the field of titanium-silicon molecular sieve catalyst preparation, specifically to a titanium-silicon molecular sieve catalyst, its preparation method, and its uses. Background Technology

[0002] Titanium silicate molecular sieves, as a novel and highly efficient catalytic oxidation material, have become important heterogeneous solid catalysts in industry due to their hierarchical and regular pore structure, ultra-high specific surface area, and high catalytic activity and selectivity. They are widely used in a series of key reactions, such as the amination of benzene, the oxidation of cyclohexane, the epoxidation of propane, and the hydroxylation of phenol, demonstrating enormous application potential.

[0003] However, the raw titanium-silicon molecular sieve crystals are extremely small, typically ranging from 100 to 500 nanometers in size. This tiny size leads to significant problems in industrial operation, namely, the difficulty in separating and recovering the catalyst from the reaction products, limiting its direct industrial application. Therefore, shaping titanium-silicon molecular sieves is a crucial step in realizing their industrial application. Shaping not only solves the separation and recovery challenges but also significantly improves the mechanical strength of the catalyst, reduces the pressure drop caused by fluid flow, prevents channeling, and ensures uniform distribution of the fluid in the reaction bed, thereby maximizing catalytic efficiency.

[0004] An ideal high-performance molecular sieve catalyst should possess high and stable activity and high selectivity, which largely depend on the physicochemical properties of the catalyst after molding. Among various shapes, spherical particles are considered the most ideal catalyst morphology due to their advantages such as the absence of sharp edges, uniform packing, easy loading and unloading, good flowability, and low bed pressure. To fully utilize the catalytic efficiency of molecular sieves, the molded spherical particles should possess characteristics such as high specific surface area, uniform and controllable shape, narrow particle size distribution, and high mechanical strength.

[0005] Currently, the molding methods commonly used in the industry (such as US4701428, CN103212435A, etc.) have significant drawbacks, mainly including severe loss of catalytic activity, complex molding processes, and insufficient mechanical strength of the resulting catalysts. Therefore, developing a controllable and efficient novel molding method to prepare high-performance spherical titanium-silicon molecular sieve catalysts has become an urgent technical challenge to be solved.

[0006] Furthermore, the unique hierarchical pore structure of titanium-silicon molecular sieve catalysts presents a particular challenge during the molding process: processing aids (such as binders and plasticizers) can easily enter and clog the pores, resulting in the loss of effective mass transfer channels and severely affecting the porosity and specific surface area of ​​the molded catalyst, ultimately leading to a decrease in catalytic efficiency. Currently, methods for preparing high-performance spherical titanium-silicon molecular sieves based on pore-filling protection strategies to address this problem are rarely reported in related technologies and patents. Summary of the Invention

[0007] The purpose of this disclosure is to provide a titanium-silicon molecular sieve catalyst and its preparation method.

[0008] To achieve the above objectives, the first aspect of this disclosure provides a method for preparing titanium-silicon molecular sieve catalysts, the method comprising the following steps:

[0009] S1. The material based on titanium-silicon molecular sieve powder, a first binder, water and an optional first surfactant are mixed and subjected to a first molding process, and the solid product obtained from the first molding process is subjected to a first calcination treatment to obtain titanium-silicon molecular sieve microspheres.

[0010] S2. Mix the titanium-silicon molecular sieve microspheres, the second binder, water and an optional second surfactant and perform a second molding process to obtain the titanium-silicon molecular sieve catalyst precursor.

[0011] S3. The titanium-silicon molecular sieve catalyst precursor is aged with water vapor and / or alkaline vapor to obtain a titanium-silicon molecular sieve catalyst pre-product.

[0012] S4. The titanium-silicon molecular sieve catalyst preproduct is subjected to a second calcination treatment.

[0013] The material based on titanium-silicon molecular sieve powder can be selected from: uncalcined titanium-silicon molecular sieve powder, calcined titanium-silicon molecular sieve powder, unfilled titanium-silicon molecular sieve powder, and filled titanium-silicon molecular sieve powder.

[0014] Furthermore, the titanium-silicon molecular sieve raw powder can be uncalcined and unfilled titanium-silicon molecular sieve raw powder, uncalcined but filled titanium-silicon molecular sieve raw powder, calcined but unfilled titanium-silicon molecular sieve raw powder, and calcined and filled titanium-silicon molecular sieve raw powder.

[0015] The uncalcined and unfilled titanium-silicon molecular sieve raw powder is obtained by hydrothermal crystallization of a mixture of materials including a titanium source, a silicon source and a template agent (e.g., a mixture of a titanium source, a silicon source and a template agent).

[0016] The pore-filled titanium-silicon molecular sieve raw powder can be obtained by mixing the titanium-silicon molecular sieve raw powder as raw material with the pore filler and drying it.

[0017] Calcined titanium-silicon molecular sieve raw powder can be obtained by pre-calcining the titanium-silicon molecular sieve raw powder used as raw material;

[0018] The calcined and pore-filled titanium-silicon molecular sieve raw powder can be obtained by pre-calcining the titanium-silicon molecular sieve raw powder as raw material, then mixing the pre-calcined titanium-silicon molecular sieve raw powder with the pore filler and drying it.

[0019] The drying conditions include: a temperature not exceeding 200°C, for example 50-200°C (excluding the endpoint 200°C), 100-200°C (excluding the endpoint 200°C), or 50-180°C, or 80-180°C, or 120-180°C, or 120-160°C; and a time of 0.5-144 hours, for example 1-72 hours, or 1-24 hours, or 2-12 hours, or 2-6 hours; and a mixing time of 0.1-144 hours, for example 0.1-72 hours, or 0.1-24 hours, or 0.1-12 hours, or 0.1-6 hours, 0.2-6 hours, 0.5-6 hours, 1-6 hours, 2-5 hours, or 3-4 hours.

[0020] The pre-calcination conditions include: a time of 0.5-144 hours, for example 1-72 hours, or 1-24 hours, or 2-12 hours, or 2-6 hours; a temperature of 200-650℃, for example 200-600℃, or 300-600℃, or 400-600℃, or 500-600℃, or 520-580℃, or 540-560℃, or about 550℃; and a calcination atmosphere of pure oxygen, air, or a combination thereof.

[0021] In this article, to distinguish it from "first roasting treatment" and "second roasting treatment", the step of roasting the raw titanium silicon molecular sieve powder is referred to as "pre-roasting".

[0022] The pore filler may include / be selected from one or more saturated polyols having 2-5 carbon atoms, preferably one or more of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol and glycerol.

[0023] The first binder may include / be selected from one or more of silica sol, water glass, fumed silica and alumina sol, such as one or more of silica sol, water glass and alumina sol, or one or more of silica sol and fumed silica.

[0024] The second binder may include / be selected from one or more of silica sol, water glass, fumed silica and alumina sol, such as one or more of silica sol, water glass and alumina sol, or one or more of silica sol and fumed silica.

[0025] The first surfactant may be a Span surfactant and / or a Tween surfactant, for example including / selected from one or more of Span-20, Span-40, Span-60, Span-65, Span-80, Span-85, Tween-20, Tween-21, Tween-40, Tween-60, Tween-61, Tween-80, Tween-81 and Tween-85.

[0026] The second surfactant may be a Span-type surfactant or a Tween-type surfactant, such as including / selected from one or more of Span-20, Span-40, Span-60, Span-65, Span-80, Span-85, Tween-20, Tween-21, Tween-40, Tween-60, Tween-61, Tween-80, Tween-81 and Tween-85.

[0027] Optionally, step S1 includes: mixing the material based on titanium-silicon molecular sieve powder with a first solution containing the first binder, optionally the alkali and optionally the first surfactant, and performing the first molding, and performing a first calcination treatment on the solid product obtained from the first molding to obtain the titanium-silicon molecular sieve microspheres.

[0028] Relative to the total weight of the material based on titanium-silicon molecular sieve powder, the first binder, the alkali, and the first surfactant, the amount of the material based on titanium-silicon molecular sieve powder is 65-99.9% by weight (e.g., 70-99.9% by weight), the amount of the first binder is 0.1-20% by weight (e.g., 0.1-15% by weight), the amount of the alkali is 0-10% by weight, and the amount of the first surfactant is 0-5% by weight.

[0029] Optionally, in step S1, the conditions for the first calcination treatment include: a temperature of 200-600℃ and a time of 2-6 hours. The calcination atmosphere can be a pure oxygen atmosphere, an air atmosphere, or a combination thereof.

[0030] Optionally, the particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm.

[0031] Optionally, step S2 includes: mixing the titanium-silicon molecular sieve microspheres with a second solution containing the second binder, optionally the alkali, and optionally the second surfactant, and performing the second molding to obtain the titanium-silicon molecular sieve catalyst precursor.

[0032] Relative to the total weight of the titanium-silicon molecular sieve microspheres, the second binder, the alkali, and the second surfactant, the amount of the titanium-silicon molecular sieve microspheres is 65-99.9% by weight (e.g., 70-99.9% by weight), the amount of the second binder is 0.1-20% by weight (e.g., 0.1-15% by weight), the amount of the alkali is 0-10% by weight, and the amount of the second surfactant is 0-5% by weight.

[0033] Optionally, in step S3, the conditions for water vapor aging include: a temperature of 50-600℃, a time of 0.5-48h, a pressure of 0-2MPa, and a water vapor humidity of 50-100%.

[0034] Optionally, in step S3, the conditions for alkaline vapor aging include: a temperature of 50-600℃, a time of 0.5-48h, and a pressure of 0-2MPa; the alkaline vapor includes / is selected from one or more of ammonia vapor, methylamine vapor, dimethylamine vapor, trimethylamine vapor, and ethylamine vapor.

[0035] Optionally, in step S3, the steam aging and the alkaline vapor aging can be performed separately, simultaneously, or sequentially. When the steam aging and the alkaline vapor aging are performed simultaneously, the aging conditions include: a temperature of 50-600℃, a time of 0.5-48h, a pressure of 0-2MPa, a steam humidity of 50-100%, and a volume fraction of alkaline vapor of 0.1-10 vol%. The alkaline vapor includes / is selected from one or more of ammonia vapor, methylamine vapor, dimethylamine vapor, trimethylamine vapor, and ethylamine vapor. When the water vapor aging and the alkaline vapor aging are performed sequentially, water vapor aging can be performed first, followed by alkaline vapor aging, or vice versa. The conditions for water vapor aging include: a temperature of 50-600℃, a time of 0.5-48h, a pressure of 0-2MPa, and a water vapor humidity of 50-100%. The conditions for alkaline vapor aging include: a temperature of 50-600℃, a time of 0.5-48h, and a pressure of 0-2MPa. The alkaline vapor includes / is selected from one or more of ammonia vapor, methylamine vapor, dimethylamine vapor, trimethylamine vapor, and ethylamine vapor.

[0036] Optionally, in step S4, the conditions for the second calcination treatment include: a temperature of 200-600℃, preferably 300-600℃, or 350-600℃, or 400-600℃, and a time of 2-6 hours. The calcination atmosphere can be a pure oxygen atmosphere, an air atmosphere, or a combination thereof.

[0037] Optionally, an alkali is added during the first molding and / or the second molding; preferably, the alkali is added during the first molding and the second molding; the alkali includes one or more organic alkalis, preferably one or more of hexamethylenetetramine, urea, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

[0038] Optionally, the first forming and the second forming can be carried out by extrusion forming, sugar coating pan forming, granulation machine forming or spray forming, for example, sugar coating pan forming or granulation machine forming, or sugar coating pan forming, granulation machine forming or spray forming; preferably, the first forming is spray forming, and the outlet air temperature is 100-150℃.

[0039] The second aspect of this disclosure provides a titanium-silicon molecular sieve catalyst prepared using the method described in the first aspect of this disclosure.

[0040] Optionally, the titanium-silicon molecular sieve catalyst has a particle size of 1.0-1.4 mm and a specific surface area of ​​360-470 m². 2 / g, for example, 360-450m 2 / g, or 360-430m 2 / g, strength is 8-30N / piece, for example 10-20N / piece.

[0041] According to the method of the present invention, titanium silicon molecular sieve raw powder (optionally calcined) is mixed with a pore filler to perform pore filling treatment on the titanium silicon molecular sieve raw powder, which effectively reduces the loss of mass transfer channels in the titanium silicon molecular sieve during the molding process, and / or titanium silicon molecular sieve microspheres are prepared by first molding using uncalcined titanium silicon molecular sieve raw powder as raw material, pre-forming molding nuclei, and filling the pores of the molecular sieve raw powder with a template agent of the molecular sieve raw powder, so that the method of the present invention can avoid the pores of the titanium silicon molecular sieve being blocked by additives (or auxiliaries) during the molding process. The method of this invention prepares titanium-silicon molecular sieve microspheres through a first molding process, pre-forming crystalline nuclei; then, a second molding process is used for shaping, improving the size and shape uniformity of the molecular sieve during the molding process; after molding, the bonding interface of the titanium-silicon molecular sieve is treated by steam aging and / or alkaline steam aging, significantly improving the mechanical strength of the titanium-silicon molecular sieve catalyst, thus preparing a titanium-silicon molecular sieve catalyst with high mechanical strength. The steam aging optimizes the physicochemical environment of the interface, thereby forming a covalent bond-based adhesive structure at the interface. The alkaline steam aging enables in-situ crystallization at the molecular sieve bonding interface, thereby improving the bonding strength between molecular sieve particles at the interface. This method has the advantages of simple preparation process, short process, mild and controllable reaction conditions, environmental friendliness, and no use of organic solvents. The prepared titanium-silicon molecular sieve catalyst has high mechanical strength, good pore connectivity, high porosity, and large specific surface area.

[0042] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Detailed Implementation

[0043] 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.

[0044] The first aspect of this disclosure provides a method for preparing titanium-silicon molecular sieve catalysts, the method comprising the following steps:

[0045] S1. The material based on titanium-silicon molecular sieve powder, a first binder, water and an optional first surfactant are mixed and subjected to a first molding process, and the solid product obtained from the first molding process is subjected to a first calcination treatment to obtain titanium-silicon molecular sieve microspheres.

[0046] S2. Mix the titanium-silicon molecular sieve microspheres, the second binder, water and an optional second surfactant and perform a second molding process to obtain the titanium-silicon molecular sieve catalyst precursor.

[0047] S3. The titanium-silicon molecular sieve catalyst precursor is aged to obtain a titanium-silicon molecular sieve catalyst pre-product.

[0048] S4. The titanium-silicon molecular sieve catalyst preproduct is subjected to a second calcination treatment.

