CN116178226A - Method for preparing disulfide by oxidizing mercaptan - Google Patents

Abstract

The present disclosure relates to a method of thiol oxidation comprising the steps of: in the presence of oxygen, contacting a mercaptan compound with a catalyst for oxidation reaction; the catalyst is a composite catalytic material, and the composite catalytic material comprises an all-silicon molecular sieve and metal elements M dispersed in 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 method adopts the metal-containing hierarchical pore molecular sieve for oxidative dehydrogenation of mercaptan, does not need to add extra alkali, can obtain high conversion rate and disulfide selectivity at a lower temperature, and has high industrial application value.

Description

Method for preparing disulfide by oxidizing mercaptan

Technical Field

The present disclosure relates to the field of organic chemical industry, and in particular, to a method for preparing disulfide by oxidizing thiol.

Background

Disulfide is also an important intermediate in the field of organic synthetic chemistry and can be used in synthetic rubber scorch retarders, fine fragrances, dietary supplements, antioxidants, and the like. In particular to dimethyl disulfide, which can be used as coking inhibitor, passivating agent and vulcanizing agent in industry and can be used as effective soil fumigant in agriculture, the global annual demand of the dimethyl disulfide reaches 30 ten thousand tons, and the domestic demand is about 7 ten thousand tons/year.

Because of the existence of thiol compounds in crude oil, the Merox deodorization process of fuel oil is started to be developed in 50 s as early as the process of the Merox deodorization process, which comprises the steps of firstly activating thiol by sodium hydroxide to obtain sodium mercaptide, and then coupling under the action of cobalt phthalocyanine and oxygen to obtain disulfide. As the reaction proceeds, the production of water causes a portion of the lye to be removed, which also results in the production of solid alkali residues and the loss of cobalt phthalocyanine. Although the technology of alkali-free deodorization developed later has obvious breakthrough in technology, alkaline thiol activators such as quaternary ammonium hydroxide and the like are required to be continuously injected.

Therefore, the development of alkali-free heterogeneous systems for oxidative coupling of thiols to disulfide is a direction of efforts by researchers. However, most reports focus on the use of hydrogen peroxide and urea hydrogen peroxide as oxidizing agents, and in mild stripsLess research is being done on the oxidation of mercaptans under the piece with oxygen or air as the oxidant. In noble metal catalysts, for example in the form of Ag nanoparticles (Gaur R, yadav M, gupta R, arora G, rana P, shalma RK. Chemistry select 2018,3 (9)) and Au/CeO ₂ (Corma A, R, midens T, sabater MJ. Chemical Science 2012,3 (2): 398-404.) although all have good activity, the cost problem is still not well resolved. Nickel nano particles are used as catalysts (Saxena A, kumar A, mozumdar S.Ni-nanoparticles: journal of Molecular Catalysis A Chemical 2007,269 (1-2): 35-40.) and can realize the oxidative coupling of aliphatic, aromatic and cyclic aromatic thiols to prepare various disulfides at room temperature, but the method has the problems of easy deactivation and less cycle times.

Disclosure of Invention

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

To achieve the above object, the present disclosure provides a method of oxidizing a thiol, comprising the steps of: in the presence of oxygen, contacting a mercaptan compound with a catalyst for oxidation reaction;

the catalyst is a composite catalytic material, and the composite catalytic material comprises an all-silicon molecular sieve and metal elements M dispersed in 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.

Alternatively, the metal element M is a metal element capable of forming an oxide aggregate; 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 T ₁ The binding energy of the electrons of the metal element M in the oxide aggregate is denoted as T ₂ T as defined by the following formula (1) ₀ Is any value between 0.5 and 1.0 eV; t (T) ₀ ＝T ₁ -T ₂ Formula (1); preferably, said T ₀ Has a value of 0.6 toAny value between 0.8 eV.

Optionally, the mercaptan compound is selected from any one or more of alkyl mercaptan or thiophenol containing benzene ring and derivatives thereof; wherein the alkyl mercaptan comprises one or more of 2-propanethiol, 1-octanethiol, 1-decanethiol, 1-nonanthiol, 1-heptanethiol and cyclohexanediol; the thiophenol and the derivative thereof containing benzene ring comprise one or more of thiophenol, 4-methoxy thiophenol, 3-methyl thiophenol, 1-phenethyl mercaptan and 4-nitrobenzene mercaptan; preferably, the method further comprises: contacting the thiol compound with the catalyst in a solvent to perform an oxidation reaction; the molar ratio of the mercaptan compound to the solvent is 1: (50 to 200), preferably 1: (60-100); the solvent is selected from one or more of methanol, acetonitrile, acetone, toluene, tetrahydrofuran and cyclohexane.

Optionally, the oxidation reaction conditions include: the temperature is 40-100 ℃, preferably 60-80 ℃; the reaction time is 1 to 48 hours, preferably 6 to 24 hours; the weight ratio of the mercaptan compound to the catalyst is (1-100): 1, preferably (1 to 20): 1, the oxygen pressure is 0.1-0.5 MPa, preferably 0.1-0.3 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 suspension bed reactor or a slurry bed reactor.

Optionally, the all-silicon molecular sieve in the composite catalytic material is at least one of an MFI structure molecular sieve, an MEL structure molecular sieve, a BEA structure molecular sieve, an MWW structure molecular sieve, a two-dimensional hexagonal structure molecular sieve, an MOR structure molecular sieve and a TUN structure molecular sieve; preferably 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 preferred are one or more of MFI structure molecular sieves, MEL structure molecular sieves and BEA structure molecular sieves.

