A process for the oxidation of olefins with oxygen

Abstract

The present disclosure relates to a method for olefin oxygen oxidation, comprising the following steps: contacting an olefin compound with a catalyst under oxygen condition to perform an oxidation reaction; the catalyst is a composite catalytic material, the composite catalytic material comprises a framework heteroatom molecular sieve and a metal element M dispersed in the intracrystalline of the molecular sieve; the framework heteroatom molecular sieve is a molecular sieve in which at least part of silicon in a full-silicon molecular sieve framework is replaced by a heteroatom element Q, and the heteroatom element Q is selected from one of titanium, boron, zirconium, aluminum, tin, phosphorus and germanium. The method uses a metal-containing multi-level porous heteroatom molecular sieve for olefin oxygen oxidation reaction, and high conversion rate of olefin and high selectivity of ketone and dihydroxyl compound can be obtained under relatively mild conditions.

Description

Technical Field

[0001] This disclosure relates to the field of organic chemical engineering, and more specifically, to a method for the oxygen oxidation of olefins. Background Technology

[0002] Lower fatty ketones have a wide range of applications, serving as solvents and intermediates in the synthesis of pharmaceuticals, resins, rubber, and other organic materials. Higher fatty ketones are more widely used in the fragrance and food industries. For example, cyclohexanone is an important chemical raw material and a major intermediate in the manufacture of nylon, caprolactam, and adipic acid. They are also important industrial solvents, used in paints, especially those containing nitrocellulose, vinyl chloride polymers and their copolymers, or methacrylate polymers; as an excellent solvent for organophosphorus pesticides and many similar pesticides; as a solvent for dyes; as a viscous solvent for piston-type aviation lubricants; as a solvent for greases, waxes, and rubbers; as a homogenizing agent for dyeing and bleaching silks; as a degreasing agent for polishing metals; for wood staining and varnishing; and as a high-boiling-point solvent for cosmetics such as nail polish. They are usually formulated into mixed solvents with low-boiling-point and medium-boiling-point solvents to obtain suitable evaporation rates and viscosities. Currently, the main methods for industrial production of cyclohexanone include cyclohexane liquid-phase oxidation, phenol hydrogenation, and cyclohexene hydration. Among these, the cyclohexane liquid-phase oxidation process is gradually being phased out due to numerous problems such as low single-pass yield, high energy consumption, heavy pollution, and severe equipment corrosion. The process of producing cyclohexanone from phenol via one-step catalytic hydrogenation has been industrialized and has attracted much attention in the industry due to its simple operation, high yield, and few byproducts. However, excessive hydrogenation of phenol can easily produce cyclohexanol, which makes the requirements for the catalyst of the hydrogenation reaction very high. The cyclohexene hydration process requires two steps. The conversion rate of cyclohexene hydration in the first step is generally low, and the dehydrogenation of cyclohexanol in the second step often requires high temperatures and high energy consumption.

[0003] Therefore, greener and more economical synthetic routes are needed to synthesize ketones such as cyclohexanone. Summary of the Invention

[0004] The purpose of this disclosure is to provide a method for the oxygen oxidation of olefins, which uses a composite catalytic material comprising a framework heteroatom molecular sieve and metal elements dispersed within the crystals of the molecular sieve, so that the oxygen oxidation reaction of olefins can achieve high conversion and selectivity for ketones and dihydroxy compounds under relatively mild conditions.

[0005] To achieve the above objectives, this disclosure provides a method for the oxygen oxidation of olefins, the method comprising the following steps:

[0006] Under oxygen conditions, olefins and aldehydes are brought into contact with a catalyst to undergo oxidation reactions.

[0007] The catalyst is a composite catalytic material, which includes a framework heteroatom molecular sieve and a metal element M dispersed within the crystals of the molecular sieve; the framework heteroatom molecular sieve is a molecular sieve in which at least part of the silicon in the all-silicon molecular sieve framework is replaced by a heteroatom element Q, and the heteroatom element Q is selected from one of titanium, boron, zirconium, aluminum, tin, phosphorus and germanium.

[0008] Optionally, the metal element M is a metal element capable of forming stable oxide aggregates;

[0009] The composite catalytic material exhibits the following XPS characteristics:

[0010] The electron binding energy of the metal element M in the composite catalytic material is denoted as T1;

[0011] The electron binding energy of the metal element M in the stable oxide aggregate is denoted as T2, and T0 is defined as any value between 0.4 and 1.5 eV as in equation (1).

[0012] T0 = ​​T1 - T2 (Equation 1);

[0013] Preferably, T0 is any value between 0.50 and 1.3 eV.

[0014] Optionally, the olefin compound is selected from one or more aliphatic olefins having 6 to 20 carbon atoms;

[0015] The aldehyde compounds are selected from one or more of aliphatic aldehydes with 4 to 10 carbon atoms and aromatic aldehydes with 7 to 14 carbon atoms.

[0016] Optionally, the molar ratio of the olefin compound to the aldehyde compound is 1:(1-8), preferably 1:(1-3).

[0017] Optionally, the conditions for the oxidation reaction include: a reaction temperature of 20-100℃, preferably 40-80℃; a time of 1-48h, preferably 2-24h; and an oxygen pressure of 0.1-0.5MPa, preferably 0.1-0.3MPa.

[0018] Optionally, the weight ratio of the catalyst to the olefin compound is 1:(1-20), preferably 1:(1-10).

[0019] Optionally, the method further includes: after the oxidation reaction has been carried out for 2 to 24 hours, adding water to the reaction system and continuing the reaction for 2 to 12 hours, wherein the weight ratio of water to the olefin compound is (0.05 to 2): 1.

[0020] Optionally, the framework heteroatom 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 selected from one or more of MFI structure molecular sieve, MEL structure molecular sieve, BEA structure molecular sieve, MCM structure molecular sieve, and SBA structure molecular sieve; more preferably, it is selected from one or more of MFI structure molecular sieve, MEL structure molecular sieve, and BEA structure molecular sieve.

[0021] Optionally, the metallic element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold;

[0022] Preferably, when the metal M is Co, the stable oxide aggregate is a Co3O4 aggregate;

[0023] When the metal M is Mn, the stable oxide aggregate is a MnO2 aggregate;

[0024] When the metal M is Fe, the stable oxide aggregate is a Fe2O3 aggregate;

[0025] When the metal M is Ni, the stable oxide aggregate is a NiO aggregate;

[0026] When the metal M is Pd, the stable oxide aggregate is a PdO aggregate;

[0027] When the metal M is Pt, the stable oxide aggregate is a PtO2 aggregate; or,

[0028] When the metal M is Cu, the stable oxide aggregate is a CuO aggregate;

[0029] Preferably, 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 binding energy; when the metal element M is Pt or Au, the electron binding energy of the metal element M is 4f. 7 / 2 Electron binding energy; when the metal element M is Pd, the electron binding energy of the metal element M is the 3d electron binding energy of the metal element M. 5 / 2 The binding energy of electrons.

[0030] Optionally, in the composite catalytic material, the molar ratio of the framework heteroatom elements to silicon elements is (0.001–0.05):1, preferably (0.002–0.043):1;

[0031] Optionally, the molar ratio of metal M to silicon is (0.001 to 0.18):1, preferably (0.002 to 0.14):1.

[0032] Optionally, the BET specific surface area of ​​the composite catalytic material is 400–800 m². 2 / g, with a total pore volume of 0.3-0.65 mL / g, a micropore volume of 0.1-0.19 mL / g, and a mesopore volume of 0.2-0.46 mL / g. The metal element M in the composite catalytic material exists in the form of metal nanoparticles, with an average particle size of 0.5-12 nm.

[0033] Optionally, the catalyst is prepared by a method comprising the following steps:

[0034] S1. Mix the template agent, silicon source, framework heteroatom precursor, water, metal M precursor, nitrogen-containing ligand and silanizing agent to obtain a reaction mixture;

[0035] S2. The reaction mixture is subjected to hydrothermal crystallization treatment to obtain a crystallized product, and the crystallized product is then subjected to calcination treatment.