[0049] According to the present invention, a titanium-silicon molecular sieve catalyst is prepared by a stepwise molding process combined with aging using steam and / or alkaline steam. The process involves first molding titanium-silicon molecular sieve microspheres to pre-form crystalline nuclei, followed by a second molding process to improve the size and shape uniformity of the molecular sieve during molding. Finally, an aging treatment is performed after the second molding to produce a titanium-silicon molecular sieve catalyst with high mechanical strength, good pore connectivity, high porosity, and large specific surface area. Preferably, before the first molding, either calcined titanium-silicon molecular sieve powder is used as raw material, and the pores are filled with a pore-filling agent; or uncalcined titanium-silicon molecular sieve powder is used as raw material, and the pores are filled with residual template agent; or uncalcined titanium-silicon molecular sieve powder is used as raw material, and the pores are filled with both residual template agent and additionally added pore-filling agent. This avoids clogging of the pores of the titanium-silicon molecular sieve by additives or auxiliaries during the molding process. According to the present invention, the aging process after molding can be steam aging and / or alkaline steam aging. Steam aging treats the bonding interface of the titanium-silicon molecular sieve, optimizing the interfacial physicochemical environment and forming a covalent bond-based bonding structure at the interface, thereby improving the mechanical strength of the molecular sieve microspheres. Alkaline steam aging, on the other hand, performs in-situ crystallization at the molecular sieve bonding interface, increasing the bonding strength between the molecular sieve particles at the interface. The method of the present invention features a simple preparation process, short flow, mild and controllable reaction conditions, environmental friendliness, and the absence of organic solvents. The titanium-silicon molecular sieve catalyst of the present invention exhibits high mechanical strength, good pore connectivity, high porosity, and large specific surface area.

[0050] In step S1, the material based on titanium-silicon molecular sieve powder can be selected from: uncalcined titanium-silicon molecular sieve powder, calcined titanium-silicon molecular sieve powder, unfilled titanium-silicon molecular sieve powder, and filled titanium-silicon molecular sieve powder.

[0051] Furthermore, the titanium silicon molecular sieve raw powder can be uncalcined and unfilled titanium silicon molecular sieve raw powder, uncalcined but filled titanium silicon molecular sieve raw powder, calcined but unfilled titanium silicon molecular sieve raw powder, and calcined and filled titanium silicon molecular sieve raw powder.

[0052] Preferably, the titanium-silicon molecular sieve raw powder can be uncalcined and unfilled titanium-silicon molecular sieve raw powder, or calcined and filled titanium-silicon molecular sieve raw powder.

[0053] As mentioned above, although the template agent remaining in the molecular sieve powder can fill the pores of the molecular sieve powder, the "pore filling" mentioned in this invention refers to filling the pores with an external pore filler.

[0054] The uncalcined and unfilled titanium-silicon molecular sieve powder, also referred to herein as "titanium-silicon molecular sieve powder," is obtained by hydrothermal crystallization of a mixture comprising a titanium source, a silicon source, and a template agent (e.g., a mixture of the titanium source, silicon source, and template agent) and optionally drying. In this invention, methods for synthesizing titanium-silicon molecular sieve powder are known in the art, for example, with reference to CN102205974A, CN103420393A, CN103570035A, CN103896301A, CN104556111A, CN104556113A, CN104944440A, CN104944441A, CN104556104A, CN104556115A, CN106276944A, CN106904632A, and CN10787. The methods described in CN107879357A, CN107879356A, CN107986293A, CN107986292A, CN109019627A, CN109721068A, CN109721065A, CN109721064A, CN109721066A, CN109721070A, CN109721071A, CN109721069A, CN110314699A, and CN112744830A. For example, during hydrothermal crystallization, the molar ratio of silicon source:titanium source:templating agent:water can be 100:(0.005-20.0):(0.005-20.0):(20-500); the silicon source can be silica gel, silica sol, or organosilicate (R... 1 SiO4, R 1 The titanium source can be an inorganic titanium salt (e.g., TiCl4, Ti(SO4)2, TiOCl2) or an organic titanium ester (R... 2 TiO4,R 2The template agent is C1-C6 alkyl, and can be selected from tetraalkylammonium hydroxide (such as tetramethylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium hydroxide and tetrabutylammonium hydroxide), alkanolamine (such as monoethanolamine, diethanolamine and triethanolamine) and alkylamine (such as ethylamine, n-butylamine, butanediamine and hexamethylenediamine); the hydrothermal crystallization temperature can be 100-200℃, for example 140-180℃; the hydrothermal crystallization time can be 0.5-144 hours, for example 1-72 hours, or 4-24 hours. After hydrothermal crystallization, drying can be performed (e.g., at temperatures not exceeding 200°C, such as 50-200°C (excluding the endpoint 200°C), 100-200°C (excluding the endpoint 200°C), or 50-180°C, or 80-180°C, or 120-180°C, or 120-160°C, for a time of 0.5-144 hours, such as 1-72 hours, or 1-24 hours, or 2-12 hours, or 2-6 hours). However, before obtaining the titanium silicate molecular sieve powder, heat treatment at temperatures exceeding 200°C (e.g., 200-650°C, such as 200-600°C, or 300-600°C, or 400-600°C, or 500-600°C, or 520-580°C, or 540-560°C, or about 550°C) cannot be performed after hydrothermal crystallization (such heat treatment is referred to as calcination in this document).

[0055] Pore-filled titanium-silicon molecular sieve raw powder can be obtained by mixing titanium-silicon molecular sieve raw powder with a pore-filling agent and then drying it. The drying conditions include: a temperature not exceeding 200℃, for example 50-200℃ (excluding the endpoint 200℃), 100-200℃ (excluding the endpoint 200℃), or 50-180℃, or 80-180℃, or 120-180℃, or 120-160℃; and a time of 0.5-144 hours, for example 1-72 hours, or 1-24 hours, or 2-12 hours, or 2-6 hours. The mixing time is 0.1-144 hours. The time interval can be, for example, 0.1-72 hours, or 0.1-24 hours, or 0.1-12 hours, or 0.1-6 hours, 0.2-6 hours, 0.5-6 hours, 1-6 hours, 2-5 hours, or 3-4 hours; the pore filler may include / be selected from one or more saturated polyols having 2-5 carbon atoms, preferably one or more of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and glycerol. When the pore filler includes two or more, there is no specific limitation on their ratio, for example, the ratio of any two can be 1:1000 to 1000:1. For example, the pore-filled titanium-silicon molecular sieve raw powder can be obtained by mixing the titanium-silicon molecular sieve raw powder with a pore filler, immersing the titanium-silicon molecular sieve raw powder in the pore filler, mixing for 0.1-6 hours, and then drying at 50-200℃ for 2-6 hours to obtain the pore-filled titanium-silicon molecular sieve raw powder. The above implementation method can effectively avoid pore blockage during the titanium-silicon molecular sieve forming process and improve the pore connectivity of the molecular sieve.

[0056] The calcined titanium-silicon molecular sieve raw powder can be obtained by pre-calcining the titanium-silicon molecular sieve raw powder used as raw material; the pre-calcination conditions include: the time can be 0.5-144 hours, for example 1-72 hours, or 1-24 hours, or 2-12 hours, or 2-6 hours; the temperature can be 200-650℃, for example 200-600℃, or 300-600℃, or 400-600℃, or 500-600℃, or 520-580℃, or 540-560℃, or about 550℃; and the calcination atmosphere can be a pure oxygen atmosphere, an air atmosphere, or a combination thereof. For example, calcined titanium-silicon molecular sieve raw powder can be obtained by the following method: titanium source, silicon source and template agent are synthesized by hydrothermal synthesis. In the above hydrothermal synthesis method, after the hydrothermal crystallization step, the obtained product is calcined at 200-600℃ in air atmosphere for 2-6 hours to obtain calcined titanium-silicon molecular sieve raw powder.

[0057] Calcined and pore-filled titanium-silicon molecular sieve powder can be obtained by pre-calcining the raw titanium-silicon molecular sieve powder, then mixing the pre-calcined powder with a pore-filling agent and drying it. The pre-calcination conditions include: a time of 0.5-144 hours, for example 1-72 hours, or 1-24 hours, or 2-12 hours, or 2-6 hours; and a temperature of 200-650℃, for example 200-650℃. The roasting atmosphere may be pure oxygen, air, or a combination thereof; the drying conditions include: a temperature not exceeding 200°C, for example, 50-200°C (excluding the endpoint 200°C), 100-200°C (excluding the endpoint 200°C), or 50-180°C. The temperature can be 80-180℃, 120-180℃, or 120-160℃, and the time can be 0.5-144 hours, for example, 1-72 hours, 1-24 hours, 2-12 hours, or 2-6 hours; the mixing time is 0.1-144 hours, for example, 0.1-72 hours, 0.1-24 hours, 0.1-12 hours, 0.1-6 hours, 0.2-6 hours, 0.5-6 hours, 1-6 hours, 2-5 hours, or 3-4 hours; the pore filler can include / be selected from one or more saturated polyols with 2-5 carbon atoms, preferably one or more of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and glycerol. When the pore filler includes two or more, there is no specific limitation on their ratio, for example, the ratio of any two can be 1:1000 to 1000:1.

[0058] According to one embodiment of this disclosure, the first adhesive and the second adhesive respectively include one or more of silica sol, water glass and alumina sol. When the adhesive includes two or more, their proportions are not specifically limited. The first surfactant and the second surfactant respectively include one or more of Span-20, Span-40, Span-60, Span-65, Span-80, Span-85, Tween-20, Tween-21, Tween-40, Tween-60, Tween-61, Tween-80, Tween-81 and Tween-85. When the surfactant includes two or more, their proportions are not specifically limited.

[0059] According to one embodiment of this disclosure, an alkali is added during the first molding and / or the second molding; preferably, the alkali is added during the first molding and the second molding. The alkali includes one or more organic alkalis, preferably one or more of hexamethylenetetramine, urea, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide. When there are two or more types of alkali, their proportions are not specifically limited. The above embodiment is beneficial for further promoting the formation of silicon-oxygen bonds and improving the mechanical strength of the titanium-silicon molecular sieve catalyst. The types of alkali added during the first molding and the second molding can be the same or different.

[0060] According to one embodiment of this disclosure, step S1 includes: mixing the material based on titanium-silicon molecular sieve powder (e.g., channel-filled titanium-silicon molecular sieve powder, or uncalcined titanium-silicon molecular sieve powder) with a first solution containing the first binder, optionally the alkali, and optionally the first surfactant, and performing the first molding to obtain the titanium-silicon molecular sieve microspheres; relative to the total weight of the material based on titanium-silicon molecular sieve powder (e.g., channel-filled titanium-silicon molecular sieve powder, or uncalcined titanium-silicon molecular sieve powder), the first binder, the alkali, and the first surfactant, the material based on titanium-silicon molecular sieve powder (e.g., channel-filled titanium-silicon molecular sieve powder, or uncalcined titanium-silicon molecular sieve powder)... The amount of the alkali used is 65-99.9% by weight, for example, 77-98.8% by weight, or 70-99.9% by weight, or 80-94.5% by weight; the amount of the first binder used is 0.1-20% by weight, for example, 0.1-15% by weight, or 5-13% by weight; the amount of the alkali used is 0-10% by weight, preferably 1-5% by weight; the amount of the first surfactant used is 0-5% by weight, for example, 0.1-3% by weight, or 0.1-2% by weight. Adding alkali in the first molding process, and using the above-mentioned amounts, can further promote the formation of silicon-oxygen bonds in the molecular sieve, improve the mechanical strength of the molecular sieve product, and obtain better performance and longer service life when used in industrial production.

[0061] According to one embodiment of this disclosure, step S2 includes: mixing the titanium-silicon molecular sieve microspheres with a second solution containing the second binder, optionally the alkali, and optionally the second surfactant, and performing the second molding to obtain the titanium-silicon molecular sieve catalyst precursor; relative to the total weight of the titanium-silicon molecular sieve microspheres, the second binder, the alkali, and the second surfactant, the amount of the titanium-silicon molecular sieve microspheres is 65-99.9% by weight, for example 77-98.8% by weight, or 70-99.9% by weight, or 83-97.5% by weight; the amount of the second binder is 0.1-20% by weight, preferably 0.1-15% by weight, or 1-10% by weight; the amount of the alkali is 0-10% by weight, preferably 1-5% by weight; the amount of the second surfactant is 0-5% by weight, for example 0.1-3% by weight, or 0.5-2% by weight; adding alkali in the second molding and using the above-mentioned amounts can further promote the formation of silicon-oxygen bonds in the molecular sieve, improve the mechanical strength of the molecular sieve product, and is suitable for industrial production.

[0062] According to one embodiment of this disclosure, the amount of water used in steps S1 and S2 is conventional in the art and is not specifically limited. For example, in step S1, the amount of water used is at least 0.1 parts by weight, such as 1-100 parts by weight, or 1-10 parts by weight, relative to 1 part by weight of the material based on titanium-silicon molecular sieve powder; in step S2, the amount of water used is at least 0.1 parts by weight, such as 1-100 parts by weight, or 1-10 parts by weight, relative to 1 part by weight of the titanium-silicon molecular sieve microspheres.

[0063] According to one embodiment of this disclosure, in step S1, the conditions for the first calcination treatment include: a temperature of 200-600°C, a time of 2-6 hours, and the calcination atmosphere can be a pure oxygen atmosphere, an air atmosphere, or a combination thereof. The method of the first calcination treatment is conventional in the art; the above embodiment can remove moisture from the first-formed product, and then perform the second forming in step S2, which is beneficial for shaping and improving the mechanical strength of the molecular sieve product.

[0064] According to one embodiment of this disclosure, the particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm.

[0065] According to one embodiment of this disclosure, the first molding and the second molding are respectively performed by extrusion molding, sugar coating pan molding, granulation machine molding, or spray molding; for example, sugar coating pan molding or granulation machine molding, or sugar coating pan molding, granulation machine molding, or spray molding.

[0066] According to one specific embodiment of this disclosure, the first molding method is spray molding or extrusion molding (for example, the first molding method is spray molding, and the air outlet temperature of spray molding is 100-150°C); the second molding method is sugar coating pot molding or granulator molding.

[0067] According to one embodiment of this disclosure, the method for preparing the uncalcined titanium-silicon molecular sieve raw powder includes: mixing a titanium source, a silicon source and a template agent and then performing hydrothermal crystallization.