Alternatively, when the metal M is Co, the oxide aggregate is Co ₃ O ₄ An aggregate; when the metal M is Mn, the oxide aggregate is MnO ₂ An aggregate; when the metal M is FeThe oxide aggregate is Fe ₂ O ₃ An aggregate; when the metal M is Ni, the oxide aggregate is a NiO aggregate; when the metal M is Pd, the oxide aggregates are PdO aggregates; when the metal M is Pt, the oxide aggregate is PtO ₂ An aggregate; alternatively, when the metal M is Cu, the oxide aggregate is a 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 of the metal element M _3/2 Binding energy of electrons; when the metal element M is Pt, the electron binding energy of the metal element M is 4f of the metal element M _7/2 Binding energy of electrons; when the metal element M is Pd, the electron binding energy of the metal element M is 3d of the metal element M _5/2 Binding energy of electrons; preferably, the metal element M is one or more of Co, ni and Cu.

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 to 0.1): 1.

optionally, the BET specific surface area of the composite catalytic material is 400-800 m ² And/g, wherein 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 nano particles, and the average particle size of the metal nano particles is 0.5-10 nm.

Optionally, the composite material is prepared by a preparation method comprising the steps of: s1, mixing a template agent, a silicon source, water, a metal M precursor, a silanization reagent and a structural filler to obtain a reaction mixture, wherein the structural filler is an amphiphilic surfactant and/or a hard template agent; s2, carrying out hydrothermal crystallization treatment and roasting treatment on the reaction mixture.

Optionally, in step S1, the silicon source: template agent: water: metal M element: the molar ratio of the silylating agent is 1: (0.002-1): (5-100): (0.001-0.2): (0.025 to 0.5), preferably 1: (0.005-0.5): (10-50): (0.001-0.15): (0.025-0.4) and the reaction mixtureSiO in the composition ₂ The weight ratio of the structural filler to the structural filler is (3-100): 1.

optionally, step S1 includes: a. mixing a template agent, 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. respectively adding a silylation reagent and a structural filler into the first mixed material, and mixing to obtain a reaction mixture; preferably, the conditions of mixing in step c include: stirring at 20-80 deg.c for 0.5-2 hr.

Optionally, the silicon source is selected from at least one of silicone grease, solid silica gel, white carbon black and silica sol; preferably at least one selected from the group consisting of silicone grease, solid silica gel and white carbon black; further preferred is a silicone grease having a structure represented by the following formula (A):

wherein R is _a 、R _b 、R _c 、R _d Each independently selected from alkyl groups having 1 to 6 carbon atoms, said alkyl groups being branched or straight chain alkyl groups; 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 alkyl group having 3 to 4 carbon atoms; further preferably, the R _a 、R _b 、R _c 、R _d Each 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.

Optionally, in step S1, the template agent is an organic base, preferably at least one selected from quaternary ammonium base, aliphatic amine and aliphatic alcohol amine; further preferably, the template is at least one selected from structural quaternary ammonium bases represented by the following formula (B):

R ₁ 、R ₂ 、R ₃ and R is ₄ Each selected from alkyl groups having 1 to 4 carbon atoms, preferably straight chain alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 4 carbon atoms, more preferably R ₁ 、R ₂ 、R ₃ And R is ₄ Each is selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl; further preferably, the all-silicon molecular sieve is an MFI type 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 a 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 Beta-type 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.

Optionally, in the step a, the silicon source is organic silicone grease, and the step a further comprises hydrolysis alcohol removal treatment after the template agent, the organic silicone grease and water are mixed to obtain a hydrolysis solution of the silicon; the conditions for the hydrolysis alcohol expelling treatment comprise: stirring and hydrolyzing for 2-10 hours at 0-95 ℃; preferably at 50-95 deg.C for 2-8 hr.

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 water-soluble inorganic salt of metal M; the water-soluble inorganic salt of the metal M is selected from one or more of chloride, hydrated chloride, sulfate, hydrated sulfate and nitrate of the 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 is an aqueous solution of metal M precursor, and the molar ratio of metal M element to water in the aqueous solution of metal M precursor is 1: (50-500).

Optionally, in step S1, the silylating agent has the general formula R ₅ Si(R ₆ )(R ₇ )R ₈ Wherein R is ₅ 、R ₆ 、R ₇ 、R ₈ Each independently is halogen, alkyl, alkoxy, aryl, mercapto or amino, and R ₅ 、R ₆ 、R ₇ 、R ₈ At least one of which is alkyl, alkoxy, aryl, mercapto or amino; the carbon atoms of the alkyl, alkoxy, mercapto and amino are each independently any integer from 1 to 18, and the carbon atoms of the aryl are each any integer from 6 to 18; preferably, the silylating agent is selected from one or more of dimethyldichlorosilane, N-phenyl-3-aminopropyl trimethoxysilane, phenyl trimethoxysilane, 1, 7-dichlorooctanethyltetrasiloxane, hexadecyl trimethoxysilane, octyl triethoxysilane, 3-aminopropyl trimethoxysilane, N-beta- (aminoethyl) -gamma-aminopropyl trimethoxysilane and 3-mercaptopropyl trimethoxysilane; further preferred is at least one of N-phenyl-3-aminopropyl trimethoxysilane, N-beta- (aminoethyl) -gamma-aminopropyl trimethoxysilane and 3-mercaptopropyl trimethoxysilane.

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.

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

Through the technical scheme, the disclosure provides a mercaptan oxidation method, which uses oxygen as an oxidant to carry out heterogeneous oxidation reaction, uses a metal-containing hierarchical pore molecular sieve as a catalyst for the reaction of preparing disulfide by oxidative dehydrogenation of mercaptan, has large specific surface area, pore volume and reactivity, wherein metal oxide particles have uniform particle size and are uniformly dispersed in molecular sieve pore channels, the recycling performance is good, no additional alkali is needed in the reaction process, high conversion rate and disulfide selectivity can be obtained under mild reaction conditions, and the catalyst has high industrial application value.

Additional features and advantages of the present disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification, illustrate the disclosure and together with the description serve to explain, but do not limit the disclosure. In the drawings:

FIG. 1 is an SEM photograph of CAT-1 prepared in preparation example 1 of the disclosure.

FIG. 2 is an XRD spectrum of CAT-1 prepared in preparation example 1 of the present disclosure.

FIG. 3 is a TEM photograph of CAT-1 prepared in preparation example 1 of the present disclosure.

