A process for the preparation of a disulfide by oxidation of a mercaptan

Abstract

The present disclosure relates to a method for oxidation of mercaptans, comprising the following steps: contacting mercaptan compounds with a catalyst for oxidation reaction in the presence of oxygen; the catalyst is a composite catalytic material, which comprises a full-silica molecular sieve and a metal element M dispersed in the intracrystalline of the full-silica molecular sieve; the metal M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold. The present disclosure uses a metal-containing hierarchical porous molecular sieve for mercaptan oxidation and dehydrogenation reaction, without adding additional alkali, high conversion rate and disulfide selectivity can be obtained at a lower temperature, which has high industrial application value.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of organic chemical industry, in particular, to a method for preparing disulfide by oxidizing mercaptan. BACKGROUND

[0002] Disulfides are also important and widely used intermediates in the field of organic synthetic chemistry, which can be used to synthesize rubber scorch retarder, fine fragrance, dietary supplement and antioxidant, etc. In particular, dimethyl disulfide can be used as a coking inhibitor, a passivator and a vulcanizing agent in industry, and as an effective soil fumigant in agriculture, with a global annual demand of 300,000 tons and a domestic demand of about 70,000 tons / year.

[0003] Due to the presence of mercaptan compounds in crude oil, the Merox deodorization process for fuel oil has been developed since the 1950s. The process is that mercaptan is first activated to obtain sodium mercaptide by sodium hydroxide, and then coupled to obtain disulfide under the action of cobalt phthalocyanine and oxygen. With the reaction, the production of water requires the removal of part of the alkali liquor, which also leads to the generation of solid alkali waste residue and the loss of cobalt phthalocyanine. Although the subsequent development of alkali-free deodorization technology has made significant breakthroughs in process, it still needs to continuously inject alkaline mercaptan activators such as quaternary ammonium base.

[0004] Therefore, the development of alkali-free heterogeneous system for preparing disulfide by oxidizing mercaptan is the direction of researchers. However, most of the reports focus on using hydrogen peroxide and urea hydrogen peroxide as oxidants, and there are few studies on the oxidation of mercaptan using oxygen or air as oxidant under mild conditions. Although noble metal catalysts such as Ag nanoparticles (Gaur R, Yadav M, Gupta R, Arora G, Rana P, Sharma RK. Chemistry Select 2018, 3(9).) and Au / CeO2(Corma A, Ródenas T, Sabater MJ. Chemical Science 2012, 3(2): 398-404.) have good activity, the cost problem still cannot be well solved. Using nickel nanoparticles as catalyst (Saxena A, Kumar A, Mozumdar S. Ni-nanoparticles: Journal of Molecular Catalysis A Chemical 2007, 269(1-2): 35-40.), the oxidation coupling of aliphatic, aromatic and cyclic aromatic mercaptans can be realized to prepare various disulfides at room temperature, but it has the problems of easy deactivation and few cycles. SUMMARY

[0005] The purpose of the present disclosure is to provide a method for the oxygen oxidation of mercaptans in a heterogeneous alkali-free system, which uses a composite catalytic material including an all-silicon molecular sieve and metal elements dispersed in the molecular sieve crystals as a catalyst, so that the oxygen oxidation reaction of mercaptans has a high mercaptan conversion rate and disulfide selectivity.

[0006] To achieve the above object, the present disclosure provides a method for oxidizing mercaptans, comprising the following steps: contacting a mercaptan compound with a catalyst in the presence of oxygen to carry out an oxidation reaction;

[0007] The catalyst is a composite catalytic material, which includes an all-silicon molecular sieve and a metal element M dispersed in the crystals of the all-silicon molecular sieve; the metal M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold.

[0008] Optionally, the metal element M is a metal element that can form oxide aggregates; the composite catalytic material has the following XPS characteristics: the electron binding energy of the metal element M in the composite catalytic material is denoted as T1, and the electron binding energy of the metal element M in the oxide aggregate is denoted as T2, and T0 defined by the following formula (1) is any value between 0.5 and 1.0 eV; T0 = T1-T2 formula (1); preferably, the value of T0 is any value between 0.6 and 0.8 eV.

[0009] Optionally, the thiol compound is selected from any one or more of alkyl thiols or thiophenols containing a benzene ring and their derivatives; wherein the alkyl thiols include one or more of 2-propanethiol, 1-octanethiol, 1-decanethiol, 1-nonanethiol, 1-heptanethiol and cyclohexanethiol; the thiophenols containing a benzene ring and their derivatives include one or more of thiophenol, 4-methoxythiophenol, 3-methylthiophenol, 1-phenylethylthiol and 4-nitrobenzenethiol; preferably, the method further comprises: contacting the thiol compound with the catalyst in a solvent for an oxidation reaction; the molar ratio of the thiol compound to the solvent is 1:(50-200), preferably 1:(60-100); the solvent is selected from one or more of methanol, acetonitrile, acetone, toluene, tetrahydrofuran and cyclohexane.

[0010] Optionally, the conditions of the oxidation reaction include: a temperature of 40 to 100° C., preferably 60 to 80° C.; a reaction time of 1 to 48 hours, preferably 6 to 24 hours; a weight ratio of the thiol compound to the catalyst of (1 to 100):1, preferably (1 to 20):1, and an oxygen pressure of 0.1 to 0.5 MPa, preferably 0.1 to 0.3 MPa; preferably, the reactor for the oxidation reaction is selected from any one of a tank reactor, a fixed bed reactor, a moving bed reactor, a suspended bed reactor or a slurry bed reactor.

[0011] Optionally, the all-silica molecular sieve in the composite catalytic material is at least one of MFI structure molecular sieve, MEL structure molecular sieve, BEA structure molecular sieve, MWW structure molecular sieve, two-dimensional hexagonal structure molecular sieve, MOR structure molecular sieve and TUN structure molecular sieve; preferably one or several selected from MFI structure molecular sieve, MEL structure molecular sieve, BEA structure molecular sieve, MCM structure molecular sieve and SBA structure molecular sieve; further preferably one or several of MFI structure molecular sieve, MEL structure molecular sieve and BEA structure molecular sieve.

[0012] Optionally, when the metal M is Co, the oxide aggregate is Co3O4 aggregate; when the metal M is Mn, the oxide aggregate is MnO2 aggregate; when the metal M is Fe, the oxide aggregate is Fe2O3 aggregate; when the metal M is Ni, the oxide aggregate is NiO aggregate; when the metal M is Pd, the oxide aggregate is PdO aggregate; when the metal M is Pt, the oxide aggregate is PtO2 aggregate; or, when the metal M is Cu, the oxide aggregate is CuO aggregate; wherein when the metal element M is Co, Mn, Fe, Ni or Cu, the electron binding energy of the metal element M is 2p 3 / 2 electron of the metal element M; when the metal element M is Pt, the electron binding energy of the metal element M is 4f 7 / 2 electron of the metal element M; when the metal element M is Pd, the electron binding energy of the metal element M is 3d 5 / 2 electron of the metal element M; preferably, the metal element M is one or several of Co, Ni and Cu.

[0013] Optionally, in the composite catalytic material, the molar ratio of the metal M element to the silicon element is (0.001-0.2):1, preferably (0.001-0.1):1.