[0068] According to one embodiment of this disclosure, in step S3, the conditions for water vapor aging include: a temperature of 50-600℃, for example 50-300℃ or 50-200℃; a time of 0.5-48h, for example 0.5-20h or 0.5-5h; a pressure of 0-2MPa, for example 0-1MPa; and a water vapor humidity of 50-100%, for example 50-80% or 80-100%, where "water vapor humidity" refers to relative humidity, i.e., the ratio of the actual pressure of the water vapor to the saturated vapor pressure of water at the same temperature. The above embodiment is conducive to the formation of silicon-oxygen bonds, optimizes the interfacial physicochemical environment, forms a covalent bond-based adhesive structure at the interface, and achieves a significant improvement in the mechanical strength of the titanium-silicon molecular sieve catalyst.

[0069] According to one embodiment of this disclosure, in step S3, the conditions for the alkaline vapor aging treatment include: a temperature of 50-600℃, for example 50-300℃ or 50-200℃; a time of 0.5-48h, for example 0.5-20h or 0.5-5h; and a pressure of 0-2MPa, for example 0-1MPa. The alkaline vapor includes / is selected from one or more of ammonia vapor, methylamine vapor, dimethylamine vapor, trimethylamine vapor, and ethylamine vapor. The above embodiment is beneficial for promoting in-situ crystallization at the interface between molecular sieve particles, strengthening the interfacial bonding strength, and further improving the mechanical strength of the titanium-silicon molecular sieve catalyst.

[0070] According to one embodiment of this disclosure, in step S4, the conditions for the second calcination treatment include: a temperature of 200-600℃, preferably 300-600℃, or 350-600℃, or 400-600℃, a time of 2-6 hours, and a calcination atmosphere that can be a pure oxygen atmosphere, an air atmosphere, or a combination thereof. The second calcination treatment is conventional in the art; using the above calcination conditions can remove residual organic matter from the molecular sieve, improving its mechanical strength and structural stability.

[0071] According to one embodiment of this disclosure, the method further includes: sieving the product obtained in step S4 to obtain a titanium-silicon molecular sieve catalyst with a particle size that meets the requirements, for example, a particle size of 1.0-1.4 mm or 1.1-1.3 mm.

[0072] The second aspect of this disclosure provides a titanium-silicon molecular sieve catalyst prepared using the method described in the first aspect of this disclosure.

[0073] According to one embodiment of this disclosure, the titanium-silicon molecular sieve catalyst has a particle size of 1.0-1.4 mm and a specific surface area of ​​360-470 m². 2 / g, for example 360-450m 2 / g, or 360-430m 2 / g, with a strength of 8-35N / particle, for example 8-30N / particle, or 15-30N / particle, or 10-20N / particle; the titanium-silicon molecular sieve catalyst disclosed herein has the advantages of uniform size and shape, high mechanical strength, and large specific surface area, and is suitable for industrial production. In particular, when used in the reaction to prepare propylene oxide, it can achieve better catalytic performance.

[0074] According to one embodiment of this disclosure, the titanium-silicon molecular sieve catalyst has a spherical or near-spherical shape.

[0075] According to one embodiment of this disclosure, the sphericity of the titanium-silicon molecular sieve catalyst is greater than 85%, or greater than 90%, or greater than 91%, or greater than 92%, or greater than 93%, or greater than 94%, or greater than 95%, for example 85-100%, or 90-99%, or 91-99%, or 92-99%, or 93-99%, or 94-99%, or 95-99%, or 90-98%, or 91-98%, or 92-98%, or 93-98%, or 94-98%, or 95-98%.

[0076] In this invention, the titanium-silicon molecular sieves in the titanium-silicon molecular sieve catalyst include, but are not limited to, TS-1, Ti-Beta, Ti-MWW, Ti-MCM-41, Ti-SBA-15, and Ti-UTL.

[0077] In particular, the present invention provides the following technical solution:

[0078] Option 1. A titanium-silicon molecular sieve catalyst, characterized in that the catalyst has one or both of the following characteristics:

[0079] The catalyst has a B value of 60%-96%, for example 72%-96%, or 74%-94%, or 76.1%-92.3%, where B = B1 / B2, and B1 represents the value of the catalyst. 1 The peak area of ​​the characteristic peak with a chemical shift of 1.8 ppm in the 1H MAS NMR spectrum, B2 represents the peak area of ​​the characteristic peak at 1.8 ppm in this catalyst. 1 The peak area of ​​characteristic peaks with chemical shifts >2 ppm in ¹H MMAS NMR spectra; and / or

[0080] The catalyst has a Q value ≥ 10, for example 12-16, or 12.8-15.6, where Q = Q 4 / Q 3 Q 4 Indicated in the catalyst 29 The peak area of ​​the characteristic peak with a chemical shift at -113 ppm in the Si MAS NMR spectrum, Q 3 Indicated in the catalyst 29 The peak area of ​​the characteristic peak with a chemical shift of -103 ppm in the Si MAS NMR spectrum.

[0081] The B value represents the content of silanol groups in the catalyst that are affected by hydrogen bonding, where B = B1 / B2, and B1 represents the content of silanol groups in the catalyst. 1 The peak area of ​​the characteristic peak with a chemical shift of 1.8 ppm in the ¹H MAS NMR spectrum. The characteristic peak with a chemical shift of 1.8 ppm represents a silanol group without hydrogen bonding. B2 indicates that in this catalyst... 1 The peak area of ​​the characteristic peak with a chemical shift > 2 ppm in the H MAS NMR spectrum. The characteristic peak with a chemical shift > 2 ppm represents a silanol group with hydrogen bonding.

[0082] The Q value represents the degree of bonding of the catalyst, where Q = Q 4 / Q 3 Q 4 Indicated in the catalyst 29 The peak area of ​​the characteristic peak with a chemical shift at -113 ppm in the Si MAS NMR spectrum indicates that one Si atom is bonded to four Si-O groups. 3 Indicated in the catalyst 29 The peak area of ​​the characteristic peak with a chemical shift of -103 ppm in the Si MAS NMR spectrum. The peak at -103 ppm indicates that one Si atom is connected to three Si-O groups and one OH group.

[0083] Option 2. The titanium-silicon molecular sieve catalyst according to any one of the foregoing technical solutions, characterized in that,

[0084] The titanium-silicon molecules in the catalyst are screened from TS-1, TS-1, Ti-Beta, Ti-MWW, Ti-MCM-41, Ti-SBA-15, Ti-UTL; and / or

[0085] The catalyst contains more than 50 wt%, or more than 60 wt%, or more than 70 wt%, or more than 80 wt%, for example, 70-99.9 wt%, 70-95 wt%, or 80-95 wt%; and / or

[0086] The catalyst comprises Si, Ti, and O elements, wherein the sum of the mass of Si, Ti, and O elements accounts for more than 50 wt%, or more than 60 wt%, or more than 70 wt%, or more than 80 wt%, or more than 90 wt%, or more than 95 wt%, or more than 96 wt%, or more than 97 wt%, or more than 98 wt%, or more than 99 wt%, or more than 99.5 wt%, or more than 99.9 wt% of the total weight of the catalyst, and the atomic ratio of Si to Ti is 20-300, or 20-200, or 30-150, or 50-100, or 50-70.

[0087] Option 3. The titanium-silicon molecular sieve catalyst according to any one of the foregoing technical solutions, characterized in that the catalyst is a shaped body.

[0088] Preferably,

[0089] The catalyst is spherical or near-spherical in shape, and / or

[0090] The catalyst has a particle size greater than 0.5 mm, or greater than 0.6 mm, or greater than 0.7 mm, or greater than 0.8 mm, or greater than 0.9 mm, or greater than 1.0 mm, for example...

[0091] 0.5-2mm, or 0.6-2mm, or 0.7-2mm, or 0.8-2mm, or 0.9-2mm, or 1.0-2mm, or

[0092] 0.5-1.8mm, or 0.6-1.8mm, or 0.7-1.8mm, or 0.8-1.8mm, or 0.9-1.8mm, or 1.0-1.8mm, or

[0093] 0.5-1.6mm, or 0.6-1.6mm, or 0.7-1.6mm, or 0.8-1.6mm, or 0.9-1.6mm, or 1.0-1.6mm, or

[0094] 0.5-1.5mm, or 0.6-1.5mm, or 0.7-1.5mm, or 0.8-1.5mm, or 0.9-1.5mm, or 1.0-1.5mm, or

[0095] 0.5-1.4mm, or 0.6-1.4mm, or 0.7-1.4mm, or 0.8-1.4mm, or 0.9-1.4mm, or 1.0-1.4mm, or 1.1-1.3mm; and / or

[0096] The projected area of ​​the catalyst is greater than 0.19 mm. 2 or greater than 0.28mm 2 or greater than 0.38mm 2 or greater than 0.50mm 2 or greater than 0.63mm 2 or greater than 0.78mm 2 ; and / or

[0097] The projected area of ​​the catalyst is less than 3.14 mm. 2 or less than 2.55mm 2 or less than 2.01mm 2 or less than 1.77mm 2 or less than 1.54mm 2 ; and / or

[0098] The projected area of ​​the catalyst is

[0099] 0.19-3.14mm 2 Or 0.28-3.14mm 2 Or 0.38-3.14mm 2 Or 0.50-3.14mm 2 Or 0.63-3.14mm 2 Or 0.78-3.14mm 2 ,or

[0100] 0.19-2.55mm 2 Or 0.28-2.55mm 2 Or 0.38-2.55mm 2 Or 0.50-2.55mm 2 Or 0.63-2.55mm 2 Or 0.78-2.55mm 2 ,or

[0101] 0.19-2.01mm 2 Or 0.28-2.01mm 2 Or 0.38-2.01mm 2 Or 0.50-2.01mm 2 Or 0.63-2.01mm 2 Or 0.78-2.01mm 2 ,or

[0102] 0.19-1.77mm 2 Or 0.28-1.77mm 2Or 0.38-1.77mm 2 Or 0.50-1.77mm 2 Or 0.63-1.77mm 2 Or 0.78-1.77mm 2 ,or

[0103] 0.19-1.54mm 2 Or 0.28-1.54mm 2 Or 0.38-1.54mm 2 Or 0.50-1.54mm 2 Or 0.63-1.54mm 2 Or 0.78-1.54mm 2 ,or

[0104] 0.94-1.33mm 2 .

[0105] Solution 4. The titanium-silicon molecular sieve catalyst according to any one of the foregoing technical solutions, characterized in that,

[0106] The catalyst has a micropore content β of 30%-70%, for example 40%-60%; and / or

[0107] The catalyst has a mesoporous content γ of 20%-60%, for example 25%-40%; and / or

[0108] The catalyst has a micropore content value β and a mesopore content value γ sum of 70%-95%, for example 75%-90%;

[0109] in

[0110] β=V mic-1 / (V mic-1 +V me-1 +V ma-1 )×100%,

[0111] γ=V me-1 / (V mic-1 +V me-1 +V ma-1 )×100%,

[0112] V mic-1 V me-1 V ma-1 These represent the volumes of micropores (pore size < 2 nm), mesopores (pore size 2-50 nm), and macropores (pore size > 50 nm) of the catalyst, respectively.

[0113] Solution 5. The titanium-silicon molecular sieve catalyst according to any one of the foregoing technical solutions, characterized in that,

[0114] In the catalyst, the total content of elements in group 1 (including any one of groups 1.1-1.5 as described below, hereinafter referred to as group 1.x elements), elements in group 2 (including any one of groups 2.1-2.4 as described below, hereinafter referred to as group 2.x elements), elements in group 3 (including any one of groups 3.1-3.4 as described below, hereinafter referred to as group 3.x elements), elements in group 4 (including any one of groups 4.1-4.4 as described below, hereinafter referred to as group 4.x elements), elements in group 5 (including any one of groups 5.1-5.19 as described below, hereinafter referred to as group 5.x elements), and Al is less than 20 wt% or less than 19 wt%. Or less than 18 wt%, or less than 17 wt%, or less than 16 wt%, or less than 15 wt%, or less than 14 wt%, or less than 13 wt%, or less than 12 wt%, or less than 11 wt%, or less than 10 wt%, or less than 9 wt%, or less than 8 wt%, or less than 7 wt%, or less than 6 wt%, or less than 5 wt%, or less than 4 wt%, or less than 3 wt%, or less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%, or less than 0.4 wt%, or less than 0.3 wt%, or less than 0.2 wt%, or less than 0.1 wt%, or less than 0.05 wt%, or less than 0.01 wt%, or less than 0.005 wt%; and / or

[0115] In the catalyst, the content of the elements in Group 1 (including elements in Group 1.x) is less than 20 wt%, or less than 19 wt%, or less than 18 wt%, or less than 17 wt%, or less than 16 wt%, or less than 15 wt%, or less than 14 wt%, or less than 13 wt%, or less than 12 wt%, or less than 11 wt%, or less than 10 wt%, or less than 9 wt%, or less than 8 wt%, or less than 7 wt%, or less than 6 wt%, or less than 5 wt%, or less than 4 wt%, or less than 3 wt%, or less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%, or less than 0.4 wt%, or less than 0.3 wt%, or less than 0.2 wt%, or less than 0.1 wt%, or less than 0.05 wt%, or less than 0.01 wt%, or less than 0.005 wt%; and / or;

[0116] In the catalyst, the content of the second group of elements (including the second x group of elements) is less than 20 wt%, or less than 19 wt%, or less than 18 wt%, or less than 17 wt%, or less than 16 wt%, or less than 15 wt%, or less than 14 wt%, or less than 13 wt%, or less than 12 wt%, or less than 11 wt%, or less than 10 wt%, or less than 9 wt%, or less than 8 wt%, or less than 7 wt%, or less than 6 wt%, or less than 5 wt%, or less than 4 wt%, or less than 3 wt%, or less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%, or less than 0.4 wt%, or less than 0.3 wt%, or less than 0.2 wt%, or less than 0.1 wt%, or less than 0.05 wt%, or less than 0.01 wt%, or less than 0.005 wt%; and / or;

[0117] In the catalyst, the content of the third group elements (including the third x group elements) is less than 20 wt%, or less than 19 wt%, or less than 18 wt%, or less than 17 wt%, or less than 16 wt%, or less than 15 wt%, or less than 14 wt%, or less than 13 wt%, or less than 12 wt%, or less than 11 wt%, or less than 10 wt%, or less than 9 wt%, or less than 8 wt%, or less than 7 wt%, or less than 6 wt%, or less than 5 wt%, or less than 4 wt%, or less than 3 wt%, or less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%, or less than 0.4 wt%, or less than 0.3 wt%, or less than 0.2 wt%, or less than 0.1 wt%, or less than 0.05 wt%, or less than 0.01 wt%, or less than 0.005 wt%; and / or;