FIG. 4 is an infrared (FT-IR) spectrum of CAT-1 prepared in preparation example 1 of the present disclosure.

FIG. 5 is a graph of the diffuse reflection of ultraviolet-visible light (UV-Vis) of CAT-1 prepared in preparation example 1 of the present disclosure.

FIG. 6 is an EDX spectrum of CAT-1 prepared in preparation example 1 of the present disclosure.

Fig. 7 is a graph of a metal element coxs spectrum of the product obtained in preparation example 1 of the present disclosure.

Detailed Description

Specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the disclosure, are not intended to limit the disclosure.

The present disclosure provides a method of thiol oxidation comprising the steps of: in the presence of oxygen, contacting a mercaptan compound with a catalyst for oxidation reaction; the catalyst is a composite catalytic material, and the composite catalytic material comprises an all-silicon molecular sieve and metal elements M dispersed in 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 method adopts the all-silicon molecular sieve composite catalytic material containing the metal element M in the crystal for thiol oxidative dehydrogenation reaction, does not need to add extra alkali, can obtain high conversion rate and disulfide selectivity at a lower temperature, and has high industrial application value.

The inventor of the present disclosure surprisingly found in experiments that, a metal precursor is introduced during the synthesis process of a molecular sieve, then a silylation agent and a structural filler are continuously introduced, and after hydrothermal crystallization, washing and roasting are performed on the obtained mixed material, the obtained composite catalytic material comprising the all-silicon molecular sieve and metal M-oxide nanoparticles has a larger specific surface area and pore volume, the metal oxide nanoparticles have uniform particle size and are uniformly dispersed in the pore channels of the molecular sieve, and the composite material has good catalytic activity in the reaction of preparing disulfide by oxidizing thiol. And when T in the composite material ₀ (i.e.T ₁ -T ₂ ) Has a value of 0.5eV or more (T ₁ Represents XPS binding energy, T of metal M element in the composite catalytic material ₂ Representing the XPS binding energy of the metal M element in the oxide aggregate of the metal M), the catalytic activity of the composite material is further improved when the composite material is used as a catalyst for preparing disulfide by thiol oxidation.

In one embodiment, in the composite material, the metal element M is a metal element capable of forming an oxide aggregate; 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 T ₁ ，

The binding energy of the electrons of the metal element M in the oxide aggregate is denoted as T ₂ T as defined by the following formula (1) ₀ Is any value between 0.5 and 1.0 eV;

T ₀ ＝T ₁ -T ₂ formula (1).

The molecular sieve of the composite material provided by the disclosure has large specific surface area, pore volume and macromolecular substrate reaction activity; the metal oxide nano particles have uniform particle size and are uniformly dispersed in mesoporous pore canals of the multi-level pore molecular sieve.

In the present disclosure, metal M oxide aggregates refer to the species of conventional oxides obtained after calcination treatment of metal M precursors (e.g., nitrates, chlorides, etc.) known in the art during molecular sieve synthesis, e.g., metal cobalt oxide aggregates are Co ₃ O ₄ The aggregate of the oxide of the metal Cu is CuO.

In a preferred embodiment, T ₀ The value of (2) is any value between 0.6 and 0.8eV, and the T of the composite catalytic material ₀ Within this range, the composite catalytic material has a higher catalytic activity.

In one embodiment, the all-silicon molecular sieve in the composite catalytic material is at least one of an MFI structure molecular sieve, an MEL structure molecular sieve, a BEA structure molecular sieve, an MWW structure molecular sieve, a two-dimensional hexagonal structure molecular sieve, an MOR structure molecular sieve and a TUN structure molecular sieve; preferably 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 preferred are one or more of MFI structure molecular sieves, MEL structure molecular sieves and BEA structure molecular sieves.

In an alternative embodiment, when the metal M is Co, the oxide aggregate is Co ₃ O ₄ An aggregate;

in an alternative embodiment, when the metal M is Mn, the oxide aggregate is MnO ₂ An aggregate;

in an alternative embodiment, when the metal M is Fe, the oxide aggregate is Fe ₂ O ₃ An aggregate;

in an alternative embodiment, when the metal M is Ni, the oxide aggregate is a NiO aggregate;

in an alternative embodiment, when the metal M is Pd, the oxide aggregates are PdO aggregates;

in an alternative embodiment, when the metal M is Pt, the oxide aggregate is PtO ₂ An aggregate;

in an alternative embodiment, when the metal M is Cu, the oxide aggregate is a CuO aggregate;

in an alternative embodiment, when the metal M is Au, the oxide aggregate is an Au 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 of the metal element M _3/2 Binding energy of electrons; when the metal element M is Pt, the electron binding energy of the metal element M is 4f of the metal element M _7/2 Binding energy of electrons; when the metal element M is Pd, the electron binding energy of the metal element M is 3d of the metal element M _5/2 Binding energy of electrons.

In the present disclosure, XPS features are described as 2p _3/2 The specific meaning of the electron is as follows: 2p denotes the 2p orbitals and 3/2 denotes the number of spin-rail coupled quanta.

In a preferred embodiment, the metal element M is one or more of Co, ni and Cu.

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

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

In one embodiment, the composite material is prepared by a preparation method comprising the steps of:

s1, mixing a template agent, a silicon source, water, a metal M precursor, a silanization reagent and a structural filler to obtain a reaction mixture, wherein the structural filler is an amphiphilic surfactant and/or a hard template agent;

s2, carrying out hydrothermal crystallization treatment and roasting treatment on the reaction mixture.

The metal precursor, the silanization reagent and the macromolecular structure filler are introduced into the molecular sieve synthesis raw material, so that the hole expanding effect of the highly dispersed metal oxide nano particles and the molecular sieve support layer can be considered, and the multistage pore molecular sieve composite catalytic material of the highly dispersed metal oxide nano particles can be prepared.