[0014] Optionally, it is characterized in that the BET specific surface area of the composite catalytic material is 400-800 m 2 / g, the total pore volume is 0.3-0.65 mL / g, the micropore volume is 0.1-0.19 mL / g, the mesopore volume is 0.15-0.50 mL / g, the metal element M in the composite catalytic material exists in the form of metal nanoparticles, and the average particle size of the metal nanoparticles is 0.5-10 nm.

[0015] Optionally, the composite material is prepared by a preparation method comprising the following steps: S1, mixing a template, a silicon source, water, a metal M precursor, a silanization agent and a structural filler to obtain a reaction mixture, wherein the structural filler is an amphiphilic surfactant and / or a hard template; S2, performing hydrothermal crystallization and calcination on the reaction mixture.

[0016] Optionally, in step S1, the molar ratio of silicon source: template: water: metal M element: silanization agent is 1: (0.002~1): (5~100): (0.001~0.2): (0.025~0.5), preferably 1: (0.005~0.5): (10~50): (0.001~0.15): (0.025~0.4), and the weight ratio of SiO2 to structural filler in the reaction mixture is (3~100): 1.

[0017] Optionally, step S1 includes: a. mixing a template, a silicon source and water to obtain a silicon hydrolysis solution; b. mixing a metal M precursor and the silicon hydrolysis solution to obtain a first mixed material; c. adding a silanization agent and a structural filler to the first mixed material respectively, and mixing to obtain the reaction mixture; preferably, the mixing conditions in step c include: stirring at 20-80°C for 0.5-2 hours.

[0018] Optionally, the silicon source is selected from at least one of organic silicone grease, solid silica gel, white carbon black and silica sol; preferably, it is selected from at least one of organic silicone grease, solid silica gel and white carbon black; further preferably, the organic silicone grease has the general formula of the structure shown in the following formula (A):

[0019] where R a 、R b 、R c 、R d are independently selected from an alkyl group having 1 to 6 carbon atoms, wherein the alkyl group is a branched or straight chain alkyl group; preferably, R a 、R b 、R c 、R d Each independently selected from a straight-chain alkyl group having 1 to 4 carbon atoms or a branched-chain alkyl group having 3 to 4 carbon atoms; further preferably, the R a 、R b 、R c 、R d Each is independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl; further preferably, the organic silicone grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate and dimethyl diethyl silicone grease.

[0020] Optionally, in step S1, the template is an organic base, preferably at least one selected from quaternary ammonium bases, aliphatic amines, and aliphatic alcoholamines; further preferably, the template is at least one selected from quaternary ammonium bases having a structure represented by the following formula (B):

[0021] R1, R2, R3 and R4 are independently selected from alkyl groups having 1 to 4 carbon atoms, preferably straight-chain alkyl groups having 1 to 4 carbon atoms and branched-chain alkyl groups having 3 to 4 carbon atoms, more preferably R1, R2, R3 and R4 are independently selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl groups; further preferably, the all-silicon molecular sieve is an MFI molecular sieve, the template is tetrapropylammonium hydroxide or a mixture of tetrapropylammonium hydroxide and one or more selected from tetrapropylammonium chloride and tetrapropylammonium bromide; or the all-silicon molecular sieve is an MEL molecular sieve, the template is tetrabutylammonium hydroxide or a mixture of tetrabutylammonium hydroxide and one or more selected from tetrabutylammonium chloride and tetrabutylammonium bromide; or the molecular sieve is a Beta molecular sieve, the template is tetraethylammonium hydroxide or a mixture of tetraethylammonium hydroxide and one or more selected from tetraethylammonium chloride and tetraethylammonium bromide.

[0022] Optionally, in step a, the silicon source is organic silicone grease, and after mixing the template, organic silicone grease and water, a hydrolysis and alcohol removal treatment is further performed to obtain a hydrolyzed solution of the silicon; the conditions for the hydrolysis and alcohol removal treatment include: stirring and hydrolyzing at 0-95°C for 2-10 hours; preferably, stirring and hydrolyzing at 50-95°C for 2-8 hours.

[0023] Optionally, in step S1, the metal M precursor is one or more of an inorganic metal compound and an organic metal compound; the inorganic metal compound is a water-soluble inorganic salt of metal M; the water-soluble inorganic salt of metal M is selected from one or more of the chloride, hydrated chloride, sulfate, hydrated sulfate and nitrate of metal M; the organic metal compound is an organic ligand compound of metal M; preferably, the metal M precursor is a water-soluble inorganic salt of metal M; the metal M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold; preferably, the metal M precursor uses an aqueous solution of a metal M precursor, and the molar ratio of the metal M element to water in the metal M precursor aqueous solution is 1:(50~500).

[0024] Optionally, in step S1, the general formula of the silanization agent is R5Si(R6)(R7)R8, wherein R5, R6, R7, and R8 are each independently a halogen, an alkyl group, an alkoxy group, an aromatic group, a thiol group, or an amino group, and at least one of R5, R6, R7, and R8 is an alkyl group, an alkoxy group, an aromatic group, a thiol group, or an amino group; the number of carbon atoms of the alkyl group, the alkoxy group, the thiol group, and the amino group is each independently any integer from 1 to 18, and the number of carbon atoms of the aromatic group is any integer from 6 to 18; preferably, the silanization agent is selected from dimethyldichlorosilane, N- One or more of phenyl-3-aminopropyltrimethoxysilane, phenyltrimethoxysilane, 1,7-dichlorooctylmethyltetrasiloxane, hexadecyltrimethoxysilane, octyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane; further preferably at least one of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

[0025] Optionally, in step S1, the structural filler is selected from one or more of cetyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, PEO-PPO-PEO triblock copolymer, mesoporous carbon and natural cellulose.

[0026] Optionally, in step S2, the conditions of the hydrothermal crystallization treatment include: under autogenous pressure, the hydrothermal crystallization time is 0.5 to 10 days, and the hydrothermal crystallization temperature is 110 to 200°C; preferably, the hydrothermal crystallization time is 0.5 to 5 days, and the hydrothermal crystallization temperature is 150 to 200°C; the conditions of the calcination treatment include: the calcination temperature is 400 to 900°C, and the calcination time is 1 to 16 hours; preferably, the calcination temperature is 400 to 800°C, and the calcination time is 2 to 8 hours.

[0027] Through the above technical solution, the present disclosure provides a method for oxidizing mercaptans, which uses oxygen as an oxidant to carry out a heterogeneous oxidation reaction, and uses a metal-containing multi-level porous molecular sieve as a catalyst for the reaction of oxidative dehydrogenation of mercaptans to prepare disulfides. The catalyst has a large specific surface area, pore volume and reaction activity, and the metal oxide particles therein have a uniform particle size and are evenly dispersed in the molecular sieve pores and have good recycling performance. No additional base is required during the reaction process, and high conversion rate and disulfide selectivity can be obtained under mild reaction conditions, which has high industrial application value.

[0028] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0030] Figure 1 This is a SEM image of CAT-1 prepared in Preparation Example 1 of the present disclosure.

[0031] Figure 2 This is the XRD spectrum of CAT-1 prepared in Example 1 of the present disclosure.