[0118] In the catalyst, the content of Group 4 elements (including Group 4.x elements) is less than 20 wt%, or less than 19 wt%, or less than 18 wt%, or less than 17 wt%, or less than 16 wt%, or less than 15 wt%, or less than 14 wt%, or less than 13 wt%, or less than 12 wt%, or less than 11 wt%, or less than 10 wt%, or less than 9 wt%, or less than 8 wt%, or less than 7 wt%, or less than 6 wt%, or less than 5 wt%, or less than 4 wt%, or less than 3 wt%, or less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%, or less than 0.4 wt%, or less than 0.3 wt%, or less than 0.2 wt%, or less than 0.1 wt%, or less than 0.05 wt%, or less than 0.01 wt%, or less than 0.005 wt%; and / or;

[0119] In the catalyst, the content of Group 5 elements (including Group 5.x elements) is less than 20 wt%, or less than 19 wt%, or less than 18 wt%, or less than 17 wt%, or less than 16 wt%, or less than 15 wt%, or less than 14 wt%, or less than 13 wt%, or less than 12 wt%, or less than 11 wt%, or less than 10 wt%, or less than 9 wt%, or less than 8 wt%, or less than 7 wt%, or less than 6 wt%, or less than 5 wt%, or less than 4 wt%, or less than 3 wt%, or less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%, or less than 0.4 wt%, or less than 0.3 wt%, or less than 0.2 wt%, or less than 0.1 wt%, or less than 0.05 wt%, or less than 0.01 wt%, or less than 0.005 wt%; and / or;

[0120] In the catalyst, the Al content is less than 20 wt%, or less than 19 wt%, or less than 18 wt%, or less than 17 wt%, or less than 16 wt%, or less than 15 wt%, or less than 14 wt%, or less than 13 wt%, or less than 12 wt%, or less than 11 wt%, or less than 10 wt%, or less than 9 wt%, or less than 8 wt%, or less than 7 wt%, or less than 6 wt%, or less than 5 wt%, or less than 4 wt%, or less than 3 wt%, or less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%, or less than 0.4 wt%, or less than 0.3 wt%, or less than 0.2 wt%, or less than 0.1 wt%, or less than 0.05 wt%, or less than 0.01 wt%, or less than 0.005 wt%; and / or

[0121] In the catalyst, the molar ratio of the first group of elements (including the first x group elements) to silicon is less than 0.01, for example, less than 0.001, or less than 0.0001, or less than 0.00001, or less than 0.000001; and / or

[0122] In the catalyst, the molar ratio of the second group of elements (including the second x group of elements) to silicon is less than 0.01, for example less than 0.001, or less than 0.0001, or less than 0.00001, or less than 0.000001; and / or

[0123] In the catalyst, the molar ratio of the third group element (including the third x group element) to silicon is less than 0.01, for example less than 0.001, or less than 0.0001, or less than 0.00001, or less than 0.000001; and / or

[0124] In the catalyst, the molar ratio of group 4 elements (including group 4.x elements) to silicon is less than 0.01, for example less than 0.001, or less than 0.0001, or less than 0.00001, or less than 0.000001; and / or

[0125] In the catalyst, the molar ratio of group 5 elements (including group 5.x elements) to silicon is less than 0.01, for example less than 0.001, or less than 0.0001, or less than 0.00001, or less than 0.000001; and / or

[0126] In the catalyst, the molar ratio of Al to silicon is less than 0.01, for example less than 0.001, or less than 0.0001, or less than 0.00001, or less than 0.000001; and / or

[0127] In the catalyst, the molar ratio of Group 1 elements (including Group 1.x elements) to titanium is less than 0.5, for example, less than 0.05, or less than 0.005, or less than 0.0005, or less than 0.00005; and / or

[0128] In the catalyst, the molar ratio of the second group of elements (including the second x group of elements) to titanium is less than 0.5, for example, less than 0.05, or less than 0.005, or less than 0.0005, or less than 0.00005; and / or

[0129] In the catalyst, the molar ratio of group 3 elements (including group 3.x elements) to titanium is less than 0.5, for example less than 0.05, or less than 0.005, or less than 0.0005, or less than 0.00005; and / or

[0130] In the catalyst, the molar ratio of group 4 elements (including group 4.x elements) to titanium is less than 0.5, for example less than 0.05, or less than 0.005, or less than 0.0005, or less than 0.00005; and / or

[0131] In the catalyst, the molar ratio of group 5 elements (including group 5.x elements) to titanium is less than 0.5, for example, less than 0.05, or less than 0.005, or less than 0.0005, or less than 0.00005; and / or

[0132] In the catalyst, the molar ratio of Al to titanium is less than 0.5, for example less than 0.05, or less than 0.005, or less than 0.0005, or less than 0.00005;

[0133] in

[0134] The first group of elements (rare earth metals) is selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

[0135] in,

[0136] The elements in group 1.1 are selected from Ce, La, Y, Sm, Gd, Yb, and Lu;

[0137] The elements in group 1.2 are selected from Ce and La;

[0138] The elements in group 1.3 are selected from Ce;

[0139] The elements in group 1.4 are selected from La;

[0140] The elements in group 1.5 are selected from Y, Sm, Gd, Yb, and Lu;

[0141] The second group of elements (alkali metals) is selected from Li, Na, K, Rb, and Cs;

[0142] in,

[0143] The elements in group 2.1 are selected from K and Cs;

[0144] The elements in group 2.2 are selected from K;

[0145] The elements in group 2 and 3 are selected from Cs;

[0146] The elements in group 2.4 are selected from Na;

[0147] The third group of elements (alkaline earth metals) is selected from Be, Mg, Ca, Sr, and Ba;

[0148] in,

[0149] The elements in group 3.1 are selected from Mg and Ca;

[0150] The elements in group 3.2 are selected from Mg;

[0151] The elements in group 3.3 are selected from Ca;

[0152] The elements in group 3.4 are selected from Sr and Ba;

[0153] The fourth group of elements (precious metals) is selected from Ru, Rh, Pd, Ag, Os, Ir, Pt, and Au;

[0154] in,

[0155] The elements in group 4.1 are selected from Pd and Au;

[0156] The elements in group 4.2 are selected from Pd;

[0157] The elements in group 4.3 are selected from Au;

[0158] The elements in group 4.4 are selected from Pt and Ag;

[0159] The fifth group of elements (others) is selected from: Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Y, Zr, Nb, Mo, Tc, Cd, In, Hf, Ta, W, Re, Tl, Sn, Pb;

[0160] in,

[0161] Group 5.1 elements are selected from Cu, Fe, Sn, Zr, Cr, Mn, Ni, Zn, Mo, V, Co, Ga, Nb, Hf, W, and Y;

[0162] The elements in group 5.2 are selected from Cu;

[0163] The elements in group 5.3 are selected from Fe;

[0164] The elements in group 5.4 are selected from Sn;

[0165] The elements in group 5.5 are selected from Zr;

[0166] The elements in group 5 and 6 are selected from Cu and Fe;

[0167] The elements in group 5.7 are selected from Sn and Zr;

[0168] The elements in group 5.8 are selected from Cr, Mn, Ni, Zn, and Mo;

[0169] The elements in group 5.9 are selected from V, Co, Ga, Nb, Hf, W, and Y;

[0170] The elements in group 5.10 are selected from Cu, Fe, Sn, and Zr;

[0171] The elements in group 5.11 are selected from Cu, Fe, Cr, Mn, Ni, Zn, and Mo;

[0172] The elements in group 5.12 are selected from Cu, Fe, V, Co, Ga, Nb, Hf, W, and Y;

[0173] The elements in group 5.13 are selected from Sn, Zr, Cr, Mn, Ni, Zn, and Mo;

[0174] The elements in group 5.14 are selected from Sn, Zr, V, Co, Ga, Nb, Hf, W, and Y;

[0175] The elements in group 5.15 are selected from Cr, Mn, Ni, Zn, Mo, V, Co, Ga, Nb, Hf, W, and Y;

[0176] The elements in group 5.16 are selected from Cu, Fe, Sn, Zr, Cr, Mn, Ni, Zn, and Mo;

[0177] The elements in group 5.17 are selected from Cu, Fe, Sn, Zr, V, Co, Ga, Nb, Hf, W, and Y;

[0178] The elements in group 5.18 are selected from Cu, Fe, Cr, Mn, Ni, Zn, Mo, V, Co, Ga, Nb, Hf, W, and Y;

[0179] Group 5.19 elements are selected from Sn, Zr, Cr, Mn, Ni, Zn, Mo, V, Co, Ga, Nb, Hf, W, and Y.

[0180] Solution 6. The titanium-silicon molecular sieve catalyst according to any one of the foregoing technical solutions, characterized in that,

[0181] The catalyst has a specific surface area >300m². 2 / g, for example 330-500m 2 / g, or >400m 2 / g, or 400-480m 2 / g; and / or

[0182] The strength of the catalyst is 8-30 N / particle, for example 10-20 N / particle.

[0183] Solution 7. A method for preparing the titanium-silicon molecular sieve catalyst according to any one of the foregoing technical solutions, characterized in that the method comprises the following steps:

[0184] S1. The material based on titanium-silicon molecular sieve powder, a first binder, water and an optional first surfactant are mixed and subjected to a first molding process, and the solid product obtained from the first molding process is subjected to a first calcination treatment to obtain titanium-silicon molecular sieve microspheres.

[0185] Preferably, the material based on the titanium-silicon molecular sieve powder is selected from: uncalcined and unfilled titanium-silicon molecular sieve powder, uncalcined but filled titanium-silicon molecular sieve powder, calcined but unfilled titanium-silicon molecular sieve powder, and calcined and filled titanium-silicon molecular sieve powder.

[0186] More preferably, the material based on the titanium-silicon molecular sieve powder is selected from: uncalcined and unfilled titanium-silicon molecular sieve powder, and calcined and filled titanium-silicon molecular sieve powder.

[0187] S2. Mix the titanium-silicon molecular sieve microspheres, the second binder, water and an optional second surfactant and perform a second molding process to obtain the titanium-silicon molecular sieve catalyst precursor.

[0188] S3. The titanium-silicon molecular sieve catalyst precursor is aged with water vapor and / or alkaline vapor to obtain a titanium-silicon molecular sieve catalyst pre-product.

[0189] S4. The titanium-silicon molecular sieve catalyst preproduct is subjected to a second calcination treatment.

[0190] Optionally, an alkali is added during the first molding and / or the second molding; preferably, the alkali is added during the first molding and the second molding.

[0191] Solution 8. The method according to technical solution 7, characterized in that the relative micropore retention α of the catalyst is 80-130%, 90%-110%, and the relative micropore retention α = V mic-1 / (w×V mic-2 )×100%, where V mic-1 V represents the micropore volume of a given mass of catalyst. mic-2 The term "micropore volume" represents the micropore volume of the product obtained by calcining the same mass of titanium-silicon molecular sieve powder in a pure oxygen environment at 600°C for 6 hours (to remove the template agent); w represents the weight content of titanium-silicon molecular sieve in the catalyst; and / or

[0192] The ratio of titanium content in the titanium-silicon molecular sieve before and after molding, characterized by STEM-EDX, is A = 0.9-1.1, where A = A1 / A2. A1 represents the titanium content of the titanium-silicon molecular sieve in the catalyst, and A2 represents the titanium content of the product obtained after calcining the titanium-silicon molecular sieve powder in a pure oxygen environment at 600℃ for 6 hours (to remove the template agent).

[0193] Solution 9. The method according to any one of technical solutions 7-8, characterized in that,

[0194] The first binder and the second binder respectively comprise one or more of silica sol, water glass, silica, and alumina sol; and / or

[0195] The first surfactant and the second surfactant are respectively Span-type surfactants and / or Tween-type surfactants, preferably including one or more of Span-20, Span-40, Span-60, Span-65, Span-80, Span-85, Tween-20, Tween-21, Tween-40, Tween-60, Tween-61, Tween-80, Tween-81, and Tween-85; and / or

[0196] The pore filler comprises one or more saturated polyols having 2-5 carbon atoms, preferably one or more of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and glycerol; and / or

[0197] The alkali includes one or more organic alkalis, preferably one or more of hexamethylenetetramine, urea, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

[0198] Solution 10. The method according to any one of technical solutions 7-9, characterized in that,

[0199] In step S1, relative to the total weight of the material based on the titanium-silicon molecular sieve powder, the first binder, the alkali, and the first surfactant, the amount of the material based on the titanium-silicon molecular sieve powder is 65-99.9% by weight (e.g., 70-99.9% by weight), the amount of the first binder is 0.1-20% by weight (e.g., 0.1-15% by weight), the amount of the alkali is 0-10% by weight, and the amount of the first surfactant is 0-5% by weight; and / or

[0200] In step S2, relative to the total weight of the titanium-silicon molecular sieve microspheres, the second binder, the alkali, and the second surfactant, the amount of the titanium-silicon molecular sieve microspheres is 65-99.9% by weight (e.g., 70-99.9% by weight), the amount of the second binder is 0.1-20% by weight (e.g., 0.1-15% by weight), the amount of the alkali is 0-10% by weight, and the amount of the second surfactant is 0-5% by weight.

[0201] Preferably, step S1 includes: mixing the material based on titanium-silicon molecular sieve powder with a first solution containing the first binder, optionally the alkali, and optionally the first surfactant, and performing the first molding, and subjecting the solid product obtained from the first molding to a first calcination treatment to obtain the titanium-silicon molecular sieve microspheres; and / or, step S2 includes: mixing the titanium-silicon molecular sieve microspheres with a second solution containing the second binder, optionally the alkali, and optionally the second surfactant, and performing the second molding to obtain the titanium-silicon molecular sieve catalyst precursor;

[0202] More preferably, in step S1, the amount of water used is at least 0.1 parts by weight, for example 1-100 parts by weight, or 1-10 parts by weight, relative to 1 part by weight of the material based on the titanium-silicon molecular sieve powder; in step S2, the amount of water used is at least 0.1 parts by weight, for example 1-100 parts by weight, or 1-10 parts by weight, relative to 1 part by weight of the titanium-silicon molecular sieve microspheres.

[0203] Solution 11. The method according to any one of technical solutions 7-10, characterized in that,

[0204] In step S1, the conditions for the first calcination treatment include: a temperature of 200-600℃, a time of 2-6 hours, and the calcination atmosphere being pure oxygen, air, or a combination thereof; and / or

[0205] In step S3, the conditions for steam aging include: a temperature of 50-600℃, for example 50-300℃ or 50-200℃; a time of 0.5-48h, for example 0.5-20h or 0.5-5h; a pressure of 0-2MPa, for example 0-1MPa; and a steam humidity of 50-100%, for example 50-80% or 80-100%. The conditions for alkaline steam aging include: a temperature of 50-600℃, for example 50-300℃ or 50-200℃; a time of 0.5-48h, for example 0.5-20h or 0.5-5h; and a pressure of 0-2MPa, for example 0-1MPa. The alkaline steam includes / is selected from one or more of ammonia steam, methylamine steam, dimethylamine steam, trimethylamine steam, and ethylamine steam.