In the method, metal ions and a silanization reagent form a complex, and metal oxide nano particles in a pore canal of a molecular sieve obtained after hydrothermal crystallization and roasting have high dispersity; and the silicon hydroxyl of the silanization reagent and the silicon hydroxyl of the organic silicon source are hydrolyzed and condensed to generate stable Si-O-Si bond, thereby ensuring the realization of the hole expanding effect of the support layer. In addition, the long carbon chain of the silylation agent and the structural filler of the amphiphilic surfactant can form a stable and controllable structural unit (wherein the long carbon chain of the silylation agent and the hydrophobic group of the surfactant are close to each other and interact with each other by Van der Waals force), so that fine adjustment effect on expanding the support layer is achieved; or the space filling function is realized by using a hard template agent with controllable size. The molecular sieve of the finally obtained composite catalytic material generates a mesoporous structure with ordered and controllable pore diameter (controlled by the chain length of the alkyl chain of the silylating agent). And metal M oxide nano particles formed by metal M introduced in the molecular sieve synthesis process can be uniformly dispersed in mesoporous pore channels of the hierarchical pore molecular sieve.

In one embodiment, in step S1, the silicon source: template agent: water: metal M element: the molar ratio of the silylating agent is 1: (0.002-1): (5-100): (0.001-0.2): (0.025 to 0.5), preferably 1: (0.005-0.5): (10-50): (0.001-0.15): (0.025-0.4), siO in the reaction mixture ₂ The weight ratio of the structural filler to the structural filler is (3-100): 1. specifically, the steps ofThe water used in S1 may be water commonly used in the synthesis of molecular sieves, and deionized water is preferred to avoid the introduction of heteroatoms.

In a preferred embodiment, step S1 comprises:

a. mixing a template agent, 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. respectively adding a silylation reagent and a structural filler into the first mixed material, and mixing to obtain a reaction mixture; preferably, the conditions of mixing in step c include: stirring at 20-80 deg.c for 0.5-2 hr.

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

Wherein R is _a 、R _b 、R _c 、R _d Each independently selected from alkyl groups having 1 to 6 carbon atoms, said alkyl groups being branched or straight chain alkyl groups; 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 alkyl group having 3 to 4 carbon atoms. For example R _a 、R _b 、R _c 、R _d Each independently is methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl. Further preferably R _a 、R _b 、R _c 、R _d Each independently is methyl or ethyl.

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

According to the present disclosure, in step S1, the template agent is an organic base, preferably at least one selected from the group consisting of quaternary ammonium bases, aliphatic amines, and aliphatic alcohol amines. Wherein, the quaternary ammonium base can be organic quaternary ammonium base; the aliphatic amine may be NH ₃ A compound formed by substituting at least one hydrogen of the compound with an aliphatic hydrocarbon group (e.g., an alkyl group); the aliphatic alcohol amine can be various NH ₃ A compound in which at least one hydrogen is substituted with an aliphatic group having a hydroxyl group (e.g., an alkyl group).

Further preferably, the template is at least one selected from structural quaternary ammonium bases represented by the following formula (B):

R ₁ 、R ₂ 、R ₃ And R is ₄ Each selected from alkyl groups having 1 to 4 carbon atoms, preferably straight chain alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 4 carbon atoms, more preferably R ₁ 、R ₂ 、R ₃ And R is ₄ Each is selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl.

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).

In a preferred embodiment, the all-silicon molecular sieve is an MFI-type 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 a 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 Beta-type 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. The molecular sieve with different structures can be prepared by selecting different templates.

In one embodiment, in the step a, the silicon source is organic silicone grease, and the step a further comprises hydrolysis alcohol removal treatment after the template agent, the organic silicone grease and the water are mixed to obtain a hydrolysis solution of the silicon;

the conditions for the hydrolysis alcohol expelling treatment comprise: stirring and hydrolyzing for 2-10 hours at 0-95 ℃; preferably, the hydrolysis is carried out for 2 to 8 hours under stirring at 50 to 95 ℃;

preferably, the hydrolysis alcohol-expelling treatment is performed so that the mass content of alcohol produced by hydrolysis of the obtained silicone grease in the silicon hydrolysis solution is 10ppm or less.

According to the present disclosure, the metal precursor may have a wide range of types, and any material containing the metal (e.g., a compound containing a metal element and/or a metal simple substance) may achieve the object of the present disclosure.

In one 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 water-soluble inorganic salt of metal M; the water-soluble inorganic salt of the metal M is selected from one or more of chloride, hydrated chloride, sulfate, hydrated sulfate and nitrate of the 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 is an aqueous solution of metal M precursor, and the molar ratio of metal M element to water in the aqueous solution of metal M precursor is 1: (50-500).

In one embodiment, in step S1, the silylating agent has the general formula R ₅ Si(R ₆ )(R ₇ )R ₈ Wherein R is ₅ 、R ₆ 、R ₇ 、R ₈ Each independently is halogen, alkyl, alkoxy, aryl, mercapto or amino, and R ₅ 、R ₆ 、R ₇ 、R ₈ At least one of which is alkyl, alkoxy, aryl, mercapto or amino; the number of carbon atoms of the alkyl group, the alkoxy group, the mercapto group and the amine group is 1 to 18, preferably 1 to 12; the number of carbon atoms of the aromatic group may be 6 to 18, preferably 6 to 12.

Preferably, the silylating agent is selected from one or more of dimethyldichlorosilane, N-phenyl-3-aminopropyl trimethoxysilane, phenyl trimethoxysilane, 1, 7-dichlorooctanethyltetrasiloxane, hexadecyl trimethoxysilane, octyl triethoxysilane, 3-aminopropyl trimethoxysilane, N-beta- (aminoethyl) -gamma-aminopropyl trimethoxysilane and 3-mercaptopropyl trimethoxysilane; further preferred is one or more selected from the group consisting of N-phenyl-3-aminopropyl trimethoxysilane, N-beta- (aminoethyl) -gamma-aminopropyl trimethoxysilane and 3-mercaptopropyl trimethoxysilane.