[0032] Figure 3 This is a TEM image of CAT-1 prepared in Preparation Example 1 of the present disclosure.

[0033] Figure 4 This is the infrared (FT-IR) spectrum of CAT-1 prepared in Example 1 of the present disclosure.

[0034] Figure 5 This is the ultraviolet-visible diffuse reflectance (UV-Vis) spectrum of CAT-1 prepared in Preparation Example 1 of the present disclosure.

[0035] Figure 6 This is the EDX spectrum of CAT-1 prepared in Example 1 of the present disclosure.

[0036] Figure 7 This is the CoXPS spectrum of the metal elements of the product prepared in Example 1 of the present disclosure. DETAILED DESCRIPTION

[0037] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0038] The present disclosure provides a method for oxidizing mercaptans, comprising the following steps: contacting a mercaptan compound with a catalyst in the presence of oxygen to carry out an oxidation reaction; wherein the catalyst is a composite catalytic material, comprising an all-silicon molecular sieve and a metal element M dispersed within the crystals of the all-silicon molecular sieve; the metal M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold.

[0039] The present invention discloses an all-silicon molecular sieve composite catalytic material containing a metal element M in the crystal for the oxidative dehydrogenation reaction of mercaptans, which can achieve high conversion rate and disulfide selectivity at a relatively low temperature without the addition of additional base, and has high industrial application value.

[0040] The inventors of the present disclosure surprisingly discovered during experiments that, by introducing a metal precursor during the molecular sieve synthesis process, followed by the introduction of a silanization agent and a structural filler, and subjecting the resulting mixture to hydrothermal crystallization, washing, and calcination, a composite catalytic material comprising an all-silicon molecular sieve and metal M oxide nanoparticles exhibits not only a large specific surface area and pore volume, but also uniform metal oxide nanoparticle size and uniform dispersion within the molecular sieve pores. Furthermore, the composite material exhibits excellent catalytic activity in the oxidation of mercaptans to disulfides. Furthermore, when the T0 (i.e., T1-T2) value in the composite material is 0.5 eV or greater (T1 represents the XPS binding energy of the metal M element in the composite catalytic material, and T2 represents the XPS binding energy of the metal M element in the metal M oxide aggregates), the catalytic activity of the composite material as a catalyst for the oxidation of mercaptans to disulfides is further enhanced.

[0041] In one embodiment, in the composite material, the metal element M is a metal element capable of forming oxide aggregates; and the composite catalytic material has the following XPS characteristics:

[0042] The electron binding energy of the metal element M in the composite catalytic material is denoted as T1.

[0043] The binding energy of the electrons of the metal element M in the oxide aggregate is recorded as T2, and T0 defined by the following formula (1) is any value between 0.5 and 1.0 eV;

[0044] T0=T1-T2 formula (1).

[0045] The molecular sieve of the composite material provided by the present disclosure has a large specific surface area, pore volume and macromolecular substrate reaction activity; the metal oxide nanoparticles have uniform particle size and are evenly dispersed in the mesoporous channels of the multi-level pore molecular sieve.

[0046] In the present disclosure, metal M oxide aggregates refer to the types of conventional oxides obtained by calcining metal M precursors (such as nitrates, chlorides, etc.) known in the art during the synthesis of molecular sieves, for example, the oxide aggregates of metal cobalt are Co3O4 and the oxide aggregates of metal Cu are CuO.

[0047] In a preferred embodiment, the value of T0 is any value between 0.6 and 0.8 eV. When T0 of the composite catalytic material is within this range, the composite catalytic material has higher catalytic activity.

[0048] In one embodiment, the all-silicon molecular sieve in the composite catalytic material is at least one of MFI structure molecular sieve, MEL structure molecular sieve, BEA structure molecular sieve, MWW structure molecular sieve, two-dimensional hexagonal structure molecular sieve, MOR structure molecular sieve and TUN structure molecular sieve; preferably, it is one or more selected from MFI structure molecular sieve, MEL structure molecular sieve, BEA structure molecular sieve, MCM structure molecular sieve and SBA structure molecular sieve; further preferably, it is one or more selected from MFI structure molecular sieve, MEL structure molecular sieve and BEA structure molecular sieve.

[0049] In an optional embodiment, when the metal M is Co, the oxide aggregate is a Co3O4 aggregate;

[0050] In an optional embodiment, when the metal M is Mn, the oxide aggregate is a MnO2 aggregate;

[0051] In an optional embodiment, when the metal M is Fe, the oxide aggregate is Fe2O3 aggregate;

[0052] In an optional embodiment, when the metal M is Ni, the oxide aggregate is a NiO aggregate;

[0053] In an optional embodiment, when the metal M is Pd, the oxide aggregate is a PdO aggregate;

[0054] In an optional embodiment, when the metal M is Pt, the oxide aggregate is a PtO2 aggregate;

[0055] In an optional embodiment, when the metal M is Cu, the oxide aggregates are CuO aggregates;

[0056] In an optional embodiment, when the metal M is Au, the oxide aggregates are Au aggregates.

[0057] When the metal element M is Co, Mn, Fe, Ni or Cu, the electron binding energy of the metal element M is 2p 3 / 2 When the metal element M is Pt, the electron binding energy of the metal element M is 4f 7 / 2 When the metal element M is Pd, the electron binding energy of the metal element M is the 3d 5 / 2 The binding energy of electrons.

[0058] In this disclosure, the XPS characteristics are based on 2p 3 / 2Taking electrons as an example, its specific meaning is: 2p represents 2p orbital, and 3 / 2 represents the spin-orbit coupling quantum number.

[0059] In a preferred embodiment, the metal element M is one or more of Co, Ni and Cu.

[0060] In one embodiment, in the composite catalytic material, the molar ratio of the metal M element to the silicon element is (0.001-0.2):1, preferably (0.001-0.1):1.

[0061] In one embodiment, the average particle size of the metal nanoparticles in the composite catalytic material is 0.5 to 10 nm, preferably 0.5 to 9 nm; the BET specific surface area is 400 to 800 m 2 / g, preferably 400 to 790 m 2 / g; total pore volume of 0.3-0.65 mL / g, preferably 0.31-0.63 mL / g; micropore volume of 0.1-0.19 mL / g, preferably 0.11-0.18 mL / g; mesopore volume of 0.15-0.50 mL / g, preferably 0.15-0.46 mL / g. The composite catalytic material disclosed herein also has a multi-level pore structure, which is beneficial for catalyzing reaction substrates of different sizes.

[0062] In one embodiment, the composite material is prepared by a preparation method comprising the following steps:

[0063] S1, mixing a template, a silicon source, water, a metal M precursor, a silanization agent and a structural filler to obtain a reaction mixture, wherein the structural filler is an amphiphilic surfactant and / or a hard template;

[0064] S2. performing hydrothermal crystallization and calcination on the reaction mixture.

[0065] The present invention introduces metal precursors, silanization agents and macromolecular structure fillers into the molecular sieve synthesis raw materials, which can take into account the effects of highly dispersed metal oxide nanoparticles and molecular sieve support layer pore expansion, and prepare a multi-level porous molecular sieve composite catalytic material with highly dispersed metal oxide nanoparticles.