[0206] and / or

[0207] In step S4, the conditions for the second calcination treatment include: a temperature of 200-600℃, preferably 300-600℃, or 350-600℃, or 400-600℃, a time of 2-6 hours, and a calcination atmosphere of pure oxygen, air, or a combination thereof.

[0208] Scheme 12. The method according to any one of technical solutions 7-11, characterized in that the particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm.

[0209] Solution 13. The method according to any one of technical solutions 7-12, characterized in that the first molding and the second molding are respectively performed by extrusion molding, sugar coating pan molding, granulator molding or spray molding.

[0210] Scheme 14. The use of the titanium-silicon molecular sieve catalyst described in any one of technical schemes 1-6 in catalytic oxidation reactions such as the epoxidation of propylene to prepare propylene oxide.

[0211] Example

[0212] The present invention will be described in detail below through embodiments, but is not limited to the following embodiments.

[0213] Unless otherwise specified, the instruments, reagents, and materials used in the following examples are all conventional instruments, reagents, and materials that are already available in the prior art and can be purchased through legitimate commercial channels.

[0214] The method for measuring pore size is RIPP 151-90 (Determination of pore volume and pore size distribution of catalysts by nitrogen adsorption capacity method, Petrochemical Analytical Methods (RIPP Test Method), Yang Cuiding, Science Press, 1990).

[0215] In this invention, unless otherwise specified, pressure refers to gauge pressure.

[0216] In this invention, unless otherwise specified, particle size refers to the volume equivalent diameter of the particle (e.g., D). 50 The particle size was measured using a laser particle size analyzer.

[0217] Sphericity refers to the ratio of the surface area of ​​a sphere of the same volume to the surface area of ​​the object. Projected area refers to the area of ​​the shadow cast by an object when it is illuminated by a parallel beam of light, on a plane perpendicular to the beam (projection plane), where the object completely blocks the light. The projected area of ​​a catalyst refers to the area of ​​the largest shadow area obtained when the catalyst is illuminated by parallel beams of light from different directions.

[0218] The particle size of titanium-silicon molecular sieve microspheres, the particle size of catalysts, the projected area of ​​catalysts, and the sphericity of catalysts can be measured using static or dynamic digital image analyzers, such as the Camsizer static or dynamic digital imaging particle analyzer from RETSCH GmbH, Germany.

[0219] 1 HMAS NMR spectra were obtained on a Varian Infinity Plus-400 nuclear magnetic resonance spectrometer, using a 4mm dual resonance probe, a 4mm ZrO2 rotor, a resonance frequency of 400.1MHz, a magic angle rotation speed of 10kHz, a pulse width of 3.57μs, a cycle delay time of 1s, and approximately 4000 scans.

[0220] 29 The Si MAS NMR spectrum was obtained on an AVANCEⅢ500WB nuclear magnetic resonance spectrometer using a 7mm dual resonance probe, a Φ7mm ZrO2 rotor, a resonance frequency of 99.3MHz, a magic angle rotation speed of 5kHz, a pulse width of 1.8μs, a cycle delay time of 2s, and approximately 3000 scans.

[0221] Test method for specific surface area: N2 adsorption-desorption analysis (GB / T 19587-2017).

[0222] In this invention, strength refers to the crushing strength of the particles, measured in N / particle. Strength can be measured using the DL5-50 intelligent particle strength tester manufactured by Dalian Penghui Technology Development Co., Ltd.

[0223] The titanium content of the titanium-silicon molecular sieve in the catalyst can be measured using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and aberration-corrected transmission electron microscopy (Ac-TEM). For example, it can be measured using a scanning transmission electron microscope-energy dispersive X-ray spectrometer (STEM-EDX). The instrument used can be a JEM-ARM200F aberration-corrected cold field emission transmission electron microscope (manufactured by JEOL Corporation, with an X-ray energy dispersive spectrometer as an accessory). The test conditions are: accelerating voltage 200kV. The test method includes: after the sample is dispersed in an ethanol solution, it is placed in a porous microgrid, dried, and a selected area is focused for observation. Selective surface distribution analysis is used to collect images.

[0224] Methods for measuring the content of titanium-silicon molecular sieve in catalyst: (1) Determine the crystal type of titanium-silicon molecular sieve in catalyst by XRD method; (2) Prepare pure titanium-silicon molecular sieve of the same crystal type as standard sample; (3) Perform XRD tests on the standard sample and the catalyst sample to be tested with the same mass respectively; (4) Select one or more characteristic diffraction peaks (for example, for TS-1 titanium-silicon molecular sieve, select the main peak with 2θ around 23°), measure the peak area of ​​the sample to be tested and the standard sample and calculate the ratio between the two to obtain the content of titanium-silicon molecular sieve in catalyst. XRD was measured on Siemens D5005 X-ray diffractometer, the X-ray source was Kα (Cu), and the test range was 2θ in 0.5-70°.

[0225] The elemental content in the catalyst can be determined according to analytical methods known in the field, such as those described in "Analytical Methods in Petrochemical Industry (RIPP Test Method)" (Yang Cuiding, Science Press, 1990), specifically including but not limited to: colorimetric methods (RIPP35-90, RIPP36-90, RIPP37-90, RIPP38-90); atomic absorption spectrometry (such as RIPP114-90, RIPP115-90, RIPP116-90, RIPP117-90, RIPP118-90, etc.). RIPP119-90, RIPP120-90, RIPP121-90, RIPP122-90, RIPP123-90); Inductively Coupled Plasma Emission Spectroscopy (ICP / AES) (e.g., RIPP126-90, RIPP127-90, RIPP128-90, RIPP129-90); X-ray Fluorescence Spectroscopy (e.g., RIPP131-90, RIPP132-90, RIPP133-90, RIPP134-90, RIPP135-90).

[0226] The preparation method of the uncalcined titanium-silicon molecular sieve raw powder used in the examples and comparative examples: hydrothermal synthesis method, in which titanium source (e.g., tetrabutyl titanate), silicon source (e.g., tetraethyl silicate) and template agent (e.g., tetrapropylammonium hydroxide) are mixed and then subjected to hydrothermal crystallization (temperature: 180°C, time: 24 hours). The product obtained by hydrothermal crystallization is the uncalcined titanium-silicon molecular sieve raw powder G.

[0227] The preparation method of the calcined titanium-silicon molecular sieve raw powder used in the examples and comparative examples: hydrothermal synthesis method, the product obtained by hydrothermal crystallization is calcined at 550°C in air atmosphere for 3 hours to obtain calcined titanium-silicon molecular sieve raw powder H.

[0228] All raw materials used in the examples are commercially available (unless otherwise specified, the product specifications are industrial grade or analytical grade), including: silica sol (30% concentration), ethylene glycol, 1,3-propanediol, 1,4-butanediol, Span-40, Span-60, Span-80, urea, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, Tween-20, Tween-40, and Tween-80.

[0229] Example A1

[0230] Titanium-silicon molecular sieve A1 was prepared using the following steps:

[0231] (1) The uncalcined titanium silicon molecular sieve powder G is mixed with a first solution containing silica sol and tetramethylammonium hydroxide and slurryed. The resulting slurry is then formed for the first time by extrusion molding. The resulting solid product is then calcined at 600℃ for 4 hours to obtain titanium silicon molecular sieve microspheres with a particle size of 20-80μm.

[0232] Relative to the total weight of the material based on titanium-silicon molecular sieve powder, silica sol, and tetramethylammonium hydroxide, the content of the material based on titanium-silicon molecular sieve powder is 83% by weight, the content of silica sol is 12% by weight, and the content of tetramethylammonium hydroxide is 5% by weight.

[0233] (2) The titanium-silicon molecular sieve microspheres prepared in step (1) are mixed with a second solution containing tetramethylammonium hydroxide, silica sol and Tween-80 to obtain a mixture for a second molding process. The molding method is to roll the mixture into balls in a sugar coating machine to prepare a titanium-silicon molecular sieve catalyst precursor.

[0234] Relative to the total weight of titanium-silicon molecular sieve microspheres, silica sol, tetramethylammonium hydroxide, and Tween-80, the content of titanium-silicon molecular sieve microspheres is 95% by weight, the content of silica sol is 2% by weight, the content of tetramethylammonium hydroxide is 2.5% by weight, and the content of Tween-80 is 0.5% by weight.

[0235] (3) The titanium-silicon molecular sieve catalyst precursor prepared in step (2) is subjected to steam aging treatment at a pressure of 0.1 MPa, a temperature of 200 °C, a steam humidity of 80%, and a time of 2 h to obtain the titanium-silicon molecular sieve catalyst pre-product.

[0236] (4) The titanium-silicon molecular sieve catalyst preproduct prepared in step (3) is calcined for a second time at 400℃ for 4h. The titanium-silicon molecular sieve product obtained from the second calcination is sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.1-1.3mm, namely titanium-silicon molecular sieve A1. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0237] Example A2

[0238] Titanium-silicon molecular sieve A2 was prepared using the method of Example A1, with the difference being:

[0239] In step (1), tetramethylammonium hydroxide is replaced with urea;

[0240] Relative to the total weight of the material, silica sol, and urea based on the titanium-silicon molecular sieve raw powder, the content of the material based on the titanium-silicon molecular sieve raw powder is 87% by weight, the content of the silica sol is 10% by weight, and the content of the urea is 3% by weight.

[0241] The particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm;

[0242] In step (2), tetramethylammonium hydroxide is replaced with an equal weight of urea, and Tween-80 is replaced with an equal weight of Span-80;

[0243] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.1-1.3 mm, namely titanium-silicon molecular sieve A2. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0244] Example A3

[0245] Titanium-silicon molecular sieve A3 was prepared using the method of Example A1, with the difference being:

[0246] In step (1), tetramethylammonium hydroxide is replaced with tetrabutylammonium hydroxide;

[0247] Relative to the total weight of the material based on titanium-silicon molecular sieve powder, silica sol, and tetrabutylammonium hydroxide, the content of the material based on titanium-silicon molecular sieve powder is 93% by weight, the content of silica sol is 5% by weight, and the content of tetrabutylammonium hydroxide is 2% by weight.

[0248] The particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm;

[0249] In step (2), in step (1), tetramethylammonium hydroxide is replaced with an equal weight of tetrabutylammonium hydroxide, and Tween-80 is replaced with an equal weight of Span-40;

[0250] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.1-1.3 mm, namely titanium-silicon molecular sieve A3. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0251] Example A4

[0252] Titanium silicate molecular sieve A4 was prepared using the method of Example A1. The difference is that in step (1), the temperature of the first calcination treatment was 200℃ and the time was 2h, and the particle size of the titanium silicate molecular sieve microspheres was 20-80μm; in step (4), the temperature of the second calcination treatment was 200℃ and the time was 2h; the titanium silicate molecular sieve product obtained from the second calcination was sieved to obtain a titanium silicate molecular sieve catalyst with a particle size of 1.1-1.3mm, namely titanium silicate molecular sieve A4. The parameters are listed in Table 1. The titanium silicate molecular sieve catalyst is spherical and has a uniform size.

[0253] Example A5

[0254] Titanium silicate molecular sieve A5 was prepared using the method of Example A1. The difference is that in step (1), the temperature of the first calcination treatment was 600℃ and the time was 6h, and the particle size of the titanium silicate molecular sieve microspheres was 20-80μm; in step (4), the temperature of the second calcination treatment was 600℃ and the time was 6h; the titanium silicate molecular sieve product obtained by the second calcination was sieved to obtain a titanium silicate molecular sieve catalyst with a particle size of 1.1-1.3mm, namely titanium silicate molecular sieve A5. The parameters are listed in Table 1. The titanium silicate molecular sieve catalyst is spherical and has a uniform size.

[0255] Example A6

[0256] Titanium silicate molecular sieve A6 was prepared using the method of Example A1. The difference is that in step (3), the temperature of water vapor aging was 100℃ and the time was 1h. The titanium silicate molecular sieve product obtained by the second calcination was sieved to obtain titanium silicate molecular sieve catalyst with a particle size of 1.1-1.3mm, namely titanium silicate molecular sieve A6. The parameters are listed in Table 1. The titanium silicate molecular sieve catalyst is spherical and has a uniform size.

[0257] Example A7

[0258] Titanium silicon molecular sieve A7 was prepared using the method of Example A1. The difference is that in step (3), the temperature of water vapor aging was 300℃ and the time was 3h. The titanium silicon molecular sieve product obtained by the second calcination was sieved to obtain titanium silicon molecular sieve catalyst with a particle size of 1.1-1.3mm, namely titanium silicon molecular sieve A7. The parameters are listed in Table 1. The titanium silicon molecular sieve catalyst is spherical and has a uniform size.

[0259] Comparative Example A1

[0260] Uncalcined titanium-silicon molecular sieve powder G was mixed with a solution containing silica sol and tetraethylammonium hydroxide and slurried. Relative to the total weight of the titanium-silicon molecular sieve powder, silica sol, and tetraethylammonium hydroxide, the content of the titanium-silicon molecular sieve powder was 83% by weight, the content of the silica sol was 15% by weight, and the content of the tetraethylammonium hydroxide was 2% by weight. The resulting mixture was directly ball-formed in a coating pan. The prepared titanium-silicon molecular sieve AD1 did not have a spherical particle morphology and was in powder form.

[0261] Example B1

[0262] Titanium-silicon molecular sieve B1 was prepared using the following steps:

[0263] (1) The calcined titanium silicon molecular sieve raw powder H is mixed with a first solution containing silica sol, urea and Tween-80 and slurryed. The slurry is then formed for the first time using a sugar coating pot molding method. The solid product is then calcined at 400℃ for 4 hours to obtain titanium silicon molecular sieve microspheres with a particle size of 20-80μm.

[0264] Relative to the total weight of the material based on titanium-silicon molecular sieve powder, silica sol, urea, and Tween-80, the content of the material based on titanium-silicon molecular sieve powder is 87% by weight, the content of silica sol is 10% by weight, the content of urea is 2.5% by weight, and the content of Tween-80 is 0.5% by weight.

[0265] (2) The titanium-silicon molecular sieve microspheres prepared in step (1) are mixed with a second solution containing urea, silica sol and Span-80 to obtain a mixture for a second molding process. The molding method is to roll the mixture into balls in a sugar coating pan to prepare a titanium-silicon molecular sieve catalyst precursor.