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 PEO-PPO-PEO triblock copolymers, mesoporous carbon and natural cellulosic structural fillers in this disclosure can vary over a wide range, based on products that are routinely commercially available in the art.

In one embodiment, in step S2, the conditions of the hydrothermal crystallization treatment include: the hydrothermal crystallization time is 0.5-10 days, and the hydrothermal crystallization temperature is 110-200 ℃; preferably, the hydrothermal crystallization time is 0.5-5 days, and the hydrothermal crystallization temperature is 150-200 ℃; the pressure is autogenous pressure.

In one embodiment, in step S2, the conditions of the baking process include: roasting temperature is 400-900 ℃ and roasting time is 1-16 hours; preferably, the roasting temperature is 400-800 ℃ and the roasting time is 2-8 hours.

In one embodiment, the mercaptan compound is selected from one or more of alkyl mercaptan, thiophenol containing benzene ring and derivatives thereof; wherein the alkyl mercaptan comprises one or more of 2-propanethiol, 1-octanethiol, 1-decanethiol, 1-nonanthiol, 1-heptanethiol and cyclohexanediol; the thiophenol and the derivative thereof containing benzene ring comprise one or more of thiophenol, 4-methoxy thiophenol, 3-methyl thiophenol, 1-phenethyl mercaptan and 4-nitrobenzene mercaptan;

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

In one embodiment, the oxidation reaction conditions include: the temperature is 40-100 ℃, preferably 60-80 ℃; the reaction time is 1 to 48 hours, preferably 6 to 24 hours; the weight ratio of the mercaptan compound to the catalyst is (1-100): 1, preferably (1 to 20): 1, the oxygen pressure is 0.1-0.5 MPa, preferably 0.1-0.3 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 suspension bed reactor or a slurry bed reactor.

The present disclosure will be further illustrated by the following examples.

In the present disclosure, the X-ray diffraction (XRD) pattern measurement of the sample was performed on a siemens d5005 type X-ray diffractometer with a source of kα (Cu) and a test range of 2θ from 0.5 ° to 70 °.

The Fourier infrared (FT-IR) spectrum of the sample is measured on a Nicolet8210 type Fourier infrared spectrometer, and the measuring range is 400-4000 cm ^-1 。

The solid ultraviolet-visible diffuse reflectance spectrum (UV-vis) of the sample is measured on a SHIMADZUUV-3100 ultraviolet-visible spectrometer with a test range of 400-4000 cm ^-1 。

SEM images of the samples were obtained on a high resolution cold field emission scanning electron microscope in hitachi S4800.

The total specific surface area and total pore volume of the samples were measured on a Micromeritics company ASAP245 static nitrogen adsorber according to the standard method of ASTMD 4222-98. The determination of adsorption isotherms and desorption isotherms for low temperature nitrogen adsorption of the samples was performed according to astm d4222-98 standard method.

Transmission electron microscopy TEM of the samples was obtained on a Tecnai G2F20S-TWIN transmission electron microscope from FEI company. The average particle diameter of the metal oxide nanoparticles was obtained according to TEM electron microscopy.

XPS characterization of the samples was performed on an ESCALAB 250 type X-ray photoelectron spectrometer, monochromatic AlKαX-rays, energy 1486.6eV, power 150W, and C1s peak (284.8 eV) of contaminating carbon was used to correct nuclear power shift.

The cobalt nitrate used in the following preparation examples of this disclosure is cobalt nitrate hexahydrate.

Preparation example 1

(1) 1.6g of an aqueous solution of tetrapropylammonium hydroxide (TPAOH, 0.002 mol) having a concentration of 25.05 wt%, 20.8g of tetraethyl silicate (0.1 mol, siO) ₂ Adding 6 g) and 52.8g (3 mol) of water into a 500mL beaker in sequence, putting the mixture on a magnetic stirrer with heating and stirring functions, uniformly mixing the mixture, stirring the mixture at 50 ℃ for 2 hours, and supplementing evaporated water at fixed time to obtain a colorless transparent silica gel solution;

(2) Uniformly stirring 0.03g of cobalt nitrate hexahydrate (0.0001 mol) and 0.18g of water (0.01 mol) to obtain a cobalt aqueous solution, and mixing the cobalt aqueous solution with the silicon hydrolysis solution obtained in the step (1);

(3) To the mixture of step (2) was added 0.64g of N-phenyl-3-aminopropyl trimethoxysilane (PHAPTMS, 0.0025 mol) and 0.3g of PEO-PPO-PEO triblock copolymer (P123, purchased from Inoki, weight average molecular weight 5800) and stirred for 0.5 hours;

(4) Transferring the mixture obtained in the step (3) into a stainless steel closed reaction kettle, crystallizing at the constant temperature of 175 ℃ for 24 hours to obtain a sample, filtering and washing the obtained sample, drying at the temperature of 110 ℃ for 6 hours, and roasting at the temperature of 600 ℃ for 6 hours in a muffle furnace to obtain the metal oxide nanoparticle and molecular sieve composite material product, namely CAT-1.

The SEM diagram of CAT-1 is shown in FIG. 1, the XRD spectrum is shown in FIG. 2, the TEM diagram is shown in FIG. 3, the IR spectrum is shown in FIG. 4, the UV-visible spectrum is shown in FIG. 5, and the EDX diagram is shown in FIG. 6. It can be seen from fig. 1 and 3 that the product CAT-1 prepared in this example is regular in shape and uniform in size; XRD analysis of fig. 2 illustrates that it has MFI structure; 960cm in FIG. 4 ^-1 The characteristic peaks in the vicinity indicate that Co is bonded to the silicon skeleton surface; the characteristic peaks at 450 to 700nm in FIG. 5 illustrate the interaction between Co and Si. The EDX plot of the sample from the TEM test is shown in fig. 6, and it can be seen that the metal Co is uniformly dispersed in the molecular sieve. XPS spectra of metallic element Co of CAT-1 is shown in FIG. 7.

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

Preparation of comparative example 1

Prepared as in preparation example 1 except without addition of silylating agent, the resulting product was designated DCAT-1.