[0066] In the present disclosure, metal ions form a complex with a silanizing agent, and the metal oxide nanoparticles obtained after hydrothermal crystallization and calcination have high dispersion in the molecular sieve pores; and the silanyl groups of the silanizing agent and the silanyl groups of the organosilicon source hydrolyze and condense to produce stable Si-O-Si bonds, thereby ensuring the realization of the support layer pore expansion effect. In addition, the long carbon chain of the silanizing agent and the structural filler of the amphiphilic surfactant can form a stable and controllable structural unit (wherein the long carbon chain of the silanizing agent and the hydrophobic group of the surfactant are close to each other and interact with each other by van der Waals forces), thereby playing a fine tuning role in the support layer pore expansion; or a size-controllable hard template agent is used to play a space filling role. The molecular sieve of the composite catalytic material finally obtained produces an ordered, pore-controllable (controlled by the chain length of the alkyl chain of the silanizing agent) mesoporous structure. In addition, the metal M oxide nanoparticles formed by the metal M introduced during the molecular sieve synthesis process can also be uniformly dispersed in the mesoporous channels of the multi-level pore molecular sieve.

[0067] In one embodiment, in step S1, the molar ratio of silicon source: template: water: metal M element: silanization agent is 1: (0.002-1): (5-100): (0.001-0.2): (0.025-0.5), preferably 1: (0.005-0.5): (10-50): (0.001-0.15): (0.025-0.4), and the weight ratio of SiO2 to structural filler in the reaction mixture is (3-100): 1. Specifically, the water used in step S1 can be water commonly used in the synthesis of molecular sieves, and is preferably deionized water to avoid the introduction of heteroatoms.

[0068] In a preferred embodiment, step S1 includes:

[0069] a. mixing a template, a silicon source and water to obtain a silicon hydrolysis solution;

[0070] b. mixing a metal M precursor and the hydrolyzed silicon solution to obtain a first mixed material;

[0071] c. Adding a silanizing agent and a structural filler to the first mixed material respectively, and mixing to obtain the reaction mixture; preferably, the mixing conditions in step c include: stirring at 20-80° C. for 0.5-2 hours.

[0072] In one embodiment, in step S1, the silicon source is selected from at least one of organic silicone grease, solid silica gel, white carbon black, and silica sol; preferably, it is selected from at least one of organic silicone grease, solid silica gel, and white carbon black; the general formula of the organic silicone grease is the structure shown in the following formula (A):

[0073]

[0074] where Ra 、R b 、R c 、R d are independently selected from an alkyl group having 1 to 6 carbon atoms, wherein the alkyl group is a branched or straight chain alkyl group; preferably, R a 、R b 、R c 、R d Each is independently selected from a straight chain alkyl group having 1 to 4 carbon atoms or a branched chain alkyl group having 3 to 4 carbon atoms. a 、R b 、R c 、R d Each is independently methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl. a 、R b 、R c 、R d Each is independently a methyl group or an ethyl group.

[0075] In a preferred embodiment, the organic silicone grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate and dimethyl diethyl silicone grease.

[0076] According to the present disclosure, in step S1, the template is an organic base, preferably at least one selected from a quaternary ammonium base, an aliphatic amine, and an aliphatic alcoholamine. The quaternary ammonium base may be an organic quaternary ammonium base; the aliphatic amine may be a compound formed by replacing at least one hydrogen in NH3 with an aliphatic hydrocarbon group (such as an alkyl group); and the aliphatic alcoholamine may be a compound formed by replacing at least one hydrogen in various NH3 with a hydroxyl-containing aliphatic group (such as an alkyl group).

[0077] Further preferably, the template is selected from at least one quaternary ammonium base having a structure represented by the following formula (B):

[0078] R1, R2, R3 and R4 are each selected from an alkyl group having 1 to 4 carbon atoms, preferably a straight-chain alkyl group having 1 to 4 carbon atoms and a branched-chain alkyl group having 3 to 4 carbon atoms, more preferably R1, R2, R3 and R4 are each selected from one of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group and a tert-butyl group.

[0079] The template is preferably at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide (including various isomers of tetrapropylammonium hydroxide, such as tetra-n-propylammonium hydroxide and tetraisopropylammonium hydroxide) and tetrabutylammonium hydroxide (including various isomers of tetrabutylammonium hydroxide, such as tetra-n-butylammonium hydroxide and tetraisobutylammonium hydroxide).

[0080] In a preferred embodiment, the all-silica molecular sieve is an MFI-type molecular sieve, the template agent is tetrapropylammonium hydroxide or a mixture of tetrapropylammonium hydroxide and one or more selected from tetrapropylammonium chloride and tetrapropylammonium bromide; or the all-silica molecular sieve is an MEL-type molecular sieve, the template agent is tetrabutylammonium hydroxide or a mixture of tetrabutylammonium hydroxide and one or more selected from tetrabutylammonium chloride and tetrabutylammonium bromide; or the molecular sieve is a Beta-type molecular sieve, the template agent is tetraethylammonium hydroxide or a mixture of tetraethylammonium hydroxide and one or more selected from tetraethylammonium chloride and tetraethylammonium bromide. The present disclosure can prepare molecular sieves with different structures by selecting different template agents.

[0081] In an embodiment, in step a, the silicon source is an organosilicon grease, and after mixing the template agent, the organosilicon grease and water, a hydrolytic alcohol-removing treatment is further included to obtain the hydrolytic solution of silicon;

[0082] The conditions of the hydrolytic alcohol-removing treatment include stirring and hydrolyzing at 0-95°C for 2-10 hours; preferably stirring and hydrolyzing at 50-95°C for 2-8 hours;

[0083] Preferably, the hydrolytic alcohol-removing treatment makes the mass content of alcohol produced by the hydrolysis of the organosilicon grease in the hydrolytic solution of silicon be 10 ppm or less.

[0084] According to the present disclosure, the optional range of the type of metal precursor is wide, and any substance containing the metal (for example, a compound containing a metal element and / or a metal element) can achieve the purpose of the present disclosure.

[0085] In an embodiment, in step S1, the metal M precursor is one or more of an inorganic metal compound and an organic metal compound; the organic metal compound is an organic ligand compound of metal M; and preferably the metal M precursor is an inorganic water-soluble salt of metal M.

[0086] The metal M is one or more selected from manganese, iron, cobalt, nickel, palladium, platinum, copper and gold.

[0087] Preferably, the metal M precursor is a metal M precursor aqueous solution, and the molar ratio of metal M element to water in the metal M precursor aqueous solution is 1:(50-500).

[0088] In one embodiment, in step S1, the general formula of the silanization reagent is R5Si(R6)(R7)R8, wherein R5, R6, R7, and R8 are each independently a halogen, an alkyl group, an alkoxy group, an aromatic group, a thiol group, or an amino group, and at least one of R5, R6, R7, and R8 is an alkyl group, an alkoxy group, an aromatic group, a thiol group, or an amino group; the number of carbon atoms of the alkyl group, the alkoxy group, the thiol group, and the amino group are each independently 1 to 18, preferably 1 to 12; the number of carbon atoms of the aromatic group can be 6 to 18, preferably 6 to 12.