[0036] Optionally, the silanizing agent comprises at least one coordinating group that is complexed with the metal element M.

[0037] Optionally, the electron binding energy of the metal element M in the product of the crystallized product after calcination is denoted as T3;

[0038] The electron binding energy of the metal element M in the crystallized product is denoted as T4;

[0039] The calcination treatment makes T0', as defined by the following formula (2), any value between 0.2 and 0.8 eV;

[0040] T0' = T3 - T4 (2).

[0041] Optionally, in step S1, the molar ratio of the silicon source (based on SiO2): template agent: framework heteroatom precursor (based on heteroatom element Q): water: metal element M: silanizing agent is 1:(0.001~1):(0.001~0.05):(5~100):(0.001~0.18):(0.025~0.4); preferably 1:(0.002~1):(0.002~0.043):(5~100):(0.002~0.14)(0.025~0.3);

[0042] Preferably, the molar ratio of the nitrogen-containing ligand to the metal element M is (0.5-5):1.

[0043] Optionally, step S1 includes the following steps:

[0044] a. Mix the template agent, silicon source, framework heteroatom precursor and water to obtain a silicon hydrolysis solution;

[0045] b. Add a nitrogen-containing ligand to an aqueous solution of the metal M precursor to obtain a first mixture; mix the first mixture with a silicon hydrolysis solution to obtain a second mixture.

[0046] c. Add the silanizing agent to the second mixture, and mix to obtain the reaction mixture;

[0047] Preferably, the mixing conditions in step c include stirring at 20–80°C for 0.5–2 hours.

[0048] The silicon source is selected from at least one of silicone grease, solid silica gel, fumed silica, and silica sol; preferably, it is selected from at least one of silicone grease, solid silica gel, and fumed silica.

[0049] A further preferred option is a silicone grease, wherein the silicone grease has the general formula shown in formula (A):

[0050]

[0051] Where R a R b R c R d Each is independently selected from alkyl groups having 1 to 6 carbon atoms, wherein the alkyl group is branched or straight-chain alkyl; preferably, R a R b R c R d Each is independently selected from straight-chain alkyl groups having 1 to 4 carbon atoms or branched alkyl groups having 3 to 4 carbon atoms; more preferably, the R a R b R c R d Each of the following is independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, or tert-butyl; more preferably, the silicone grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, and dimethyl diethyl silicone grease.

[0052] The template agent is an organic base, preferably at least one selected from quaternary ammonium bases, aliphatic amines, and aliphatic alcoholic amines; more preferably, the template agent is at least one selected from quaternary ammonium bases with the structure shown in formula (B) below:

[0053] R1, R2, R3 and R4 are 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 R1, R2, R3 and R4 are each selected from at least one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl;

[0054] More preferably, the molecular sieve in the composite catalytic material 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

[0055] The molecular sieve in the composite catalytic material is a MEL-type 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

[0056] The molecular sieve in the composite catalytic material is a 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.

[0057] Optionally, in step a, the silicon source is an organosilicon grease, and after mixing the template agent, organosilicon grease, framework heteroatom precursor and water, a hydrolysis and alcohol removal treatment is further included to obtain the hydrolysate solution;

[0058] Optionally, 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.

[0059] Optionally, in step S1, the skeletal heteroatom precursor includes at least one of an organic skeletal heteroatom precursor and an inorganic skeletal heteroatom precursor; the inorganic skeletal heteroatom precursor is at least one selected from chlorides, nitrates, and sulfates containing heteroatom element Q; the inorganic skeletal heteroatom precursor is an organic ester containing heteroatom element Q, selected from at least one structure with the general formula shown in formula (C) below:

[0060]

[0061] R5, R6, R7 and R8 are each selected from alkyl groups having 1 to 6 carbon atoms, preferably straight-chain alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms, and more preferably R5, R6, R7 and R8 are each selected from straight-chain alkyl groups having 2 to 4 carbon atoms and branched alkyl groups having 2 to 4 carbon atoms.

[0062] Optionally, R5, R6, R7 and R8 are each selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, isopentyl, hexyl or isohexyl; preferably, each is independently selected from one of ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl.

[0063] Preferably, the framework heteroatom is titanium, and the framework heteroatom precursor is selected from one or more of titanium tetrachloride, titanium sulfate, titanium nitrate, tetraethyl titanate, tetrapropyl titanate, and tetrabutyl titanate; the framework heteroatom is boron, and the framework heteroatom precursor is selected from one or more of boric acid and borate; the framework heteroatom is tin, and the framework heteroatom precursor is selected from one or more of tin halide, stannous halide, stannous sulfate, stannous sulfate, stannate, stannous nitrate, tin oxide, and stannous oxide; the framework heteroatom is aluminum, and the framework heteroatom precursor is selected from one or more of sodium aluminate, aluminum sulfate, boehmite, metallic aluminum, aluminum nitrate, aluminum isopropoxide, and aluminum hydroxide; the framework heteroatom is phosphorus, and the framework heteroatom precursor is selected from one or more of orthophosphoric acid, triethylphosphoric acid, and metaphosphate; the framework heteroatom is germanium, and the framework heteroatom precursor is selected from one or more of germanium oxide, germanium alkoxide, germanium chloride, and sodium germanate.

[0064] Optionally, in step S1, the metal M precursor is one or more of inorganic metal compounds and organometallic compounds; the inorganic metal compound is a water-soluble inorganic salt of metal element M; the water-soluble inorganic salt of metal element M is selected from one or more of chlorides, hydrated chlorides, sulfates, hydrated sulfates, and nitrates of metal element M; the organometallic compound is an organic ligand compound of metal element M; preferably, the metal M precursor is a water-soluble inorganic salt of metal element M.

[0065] Optionally, the metallic element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold;

[0066] Preferably, the metal M precursor is an aqueous solution of the metal M precursor, wherein the molar ratio of metal element M to water in the aqueous solution of the metal M precursor is 1:(50-500).

[0067] Optionally, in step S1, the nitrogen-containing ligand is an alkylamine compound containing only an amino group or an amine compound containing other coordinating groups, wherein the other coordinating groups include one or more of hydroxyl, carboxyl, carbonyl, and mercapto groups;

[0068] Preferably, the nitrogen-containing ligand is one or more of the following: alkylamine compounds containing only an amino group having the structure shown in formula (D), alcoholamine compounds having the structure shown in formula (E), and aminocarboxylic acid compounds having the structure shown in formula (F):

[0069] R9(NH2) n Formula (D);

[0070] Wherein, n is 1 or 2; when n is 1, R9 is an alkyl group having 1 to 6 carbon atoms, preferably a straight-chain alkyl group having 1 to 6 carbon atoms and a branched alkyl group having 3 to 6 carbon atoms, and more preferably one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, isopentyl, tert-pentyl, and n-hexyl; when n is 2, R9 is an alkylene group having 1 to 6 carbon atoms, preferably a straight-chain alkylene group having 1 to 6 carbon atoms and a branched alkylene group having 3 to 6 carbon atoms, and more preferably one of methylene, ethylene, n-propylene, n-butylene, n-pentylene, and n-hexylene.

[0071] (HOR 10 ) m NH (3m) Equation (E);

[0072] Where R 10 It is an alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 to 4 carbon atoms, preferably one of methylene, ethylene, n-propylene, and n-butylene; m is 1, 2, or 3, and when m is greater than 1, multiple R 10 Same or different;

[0073] (HOOCR 11 ) x NH (3x) Formula (F);

[0074] Where R 11 It is an alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 to 4 carbon atoms, preferably one of methylene, ethylene, n-propylene, and n-butylene; x is 1, 2, or 3, and when x is greater than 1, multiple R 11 Same or different;

[0075] More preferably, the nitrogen-containing ligand is selected from one or more of ethylamine, ethylenediamine, ethanolamine, and ethylenediaminetetraacetic acid.