[0266] Relative to the total weight of titanium-silicon molecular sieve microspheres, silica sol, urea, and Span-80, the content of titanium-silicon molecular sieve microspheres is 96% by weight, the content of silica sol is 1% by weight, the content of urea is 2.5% by weight, and the content of Span-80 is 0.5% by weight.

[0267] (3) The titanium-silicon molecular sieve catalyst precursor prepared in step (2) is aged with ammonia vapor at 0.05 MPa and 200 °C for 2 h to obtain the titanium-silicon molecular sieve catalyst pre-product.

[0268] (4) The titanium-silicon molecular sieve catalyst preproduct prepared in step (3) is calcined for a second time at 400℃ for 4h. The titanium-silicon molecular sieve product obtained from the second calcination is sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4mm, namely titanium-silicon molecular sieve B1. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0269] Example B2

[0270] Titanium silicate molecular sieve B2 was prepared using the method of Example B1, with the difference being:

[0271] In step (1), urea is replaced with tetrabutylammonium hydroxide, and Tween-80 is replaced with Tween-20;

[0272] Relative to the total weight of the material based on titanium-silicon molecular sieve powder, silica sol, tetrabutylammonium hydroxide, and Tween-20, the content of the material based on titanium-silicon molecular sieve powder is 82% by weight, the content of silica sol is 15% by weight, the content of tetrabutylammonium hydroxide is 2.8% by weight, and the content of Tween-20 is 0.2% by weight.

[0273] The particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm;

[0274] In step (2), urea is replaced with an equal weight of tetrabutylammonium hydroxide, and Span-80 is replaced with an equal weight of Tween-20;

[0275] In step (3), the alkaline vapor is methylamine vapor;

[0276] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve B2. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0277] Example B3

[0278] Titanium silicate molecular sieve B3 was prepared using the method of Example B1, with the difference being:

[0279] In step (1), urea is replaced with tetrapropylammonium hydroxide, and Tween-80 is replaced with Span-60;

[0280] Relative to the total weight of the material based on titanium-silicon molecular sieve powder, silica sol, tetrapropylammonium hydroxide, and Span-60, the content of the material based on titanium-silicon molecular sieve powder is 93% by weight, the content of silica sol is 5% by weight, the content of tetrapropylammonium hydroxide is 1.8% by weight, and the content of Span-60 is 0.2% by weight.

[0281] The particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm;

[0282] In step (2), Span-80 is replaced with Span-60 of equal weight;

[0283] In step (3), the alkaline vapor is ethylamine vapor;

[0284] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve B3. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0285] Example B4

[0286] Titanium silicate molecular sieve B4 was prepared using the method of Example B1, with the difference being:

[0287] In step (1), the temperature of the first roasting treatment is 200℃ and the time is 2h;

[0288] In step (2), Span-80 is replaced with an equal weight of Tween-40;

[0289] In step (3), the alkaline vapor is trimethylamine vapor;

[0290] In step (4), the temperature of the second calcination treatment is 600℃ and the time is 6h; the titanium silicon molecular sieve product obtained from the second calcination is sieved to obtain a titanium silicon molecular sieve catalyst with a particle size of 1.0-1.4mm, namely titanium silicon molecular sieve B4. The parameters are listed in Table 1. The titanium silicon molecular sieve catalyst is spherical and has a uniform size.

[0291] Example B5

[0292] Titanium silicate molecular sieve B5 was prepared using the method of Example B1, with the difference being:

[0293] In step (1), the temperature of the first roasting treatment is 600℃ and the time is 6h;

[0294] In step (3), the alkaline vapor is methylamine vapor;

[0295] In step (4), the temperature of the second calcination treatment is 200℃ and the time is 2h. The titanium silicon molecular sieve product obtained from the second calcination is sieved to obtain a titanium silicon molecular sieve catalyst with a particle size of 1.0-1.4mm, namely titanium silicon molecular sieve B5. The parameters are listed in Table 1. The titanium silicon molecular sieve catalyst is spherical and has a uniform size.

[0296] Example B6

[0297] Titanium silicate molecular sieve B6 was prepared using the method of Example B1, with the difference being:

[0298] In step (3), the aging temperature is 100℃ and the time is 1 hour;

[0299] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve B6. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0300] Example B7

[0301] Titanium silicate molecular sieve B7 was prepared using the method of Example B1, with the difference being:

[0302] In step (3), the aging temperature is 300℃ and the time is 3h;

[0303] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve B7. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0304] Example B8

[0305] Titanium silicate molecular sieve B8 was prepared using the method of Example B1, with the difference being:

[0306] In step (2), relative to the total weight of titanium-silicon molecular sieve microspheres, silica sol, urea and Span-80, the content of titanium-silicon molecular sieve microspheres is 81% by weight, the content of silica sol is 15% by weight, the content of urea is 3% by weight and the content of Span-80 is 1% by weight.

[0307] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve B8. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0308] Comparative Example B1

[0309] Titanium silicate molecular sieve D1 was prepared using the method of Example B1. The difference is that step (3) was not performed. Instead, the titanium silicate molecular sieve catalyst precursor obtained in step (2) was directly subjected to the second calcination treatment in step (4). The titanium silicate molecular sieve product obtained from the second calcination was sieved to obtain titanium silicate molecular sieve catalyst with a particle size of 1.0-1.4 mm. The parameters of titanium silicate molecular sieve BD1 are listed in Table 1.

[0310] Comparative Example B2

[0311] The calcined titanium-silicon molecular sieve powder H was mixed with a mixture containing silica sol, tetrapropylammonium hydroxide, and Tween-80 and slurried. Relative to the total weight of the titanium-silicon molecular sieve-based material, silica sol, tetrapropylammonium hydroxide, and Tween-80, the content of the titanium-silicon molecular sieve-based material was 87 wt%, the content of silica sol was 10 wt%, the content of tetrapropylammonium hydroxide was 2.5 wt%, and the content of Tween-80 was 0.5 wt%. The resulting mixture was directly balled in a coating pan. The prepared titanium-silicon molecular sieve BD2 did not have a spherical particle morphology and was in powder form.

[0312] Example C1

[0313] Titanium-silicon molecular sieve C1 was prepared using the following steps:

[0314] (1) The calcined titanium silicon molecular sieve raw powder H was mixed with ethylene glycol for 1 hour and then dried at 110°C for 3 hours to obtain pore-filled titanium silicon molecular sieve raw powder.

[0315] (2) The pore-filled titanium silicon molecular sieve raw powder is mixed with a first solution containing silica sol and tetraethylammonium hydroxide and slurryed. The resulting slurry is then spray-molded for the first time at an air outlet temperature of 120°C. The resulting solid product is then calcined at 550°C for the first time for 6 hours to obtain titanium silicon molecular sieve microspheres with a particle size of 20-80 μm.

[0316] Relative to the total weight of the material based on titanium-silicon molecular sieve powder, silica sol, and tetraethylammonium hydroxide, the content of the material based on titanium-silicon molecular sieve powder is 83% by weight, the content of silica sol is 15% by weight, and the content of tetraethylammonium hydroxide is 2% by weight.

[0317] (3) The titanium-silicon molecular sieve microspheres prepared in step (2) are mixed with a second solution containing tetraethylammonium hydroxide, silica sol and Tween-40 to obtain a mixture for a second molding process. The molding method is to roll the mixture into balls in a sugar coating machine to prepare a titanium-silicon molecular sieve catalyst precursor.

[0318] Relative to the total weight of titanium-silicon molecular sieve microspheres, silica sol, tetraethylammonium hydroxide, and Tween-40, the content of titanium-silicon molecular sieve microspheres is 95% by weight, the content of silica sol is 2% by weight, the content of tetraethylammonium hydroxide is 2% by weight, and the content of Tween-40 is 1% by weight.

[0319] (4) The titanium-silicon molecular sieve catalyst precursor prepared in step (3) is aged with water vapor at a pressure of 0.05 MPa, a temperature of 200 °C, a water vapor humidity of 100%, and a time of 2 h to obtain the titanium-silicon molecular sieve catalyst pre-product.

[0320] (5) The titanium-silicon molecular sieve catalyst preproduct prepared in step (4) is calcined for a second time at 400℃ for 4h. The titanium-silicon molecular sieve product obtained from the second calcination is sieved to obtain titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4mm, namely titanium-silicon molecular sieve C1. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0321] Example C2

[0322] Titanium-silicon molecular sieve C2 was prepared using the method of Example C1, with the difference being:

[0323] In step (1), ethylene glycol is replaced with 1,3-propanediol;

[0324] In steps (2) and (3), tetraethylammonium hydroxide is replaced with tetrabutylammonium hydroxide;

[0325] In step (2), relative to the total weight of the material based on the titanium-silicon molecular sieve powder, the silica sol, and the tetrabutylammonium hydroxide, the content of the material based on the titanium-silicon molecular sieve powder is 87% by weight, the content of the silica sol is 10% by weight, and the content of the tetrabutylammonium hydroxide is 3% by weight.

[0326] In step (3), relative to the total weight of titanium-silicon molecular sieve microspheres, silica sol, tetrabutylammonium hydroxide, and Tween-40, the content of titanium-silicon molecular sieve microspheres is 95% by weight, the content of silica sol is 2% by weight, the content of tetrabutylammonium hydroxide is 2% by weight, and the content of Tween-40 is 1% by weight.

[0327] The particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm;

[0328] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve C2. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0329] Example C3

[0330] Titanium silicate molecular sieve C3 was prepared using the method of Example C1, with the difference being:

[0331] In step (1), ethylene glycol is replaced with 1,4-butanediol;

[0332] In steps (2) and (3), tetraethylammonium hydroxide is replaced with urea;

[0333] In step (2), relative to the total weight of the material based on the titanium-silicon molecular sieve powder, the silica sol, and the urea, the content of the material based on the titanium-silicon molecular sieve powder is 93% by weight, the content of the silica sol is 5% by weight, and the content of the urea is 2% by weight.

[0334] In step (3), relative to the total weight of titanium-silicon molecular sieve microspheres, silica sol, urea, and Tween-40, the content of titanium-silicon molecular sieve microspheres is 95% by weight, the content of silica sol is 2% by weight, the content of urea is 2% by weight, and the content of Tween-40 is 1% by weight.

[0335] The particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm;

[0336] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve C3. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0337] Example C4

[0338] Titanium silicate molecular sieve C4 was prepared using the method of Example C1, with the difference being:

[0339] In step (1), ethylene glycol is replaced with 1,4-butanediol;

[0340] In step (2), the temperature of the first calcination treatment is 200℃ and the time is 2h, and the particle size of the titanium silicon molecular sieve microspheres is 20-80μm;

[0341] In step (5), the temperature of the second roasting treatment is 200℃ and the time is 2h;

[0342] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve C4. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0343] Example C5

[0344] Titanium silicate molecular sieve C5 was prepared using the method of Example C1, with the difference being:

[0345] In step (1), ethylene glycol is replaced with 1,4-butanediol;

[0346] In step (2), the temperature of the first calcination treatment is 600℃ and the time is 6h, and the particle size of the titanium silicon molecular sieve microspheres is 20-80μm;

[0347] In step (5), the temperature of the second roasting treatment is 600℃ and the time is 6h;

[0348] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve C5. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0349] Example C6

[0350] Titanium silicate molecular sieve C6 was prepared using the method of Example C1. The difference is that in step (4), the temperature of water vapor aging is 100°C and the time is 1h. The titanium silicate molecular sieve product obtained by the second calcination was sieved to obtain titanium silicate molecular sieve catalyst with a particle size of 1.0-1.4mm, namely titanium silicate molecular sieve C6. The parameters are listed in Table 1. The titanium silicate molecular sieve catalyst is spherical and has a uniform size.

[0351] Example C7

[0352] Titanium silicate molecular sieve C7 was prepared using the method of Example C1. The difference is that in step (4), the temperature of water vapor aging is 300℃ and the time is 3h. The titanium silicate molecular sieve product obtained by the second calcination is sieved to obtain titanium silicate molecular sieve catalyst with a particle size of 1.0-1.4mm, namely titanium silicate molecular sieve C7. The parameters are listed in Table 1. The titanium silicate molecular sieve catalyst is spherical and has a uniform size.

[0353] Example C8

[0354] Titanium silicate molecular sieve C8 was prepared using the method of Example C1, with the difference being:

[0355] In step (3), relative to the total weight of titanium-silicon molecular sieve microspheres, silica sol, tetraethylammonium hydroxide, and Tween-40, the content of titanium-silicon molecular sieve microspheres is 87% by weight, the content of silica sol is 10% by weight, the content of tetraethylammonium hydroxide is 2% by weight, and the content of Tween-40 is 1% by weight.

[0356] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve C8. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0357] Example C9

[0358] Titanium silicate molecular sieve C9 was prepared using the method of Example C1, with the difference being:

[0359] In step (1), the calcined titanium silicon molecular sieve raw powder H is mixed with ethylene glycol for 2 hours and then dried at 150°C for 1 hour to obtain pore-filled titanium silicon molecular sieve raw powder.

[0360] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve C9. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0361] Comparative Example C1

[0362] The calcined titanium-silicon molecular sieve powder H was mixed with a solution containing silica sol and tetraethylammonium hydroxide and slurried. Relative to the total weight of the titanium-silicon molecular sieve powder, silica sol, and tetraethylammonium hydroxide, the content of the titanium-silicon molecular sieve powder was 83% by weight, the content of the silica sol was 15% by weight, and the content of tetraethylammonium hydroxide was 2% by weight. The resulting mixture was directly balled in a coating pan. The prepared titanium-silicon molecular sieve CD1 did not have a spherical particle morphology and was in powder form.

[0363] Example D1

[0364] Titanium-silicon molecular sieve D1 was prepared using the following steps:

[0365] (1) The calcined titanium silicon molecular sieve raw powder H was mixed with ethylene glycol for 1 hour and then dried at 110°C for 3 hours to obtain pore-filled titanium silicon molecular sieve raw powder.

[0366] (2) The pore-filled titanium silicon molecular sieve raw powder is mixed with a first solution containing silica sol, tetraethylammonium hydroxide and Tween-40 and slurryed. The resulting slurry is then formed for the first time using a sugar coating pot molding method. The resulting solid product is then calcined at 550°C for the first time for 4 hours to obtain titanium silicon molecular sieve microspheres with a particle size of 20-80 μm.

[0367] Relative to the total weight of the material based on titanium-silicon molecular sieve powder, silica sol, tetraethylammonium hydroxide, and Tween-40, the content of the material based on titanium-silicon molecular sieve powder is 87% by weight, the content of silica sol is 10% by weight, the content of tetraethylammonium hydroxide is 2.5% by weight, and the content of Tween-40 is 0.5% by weight.