[0089] Preferably, the silanization agent is selected from one or more of dimethyldichlorosilane, N-phenyl-3-aminopropyltrimethoxysilane, phenyltrimethoxysilane, 1,7-dichlorooctylmethyltetrasiloxane, hexadecyltrimethoxysilane, octyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane; further preferably, it is selected from one or more of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

[0090] In one embodiment, in step S1, the structural filler is selected from one or more of cetyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, PEO-PPO-PEO triblock copolymer, mesoporous carbon, and natural cellulose. The physicochemical properties of the PEO-PPO-PEO triblock copolymer, mesoporous carbon, and natural cellulose structural fillers disclosed herein may vary widely and are based on commonly available commercial products in the art.

[0091] In one embodiment, in step S2, the conditions of the hydrothermal crystallization treatment include: a hydrothermal crystallization time of 0.5 to 10 days, a hydrothermal crystallization temperature of 110 to 200°C; preferably, the hydrothermal crystallization time is 0.5 to 5 days, a hydrothermal crystallization temperature of 150 to 200°C; and the pressure is autogenous pressure.

[0092] In one embodiment, in step S2, the calcination conditions include: a calcination temperature of 400-900° C. and a calcination time of 1-16 hours; preferably, the calcination temperature is 400-800° C. and the calcination time is 2-8 hours.

[0093] In one embodiment, the thiol compound is selected from any one or more of alkylthiols or benzene ring-containing thiophenols and their derivatives; wherein the alkylthiols include one or more of 2-propanethiol, 1-octanethiol, 1-decanethiol, 1-nonanethiol, 1-heptanethiol and cyclohexanethiol; the benzene ring-containing thiophenols and their derivatives include one or more of thiophenol, 4-methoxythiophenol, 3-methylthiophenol, 1-phenylethylthiol and 4-nitrobenzenethiol;

[0094] Preferably, the method further comprises: contacting the thiol compound with the catalyst in a solvent to carry out an oxidation reaction; the molar ratio of the thiol compound to the solvent is 1:(50-200), preferably 1:(60-100); the solvent is selected from one or more of methanol, acetonitrile, acetone, toluene, tetrahydrofuran and cyclohexane.

[0095] In one embodiment, the oxidation reaction conditions include: a temperature of 40 to 100° C., preferably 60 to 80° C.; a reaction time of 1 to 48 hours, preferably 6 to 24 hours; a weight ratio of the thiol compound to the catalyst of (1 to 100):1, preferably (1 to 20):1, and an oxygen pressure of 0.1 to 0.5 MPa, preferably 0.1 to 0.3 MPa;

[0096] Preferably, the reactor for the oxidation reaction is selected from any one of a tank reactor, a fixed bed reactor, a moving bed reactor, a suspended bed reactor or a slurry bed reactor.

[0097] The present disclosure will be further described below using examples.

[0098] In the present disclosure, X-ray diffraction (XRD) crystal phase diagrams of samples were measured on a Siemens D5005 X-ray diffractometer, with a radiation source of Kα (Cu) and a test range of 2θ of 0.5° to 70°.

[0099] The Fourier transform infrared (FT-IR) spectra of the samples were measured on a Nicolet 8210 Fourier transform infrared spectrometer in the range of 400 to 4000 cm -1 .

[0100] The UV-visible diffuse reflectance spectrum (UV-vis) of the sample was measured on a SHIMADZUUV-3100 UV-visible spectrometer in the range of 400 to 4000 cm -1 .

[0101] The SEM images of the samples were obtained on a Hitachi S4800 high-resolution cold field emission scanning electron microscope.

[0102] The total specific surface area and total pore volume of the sample were determined according to the standard method of ASTM D4222-98 on a Micromeritics ASAP 245 static nitrogen adsorption instrument. The adsorption and desorption isotherms of the sample were determined according to the standard method of ASTM D4222-98 by low temperature nitrogen adsorption.

[0103] The transmission electron microscope (TEM) picture of the sample was obtained on a FEI Tecnai G2 F20 S-TWIN transmission electron microscope. The average particle size of the metal oxide nanoparticles was obtained according to the TEM electron microscope test.

[0104] The XPS characterization of the sample was performed on an ESCALAB 250 X-ray photoelectron spectrometer, monochromatic Al Kα X-ray, energy 1486.6 eV, power 150 W, using the C1s peak of the contaminating carbon (284.8 eV) to correct the nuclear potential shift.

[0105] The cobalt nitrate used in the following preparation examples of the present disclosure is all cobalt nitrate hexahydrate.

[0106] Preparation Example 1

[0107] (1) 1.6 g of a 25.05 wt% tetrapropylammonium hydroxide (TPAOH, 0.002 mol) aqueous solution, 20.8 g of tetraethyl silicate (0.1 mol, SiO2 mass 6 g), and 52.8 g (3 mol) of water were sequentially added to a 500 mL beaker, placed on a magnetic stirrer with heating and stirring functions, mixed uniformly, and stirred at 50°C for 2 hours, with the evaporation of water being replenished in a timely manner, to obtain a colorless transparent silica gel solution;

[0108] (2) 0.03 g of cobalt nitrate hexahydrate (0.0001 mol) and 0.18 g (0.01 mol) of water were stirred uniformly to obtain a cobalt aqueous solution, and the cobalt aqueous solution was mixed with the silica hydrolysis solution obtained in step (1);

[0109] (3) 0.64 g of N-phenyl-3-aminopropyltrimethoxysilane (PHAPTMS, 0.0025 mol) and 0.3 g of PEO-PPO-PEO triblock copolymer (P123, purchased from Innoke, weight average molecular mass 5800) were added to the mixture of step (2), and stirred for 0.5 hours;

[0110] (4) The mixture obtained in step (3) was transferred to a stainless steel sealed autoclave, and crystallized at 175°C for 24 hours to obtain a sample, which was filtered, washed, dried at 110°C for 6 hours, and then calcined at 600°C in a muffle furnace for 6 hours, to obtain the metal oxide nanoparticle and molecular sieve composite material product, denoted as CAT-1.

[0111] The SEM image of CAT-1 is as follows Figure 1 As shown, the XRD spectrum is Figure 2 As shown in the TEM image Figure 3 As shown in the infrared spectrum Figure 4 As shown in the UV-visible spectrum Figure 5 As shown, the EDX image is as follows Figure 6 As shown. Figure 1 、 Figure 3 It can be seen that the product CAT-1 prepared in this example has a regular shape and uniform size; Figure 2 The XRD analysis showed that it had an MFI structure; Figure 4 Medium 960cm -1 The characteristic peaks nearby indicate that Co is bound to the surface of the silicon skeleton; Figure 5 The characteristic peaks in the range of 450-700 nm indicate the interaction between Co and Si. Figure 6 As shown, it can be seen that the metal Co is evenly dispersed in the molecular sieve. The XPS spectrum of the metal element Co of CAT-1 is as follows Figure 7 shown.

[0112] The average particle size, BET specific surface area, total pore volume, micropore volume and mesopore volume of the metal nanoparticles of CAT-1 are listed in Table 2.