[0076] Optionally, in step S1, the silanizing agent has the general formula R. 12 Si(R 13 (R) 14 )R 15 , where R 12 R 13 R 14 R 15 Each group can be independently halogenated, alkyl, alkoxy, aromatic, mercapto, or amino, and R 12 R13 R 14 R 15 At least one of them is an alkyl, alkoxy, aromatic, mercapto, or amino group; the alkyl, alkoxy, mercapto, and amino groups each have 1 to 18 carbon atoms, and the aromatic group has 6 to 18 carbon atoms.

[0077] Preferably, the silanizing 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; more preferably, at least one of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0078] Optionally, in step S2, the conditions for the hydrothermal crystallization treatment include: being carried out under autogenous pressure, with a hydrothermal crystallization time of 0.5 to 10 days and a hydrothermal crystallization temperature of 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.

[0079] Optionally, 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.

[0080] Through the above technical solution, this disclosure provides a method for olefin oxygen oxidation. The method uses oxygen as an oxidant to carry out a heterogeneous oxidation reaction and uses a metal-containing hierarchical porous molecular sieve composite catalytic material as a catalyst. The molecular sieve of the composite catalytic material has a large specific surface area, pore volume and macromolecular substrate reactivity, and the metal nanoparticles have a high degree of dispersion in the molecular sieve. High conversion rate and selectivity for ketones and dihydroxy compounds can be obtained under relatively mild conditions.

[0081] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0082] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0083] Figure 1 The image shows the XPS spectrum of the product prepared in Example 1.

[0084] Figure 2 The image shows the Ti XPS spectrum of the product prepared in Example 1.

[0085] Figure 3 The image shown is an SEM image of the product prepared in Example 1.

[0086] Figure 4 The image shows the XRD pattern of the product prepared in Example 1. Detailed Implementation

[0087] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0088] This disclosure provides a method for the oxygen oxidation of olefins, the method comprising the following steps:

[0089] Under oxygen conditions, olefins and aldehydes are brought into contact with a catalyst to undergo oxidation reactions.

[0090] The catalyst is a composite catalytic material, which includes a framework heteroatom molecular sieve and a metal element M dispersed within the crystals of the molecular sieve; the framework heteroatom molecular sieve is a molecular sieve in which at least part of the silicon in the all-silicon molecular sieve framework is replaced by a heteroatom element Q, and the heteroatom element Q is selected from one of titanium, boron, zirconium, aluminum, tin, phosphorus and germanium.

[0091] The inventors of this disclosure unexpectedly discovered that using a composite catalytic material of metal nanoparticles and framework heteroatom molecular sieves as a catalyst to carry out the olefin oxygen oxidation reaction can effectively improve the oxidation reaction rate, shorten the reaction time, and achieve high conversion rate of olefins and high selectivity of ketones and dihydroxy compounds under relatively mild conditions.

[0092] The olefin oxidation reaction disclosed herein is specifically shown in formula (1):

[0093]

[0094] Through extensive experimentation, the inventors of this disclosure have surprisingly discovered that by introducing heteroatom precursors, metal M precursors, nitrogen-containing ligands, and silanizing reagents (containing at least one coordinating group complexed with metal element M) into the reaction raw materials for the crystallization synthesis of molecular sieves, followed by hydrothermal crystallization and calcination, heteroatoms can be introduced into the molecular sieve framework. The resulting composite catalytic material exhibits a hierarchical porous structure (micropores and mesopores) and a large specific surface area and pore volume. The metal oxide nanoparticles have a high uniformity in size and are uniformly dispersed within the channels of the molecular sieve framework. A certain amount of metal M nanoparticles also exist on the surface of the channels. The heteroatom metal sites on the molecular sieve framework and the metal sites (nano-) of metal element M within the channels... The rice particles can also play a synergistic catalytic role, further improving the catalytic activity in the co-oxidation reaction of macromolecular aldehydes / olefins. Through in-depth research, the inventors also found that the XPS binding energy of the metal M element introduced into the composite catalytic material in this disclosure has changed compared with the XPS binding energy of the metal M element in the stable oxide aggregate. Furthermore, heteroatoms in the framework can also affect the XPS binding energy of the metal M element in the composite catalytic material. When the change in the XPS chemical binding energy of the metal M element in the composite catalytic material compared with the XPS chemical binding energy of the metal M element in its stable oxide is within a certain range, the composite catalytic material can obtain a higher olefin conversion rate and ketone / dihydroxy compound selectivity.

[0095] In a preferred embodiment, the metal element M is a metal element capable of forming stable oxide aggregates; the composite catalytic material has the following XPS characteristics:

[0096] The electron binding energy of the metal element M in the composite catalytic material is denoted as T1;

[0097] The electron binding energy of the metal element M in the stable oxide aggregate is denoted as T2.

[0098] T0 is defined by the following formula (1) as any value between 0.4 and 1.5 eV;

[0099] T0 = ​​T1 - T2 (1). In this disclosure, a stable oxide aggregate refers to an oxide aggregate of a metal element M that is most stable in its natural state, as known in the art.

[0100] This disclosure provides a composite catalytic material of metal oxide nanoparticles and molecular sieves. The molecular sieve in this composite catalytic material has a hierarchical porous structure and a large specific surface area, pore volume, and high reactivity with macromolecular substrates. Furthermore, the metal oxide nanoparticles are uniformly sized and dispersed within the mesoporous channels of the hierarchical heteroatom framework molecular sieve. A significant interaction exists between the metal element in the metal oxide particles and the heteroatoms within the framework. Introducing heteroatoms into the molecular sieve framework allows the two metal sites in the composite catalytic material to exert a synergistic catalytic effect, effectively improving the catalytic activity of the composite catalytic material for macromolecular substrates.

[0101] In a preferred embodiment, T0 is any value between 0.50 and 1.3 eV. When the T0 of the composite catalyst is within this range, the composite catalyst exhibits higher catalytic activity, higher olefin conversion, and higher selectivity for ketones / dihydroxy compounds.

[0102] In one embodiment, the olefin compound is selected from one or more aliphatic olefins having 6 to 20 carbon atoms;

[0103] The aldehyde compounds are selected from one or more of aliphatic aldehydes with 4 to 10 carbon atoms and aromatic aldehydes with 7 to 14 carbon atoms.

[0104] The molar ratio of the olefin compound to the aldehyde compound is 1:(1-8), preferably 1:(1-3).

[0105] In one embodiment, the conditions for the oxidation reaction include: a reaction temperature of 20-100°C, preferably 40-80°C; a time of 1-48 h, preferably 2-24 h; and an oxygen pressure of 0.1-0.5 MPa, preferably 0.1-0.3 MPa.

[0106] The weight ratio of the catalyst to the olefin compound is 1:(1-20), preferably 1:(1-10).

[0107] In one embodiment, the method further includes: after the oxidation reaction has been carried out for 2 to 24 hours, adding water to the reaction system and continuing the reaction for 2 to 12 hours, wherein the weight ratio of water to the olefin compound is (0.05 to 2): 1.

[0108] In one embodiment, the framework heteroatom molecular sieve in the composite catalytic material is one or more of the following: MFI structure molecular sieve (e.g., S-1), MEL structure molecular sieve (e.g., S-2), BEA structure molecular sieve (e.g., Beta), MWW structure molecular sieve (e.g., MCM-22), two-dimensional hexagonal structure molecular sieve (e.g., MCM-41, SBA-15), MOR structure molecular sieve (e.g., MOR), TUN structure molecular sieve (e.g., TUN), and other structured silicon molecular sieves (e.g., ZSM-48, MCM-48); preferably selected from one or more of MFI structure molecular sieve, MEL structure molecular sieve, BEA structure molecular sieve, MCM structure molecular sieve, and SBA structure molecular sieve; more preferably selected from one or more of MFI structure molecular sieve, MEL structure molecular sieve, and BEA structure molecular sieve, such as the silicon molecular sieve being one of S-1, S-2, and Beta; even more preferably selected from MFI structure molecular sieve, such as S-1.

[0109] In one embodiment, the metallic element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper, and gold.