Preparation of comparative example 2

0.03g of cobalt nitrate hexahydrate and 0.18g of water were stirred uniformly to obtain an aqueous cobalt solution. 10.2g of alumina support (purchased from Innochem, cat. A17263) were then added, stirred for 4h and the solvent was evaporated. The solid was collected and dried at 110℃for 6 hours, after which it was calcined in a muffle furnace at 550℃for 6 hours, the resulting product was designated DCAT-2.

Preparation of comparative example 3

0.03g of cobalt nitrate hexahydrate and 0.18g of water were stirred uniformly to obtain an aqueous cobalt solution. Then 6g of all-silicon MFI molecular sieve carrier is added, stirred for 4h and the solvent is evaporated. The solid was collected and dried at 110℃for 6 hours, after which it was calcined in a muffle furnace at 550℃for 6 hours, the resulting product was designated DCAT-3. The preparation process of the all-silicon MFI molecular sieve is referred to in preparation example 1, and is different from preparation example 1 in that: cobalt nitrate hexahydrate and a structural filler were not introduced in the synthesis process of the molecular sieve, and the rest of the process was the same as that of preparation example 1.

Preparation examples 2 to 9

The respective products CAT-2 to CAT-9 were prepared in the same manner as in preparation example 1, and the proportions and synthesis conditions thereof were as shown in Table 1. Other conditions and operations refer to example 1. The SEM image is similar to that of fig. 1; the XRD spectrum is similar to that of FIG. 2, with the MFI structure; the TEM image is similar to that of fig. 3; the FT-IR spectrum is similar to that of FIG. 4; the UV-Vis spectrum is similar to that of FIG. 5.

Preparation example 10

Preparation of cobalt-containing hierarchical pore beta molecular sieves referring to the method of preparation example 1, the ratio and template agent were changed, the template agent used was tetraethylammonium hydroxide (TEAOH), and the obtained product was designated CAT-10, and the ratio and synthesis conditions and results are shown in table 1.

Preparation example 11

Cobalt-containing hierarchical pore MEL molecular sieves were prepared in practice, the ratio and the template were changed by the method of example 1, the template used was tetrabutylammonium hydroxide (TBAOH), and the obtained product was designated CAT-11, and the ratio and synthesis conditions and results are shown in Table 1.

Preparation example 12

The corresponding products were prepared according to the procedure of example 1, with the proportions and synthesis conditions and the results shown in Table 1. Other conditions and operations refer to example 1. The resulting product was designated CAT-12.

Wherein the hydrothermal crystallization temperature is 120 ℃ and the hydrothermal crystallization time is 6 days; the roasting temperature is 870 ℃ and the roasting time is 9 hours.

The average particle diameters, BET specific surface areas, total pore volumes, micropore volumes, and mesopore volumes of the metal nanoparticles of the products obtained in the above examples and comparative examples are listed in table 2 below.

TABLE 1

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In table 1, TPAOH is tetrapropylammonium hydroxide, TPABr is tetrapropylammonium bromide, TBAOH is tetrabutylammonium hydroxide, TEAOH is tetraethylammonium hydroxide; PHAPTMS is N-phenyl-3-aminopropyl trimethoxy silane, APTES is 3-aminopropyl triethoxy silane, KH792 is silane coupling agent KH792 (diamino functional silane); p123 is PEO-PPO-PEO triblock copolymer, CTAB is cetyl trimethyl ammonium bromide, SDBS is sodium dodecyl benzene sulfonate. Reagents employed in the present disclosure may be obtained through conventional purchase channels.

TABLE 2

Wherein the pores with the diameter smaller than 2nm are micropore diameters; the pores with the diameter of 2-50 nm are mesoporous.

According to table 2, compared with DCAT-1 (no silylation agent added), the composite catalytic materials CAT-1 to CAT-12 provided by the present disclosure have higher mesoporous volume and lower metal nanoparticle particle size, which indicates that the method provided by the present disclosure can effectively ream the molecular sieve, and belongs to the field of nanoparticle aggregation with lower aggregation degree and higher dispersity.

Compared with DCAT-2 and DCAT-3, the composite catalytic materials CAT-1 to CAT-12 provided by the disclosure can have large mesoporous volume, large specific surface area and smaller metal nanoparticle particle size, which indicates that the aggregation degree of the metal nanoparticles in the composite catalytic material obtained by the disclosure is lower and the dispersity is higher.

Reaction example 1

To illustrate the effectiveness of the thiol oxidation reaction provided by the present invention.

The samples prepared in the above preparation examples and comparative examples were used as catalysts for the oxidative dehydrogenation of mercaptans to prepare disulfide, 1mmol of mercaptans (specific substances are listed in Table 3) was mixed with 2.5mL of methanol solvent (molar ratio of mercaptans to methanol: 1:62.5), and contacted with 50mg of catalyst in a slurry bed reactor at 60℃for 12 hours and oxygen pressure of 0.1MPa, with the results shown in Table 3 below.

TABLE 3 Table 3

Wherein, cobalt oxide aggregate Co ₃ O ₄ T of (2) ₂ A value of 781.25eV; iron oxide aggregate Fe ₂ O ₃ T of (2) ₂ A value of 710.80eV; t of Nickel oxide aggregate NiO ₂ A value of 854.80eV; t of copper oxide aggregate CuO ₂ The value was 933.60eV.

Reaction comparative example 1

According to the literature Saxena A, kumar A, mozumdar S.Ni-nanoparticles: journal of Molecular Catalysis AChemical 2007,269 (1-2): and 35-40, preparing nickel nano particles serving as DCAT-4 catalyst. The nickel nanoparticle DCAT-4 catalyst was reacted according to the method using catalyst CAT-4 in the reaction example, and the remaining reaction conditions were the same as in reaction example 1.

The reaction results are: the thiophenol conversion was 98mol%, and the disulfide selectivity was 99mol%.