[0113] Preparation Comparative Example 1

[0114] The product was prepared according to the method of Preparation Example 1, except that no silanization agent was added. The obtained product was recorded as DCAT-1.

[0115] Preparation Comparative Example 2

[0116] 0.03g of cobalt nitrate hexahydrate and 0.18g of water were stirred to obtain a cobalt aqueous solution. 10.2g of alumina support (purchased from Innochem, Catalog No. A17263) was then added, stirred for 4 hours, and the solvent was evaporated to dryness. The solid was collected and dried at 110°C for 6 hours, then calcined in a muffle furnace at 550°C for 6 hours. The resulting product was designated DCAT-2.

[0117] Preparation Comparative Example 3

[0118] A solution of cobalt was prepared by stirring 0.03 g of cobalt nitrate hexahydrate and 0.18 g of water to homogeneity. Then 6 g of the all-silica MFI molecular sieve support was added and stirred for 4 h, and the solvent was evaporated. The solid was collected and dried at 110 °C for 6 h, and then calcined in a muffle furnace at 550 °C for 6 h. The product was labeled as DCAT-3. The all-silica MFI molecular sieve was prepared according to the procedure of Preparation Example 1, except that no cobalt nitrate hexahydrate and no structure-directing agent were added during the synthesis of the molecular sieve, and the rest of the procedure was the same as that of Preparation Example 1.

[0119] Preparation Examples 2-9

[0120] CAT-2 to CAT-9 were prepared according to the procedure of Preparation Example 1, respectively. The ratios and the synthesis conditions and results are listed in Table 1. The other conditions and operations were according to Example 1. The SEM images were similar to those of Figure 1 Example 1; the XRD patterns were similar to those of Figure 2 Example 1, with MFI structure; the TEM images were similar to those of Figure 3 Example 1; the FT-IR spectra were similar to those of Figure 4 Example 1; and the UV-Vis spectra were similar to those of Figure 5 Example 1.

[0121] Preparation Example 10

[0122] A cobalt-containing hierarchical-pore β molecular sieve was prepared according to the procedure of Preparation Example 1, except that the ratio and the template agent were changed. The template agent used was tetraethylammonium hydroxide (TEAOH), and the product was labeled as CAT-10. The ratio and the synthesis conditions and results are listed in Table 1.

[0123] Preparation Example 11

[0124] A cobalt-containing hierarchical-pore MEL molecular sieve was prepared according to the procedure of Preparation Example 1, except that the ratio and the template agent were changed. The template agent used was tetrabutylammonium hydroxide (TBAOH), and the product was labeled as CAT-11. The ratio and the synthesis conditions and results are listed in Table 1.

[0125] Preparation Example 12

[0126] CAT-12 was prepared according to the procedure of Example 1. The ratio and the synthesis conditions and results are listed in Table 1. The other conditions and operations were according to Example 1.

[0127] The hydrothermal crystallization temperature was 120 °C, the hydrothermal crystallization time was 6 days, the calcination temperature was 870 °C, and the calcination time was 9 h.

[0128] The average particle size of the metal nanoparticles, the BET specific surface area, the total pore volume, the micropore volume, and the mesopore volume of the products of the above examples and comparative examples are listed in Table 2 below.

[0129] Table 1

[0130]

[0131]

[0132] In Table 1, TPAOH is tetrapropylammonium hydroxide, TPABr is tetrapropylammonium bromide, TBAOH is tetrabutylammonium hydroxide, and TEAOH is tetraethylammonium hydroxide; PHAPTMS is N-phenyl-3-aminopropyltrimethoxysilane, APTES is 3-aminopropyltriethoxysilane, KH792 is a silane coupling agent KH792 (bisamino functional silane); P123 is a PEO-PPO-PEO triblock copolymer, CTAB is hexadecyltrimethylammonium bromide, and SDBS is sodium dodecylbenzenesulfonate. The reagents used in this disclosure can be obtained through conventional purchasing channels.

[0133] Table 2

[0134]

[0135]

[0136] Among them, pores with a diameter less than 2nm are micropores; pores with a diameter between 2 and 50nm are mesopores.

[0137] According to Table 2, compared with DCAT-1 (without the addition of silanization agent), the composite catalytic materials CAT-1 to CAT-12 provided by the present disclosure have a higher mesopore volume and a lower metal nanoparticle size, indicating that the method provided by the present disclosure can effectively expand the pores of the molecular sieve, and the degree of nanoparticle aggregation is lower and the dispersion is higher.

[0138] Compared with DCAT-2 and DCAT-3, the composite catalytic materials CAT-1 to CAT-12 provided in the present disclosure can simultaneously have a large mesopore volume, a large specific surface area and a smaller metal nanoparticle size, indicating that the metal nanoparticles in the composite catalytic materials obtained in the present disclosure have a lower degree of aggregation and a higher degree of dispersion.

[0139] Reaction Example 1

[0140] It is used to illustrate the effect of the mercaptan oxidation reaction provided by the present invention.

[0141] The samples prepared in the above-mentioned Preparation Examples and Comparative Examples were used as catalysts for the oxidative dehydrogenation of mercaptans to prepare disulfides. 1 mmol of mercaptans (specific substances are listed in Table 3) were mixed with 2.5 mL of methanol solvent (the molar ratio of mercaptans to methanol was 1:62.5), and then contacted with 50 mg of the catalyst in a slurry bed reactor. The contact temperature was 60° C., the time was 12 h, and the oxygen pressure was 0.1 MPa. The results are shown in Table 3 below.

[0142] Table 3

[0143]

[0144]

[0145] Among them, the T2 value of cobalt oxide aggregate Co3O4 is 781.25eV; the T2 value of iron oxide aggregate Fe2O3 is 710.80eV; the T2 value of nickel oxide aggregate NiO is 854.80eV; and the T2 value of copper oxide aggregate CuO is 933.60eV.

[0146] Comparative Reaction Example 1

[0147] Nickel nanoparticles were prepared as a DCAT-4 catalyst according to the method described in Saxena A, Kumar A, and Mozumdar S. Ni-nanoparticles: Journal of Molecular Catalysis AChemical 2007, 269(1-2):35-40. The nickel nanoparticle DCAT-4 catalyst was reacted according to the method described in Reaction Example 1 using catalyst CAT-4. All other reaction conditions were the same as in Reaction Example 1.

[0148] The reaction results were: thiophenol conversion rate was 98 mol %, and disulfide selectivity was 99 mol %.

[0149] According to the data in Table 3 and the reaction results obtained in Comparative Reaction Example 1, compared with DCAT-1 to DCAT-4, the composite catalytic materials CAT-1 to CAT-12 provided in the present disclosure have higher catalytic activity, and higher thiophenol conversion rate and disulfide selectivity when used in the oxidative dehydrogenation reaction of mercaptans.

[0150] Comparing CAT-1 to CAT-12, it can be seen that compared with CAT-12, the T0 values ​​of CAT-1 to CAT-11 are between 0.6 and 0.8 eV, and CAT-1 to CAT-11 have higher catalytic activity, and the conversion rate of thiophenol and disulfide selectivity are higher when used for the oxidative dehydrogenation reaction of mercaptans.

[0151] Reaction Example 2

[0152] It is used to illustrate the effect of the mercaptan oxidation reaction provided by the present invention.