[0110] In one optional embodiment, when the metal M is Co, the stable oxide aggregate is a Co3O4 aggregate;

[0111] In one optional embodiment, when the metal M is Mn, the stable oxide aggregate is a MnO2 aggregate;

[0112] In one optional embodiment, when the metal M is Fe, the stable oxide aggregate is a Fe2O3 aggregate;

[0113] In one optional embodiment, when the metal M is Ni, the stable oxide aggregate is a NiO aggregate;

[0114] In one optional embodiment, when the metal M is Pd, the stable oxide aggregate is a PdO aggregate;

[0115] In one optional embodiment, when the metal M is Pt, the stable oxide aggregate is a PtO2 aggregate;

[0116] In one optional embodiment, when the metal M is Cu, the stable oxide aggregate is a CuO aggregate.

[0117] Preferably, 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 binding energy; when the metal element M is Pt or Au, the electron binding energy of the metal element M is 4f.7 / 2 Electron binding energy; when the metal element M is Pd, the electron binding energy of the metal element M is the 3d electron binding energy of the metal element M. 5 / 2 The binding energy of electrons.

[0118] In one embodiment, the molar ratio of the framework heteroatom element to silicon element in the composite catalytic material is (0.001-0.05):1, preferably (0.002-0.043):1;

[0119] The molar ratio of metal M to silicon is (0.001 to 0.18):1, preferably (0.002 to 0.14):1.

[0120] In one embodiment, the BET specific surface area of ​​the composite catalytic material is 400–800 m². 2 The composite catalytic material has a total pore volume of 0.3–0.65 mL / g, a micropore volume of 0.1–0.19 mL / g, and a mesopore volume of 0.2–0.46 mL / g. The metal element M in the composite catalytic material exists in the form of metal nanoparticles with an average particle size of 0.5–12 nm. The composite catalytic material of this disclosure has a hierarchical porous structure, which is beneficial for catalyzing reaction substrates of different sizes, especially for catalyzing reactions of macromolecular substrates.

[0121] In one embodiment, the catalyst is prepared by a method comprising the following steps:

[0122] S1. Mix the template agent, silicon source, framework heteroatom precursor, water, metal M precursor, nitrogen-containing ligand and silanizing agent to obtain a reaction mixture;

[0123] S2. The reaction mixture is subjected to hydrothermal crystallization treatment to obtain a crystallized product, and the crystallized product is then subjected to calcination treatment.

[0124] The silanizing agent contains at least one coordinating group that is complexed with the metal element M.

[0125] This disclosure introduces heteroatom precursors into the reaction mixture for molecular sieve synthesis. During crystallization, the heteroatoms primarily enter the molecular sieve framework. The disclosure also introduces a metal element precursor, a nitrogen-containing ligand, and a silanizing agent into the reaction mixture. The nitrogen-containing ligand can complex with metal M ions, thus fixing and dispersing the metal element; the silanizing agent's coordinating groups complex with the metal, also fixing and dispersing the metal element, while the alkyl chain's supporting layer effect expands the pores. This results in the final preparation of a framework heteroatom molecular sieve with a hierarchical porous structure, where metal M oxide nanoparticles can be uniformly dispersed within the mesoporous channels of the hierarchical framework heteroatom molecular sieve.

[0126] The inventors of this disclosure surprisingly discovered in experiments that, compared with the composite catalytic material before calcination, the electron binding energy of the metal element M in the XPS spectrum of the composite catalytic material obtained after hydrothermal crystallization and calcination was significantly increased. This indicates that there is an interaction between the metal nanoparticles and the framework heteroatoms in the composite catalytic material obtained after calcination. The inventors conducted in-depth research on the change of the electron binding energy of the metal element M in the composite catalytic material before and after calcination, and found that T0' (T0' = T3 - T4; T3 is the electron binding energy of the metal element M in the product after calcination of the crystallized product, and T4 is the electron binding energy of the metal element M in the crystallized product) is related to the catalytic activity of the composite catalytic material. That is, the interaction between the metal element M and the framework heteroatoms Q in the composite catalytic material can further affect the catalytic activity of the composite catalytic material. When T0' is any value between 0.2 and 0.8 eV, the composite catalytic material can obtain high catalytic activity, effectively improving the conversion rate of olefins and the selectivity of ketones and dihydroxy compounds.

[0127] In a preferred embodiment, the electron binding energy of the metal element M in the product of calcining the crystallized product is denoted as T3.

[0128] The electron binding energy of the metal element M in the crystallized product is denoted as T4;

[0129] The calcination treatment makes T0', as defined by the following formula (2), any value between 0.2 and 0.8 eV;

[0130] T0' = T3 - T4 Equation (2).

[0131] In one embodiment, in step S1, the molar ratio of the silicon source (based on SiO2): template agent: framework heteroatom precursor (based on heteroatom element Q): water: metal element M: silanizing agent is 1:(0.001~1):(0.001~0.05):(5~100):(0.001~0.18):(0.025~0.4); preferably 1:(0.002~1):(0.002~0.043):(5~100):(0.002~0.14)(0.025~0.3);

[0132] Preferably, the molar ratio of the nitrogen-containing ligand to the metal element M is (0.5-5):1.

[0133] Specifically, the water used in step S1 can be the water commonly used in the synthesis of molecular sieves, and deionized water is preferred to avoid the introduction of heteroatoms.

[0134] In a preferred embodiment, step S1 includes the following steps:

[0135] a. Mix the template agent, silicon source, framework heteroatom precursor and water to obtain a silicon hydrolysis solution;

[0136] b. Add a nitrogen-containing ligand to an aqueous solution of the metal M precursor to obtain a first mixture; mix the first mixture with a silicon hydrolysis solution to obtain a second mixture.

[0137] c. Add the silanizing agent to the second mixture, and mix to obtain the reaction mixture;

[0138] Preferably, the mixing conditions in step c include stirring at 20–80°C for 0.5–2 hours.

[0139] In one embodiment, the silicon source is selected from at least one of silicone grease, solid silica gel, fumed silica, and silica sol; preferably, it is selected from at least one of silicone grease, solid silica gel, and fumed silica.

[0140] A further preferred option is a silicone grease, wherein the silicone grease has the general formula shown in formula (A):

[0141]

[0142] Where R a R b R c R d Each is independently selected from alkyl groups having 1 to 6 carbon atoms, wherein the alkyl group is branched or straight-chain alkyl; preferably, R a R b R c R d Each is independently selected from straight-chain alkyl groups having 1 to 4 carbon atoms or branched alkyl groups having 3 to 4 carbon atoms; more 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.

[0143] 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.

[0144] According to this disclosure, in step S1, the template agent is an organic base, preferably at least one selected from quaternary ammonium bases, aliphatic amines, and aliphatic alcoholic amines. The quaternary ammonium base can be an organic quaternary ammonium base; the aliphatic amine can be a compound formed by replacing at least one hydrogen atom in NH3 with an aliphatic hydrocarbon group (such as an alkyl group); the aliphatic alcoholic amine can be a compound formed by replacing at least one hydrogen atom in various NH3 groups with a hydroxyl-containing aliphatic group (such as an alkyl group).

[0145] In a further preferred embodiment, the template agent is selected from at least one of quaternary ammonium bases with the structure shown in formula (B):

[0146] R1, R2, R3 and R4 are 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 R1, R2, R3 and R4 are each selected from at least one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl.

[0147] In a preferred embodiment, the molecular sieve in the composite catalytic material 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

[0148] In another preferred embodiment, the molecular sieve in the composite catalytic material is a MEL-type 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

[0149] In another preferred embodiment, the molecular sieve in the composite catalytic material is a 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.

[0150] In one embodiment, in step a, the silicon source is an organosilicon grease, and after mixing the template agent, organosilicon grease, framework heteroatom precursor and water, a hydrolysis and alcohol removal treatment is further included to obtain the hydrolysate solution.

[0151] The conditions for the hydrolysis-induced 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; wherein the hydrolysis-induced alcohol removal treatment results in the alcohol produced by the hydrolysis of the organosilicon source having a mass content of less than 10 ppm in the hydrolysis solution.