[0368] (3) The titanium-silicon molecular sieve microspheres prepared in step (2) are mixed with a second solution containing tetraethylammonium hydroxide, silica sol and Tween-40 to obtain a mixture for a second molding process. The molding method is to roll the mixture into balls in a sugar coating machine to prepare a titanium-silicon molecular sieve catalyst precursor.

[0369] Relative to the total weight of titanium-silicon molecular sieve microspheres, silica sol, tetraethylammonium hydroxide, and Tween-40, the content of titanium-silicon molecular sieve microspheres is 95% by weight, the content of silica sol is 2% by weight, the content of tetraethylammonium hydroxide is 2% by weight, and the content of Tween-40 is 1% by weight.

[0370] (4) The titanium-silicon molecular sieve catalyst precursor prepared in step (3) is aged with ammonia vapor at 0.05 MPa and 100 °C for 2 h to obtain the titanium-silicon molecular sieve catalyst pre-product.

[0371] (5) The titanium-silicon molecular sieve catalyst preproduct prepared in step (4) is calcined for a second time at 400℃ for 4h. The titanium-silicon molecular sieve product obtained from the second calcination is sieved to obtain titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4mm, namely titanium-silicon molecular sieve D1. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0372] Example D2

[0373] Titanium-silicon molecular sieve D2 was prepared using the method of Example D1, with the difference being:

[0374] In step (2), tetraethylammonium hydroxide is replaced with urea;

[0375] Relative to the total weight of the material based on titanium-silicon molecular sieve powder, silica sol, urea, and Tween-40, the content of the material based on titanium-silicon molecular sieve powder is 82% by weight, the content of silica sol is 15% by weight, the content of urea is 2.8% by weight, and the content of Tween-40 is 0.2% by weight.

[0376] In step (3), relative to the total weight of titanium-silicon molecular sieve microspheres, silica sol, tetraethylammonium hydroxide, and Tween-40, the content of titanium-silicon molecular sieve microspheres is 96% by weight, the content of silica sol is 1% by weight, the content of tetraethylammonium hydroxide is 2.5% by weight, and the content of Tween-40 is 0.5% by weight.

[0377] In step (4), the titanium-silicon molecular sieve catalyst precursor prepared in step (3) is aged with ammonia vapor at 0.05 MPa and 80 °C for 3 h to obtain the titanium-silicon molecular sieve catalyst pre-product.

[0378] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve D2. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0379] Example D3

[0380] Titanium silicate molecular sieve D3 was prepared using the method of Example D1, with the difference being:

[0381] In step (2), relative to the total weight of the material based on the titanium-silicon molecular sieve powder, silica sol, tetraethylammonium hydroxide and Tween-40, the content of the material based on the titanium-silicon molecular sieve powder is 82% by weight, the content of silica sol is 15% by weight, the content of tetraethylammonium hydroxide is 2.8% by weight, and the content of Tween-40 is 0.2% by weight.

[0382] In step (3), tetraethylammonium hydroxide is replaced with urea;

[0383] Relative to the total weight of titanium-silicon molecular sieve microspheres, silica sol, urea, and Tween-40, the content of titanium-silicon molecular sieve microspheres is 95% by weight, the content of silica sol is 2% by weight, the content of urea is 2% by weight, and the content of Tween-40 is 1% by weight.

[0384] In step (4), the titanium-silicon molecular sieve catalyst precursor prepared in step (3) is aged with ammonia vapor at 0.05 MPa and 100 °C for 1 h to obtain the titanium-silicon molecular sieve catalyst pre-product.

[0385] The titanium-silicon molecular sieve product obtained from the second calcination was sieved to obtain a titanium-silicon molecular sieve catalyst with a particle size of 1.0-1.4 mm, namely titanium-silicon molecular sieve D2. The parameters are listed in Table 1. The titanium-silicon molecular sieve catalyst is spherical and has a uniform size.

[0386] Based on the above data, it can be seen that the titanium-silicon molecular sieve catalyst prepared by the method disclosed herein has high mechanical strength and large specific surface area, which meets the needs of industrial production.

[0387] Application Examples

[0388] The titanium-silicon molecular sieve catalyst of the present invention can be used for catalytic oxidation reactions, such as the direct oxidation of olefins to epoxides (e.g., the epoxidation of propylene to propylene oxide). In the following application examples, the reactant conversion, the selectivity of the target product, and the yield of the target product are defined as follows:

[0389] The conversion rate of reactants = (amount of reactants participating in the reaction / total amount of reactants added) * 100%;

[0390] Selectivity of the target product = (Amount of the target product produced in the reaction / Amount of the total product) * 100%;

[0391] Yield of target product = Conversion of reactants * Selectivity of target product.

[0392] Application Example 1

[0393] The titanium-silicon molecular sieve catalyst of the present invention (e.g., 0.5 g) is added to a closed reactor containing methanol (e.g., 50 ml). Then, propylene, oxygen, hydrogen, and nitrogen (diluent gas) are introduced into the reactor (e.g., molar ratio of 1:1:1:7) under certain reaction conditions (e.g., temperature 50°C, pressure 1.5 MPa, olefin space velocity 10 h⁻¹). -1 The direct oxidation of olefins is carried out under the following conditions.

[0394] Application Example 2

[0395] Allyl alcohol, oxygen (4% by volume, the remainder being nitrogen), hydrogen, solvent, and the titanium-silicon molecular sieve catalyst of this invention are reacted in a certain proportion under certain reaction conditions to prepare epoxide (e.g., the molar ratio of allyl alcohol to oxygen and hydrogen is 1:1:1, the mass ratio of solvent tert-butanol to catalyst is 200, the temperature is 60°C, the pressure is 0.5 MPa, and the total gas hourly space velocity is 1000 h⁻¹). -1 ).

[0396] Application Example 3

[0397] Propylene, hydrogen peroxide, solvent, and the titanium-silicon molecular sieve catalyst of this invention are reacted in a certain proportion under certain reaction conditions. For example, the reaction time is 0.5-8 hours, the reaction temperature is 5-60°C, the reaction pressure is 0-1 MPa, the feed molar ratio of propylene to hydrogen peroxide is (0.1-2):1, and the feed mass hourly space velocity of hydrogen peroxide is 0.05-10 h⁻¹. -1The epoxidation reaction is carried out in the presence of a solvent, which is conventional in the art, such as methanol. The molar ratio of solvent to propylene is (2-20):1; the mass ratio of propylene to catalyst is 1:(0.1-10).

[0398] Application Example 4

[0399] Hydroquinone is prepared by reacting phenol, hydrogen peroxide, solvent (acetone), and the titanium-silicon molecular sieve catalyst of the present invention in a certain proportion under certain reaction conditions (for example, the weight ratio of catalyst:phenol:acetone = 1:20:16, the molar ratio of phenol:hydrogen peroxide (30% aqueous solution) = 3:1, the reaction temperature is 80°C, and the reaction time is 3 hours).

[0400] Application examples show that when the titanium-silicon molecular sieve catalyst prepared by the method of this disclosure is applied to olefin oxidation, it can maintain high selectivity and high yield during long-term reaction processes, meeting the needs of industrial production. For example, in the process of preparing propylene oxide from propylene and hydrogen peroxide, the selectivity of propylene oxide can reach 98% or higher, such as 98.6% or higher, and the yield of propylene oxide can reach 97% or higher, such as 97.3% or higher.

[0401] The present invention also provides the following technical solutions:

[0402] Scheme A1, a method for preparing titanium-silicon molecular sieves, characterized in that the method includes the following steps:

[0403] S1. Mix the titanium silicon molecular sieve raw powder with the pore filler and dry it to obtain the pore-filled titanium silicon molecular sieve raw powder.

[0404] S2. The titanium-silicon molecular sieve raw powder filling the pores, the first binder, water and optional first surfactant are mixed and subjected to a first molding, and the solid product obtained from the first molding is subjected to a first calcination treatment to obtain titanium-silicon molecular sieve microspheres.

[0405] S3. Mix the titanium-silicon molecular sieve microspheres, the second binder, water and an optional second surfactant and perform a second molding process to obtain the titanium-silicon molecular sieve precursor.

[0406] S4. The titanium-silicon molecular sieve precursor is aged with water vapor to obtain a titanium-silicon molecular sieve pre-product.

[0407] S5. The titanium-silicon molecular sieve pre-product is subjected to a second calcination treatment.

[0408] Solution A2: According to the method described in technical solution A1, wherein the first adhesive and the second adhesive respectively include one or more of silica sol, water glass and alumina sol;

[0409] The first surfactant and the second surfactant respectively include one or more of Span-20, Span-40, Span-60, Span-65, Span-80, Span-85, Tween-20, Tween-21, Tween-40, Tween-60, Tween-61, Tween-80, Tween-81 and Tween-85;

[0410] The pore filler comprises one or more of saturated polyols having 2-5 carbon atoms, preferably one or more of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and glycerol.

[0411] Solution A3: According to the method described in technical solution A1, in step S1, the drying conditions include: a time of 2-6 hours and a temperature of 50-200°C; the mixing time is 0.1-6 hours.

[0412] Solution A4: The method according to technical solution A1, wherein an alkali is added during the first molding and / or the second molding;

[0413] Preferably, the alkali is added during the first molding and the second molding;

[0414] The alkali includes one or more organic alkalis, preferably one or more of hexamethylenetetramine, urea, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

[0415] Solution A5: According to the method described in technical solution A4, step S2 includes: mixing the pore-filled titanium-silicon molecular sieve raw powder with a first solution containing the first binder, optionally the alkali and optionally the first surfactant, and performing the first molding to obtain the titanium-silicon molecular sieve microspheres;

[0416] Relative to the total weight of the titanium-silicon molecular sieve raw powder, the first binder, the alkali, and the first surfactant, the content of the titanium-silicon molecular sieve raw powder is 65-99.9% by weight, the content of the first binder is 0.1-20% by weight, the content of the alkali is 0-10% by weight, and the content of the first surfactant is 0-5% by weight.

[0417] Solution A6: According to the method described in technical solution A4, step S3 includes: mixing the titanium-silicon molecular sieve microspheres with a second solution containing the second binder, optionally the alkali and optionally the second surfactant, and performing the second molding to obtain the titanium-silicon molecular sieve precursor;

[0418] Relative to the total weight of the titanium-silicon molecular sieve microspheres, the second binder, the alkali, and the second surfactant, the content of the titanium-silicon molecular sieve microspheres is 65-99.9% by weight, the content of the second binder is 0.1-20% by weight, the content of the alkali is 0-10% by weight, and the content of the second surfactant is 0-5% by weight.

[0419] Solution A7: According to the method described in technical solution A1, wherein in step S2, the conditions for the first calcination treatment include: a temperature of 200-600℃ and a time of 2-6h.

[0420] Scheme A8: According to the method described in technical solution A1, the particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm.

[0421] Solution A9: According to the method described in technical solution A1, the first molding and the second molding are respectively sugar coating pot molding, granulator molding or spray molding;

[0422] Preferably, the first molding method is spray molding, and the outlet air temperature is 100-150℃.

[0423] Solution A10: According to the method described in technical solution A1, in step S4, the conditions for water vapor aging include: temperature of 50-600℃, time of 0.5-48h, pressure of 0-2MPa, and water vapor humidity of 50-100%.

[0424] Solution A11: According to the method described in technical solution A1, in step S5, the conditions for the second calcination treatment include: a temperature of 200-600℃ and a time of 2-6h.

[0425] Scheme A12: Titanium-silicon molecular sieves prepared by the method described in any one of technical schemes A1-A11.

[0426] Option A13: The titanium-silicon molecular sieve according to technical option A12, wherein the particle size of the titanium-silicon molecular sieve is 1.0-1.4 mm and the specific surface area is 360-470 m². 2 / g, strength is 8-30N / particle.

[0427] Scheme B1, a method for preparing titanium-silicon molecular sieves, characterized in that the method includes the following steps:

[0428] S1. Mix the titanium-silicon molecular sieve raw powder, the first binder, water and optional first surfactant and perform a first molding, and then perform a first calcination treatment on the solid product obtained by the first molding to obtain titanium-silicon molecular sieve microspheres.

[0429] S2. Mix the titanium-silicon molecular sieve microspheres, the second binder, water and an optional second surfactant and perform a second molding process to obtain the titanium-silicon molecular sieve precursor.

[0430] S3. The titanium-silicon molecular sieve precursor is subjected to alkaline steam aging treatment to obtain a titanium-silicon molecular sieve pre-product.

[0431] S4. The titanium-silicon molecular sieve pre-product is subjected to a second calcination treatment.

[0432] Solution B2, the method according to technical solution B1, wherein the first adhesive and the second adhesive respectively include one or more of silica sol, water glass and aluminosilicate;

[0433] The first surfactant and the second surfactant respectively include one or more of Span-20, Span-40, Span-60, Span-65, Span-80, Span-85, Tween-20, Tween-21, Tween-40, Tween-60, Tween-61, Tween-80, Tween-81 and Tween-85.

[0434] Option B3: The method according to technical solution B1, wherein an alkali is added during the first molding and / or the second molding;

[0435] Preferably, the alkali is added during the first molding and the second molding;

[0436] The alkali includes one or more organic alkalis, preferably one or more of hexamethylenetetramine, urea, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

[0437] Solution B4, the method according to technical solution B3, wherein step S1 includes: mixing the titanium silicon molecular sieve raw powder with a first solution containing the first binder, optionally the alkali and optionally the first surfactant, and performing the first molding to obtain the titanium silicon molecular sieve microspheres;

[0438] Relative to the total weight of the titanium-silicon molecular sieve raw powder, the first binder, the alkali, and the first surfactant, the content of the titanium-silicon molecular sieve raw powder is 65-99.9% by weight, the content of the first binder is 0.1-20% by weight, the content of the alkali is 0-10% by weight, and the content of the first surfactant is 0-5% by weight.

[0439] Solution B5, the method according to technical solution B3, wherein step S2 includes: mixing the titanium-silicon molecular sieve microspheres with a second solution containing the second binder, optionally the alkali and optionally the second surfactant, and performing the second molding to obtain the titanium-silicon molecular sieve precursor;

[0440] Relative to the total weight of the titanium-silicon molecular sieve microspheres, the second binder, the alkali, and the second surfactant, the content of the titanium-silicon molecular sieve microspheres is 65-99.9% by weight, the content of the second binder is 0.1-20% by weight, the content of the alkali is 0-10% by weight, and the content of the second surfactant is 0-5% by weight.

[0441] Scheme B6: According to the method described in technical solution B1, wherein in step S1, the conditions for the first calcination treatment include: a temperature of 200-600℃ and a time of 2-6h.