[0153] The samples prepared in the above Preparation Examples and Comparative Examples were used as catalysts for the oxidative dehydrogenation cross-coupling of thiols. 1 mmol of thiol A and 1 mmol of thiol B (for details of thiol A and thiol B, see Table 4) were mixed and then contacted with 50 mg of the catalyst in a slurry bed reactor at 60°C for 12 hours. The results are shown in Table 4 below.

[0154] The obtained products were analyzed on an Agilent 6890N chromatograph using an HP-5 capillary column (30 m×0.25 mm).

[0155] Mercaptan conversion rate (%) = number of moles of mercaptan participating in the reaction / number of moles of mercaptan added × 100%.

[0156] Disulfide selectivity (%) = (number of moles of disulfide × 2 / number of moles of mercaptans participating in the reaction) × 100%.

[0157] The number of moles of mercaptan participating in the reaction = the number of moles of mercaptan fed - the number of moles of mercaptan remaining in the obtained reaction mixture.

[0158] Table 4

[0159]

[0160] According to the data in Table 4, compared with DCAT-1 to DCAT-3, the reaction method provided by the present invention and the composite catalytic material prepared therefrom have high catalytic activity. When the prepared metal-containing silicon molecular sieve composite catalytic material is used to catalyze the cross-oxidative dehydrogenation coupling reaction of thiols, the conversion rate of thiol A and thiol B is higher, and the selectivity of the three coupling products (three disulfides AA, AB and BB) can all reach a high level, so that the total selectivity of all coupling products is higher.

[0161] Reaction Example 3

[0162] The method of reaction example 1 using CAT-4 as a catalyst and thiophenol as a raw material was used to test the reaction effects under different mercaptan reaction conditions. The specific reaction conditions and reaction results are listed in Table 5 below.

[0163] Table 5

[0164]

[0165] According to the data in Table 5, in the first experiment, when the weight ratio of the CAT-4 catalyst to the thiol compound was 2.2 (satisfying the weight ratio of the catalyst to the thiol compound of 1:(1-20)), the thiol conversion rate and disulfide selectivity were higher.

[0166] In the 10th test, compared with DCAT-4, the composite catalytic material CAT-4 provided by the present disclosure can obtain better cyclic use performance, and can still maintain a high mercaptan conversion rate and a higher disulfide selectivity in the 10th test.

[0167] The preferred embodiments of the present disclosure are described in detail above with reference to the drawings, but the present disclosure is not limited to the specific details in the above-described embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0168] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again in the present disclosure.

[0169] In addition, various different embodiments of the present disclosure can also be combined in any manner, as long as they do not deviate from the idea of the present disclosure, and they should also be considered as disclosed by the present disclosure.

Claims

1. A method for preparing disulfide by oxidizing mercaptans, characterized in that: The following steps are involved: In the presence of oxygen, the thiol compound is brought into contact with the catalyst to carry out an oxidation reaction; Wherein, the catalyst is a composite catalytic material, which includes an all-silicon molecular sieve and a metal element M dispersed in the crystals of the all-silicon molecular sieve; the metal M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold; The composite material is prepared by a preparation method comprising the following steps: S1. a. mixing a template, a silicon source and water to obtain a silicon hydrolysis solution; b. mixing a metal M precursor and the hydrolyzed silicon solution to obtain a first mixed material; c. adding a silanization agent and a structural filler to the first mixed material, respectively, and mixing to obtain a reaction mixture; wherein the structural filler is an amphiphilic surfactant and / or a hard template; S2. performing hydrothermal crystallization and calcination on the reaction mixture.

2. The method according to claim 1, characterized in that The metal element M is a metal element capable of forming oxide aggregates; the composite catalytic material has the following XPS characteristics: The electron binding energy of the metal element M in the composite catalytic material is denoted as T1. The binding energy of the electrons of the metal element M in the oxide aggregate is denoted as T2, T0, as defined in the following formula (1), is any value between 0.5 and 1.0 eV; T0= T1-T2 formula (1).

3. The method according to claim 2, characterized in that The value of T0 is any value between 0.6 and 0.8 eV.

4. The method according to claim 1, wherein The thiol compound is selected from any one or more of alkylthiols or thiophenols containing a benzene ring and their derivatives; wherein the alkyl mercaptan comprises one or more of 2-propanethiol, 1-octanethiol, 1-decanethiol, 1-nonanethiol, 1-heptanethiol and cyclohexanethiol; The benzene ring-containing thiophenol and its derivatives include one or more of thiophenol, 4-methoxythiophenol, 3-methylthiophenol, 1-phenylethyl mercaptan and 4-nitrobenzene mercaptan.

5. The method according to claim 1, wherein The method further comprises: contacting the thiol compound with the catalyst in a solvent to perform an oxidation reaction; the molar ratio of the thiol compound to the solvent is 1:(50-200); The solvent is selected from one or more of methanol, acetonitrile, acetone, toluene, tetrahydrofuran and cyclohexane.

6. The method according to claim 5, characterized in that The molar ratio of the thiol compound to the solvent is 1:(60-100).

7. The method according to claim 1, characterized in that The conditions of the oxidation reaction include: a temperature of 40-100° C.; a reaction time of 1-48 hours; a weight ratio of the thiol compound to the catalyst of (1-100):1, and an oxygen pressure of 0.1-0.5 MPa.

8. The method according to claim 1, characterized in that The reactor for the oxidation reaction is selected from any one of a tank reactor, a fixed bed reactor, a moving bed reactor, a suspension bed reactor or a slurry bed reactor.

9. The method according to claim 7, characterized in that The conditions of the oxidation reaction include: a temperature of 60-80° C.; a reaction time of 6-24 hours; a weight ratio of the thiol compound to the catalyst of (1-20):1, and an oxygen pressure of 0.1-0.3 MPa.

10. The method according to claim 2, characterized in that The all-silicon molecular sieve in the composite catalytic material is at least one of an MFI structure molecular sieve, a MEL structure molecular sieve, a BEA structure molecular sieve, an MWW structure molecular sieve, a two-dimensional hexagonal structure molecular sieve, a MOR structure molecular sieve and a TUN structure molecular sieve.

11. The method according to claim 10, characterized in that The all-silicon molecular sieve is one or more selected from the group consisting of MFI structure molecular sieve, MEL structure molecular sieve, BEA structure molecular sieve, MCM structure molecular sieve and SBA structure molecular sieve.

12. The method according to claim 11, characterized in that The all-silicon molecular sieve is one or more of an MFI structure molecular sieve, an MEL structure molecular sieve and a BEA structure molecular sieve.

13. The method according to claim 2, characterized in that When the metal M is Co, the oxide aggregate is a Co3O4 aggregate; When the metal M is Mn, the oxide aggregate is a MnO2 aggregate; When the metal M is Fe, the oxide aggregate is Fe2O3 aggregate; When the metal M is Ni, the oxide aggregates are NiO aggregates; when the metal M is Pd, the oxide aggregates are PdO aggregates; When the metal M is Pt, the oxide aggregate is a PtO2 aggregate; or When the metal M is Cu, the oxide aggregates are CuO aggregates; When the metal element M is Co, Mn, Fe, Ni or Cu, the electron binding energy of the metal element M is 2p 3 / 2 When the metal element M is Pt, the electron binding energy of the metal element M is 4f 7 / 2 When the metal element M is Pd, the electron binding energy of the metal element M is the 3d 5 / 2 The binding energy of electrons.