[0152] According to this disclosure, the range of types of metal precursors is relatively wide, and any substance containing the metal element (e.g., a compound containing the metal element and / or a metal element) can achieve the purpose of this disclosure.

[0153] In one embodiment, in step S1, the skeletal heteroatom precursor includes at least one of an organic skeletal heteroatom precursor and an inorganic skeletal heteroatom precursor; the inorganic skeletal heteroatom precursor is at least one of a chloride, nitrate, or sulfate of a heteroatom element; the inorganic skeletal heteroatom precursor is an organic ester containing a heteroatom element, selected from at least one structure with the general formula shown in formula (C) below:

[0154]

[0155] R5, R6, R7 and R8 are each selected from alkyl groups having 1 to 6 carbon atoms, preferably straight-chain alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms, and more preferably R5, R6, R7 and R8 are each selected from straight-chain alkyl groups having 2 to 4 carbon atoms and branched alkyl groups having 2 to 4 carbon atoms.

[0156] Optionally, R5, R6, R7 and R8 are each selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, isopentyl, hexyl or isohexyl; preferably, each is independently selected from one of ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl.

[0157] In one optional embodiment, the skeletal heteroatom is titanium, and the skeletal heteroatom precursor is selected from one or more of titanium tetrachloride, titanium sulfate, titanium nitrate, tetraethyl titanate, tetrapropyl titanate, and tetrabutyl titanate.

[0158] In one optional embodiment, the skeletal heteroatom is boron, and the skeletal heteroatom precursor is selected from one or more of boric acid and borate.

[0159] In one optional embodiment, the framework heteroatom is tin, and the framework heteroatom precursor is selected from one or more of tin halide, tin halide, tin sulfate, tin sulfate, stannate, stanous acid, tin nitrate, tin oxide, and tin oxide.

[0160] In one optional embodiment, the framework heteroatom is aluminum, and the framework heteroatom precursor is selected from one or more of sodium aluminate, aluminum sulfate, boehmite, metallic aluminum, aluminum nitrate, aluminum isopropoxide, and aluminum hydroxide.

[0161] In one optional embodiment, the skeletal heteroatom is phosphorus, and the skeletal heteroatom precursor is selected from one or more of orthophosphoric acid, triethylphosphoric acid, and metaphosphate.

[0162] In one optional embodiment, the framework heteroatom is germanium, and the framework heteroatom precursor is selected from one or more of germanium oxide, germanium alkoxide, germanium chloride, and sodium germanate.

[0163] In one embodiment, in step S1, the metal M precursor is one or more of inorganic metal compounds and organometallic compounds; the inorganic metal compound is a water-soluble inorganic salt of metal element M; the water-soluble inorganic salt of metal element M is selected from one or more of chlorides, hydrated chlorides, sulfates, hydrated sulfates, and nitrates of metal element M; the organometallic compound is an organic ligand compound of metal element M; preferably, the metal M precursor is a water-soluble inorganic salt of metal element M.

[0164] The metallic element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold;

[0165] Preferably, the metal M precursor is an aqueous solution of the metal M precursor, wherein the molar ratio of metal element M to water in the aqueous solution of the metal M precursor is 1:(50-500).

[0166] In one embodiment, in step S1, the nitrogen-containing ligand is an alkylamine compound containing only an amino group or an amine compound containing other coordinating groups, wherein the other coordinating groups include one or more of hydroxyl, carboxyl, carbonyl, and mercapto groups. In this disclosure, "alkylamine compound containing only an amino group" means that the alkylamine compound contains only an amino group and does not contain other types of nitrogen-containing groups, but the number of amino groups can be one or several.

[0167] In a preferred embodiment, the nitrogen-containing ligand is one or more of the following: an alkylamine compound containing only an amino group having the structure shown in formula (D), an alkanolamine compound having the structure shown in formula (E), and an aminocarboxylic acid compound having the structure shown in formula (F).

[0168] R9(NH2) n Formula (D);

[0169] Wherein, n is 1 or 2; when n is 1, R9 is an alkyl group having 1 to 6 carbon atoms, preferably a straight-chain alkyl group having 1 to 6 carbon atoms and a branched alkyl group having 3 to 6 carbon atoms, and more preferably one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, isopentyl, tert-pentyl, and n-hexyl; when n is 2, R9 is an alkylene group having 1 to 6 carbon atoms, preferably a straight-chain alkylene group having 1 to 6 carbon atoms and a branched alkylene group having 3 to 6 carbon atoms, and more preferably one of methylene, ethylene, n-propylene, n-butylene, n-pentylene, and n-hexylene.

[0170] (HOR 10 ) m NH (3m) Equation (E);

[0171] Where R 10 It is an alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 to 4 carbon atoms, preferably one of methylene, ethylene, n-propylene, and n-butylene; m is 1, 2, or 3, and when m is greater than 1, multiple R 10 Same or different;

[0172] (HOOCR 11 ) x NH (3x) Formula (F);

[0173] Where R 11 It is an alkylene group having 1 to 4 carbon atoms or a branched alkylene group having 3 to 4 carbon atoms, preferably one of methylene, ethylene, n-propylene, and n-butylene; x is 1, 2, or 3, and when x is greater than 1, multiple R 11 Same or different.

[0174] In a further preferred embodiment, the nitrogen-containing ligand is selected from one or more of ethylamine, ethylenediamine, ethanolamine, and ethylenediaminetetraacetic acid.

[0175] In one embodiment, in step S1, the silanizing agent has the general formula R. 12 Si(R 13 (R) 14 )R 15 Among them, R9 and R 10 R 11 R 12 Each can be independently a halogen, alkyl, alkoxy, aromatic, mercapto, or amino group, and R9, R 10 R 11 R 12At least one of them is an alkyl, alkoxy, aromatic, mercapto, or amino group; the alkyl, alkoxy, mercapto, and amino groups have 1 to 18 carbon atoms, preferably 1 to 12; the aromatic group has 6 to 18 carbon atoms, preferably 6 to 12.

[0176] Preferably, the silanizing 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; more preferably, at least one of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0177] In this disclosure, different silanizing agents can be selected for different metal elements M. For example, when the metal element M is Co, the silanizing agent is at least one of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane; when the metal element M is Au or Pt, the silanizing agent is at least one of 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.

[0178] In one embodiment, in step S2, the conditions for the hydrothermal crystallization treatment include: being carried out under autogenous pressure, with a hydrothermal crystallization time of 0.5 to 10 days and a hydrothermal crystallization temperature of 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.

[0179] In one embodiment, in step S2, the conditions for the calcination treatment 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.

[0180] In this disclosure, the sample was characterized by XPS on an ESCALAB 250 X-ray photoelectron spectrometer with monochromatic Al Kα X-rays, energy 1486.6 eV, power 150 W, and nuclear shift was corrected using the C1s peak (284.8 eV) of contaminated carbon.

[0181] The scanning electron microscope (SEM) images of the samples were obtained using a Hitachi S4800 high-resolution cold field emission scanning electron microscope.

[0182] Transmission electron microscopy (TEM) images of the samples were obtained using a Tecnai G2F20S-TWIN TEM microscope manufactured by FEI. The average particle size of the metal oxide nanoparticles was determined based on TEM measurements.

[0183] The samples were analyzed by X-ray diffraction (XRD) phase diagram determination using a Siemens D5005 X-ray diffractometer. The X-ray source was Kα (Cu), and the test range was 2θ from 0.5 to 70°.

[0184] The total specific surface area and total pore volume of the samples were determined using a Micromeritics ASAP245 static nitrogen adsorption analyzer according to the ASTM D4222-98 standard method. The adsorption and desorption isotherms of the samples at low temperatures were determined according to the ASTM D4222-98 standard method.