As can be seen from the data in Table 3 and the reaction results obtained in comparative reaction example 1, the composite catalytic materials CAT-1 to CAT-12 provided by the present disclosure have higher catalytic activity and higher thiophenol conversion and disulfide selectivity when used in oxidative dehydrogenation of mercaptans, as compared with DCAT-1 to DCAT-4.

As can be seen from a comparison between CAT-1 to CAT-12, T in CAT-1 to CAT-11 is compared with CAT-12 ₀ The value of (2) is between 0.6 and 0.8eV, the catalytic activity of CAT-1 to CAT-11 is higher, and the thiophenol conversion rate and the disulfide selectivity are higher when the catalyst is used for oxidative dehydrogenation of mercaptan.

Reaction example 2

To illustrate the effectiveness of the thiol oxidation reaction provided by the present invention.

The samples prepared in the above preparation examples and comparative examples were used as catalysts for oxidative dehydrogenation cross-coupling of mercaptans. 1mmol of thiol A and 1mmol of thiol B (see Table 4 for thiol A and thiol B details) were mixed separately and contacted with 50mg of catalyst in a slurry bed reactor at 60℃for 12h, with the results given in Table 4 below.

Wherein the resulting product was measured for each product distribution on an Agilent6890N chromatograph using an HP-5 capillary column (30 m.times.0.25 mm).

Thiol conversion (%) = moles of thiol involved in the reaction/moles of thiol added x 100%.

Disulfide selectivity (%) = (moles of disulfide x 2/moles of thiol participating in the reaction) x 100%.

Wherein, the mole number of the thiol participating in the reaction = mole number of the thiol charge-mole number of the thiol remaining in the resulting reaction mixture.

TABLE 4 Table 4

As can be seen from the data in Table 4, compared with DCAT-1-DCAT-3, the reaction method and the prepared composite catalytic material have high catalytic activity, the prepared metal-containing silicon molecular sieve composite catalytic material is used for catalyzing mercaptan cross oxidative dehydrogenation coupling reaction, the conversion rate of mercaptan A and mercaptan B is higher, and the selectivity of three coupling products (A-A, A-B and B-B disulfide) can reach higher level, so that the total selectivity of all final coupling products is higher.

Reaction example 3

The method of reaction example 1 using CAT-4 as a catalyst and thiophenol as a raw material was used to test the reaction effect under various thiol reaction conditions, and the specific reaction conditions and reaction results are shown in Table 5 below.

TABLE 5

As can be seen from the data in Table 5, in experiment 1, the catalyst to thiol ratio of CAT-4 was 2.2 (satisfying the weight ratio of catalyst to thiol compound of 1 (1-20)), which resulted in higher thiol conversion and disulfide selectivity.

In the 10 th test, compared with DCAT-4, the composite catalytic material CAT-4 provided by the disclosure can obtain better recycling performance, and can still keep higher mercaptan conversion rate and higher disulfide selectivity in the 10 th test.

The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, but the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solutions of the present disclosure within the scope of the technical concept of the present disclosure, and all the simple modifications belong to the protection scope of the present disclosure.

In addition, the specific features described in the above embodiments may be combined in any suitable manner without contradiction. The various possible combinations are not described further in this disclosure in order to avoid unnecessary repetition.

Moreover, any combination between the various embodiments of the present disclosure is possible as long as it does not depart from the spirit of the present disclosure, which should also be construed as the disclosure of the present disclosure.

Claims (18)

1. A process for preparing disulfide by oxidation of a thiol, comprising the steps of:

In the presence of oxygen, contacting a mercaptan compound with a catalyst for oxidation reaction;

the catalyst is a composite catalytic material, and the composite catalytic material comprises an all-silicon molecular sieve and metal elements M dispersed in 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.

2. The method according to claim 1, wherein the metal element M is a metal element capable of forming an oxide aggregate; 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 T ₁ ，

The binding energy of the electrons of the metal element M in the oxide aggregate is denoted as T ₂ ，

T as defined by the following formula (1) ₀ Is any value between 0.5 and 1.0 eV;

T ₀ ＝T ₁ -T ₂ formula (1);

preferably, said T ₀ The value of (2) is any value between 0.6 and 0.8 eV.

3. The method according to claim 1, wherein the thiol compound is selected from any one or more of alkyl thiols or thiophenols containing benzene rings and derivatives thereof;

wherein the alkyl mercaptan comprises one or more of 2-propanethiol, 1-octanethiol, 1-decanethiol, 1-nonanthiol, 1-heptanethiol and cyclohexanediol;

The thiophenol and the derivative thereof containing benzene ring comprise one or more of thiophenol, 4-methoxy thiophenol, 3-methyl thiophenol, 1-phenethyl mercaptan and 4-nitrobenzene mercaptan;

preferably, the method further comprises: contacting the thiol compound with the catalyst in a solvent to perform an oxidation reaction; the molar ratio of the mercaptan compound to the solvent is 1: (50 to 200), preferably 1: (60-100);

the solvent is selected from one or more of methanol, acetonitrile, acetone, toluene, tetrahydrofuran and cyclohexane.

4. The method of claim 1, wherein the oxidation reaction conditions comprise: the temperature is 40-100 ℃, preferably 60-80 ℃; the reaction time is 1 to 48 hours, preferably 6 to 24 hours; the weight ratio of the mercaptan compound to the catalyst is (1-100): 1, preferably (1 to 20): 1, the oxygen pressure is 0.1-0.5 MPa, preferably 0.1-0.3 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 suspension bed reactor or a slurry bed reactor.

5. The method of claim 2, wherein 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 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 preferred are one or more of MFI structure molecular sieves, MEL structure molecular sieves and BEA structure molecular sieves.