14. The method according to claim 13, characterized in that The metal element M is one or more of Co, Ni and Cu.

15. The method according to claim 2, characterized in that In the composite catalytic material, the molar ratio of the metal M element to the silicon element is (0.001-0.2):

1.

16. The method according to claim 15, characterized in that In the composite catalytic material, the molar ratio of the metal M element to the silicon element is (0.001-0.1):

1.

17. The method according to claim 2, characterized in that The BET specific surface area of ​​the composite catalytic material is 400-800 m 2 / g, the total pore volume is 0.3~0.65mL / g, the micropore volume is 0.1~0.19mL / g, the mesopore volume is 0.15~0.50mL / g, and the metal element M in the composite catalytic material exists in the form of metal nanoparticles, and the average particle size of the metal nanoparticles is 0.5~10nm.

18. The method according to claim 1, wherein In step S1, the molar ratio of silicon source: template: water: metal M element: silanization agent is 1: (0.002~1): (5~100): (0.001~0.2): (0.025~0.5), and the weight ratio of SiO2 to structural filler in the reaction mixture is (3~100):

1.

19. The method according to claim 18, characterized in that In step S1, the molar ratio of silicon source: template: water: metal M element: silanization agent is 1: (0.005-0.5): (10-50): (0.001-0.15): (0.025-0.4).

20. The method according to claim 1, wherein The mixing conditions in step c include: stirring at 20-80° C. for 0.5-2 hours.

21. The method according to claim 1, wherein The silicon source is selected from at least one of organic silicone grease, solid silica gel, white carbon black and silica sol.

22. The method according to claim 21, characterized in that The silicon source is selected from at least one of organic silicone grease, solid silica gel and white carbon black.

23. The method according to claim 22, characterized in that The silicon source is organic silicone grease, and the general formula of the organic silicone grease is the structure shown in the following formula (A): （A）； where R a 、R b 、R c 、R d Each is independently selected from an alkyl group having 1 to 6 carbon atoms, and the alkyl group is a branched or straight chain alkyl group.

24. The method according to claim 23, wherein R a 、R b 、R c 、R d Each is independently selected from a straight-chain alkyl group having 1 to 4 carbon atoms or a branched-chain alkyl group having 3 to 4 carbon atoms.

25. The method according to claim 24, characterized in that The R a 、R b 、R c 、R d Each is independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl.

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

27. The method according to claim 1, wherein In step S1, the template agent is an organic base.

28. The method according to claim 27, characterized in that The template is selected from at least one of quaternary ammonium base, aliphatic amine and aliphatic alcohol amine.

29. The method according to claim 28, characterized in that The template is selected from at least one quaternary ammonium base having a structure represented by the following formula (B): （B）； R1, R2, R3 and R4 are independently selected from alkyl groups having 1 to 4 carbon atoms.

30. The method according to claim 29, wherein R1, R2, R3 and R4 are independently selected from a linear alkyl group having 1 to 4 carbon atoms and a branched alkyl group having 3 to 4 carbon atoms.

31. The method according to claim 30, wherein R1, R2, R3 and R4 are independently selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl.

32. The method according to claim 1, wherein The all-silicon molecular sieve is an MFI molecular sieve, and the template agent is tetrapropylammonium hydroxide or a mixture of tetrapropylammonium hydroxide and one or more selected from tetrapropylammonium chloride and tetrapropylammonium bromide; or the all-silicon molecular sieve is an MEL molecular sieve, and the template agent is tetrabutylammonium hydroxide or a mixture of tetrabutylammonium hydroxide and one or more selected from tetrabutylammonium chloride and tetrabutylammonium bromide; or the molecular sieve is a Beta molecular sieve, and the template agent is tetraethylammonium hydroxide or a mixture of tetraethylammonium hydroxide and one or more selected from tetraethylammonium chloride and tetraethylammonium bromide.

33. The method according to claim 1, wherein In step a, the silicon source is organic silicone grease, and after the template, organic silicone grease and water are mixed, a hydrolysis and alcohol removal treatment is further performed to obtain a hydrolyzed solution of the silicon; The conditions for the hydrolysis and alcohol removal treatment include: stirring and hydrolyzing at 0-95° C. for 2-10 hours.

34. The method according to claim 33, wherein The conditions for the hydrolysis and alcohol removal treatment include: stirring and hydrolyzing at 50-95° C. for 2-8 hours.

35. The method according to claim 1, wherein In step S1, the metal M precursor is one or more of an inorganic metal compound and an organometallic compound; the inorganic metal compound is a water-soluble inorganic salt of metal M; the water-soluble inorganic salt of metal M is selected from one or more of chloride, hydrated chloride, sulfate, hydrated sulfate and nitrate of metal M; the organometallic compound is an organic ligand compound of metal M; The metal M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold.

36. The method according to claim 35, characterized in that The metal M precursor is a water-soluble inorganic salt of metal M.

37. The method according to claim 35, wherein The metal M precursor is an aqueous solution of the metal M precursor, and the molar ratio of the metal M element to water in the aqueous solution of the metal M precursor is 1: (50-500).

38. The method according to claim 1, wherein In step S1, the general formula of the silanization reagent is R5Si(R6)(R7)R8, wherein R5, R6, R7, and R8 are each independently a halogen, an alkyl group, an alkoxy group, an aromatic group, a thiol group, or an amino group, and at least one of R5, R6, R7, and R8 is an alkyl group, an alkoxy group, an aromatic group, a thiol group, or an amino group; the number of carbon atoms of the alkyl group, the alkoxy group, the thiol group, and the amino group is each independently any integer from 1 to 18, and the number of carbon atoms of the aromatic group is any integer from 6 to 18.

39. The method according to claim 38, characterized in that The silanization agent is selected from one or more of dimethyldichlorosilane, N-phenyl-3-aminopropyltrimethoxysilane, phenyltrimethoxysilane, 1,7-dichlorooctylmethyltetrasiloxane, hexadecyltrimethoxysilane, octyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

40. The method according to claim 39, wherein The silanization agent is selected from one or more of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

41. The method according to claim 1, wherein In step S1, the structural filler is selected from one or more of cetyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, PEO-PPO-PEO triblock copolymer, mesoporous carbon and natural cellulose.

42. The method according to claim 1, wherein In step S2, the conditions of the hydrothermal crystallization treatment include: under autogenous pressure, the hydrothermal crystallization time is 0.5 to 10 days, and the hydrothermal crystallization temperature is 110 to 200° C.; The calcination conditions include: a calcination temperature of 400-900° C. and a calcination time of 1-16 hours.

43. The method according to claim 42, wherein In step S2, the conditions of the hydrothermal crystallization treatment include: under autogenous pressure, the hydrothermal crystallization time is 0.5 to 5 days, and the hydrothermal crystallization temperature is 150 to 200° C.; The calcination conditions include: a calcination temperature of 400-800° C. and a calcination time of 2-8 hours.

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