[0185] Preparation Example 1

[0186] (1) Add 1.6g of tetrapropylammonium hydroxide (TPAOH) aqueous solution with a concentration of 25.05% by weight, 20.8g of tetraethyl silicate, 0.17g of tetrabutyl titanate and 9g of water to a 500mL beaker in sequence, place it on a magnetic stirrer with heating and stirring functions and mix evenly, stir at 80℃ for 4 hours, replenish the evaporated water in timed intervals, and obtain a colorless and transparent silica gel solution;

[0187] (2) Stir 0.3g of cobalt nitrate hexahydrate and 1.8g of water evenly, then add 0.0005mol of ethylenediamine, and mix the aqueous solution of the metal with the hydrolysis solution of silicon obtained in step (1);

[0188] (3) Add 0.64 g of N-phenyl-3-aminopropyltrimethoxysilane (PHAPTMS) to the mixture in step (2) and stir for 0.5 hours;

[0189] (4) The mixture obtained in step (3) is transferred to a stainless steel sealed reactor and crystallized at 170°C for 28 hours to obtain a sample. The sample is filtered, washed, dried at 120°C for 6 hours, and then calcined in a muffle furnace at 550°C for 6 hours to prepare a composite catalytic material product, denoted as CAT-1.

[0190] 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. The Co XPS plot of CAT-1 is shown below. Figure 1 As shown. The Ti XPS spectrum of CAT-1 is as follows. Figure 2 As shown, Figure 2A peak of framework Ti is present at position 459.97 eV, proving that Ti heteroatoms were successfully introduced into the framework in the obtained product. The SEM image of sample CAT-1 is shown below. Figure 3 As shown; the XRD pattern of sample CAT-1 is as follows. Figure 4 As shown, XRD analysis indicates that it has an MFI structure.

[0191] Preparation Examples 2-9

[0192] The corresponding products were prepared according to the method in Preparation Example 1, and were denoted as CAT-2 to CAT-9. The proportions, synthesis conditions and results are shown in Table 1.

[0193] Preparation Example 10

[0194] Cobalt-containing hierarchical porous β-zeolite was prepared by referring to the method in Preparation Example 1, but with changes to the ratio and template agent. The template agent used was tetraethylammonium hydroxide (TEAOH), denoted as CAT-10. The ratio, synthesis conditions, and results are shown in Table 1.

[0195] Preparation Example 11

[0196] Cobalt-containing hierarchical porous MEL molecular sieves were prepared by referring to the method in Example 1, but with changes to the ratio and template agent. The template agent used was tetrabutylammonium hydroxide (TBAOH), denoted as CAT-11. The ratio, synthesis conditions, and results are shown in Table 1.

[0197] Preparation Example 12

[0198] The corresponding product CAT-12 was prepared according to the method in Example 1. The formulation, synthesis conditions, and results are listed in Table 1. Other conditions and operations are the same as in Example 1. The hydrothermal crystallization temperature was 120°C for 8 days, the calcination temperature was 850°C, and the calcination time was 10 hours.

[0199] Preparation of Comparative Example 1

[0200] Prepared according to the method of Preparation Example 1, except that no silanizing agent was added, and the resulting product was denoted as DCAT-1.

[0201] Preparation of Comparative Example 2

[0202] 0.03 g of cobalt nitrate hexahydrate and 0.18 g of water were stirred evenly to obtain an aqueous solution of the metal. Then, 10.2 g of alumina support (Innochem catalog number A17263) was added and stirred for 4 h. 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 resulting product was designated as DCAT-2.

[0203] Preparation of Comparative Example 3

[0204] 0.03 g of cobalt nitrate hexahydrate and 0.18 g of water were stirred evenly to obtain an aqueous solution of the metal. Then, 6 g of titanium silicon MFI molecular sieve support (self-made, prepared according to Example 1, but without cobalt salt and ethylenediamine) was added, stirred for 4 h, 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 resulting product was designated as DCAT-3.

[0205] The BET specific surface area, total pore volume, micropore volume, and mesopore volume of the products obtained from the above examples and comparative examples, as well as the average particle size of the metal nanoparticles in the composite materials, are listed in Table 2 below.

[0206] Table 1

[0207]

[0208]

[0209] In Table 1, cobalt nitrate is always cobalt nitrate hexahydrate; TPAOH is tetrapropylammonium hydroxide, TPABr is tetrapropylammonium bromide, TBAOH is tetrabutylammonium hydroxide, TEAOH is tetraethylammonium hydroxide; PHAPTMS is N-phenyl-3-aminopropyltrimethoxysilane, APTES is 3-aminopropyltriethoxysilane, KH792 is silane coupling agent KH792 (a bisamino functional group silane, N-aminoethyl-γ-aminopropyltrimethoxysilane), cobalt nitrate is cobalt nitrate hexahydrate, and EDTA is ethylenediaminetetraacetic acid. The reagents used in this disclosure can be obtained through conventional purchasing channels.

[0210] Table 2

[0211]

[0212] Pores with a diameter less than 2 nm are classified as micropores; pores with a diameter between 2 and 50 nm are classified as mesopores.

[0213] As shown in Table 2, compared with Comparative Example 1 (without adding silanizing reagent), the products obtained by adding silanizing reagent during the preparation process in Examples 1 to 12 of this disclosure have higher mesopore volumes, indicating that the method provided in this disclosure can effectively expand the pores of molecular sieves.

[0214] Furthermore, compared with DCAT-1 to DCAT-3, the composite catalytic materials CAT-1 to CAT-12 provided in this disclosure can simultaneously possess large mesopore volume, large specific surface area, and smaller metal nanoparticle size, indicating that the composite catalytic materials obtained in this disclosure have lower metal nanoparticle aggregation and higher dispersion.

[0215] Reaction Example 1

[0216] This invention is used to illustrate the effect of the composite catalytic material provided by the present invention in the oxygen oxidation reaction of olefin compounds and aldehyde compounds.

[0217] Preparation of ketones: The samples prepared in the above preparation examples and comparative examples were used for the catalytic oxidation of olefins. 1 mmol of olefin and 3 mmol of aldehyde (the specific types of olefins and aldehydes are listed in Table 3 below) were mixed (the molar ratio of olefin to aldehyde was 1:3), and then contacted with 50 mg of catalyst in a slurry bed reactor. Simultaneously, an oxygen balloon at 0.1 MPa pressure was connected to the reactor. The contact temperature was 60°C, and the contact time was 12 h. No water was added during this process, and ketones were obtained.

[0218] Preparation of dihydroxy compounds: The reaction was carried out using the same method as for ketones described above. The specific types of alkenes and aldehydes are listed in Table 4 below. However, 1 mmol of water was added after 6 hours of reaction to prepare dihydroxy compounds, as shown in Table 4 below.

[0219] The distribution of the obtained products was determined using an HP-5 capillary column (30m × 0.25mm) on an Agilent 6890N chromatograph.

[0220] Olefin conversion (%) = (number of moles of olefins participating in the reaction / number of moles of olefins added) × 100%.

[0221] Ketone (dihydroxy compound) selectivity (%) = number of moles of ketone (dihydroxy compound) / number of moles of olefin involved in the reaction × 100%.

[0222] Wherein, the number of moles of olefins participating in the reaction = the number of moles of olefins fed into the reaction mixture - the number of moles of olefins remaining in the reaction mixture.

[0223] Table 3

[0224]

[0225]

[0226] Table 4

[0227]

[0228] The T2 value of cobalt oxide aggregate Co3O4 is 781.25 eV; the T2 value of iron oxide aggregate Fe2O3 is 710.80 eV; the T2 value of nickel oxide aggregate NiO is 854.80 eV; and the T2 value of copper oxide aggregate CuO is 933.60 eV.

[0229] According to the data in Tables 3 and 4, compared with catalysts DCAT-1 to DCAT-3, the catalysts prepared according to the method of this disclosure have a T0 range of 0.4 to 1.5 eV. This composite catalyst material has higher catalytic activity, higher olefin conversion rate, and higher selectivity for ketones (dihydroxy compounds).

[0230] Comparing preparation examples 1-11 with preparation example 12, the composite catalytic materials prepared in preparation examples 1-11 have a T0 value in the range of 0.5-1.3 eV, indicating better catalytic performance and higher olefin conversion and ketone (dihydroxy compound) selectivity.