[0442] Scheme B7: The method described in technical solution B1, wherein the particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm.

[0443] Solution B8: According to the method described in technical solution B1, the first molding and the second molding are respectively formed by sugar coating pan molding or granulator molding.

[0444] Scheme B9: According to the method described in technical solution B1, wherein in step S3, the conditions for the alkaline vapor aging treatment include: a temperature of 50-600℃, a time of 0.5-48h, and a pressure of 0-2MPa.

[0445] The alkaline vapor includes one or more of ammonia vapor, methylamine vapor, dimethylamine vapor, trimethylamine vapor, and ethylamine vapor.

[0446] Scheme B10, the method according to technical solution B1, wherein in step S4, the conditions for the second calcination treatment include: a temperature of 200-600℃ and a time of 2-6h.

[0447] Scheme B11: Titanium-silicon molecular sieves prepared by any one of the methods described in technical schemes B1-10.

[0448] Option B12: The titanium-silicon molecular sieve according to technical option B11, wherein the particle size of the titanium-silicon molecular sieve is 1.0-1.4 mm and the specific surface area is 360-430 m². 2 / g, strength is 8-30N / particle.

[0449] Scheme C1, a method for preparing titanium-silicon molecular sieves, characterized in that the method includes the following steps:

[0450] S1. Uncalcined titanium-silicon molecular sieve raw powder, first binder, water and optional first surfactant are mixed and subjected to first molding, and the solid product obtained by the first molding is subjected to first calcination treatment to obtain titanium-silicon molecular sieve microspheres.

[0451] S2. Mix the titanium-silicon molecular sieve microspheres, the second binder, water and an optional second surfactant and perform a second molding process to obtain the titanium-silicon molecular sieve precursor.

[0452] S3. The titanium-silicon molecular sieve precursor is aged with water vapor to obtain a titanium-silicon molecular sieve pre-product.

[0453] S4. The titanium-silicon molecular sieve pre-product is subjected to a second calcination treatment.

[0454] Solution C2, the method according to technical solution C1, wherein the first adhesive and the second adhesive respectively include one or more of silica sol, water glass and aluminosilicate;

[0455] The first surfactant and the second surfactant respectively include one or more of Span-20, Span-40, Span-60, Span-65, Span-80, Span-85, Tween-20, Tween-21, Tween-40, Tween-60, Tween-61, Tween-80, Tween-81 and Tween-85.

[0456] Solution C3: The method according to technical solution C1, wherein an alkali is added during the first molding and / or the second molding;

[0457] Preferably, the alkali is added during the first molding and the second molding;

[0458] The alkali includes one or more organic alkalis, preferably one or more of hexamethylenetetramine, urea, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

[0459] Solution C4, the method according to technical solution C3, wherein step S1 includes: mixing the uncalcined titanium-silicon molecular sieve raw powder with a first solution containing the first binder, optionally the alkali and optionally the first surfactant, and performing the first molding to obtain the titanium-silicon molecular sieve microspheres;

[0460] Relative to the total weight of the uncalcined titanium-silicon molecular sieve powder, the first binder, the alkali, and the first surfactant, the content of the uncalcined titanium-silicon molecular sieve powder is 70-99.9% by weight, the content of the first binder is 0.1-15% by weight, the content of the alkali is 0-10% by weight, and the content of the first surfactant is 0-5% by weight.

[0461] Solution C5, the method according to technical solution C3, wherein step S2 includes: mixing the titanium-silicon molecular sieve microspheres with a second solution containing the second binder, optionally the alkali and optionally the second surfactant, and performing the second molding to obtain the titanium-silicon molecular sieve precursor;

[0462] Relative to the total weight of the titanium-silicon molecular sieve microspheres, the second binder, the alkali, and the second surfactant, the content of the titanium-silicon molecular sieve microspheres is 70-99.9% by weight, the content of the second binder is 0.1-15% by weight, the content of the alkali is 0-10% by weight, and the content of the second surfactant is 0-5% by weight.

[0463] Scheme C6: According to the method described in technical solution C1, wherein in step S1, the conditions for the first calcination treatment include: a temperature of 200-600℃ and a time of 2-6h.

[0464] Scheme C7: The method described in technical solution C1, wherein the particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm.

[0465] Solution C8: The method described in technical solution C1, wherein the first molding and the second molding are respectively performed by extrusion molding, sugar coating pan molding, granulation machine molding, or spray molding.

[0466] Solution C9: According to the method described in technical solution C1, in step S3, the conditions for water vapor aging include: temperature of 50-600℃, time of 0.5-48h, pressure of 0-2MPa, and water vapor humidity of 50-100%.

[0467] Scheme C10, the method according to technical solution C1, wherein in step S4, the conditions for the second calcination treatment include: a temperature of 200-600℃ and a time of 2-6h.

[0468] Scheme C11, the method according to technical solution C1, wherein the method for preparing the uncalcined titanium-silicon molecular sieve raw powder includes: mixing a titanium source, a silicon source and a template agent and then performing hydrothermal crystallization.

[0469] Scheme C12: Titanium-silicon molecular sieve prepared by the method described in any one of technical schemes C1-C11.

[0470] Scheme C13: The titanium-silicon molecular sieve according to technical solution C12, wherein the particle size of the titanium-silicon molecular sieve is 1.0-1.4 mm and the specific surface area is 360-450 m². 2 / g, strength is 8-30N / particle.

[0471] 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.

[0472] 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.

[0473] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A titanium-silicon molecular sieve catalyst, characterized in that, The catalyst has one or both of the following characteristics: The catalyst has a B value of 60%-96%, for example 72%-96%, or 74%-94%, or 76.1%-92.3%, where B = B1 / B2, and B1 represents the value of the catalyst. 1 The peak area of ​​the characteristic peak with a chemical shift of 1.8 ppm in the 1H MAS NMR spectrum, B2 represents the peak area of ​​the characteristic peak at 1.8 ppm in this catalyst. 1 The peak area of ​​characteristic peaks with chemical shifts >2 ppm in ¹H MMAS NMR spectra; and / or The catalyst has a Q value ≥ 10, for example 12-16, or 12.8-15.6, where Q = Q 4 / Q 3 Q 4 Indicated in the catalyst 29 The peak area of ​​the characteristic peak with a chemical shift at -113 ppm in the Si MAS NMR spectrum, Q 3 Indicated in the catalyst 29 The peak area of ​​the characteristic peak with a chemical shift of -103 ppm in the Si MAS NMR spectrum.

2. The titanium-silicon molecular sieve catalyst according to any one of the preceding claims, characterized in that, The titanium-silicon molecules in the catalyst are screened from TS-1, TS-1, Ti-Beta, Ti-MWW, Ti-MCM-41, Ti-SBA-15, Ti-UTL; and / or The catalyst contains more than 50 wt%, or more than 60 wt%, or more than 70 wt%, or more than 80 wt%; and / or The catalyst comprises Si, Ti and O elements, wherein the sum of the masses of Si, Ti and O elements accounts for more than 50 wt%, or more than 60 wt%, or more than 70 wt%, or more than 80 wt%, or more than 90 wt%, or more than 95 wt% of the total weight of the catalyst, and the atomic ratio of Si to Ti is 20-300.

3. The titanium-silicon molecular sieve catalyst according to any one of the preceding claims, characterized in that... The catalyst is a shaped body. Preferably, The catalyst is spherical or near-spherical in shape, and / or The catalyst has a particle size greater than 0.5 mm, for example, 0.5-2 mm; and / or The projected area of ​​the catalyst is greater than 0.19 mm. 2 ; and / or The projected area of ​​the catalyst is less than 3.14 mm. 2 .

4. The titanium-silicon molecular sieve catalyst according to any one of the preceding claims, characterized in that, The catalyst has a micropore content β of 30%-70%, for example 40%-60%; and / or The catalyst has a mesoporous content γ of 20%-60%, for example 25%-40%; and / or The sum of the micropore content β and the mesopore content γ of this catalyst is 70%-95%, for example, 75%-90%; where β=V mic-1 / (V mic-1 +V me-1 +V ma-1 )×100%, γ=V me-1 / (V mic-1 +V me-1 +V ma-1 )×100%, V mic-1 V me-1 V ma-1 These represent the volumes of micropores (pore size < 2 nm), mesopores (pore size 2-50 nm), and macropores (pore size > 50 nm) of the catalyst, respectively.

5. The titanium-silicon molecular sieve catalyst according to any one of the preceding claims, characterized in that, The catalyst has a specific surface area >300m². 2 / g, or >400m 2 / g, or 400-480m 2 / g; and / or The strength of the catalyst is 8-30 N / particle, for example 10-20 N / particle.

6. A method for preparing the titanium-silicon molecular sieve catalyst according to any one of the preceding claims, characterized in that, The method includes the following steps: S1. The material based on titanium-silicon molecular sieve powder, a first binder, water and an optional first surfactant are mixed and subjected to a first molding process, and the solid product obtained from the first molding process is subjected to a first calcination treatment to obtain titanium-silicon molecular sieve microspheres. Preferably, the material based on the titanium-silicon molecular sieve powder is selected from uncalcined and unfilled titanium-silicon molecular sieve powder, uncalcined but filled titanium-silicon molecular sieve powder, calcined but unfilled titanium-silicon molecular sieve powder, and calcined and filled titanium-silicon molecular sieve powder. More preferably, the material based on the titanium-silicon molecular sieve powder is selected from uncalcined and unfilled titanium-silicon molecular sieve powder and calcined and filled titanium-silicon molecular sieve powder. S2. Mix the titanium-silicon molecular sieve microspheres, the second binder, water and an optional second surfactant and perform a second molding process to obtain the titanium-silicon molecular sieve catalyst precursor. S3. The titanium-silicon molecular sieve catalyst precursor is aged with water vapor and / or alkaline vapor to obtain a titanium-silicon molecular sieve catalyst pre-product. S4. The titanium-silicon molecular sieve catalyst preproduct is subjected to a second calcination treatment. Optionally, an alkali is added during the first molding and / or the second molding; preferably, the alkali is added during the first molding and the second molding.

7. The method according to claim 6, characterized in that, The relative micropore retention α of this catalyst is 80-130%, 90%-110%, and the relative micropore retention α = V mic-1 / (w×V mic-2 )×100%, where V mic-1 V represents the micropore volume of a given mass of catalyst. mic-2 The term represents the micropore volume of the product obtained by calcining the same mass of titanium-silicon molecular sieve powder in a pure oxygen environment at 600°C for 6 hours; w represents the weight content of titanium-silicon molecular sieve in the catalyst; and / or The ratio of titanium content in the titanium-silicon molecular sieve before and after molding, characterized by STEM-EDX, is A = 0.9-1.1, where A = A1 / A2. A1 represents the titanium content of the titanium-silicon molecular sieve in the catalyst, and A2 represents the titanium content of the product obtained by calcining the titanium-silicon molecular sieve powder in a pure oxygen environment at 600℃ for 6 hours.

8. The method according to any one of claims 6-7, characterized in that, The first binder and the second binder respectively comprise one or more of silica sol, water glass, silica, and alumina sol; and / or The first surfactant and the second surfactant are respectively Span-type surfactants and / or Tween-type surfactants, preferably including one or more of Span-20, Span-40, Span-60, Span-65, Span-80, Span-85, Tween-20, Tween-21, Tween-40, Tween-60, Tween-61, Tween-80, Tween-81 and Tween-85; and / or The pore filler comprises one or more saturated polyols having 2-5 carbon atoms, preferably one or more of ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and glycerol; and / or The alkali includes one or more organic alkalis, preferably one or more of hexamethylenetetramine, urea, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

9. The method according to any one of claims 6-8, characterized in that, In step S1, relative to the total weight of the material based on the titanium-silicon molecular sieve powder, the first binder, the alkali, and the first surfactant, the amount of the material based on the titanium-silicon molecular sieve powder is 65-99.9% by weight (e.g., 70-99.9% by weight), the amount of the first binder is 0.1-20% by weight (e.g., 0.1-15% by weight), the amount of the alkali is 0-10% by weight, and the amount of the first surfactant is 0-5% by weight; and / or In step S2, relative to the total weight of the titanium-silicon molecular sieve microspheres, the second binder, the alkali, and the second surfactant, the amount of the titanium-silicon molecular sieve microspheres is 65-99.9% by weight (e.g., 70-99.9% by weight), the amount of the second binder is 0.1-20% by weight (e.g., 0.1-15% by weight), the amount of the alkali is 0-10% by weight, and the amount of the second surfactant is 0-5% by weight. Preferably, step S1 includes: mixing the material based on titanium-silicon molecular sieve powder with a first solution containing the first binder, optionally the alkali, and optionally the first surfactant, and performing the first molding, and subjecting the solid product obtained from the first molding to a first calcination treatment to obtain the titanium-silicon molecular sieve microspheres; and / or, step S2 includes: mixing the titanium-silicon molecular sieve microspheres with a second solution containing the second binder, optionally the alkali, and optionally the second surfactant, and performing the second molding to obtain the titanium-silicon molecular sieve catalyst precursor; More preferably, in step S1, the amount of water used is at least 0.1 parts by weight, for example 1-100 parts by weight, or 1-10 parts by weight, relative to 1 part by weight of the material based on the titanium-silicon molecular sieve powder; in step S2, the amount of water used is at least 0.1 parts by weight, for example 1-100 parts by weight, or 1-10 parts by weight, relative to 1 part by weight of the titanium-silicon molecular sieve microspheres.

10. The method according to any one of claims 6-9, characterized in that, In step S1, the conditions for the first calcination treatment include: a temperature of 200-600℃ and a time of 2-6 hours; and / or In step S3, the conditions for steam aging include: temperature of 50-600℃; time of 0.5-48h; pressure of 0-2MPa; and steam humidity of 50-100%. The conditions for alkaline steam aging treatment include: temperature of 50-600℃; time of 0.5-48h; and pressure of 0-2MPa. The alkaline steam includes / is selected from one or more of ammonia steam, methylamine steam, dimethylamine steam, trimethylamine steam, and ethylamine steam. and / or In step S4, the conditions for the second calcination treatment include: a temperature of 200-600℃, preferably 300-600℃, and a time of 2-6 hours.

11. The method according to any one of claims 6-10, characterized in that, The particle size of the titanium-silicon molecular sieve microspheres is 20-80 μm.

12. The method according to any one of claims 6-11, characterized in that, The first molding and the second molding are respectively performed by extrusion molding, sugar coating pan molding, granulation machine molding, or spray molding.

13. Use of the titanium-silicon molecular sieve catalyst according to any one of claims 1-5 in catalytic oxidation reactions such as the epoxidation of propylene to prepare propylene oxide.

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