6. The method of claim 1, wherein when the metal M is Co, the oxide aggregate is Co ₃ O ₄ An aggregate;

when the metal M is Mn, the oxide aggregate is MnO ₂ An aggregate;

when the metal M is Fe, the oxide aggregate is Fe ₂ O ₃ An aggregate;

when the metal M is Ni, the oxide aggregate is a NiO aggregate; when the metal M is Pd, the oxide aggregates are PdO aggregates;

when the metal M is Pt, the oxide aggregate is PtO ₂ An aggregate; or alternatively

When the metal M is Cu, the oxide aggregate is a 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 of the metal element M _3/2 Binding energy of electrons; when the metal element M is Pt, the electron binding energy of the metal element M is 4f of the metal element M _7/2 Binding energy of electrons; when the metal element M is Pd, the electron binding energy of the metal element M is 3d of the metal element M _5/2 Binding energy of electrons;

preferably, the metal element M is one or more of Co, ni and Cu.

7. The method according to claim 2, wherein the molar ratio of the metal M element to the silicon element in the composite catalytic material is (0.001 to 0.2): 1, preferably (0.001 to 0.1): 1.

8. The method according to claim 2, wherein the BET specific surface area of the composite catalytic material is 400-800 m ² And/g, wherein 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 nano particles, and the average particle size of the metal nano particles is 0.5-10 nm.

9. The method of claim 1, wherein the composite material is prepared by a preparation method comprising the steps of:

s1, mixing a template agent, a silicon source, water, a metal M precursor, a silanization reagent and a structural filler to obtain a reaction mixture, wherein the structural filler is an amphiphilic surfactant and/or a hard template agent;

s2, carrying out hydrothermal crystallization treatment and roasting treatment on the reaction mixture.

10. The method according to claim 9, wherein in step S1, the silicon source: template agent: water: metal M element: the molar ratio of the silylating agent is 1: (0.002-1): (5-100): (0.001-0.2): (0.025 to 0.5), preferably 1: (0.005-0.5): (10-50): (0.001-0.15): (0.025-0.4), siO in the reaction mixture ₂ The weight ratio of the structural filler to the structural filler is (3-100): 1.

11. the method according to claim 9, wherein step S1 comprises:

a. mixing a template agent, 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. respectively adding a silylation reagent and a structural filler into the first mixed material, and mixing to obtain a reaction mixture; preferably, the conditions of mixing in step c include: stirring at 20-80 deg.c for 0.5-2 hr.

12. The method of claim 9, wherein the silicon source is selected from at least one of silicone grease, solid silica gel, white carbon black, and silica sol; preferably at least one selected from the group consisting of silicone grease, solid silica gel and white carbon black;

further preferred is a silicone grease having a structure represented by the following formula (A):

wherein R is _a 、R _b 、R _c 、R _d Each independently selected from alkyl groups having 1 to 6 carbon atoms, said alkyl groups being branched or straight chain alkyl groups; 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 alkyl group having 3 to 4 carbon atoms; further preferably, the R _a 、R _b 、R _c 、R _d Each 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.

13. The method according to claim 9, wherein in step S1, the template agent is an organic base, preferably at least one selected from the group consisting of quaternary ammonium bases, aliphatic amines and aliphatic alcohol amines; further preferably, the template is at least one selected from structural quaternary ammonium bases represented by the following formula (B):

R ₁ 、R ₂ 、R ₃ and R is ₄ Each selected from alkyl groups having 1 to 4 carbon atoms, preferably straight chain alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 4 carbon atoms, more preferably R ₁ 、R ₂ 、R ₃ And R is ₄ Each is selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl;

further preferably, the all-silicon molecular sieve is an MFI type 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 a 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 Beta-type 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.

14. The method of claim 11, wherein in step a, the silicon source is an organosilicon grease, and further comprising a hydrolysis alcohol-expelling treatment after mixing the template agent, the organosilicon grease and water to obtain a hydrolysis solution of the silicon;

the conditions for the hydrolysis alcohol expelling treatment comprise: stirring and hydrolyzing for 2-10 hours at 0-95 ℃; preferably at 50-95 deg.C for 2-8 hr.

15. The method according to claim 9, wherein 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 water-soluble inorganic salt of metal M; the water-soluble inorganic salt of the metal M is selected from one or more of chloride, hydrated chloride, sulfate, hydrated sulfate and nitrate of the 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 is an aqueous solution of metal M precursor, and the molar ratio of metal M element to water in the aqueous solution of metal M precursor is 1: (50-500).

16. The method according to claim 9, wherein in step S1, the silylating agent has the general formula R ₅ Si(R ₆ )(R ₇ )R ₈ Wherein R is ₅ 、R ₆ 、R ₇ 、R ₈ Each independently is halogen, alkyl, alkoxy, aryl, mercapto or amino, and R ₅ 、R ₆ 、R ₇ 、R ₈ At least one of which is alkyl, alkoxy, aryl, mercapto or amino; the carbon atoms of the alkyl, alkoxy, mercapto and amino are each independently any integer from 1 to 18, and the carbon atoms of the aryl are each any integer from 6 to 18;

preferably, the silylating agent is selected from one or more of dimethyldichlorosilane, N-phenyl-3-aminopropyl trimethoxysilane, phenyl trimethoxysilane, 1, 7-dichlorooctanethyltetrasiloxane, hexadecyl trimethoxysilane, octyl triethoxysilane, 3-aminopropyl trimethoxysilane, N-beta- (aminoethyl) -gamma-aminopropyl trimethoxysilane and 3-mercaptopropyl trimethoxysilane; further preferably one or more selected from the group consisting of N-phenyl-3-aminopropyl trimethoxysilane, N-beta- (aminoethyl) -gamma-aminopropyl trimethoxysilane and 3-mercaptopropyl trimethoxysilane.

17. The method according to claim 9, 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.

18. The method according to claim 9, wherein in step S2, the conditions of the hydrothermal crystallization treatment include: under autogenous pressure, the hydrothermal crystallization time is 0.5-10 days, and the hydrothermal crystallization temperature is 110-200 ℃; preferably, the hydrothermal crystallization time is 0.5-5 days, and the hydrothermal crystallization temperature is 150-200 ℃;

the conditions of the calcination treatment include: roasting temperature is 400-900 ℃ and roasting time is 1-16 hours; preferably, the roasting temperature is 400-800 ℃ and the roasting time is 2-8 hours.

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