[0231] Furthermore, in order to investigate the influence of framework heteroatoms on the XPS binding energy of metal elements in composite catalytic materials, this disclosure takes the catalyst CAT-1 containing cobalt elements in the preparation examples as an example, and compares the change T0' (T0'=T3-T4) of the XPS binding energy T3 of the composite catalytic material obtained after calcination with the XPS binding energy T4 of the crystallized product before calcination, as shown in Table 5 below.

[0232] Table 5

[0233] catalyst <![CDATA[T0’ / eV]]> CAT-1 0.51 DCAT-1 0.21 DCAT-2 0.03 DCAT-3 0.24

[0234] Compared to DCAT-1 to DCAT-3 prepared in Comparative Examples 1 to 3, the CAT-1 provided in Preparation Example 1 of this disclosure has a T0' of 0.4 to 0.8 eV, and it has higher cyclooctene conversion, isobutyraldehyde conversion, and epoxycyclooctene selectivity.

[0235] Reaction Example 2

[0236] An oxidation reaction was carried out using CAT-8 as a catalyst and cycloheptene as a raw material. The reaction effects under different oxidation reaction conditions were tested. The operation process of reaction example 1 was referred to, but the reaction conditions were changed. The specific reaction conditions and results are shown in Table 6 below.

[0237] Table 6

[0238]

[0239] Comparing the catalytic effects obtained using CAT-8 in Reaction Example 2 and Reaction Example 1, it can be seen that the oxidation reaction effect is better in Reaction Example 1 when the reaction temperature is in the range of 40-80℃, and the olefin conversion rate and ketone (dihydroxy compound) selectivity are higher.

[0240] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0241] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0242] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for the oxygen oxidation of olefins, characterized in that, The method includes the following steps: Under oxygen conditions, olefins and aldehydes are brought into contact with a catalyst to undergo oxidation reactions. The olefin compounds are selected from one or more of 1-hexene, methyl oleate, methyl linoleate, cyclohexene, 1-octene, cyclooctene, linolenic acid, cycloheptene, 1-dodecene, 1-heptene, oleic acid, 1,5-cyclooctadiene, 1-pentene, and 1-nonene. The aldehyde compounds are selected from one or more of aliphatic aldehydes with 4 to 10 carbon atoms and aromatic aldehydes with 7 to 14 carbon atoms; the catalyst is a composite catalytic material, which includes a framework heteroatom molecular sieve and a metal element M dispersed within the crystals of the molecular sieve; the framework heteroatom molecular sieve is a molecular sieve in which at least part of the silicon in the all-silicon molecular sieve framework is replaced by a heteroatom element Q, and the heteroatom element Q is selected from one of titanium, boron and tin; The metal element M is a metal element capable of forming stable oxide aggregates, specifically selected from one or more of manganese, iron, cobalt and copper; 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 electron binding energy of the metal element M in the stable oxide aggregate is denoted as T2. T0 is defined by the following formula (1) as any value between 0.4 and 1.5 eV; T0 = ​​T1 - T2 (1); The catalyst is prepared by a method comprising the following steps: S1, a. Mix the template agent, silicon source, framework heteroatom precursor and water to obtain a silicon hydrolysis solution; b. Add a nitrogen-containing ligand to the aqueous solution of the metal M precursor to obtain a first mixture; mix the first mixture with the silicon hydrolysis solution to obtain a second mixture; c. Add a silanizing agent to the second mixture and mix to obtain a reaction mixture; S2. The reaction mixture is subjected to hydrothermal crystallization treatment to obtain a crystallized product, and the crystallized product is then subjected to calcination treatment. The silanizing agent contains at least one coordinating group that is complexed with the metal element M.

2. The method according to claim 1, characterized in that, The T0 is any value between 0.50 and 1.3 eV.

3. The method according to claim 1, characterized in that, The molar ratio of the olefin compound to the aldehyde compound is 1:(1-8).

4. The method according to claim 3, characterized in that, The molar ratio of the olefin compound to the aldehyde compound is 1:(1-3).

5. The method according to claim 1, characterized in that, The conditions for the oxidation reaction include: a reaction temperature of 20-100℃; a reaction time of 1-48h; and an oxygen pressure of 0.1-0.5MPa. The weight ratio of the catalyst to the olefin compound is 1:(1-20).

6. The method according to claim 5, characterized in that, The conditions for the oxidation reaction include: a reaction temperature of 40-80℃; a reaction time of 2-24h; and an oxygen pressure of 0.1-0.3MPa.

7. The method according to claim 5, characterized in that, The weight ratio of the catalyst to the olefin compound is 1:(1-10).

8. The method according to claim 1, characterized in that, The method further includes: after the oxidation reaction has been carried out for 2 to 24 hours, water is added to the reaction system and the reaction continues for 2 to 12 hours, wherein the weight ratio of water to the olefin compound is (0.05 to 2):

1.

9. The method according to claim 1, characterized in that, The framework heteroatom 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.

10. The method according to claim 1, characterized in that, The skeletal heteroatom molecules are selected from one or more of the following molecular sieve structures: MFI, MEL, BEA, MCM, and SBA.

11. The method according to claim 10, characterized in that, The framework heteroatom molecular sieve is one or more of MFI structure molecular sieve, MEL structure molecular sieve and BEA structure molecular sieve.

12. The method according to claim 1, characterized in that, When the metal M is Co, the stable oxide aggregate is a Co3O4 aggregate; When the metal M is Mn, the stable oxide aggregate is a MnO2 aggregate; When the metal M is Fe, the stable oxide aggregate is a Fe2O3 aggregate; or, When the metal M is Cu, the stable oxide aggregate is a CuO aggregate.

13. The method according to claim 1, characterized in that, When the metal element M is Co, Mn, Fe, or Cu, the electron binding energy of the metal element M is 2p. 3 / 2 The binding energy of electrons.

14. The method according to claim 1, characterized in that, In the composite catalytic material, the molar ratio of the framework heteroatom elements to silicon elements is (0.001~0.05):1; The molar ratio of metal M to silicon is (0.001~0.18):

1.

15. The method according to claim 14, characterized in that, In the composite catalytic material, the molar ratio of framework heteroatom elements to silicon elements is (0.002~0.043):1; The molar ratio of metallic element M to silicon is (0.002~0.14):

1.

16. The method according to claim 1, characterized in that, The composite catalytic material has a BET specific surface area of ​​400~800 m². 2 The total pore volume is 0.3~0.65mL / g, the micropore volume is 0.1~0.19mL / g, and the mesopore volume is 0.2~0.46mL / 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 0.5~12nm.

17. The method according to claim 1, characterized in that, The electron binding energy of the metal element M in the product obtained by calcining the crystallized product is denoted as T3. The electron binding energy of the metal element M in the crystallized product is denoted as T4; The calcination treatment makes T0', as defined by the following formula (2), any value between 0.2 and 0.8 eV; T0' = T3-T4 (2).

18. The method according to claim 1, characterized in that, In step S1, the molar ratio of the silicon source (calculated as SiO2): template agent: framework heteroatom precursor (calculated as heteroatom element Q): water: metal element M: silanizing agent is 1: (0.001~1): (0.001~0.05): (5~100): (0.001~0.18): (0.025~0.4).

19. The method according to claim 18, characterized in that, The molar ratio of the silicon source (calculated as SiO2): template agent: framework heteroatom precursor (calculated as heteroatom element Q): water: metal element M: silanizing agent is 1: (0.002~1): (0.002~0.043): (5~100): (0.002~0.14): (0.025~0.3).

20. The method according to claim 1, characterized in that, The molar ratio of nitrogen-containing ligand to metal element M is (0.5~5):

1.

21. The method according to claim 11, characterized in that, The mixing conditions in step c include stirring at 20~80℃ for 0.5~2 hours.

22. The method according to claim 1, characterized in that, The silicon source is selected from at least one of silicone grease, solid silica gel, fumed silica, and silica sol.

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

24. The method according to claim 23, characterized in that, The silicon source is an organosilicone grease, and the organosilicone grease has the general formula shown in formula (A): （A）； Where R a R b R c R d Each is independently selected from alkyl groups having 1 to 6 carbon atoms, wherein the alkyl group is a branched or straight-chain alkyl group.

25. The method according to claim 24, characterized in that, R a R b R c R d Each is independently selected from straight-chain alkyl groups having 1 to 4 carbon atoms or branched alkyl groups having 3 to 4 carbon atoms.

26. The method according to claim 25, 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.

27. The method according to claim 24, characterized in that, The silicone grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, and dimethyl diethyl silicone grease.

28. The method according to claim 1, characterized in that, The template agent is an organic base.

29. The method according to claim 28, characterized in that, The template agent is selected from at least one of quaternary ammonium bases, aliphatic amines, and aliphatic alcoholic amines.

30. The method according to claim 29, characterized in that, The template agent is selected from at least one of the quaternary ammonium bases with the structure shown in formula (B) below: (B); wherein R1, R2, R3 and R4 are each selected from alkyl groups having 1 to 4 carbon atoms.

31. The method according to claim 30, characterized in that, R1, R2, R3 and R4 are each selected from straight-chain alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 4 carbon atoms.

32. The method according to claim 31, characterized in that, R1, R2, R3 and R4 are each selected from at least one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl.

33. The method according to claim 30, characterized in that, The molecular sieve in the composite catalytic material 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 molecular sieve in the composite catalytic material is a MEL-type 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 in the composite catalytic material is a 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.

34. The method according to claim 1, characterized in that, In step a, the silicon source is an organosilicone grease. After mixing the template agent, organosilicone grease, framework heteroatom precursor and water, the process further includes hydrolysis and alcohol removal treatment to obtain the hydrolysate solution. The conditions for the hydrolysis and alcohol removal treatment include: stirring and hydrolyzing at 0~95℃ for 2~10 hours.

35. The method according to claim 34, characterized in that, The conditions for the hydrolysis and alcohol removal treatment include: stirring and hydrolyzing at 50~95℃ for 2~8 hours.

36. The method according to claim 1, characterized in that, In step S1, the skeletal heteroatom precursor includes at least one of an organic skeletal heteroatom precursor and an inorganic skeletal heteroatom precursor; the inorganic skeletal heteroatom precursor is at least one selected from chlorides, nitrates, and sulfates containing heteroatom element Q; the organic skeletal heteroatom precursor is an organic ester containing heteroatom element Q, selected from at least one structure with the general formula shown in formula (C) below: （C）； R5, R6, R7 and R8 are each selected from alkyl groups having 1 to 6 carbon atoms.

37. The method according to claim 36, characterized in that, R5, R6, R7 and R8 are each selected from straight-chain alkyl groups having 1 to 4 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms.

38. The method according to claim 36, characterized in that, R5, R6, R7 and R8 are each selected from straight-chain alkyl groups having 2 to 4 carbon atoms and branched alkyl groups having 2 to 4 carbon atoms.

39. The method according to claim 36, characterized in that, R5, R6, R7 and R8 are each selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, isopentyl, hexyl or isohexyl.

40. The method according to claim 39, characterized in that, R5, R6, R7 and R8 are each independently selected from one of ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl.

41. The method according to claim 36, characterized in that, The skeletal heteroatom is titanium, and the skeletal heteroatom precursor is selected from one or more of titanium tetrachloride, titanium sulfate, titanium nitrate, tetraethyl titanate, tetrapropyl titanate, and tetrabutyl titanate; the skeletal heteroatom is boron, and the skeletal heteroatom precursor is selected from one or more of boric acid and borate; the skeletal heteroatom is tin, and the skeletal heteroatom precursor is selected from one or more of tin halide, stannous halide, stannous sulfate, stannous sulfate, stannate, stannous nitrate, tin oxide, and stannous oxide.

42. The method according to claim 1, characterized in that, In step S1, the precursor of metal M is one or more of inorganic metal compounds and organometallic compounds; the inorganic metal compound is a water-soluble inorganic salt of metal element M; the water-soluble inorganic salt of metal element M is selected from one or more of chloride, hydrated chloride, sulfate, hydrated sulfate and nitrate of metal element M; the organometallic compound is an organic ligand compound of metal element M.

43. The method according to claim 42, characterized in that, The precursor of metal M is a water-soluble inorganic salt of metal element M.

44. The method according to claim 42, characterized in that, The metal M precursor is an aqueous solution of the metal M precursor, wherein the molar ratio of metal element M to water in the aqueous solution of the metal M precursor is 1:(50~500).

45. The method according to claim 1, characterized in that, In step S1, the nitrogen-containing ligand is an alkylamine compound containing only an amino group or an amine compound containing other coordinating groups, wherein the other coordinating groups include one or more of hydroxyl, carboxyl, carbonyl, and mercapto groups.

46. ​​The method according to claim 45, characterized in that, The nitrogen-containing ligand is one or more of the following: alkylamine compounds containing only an amino group having the structure shown in formula (D), alcoholamine compounds having the structure shown in formula (E), and aminocarboxylic acid compounds having the structure shown in formula (F): R9(NH2) n Formula (D); Wherein, n is 1 or 2; when n is 1, R9 is an alkyl group with 1 to 6 carbon atoms; when n is 2, R9 is an alkylene group with 1 to 6 carbon atoms. (HOR 10 ) m NH (3m) Equation (E); Where R 10 It is an alkylene group with 1 to 4 carbon atoms; m is 1, 2 or 3, and when m is greater than 1, multiple R 10 Same or different; (HOOCR 11 ) x NH (3x) Formula (F); Where R 11 It is an alkylene group with 1 to 4 carbon atoms; x is 1, 2, or 3. When x is greater than 1, multiple R 11 Same or different.

47. The method according to claim 46, characterized in that, When n is 1, R9 is a straight-chain alkyl group with 1 to 6 carbon atoms and a branched alkyl group with 3 to 6 carbon atoms.

48. The method according to claim 47, characterized in that, When n is 1, R9 is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, isopentyl, tert-pentyl, and n-hexyl.

49. The method according to claim 46, characterized in that, When n is 2, R9 is a straight-chain alkylene with 1 to 6 carbon atoms and a branched alkylene with 3 to 6 carbon atoms.

50. The method according to claim 49, characterized in that, When n is 2, R9 is one of methylene, ethylene, n-propylene, n-butylene, n-pentylene, and n-hexylene.

51. The method according to claim 46, characterized in that, R 10 It is one of methylene, ethylene, n-propylene, and n-butylene.

52. The method according to claim 46, characterized in that, R 11 It is one of methylene, ethylene, n-propylene, and n-butylene.

53. The method according to claim 46, characterized in that, The nitrogen-containing ligand is selected from one or more of ethylamine, ethylenediamine, ethanolamine, and ethylenediaminetetraacetic acid.

54. The method according to claim 1, characterized in that, In step S1, the general formula of the silanizing agent is R. 12 Si(R 13 (R) 14 )R 15 , where R 12 R 13 R 14 R 15 Each group is independently halogenated, alkyl, alkoxy, aromatic, or amino, and R 12 R 13 R 14 R 15 At least one of them is an alkyl, alkoxy, aromatic or amino group; the alkyl, alkoxy and amino groups each have 1 to 18 carbon atoms, and the aromatic group has 6 to 18 carbon atoms.

55. The method according to claim 54, characterized in that, The silanizing agent is selected from one or more of dimethyldichlorosilane, N-phenyl-3-aminopropyltrimethoxysilane, phenyltrimethoxysilane, hexadecyltrimethoxysilane, octyltriethoxysilane, 3-aminopropyltrimethoxysilane, and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane.

56. The method according to claim 55, characterized in that, The silanizing agent is at least one of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane.

57. The method according to claim 1, characterized in that, In step S2, the conditions for the hydrothermal crystallization treatment include: being carried out under autogenous pressure, a hydrothermal crystallization time of 0.5 to 10 days, and a hydrothermal crystallization temperature of 110 to 200°C. The conditions for the calcination treatment include: a calcination temperature of 400~900℃ and a calcination time of 1~16 hours.

58. The method according to claim 57, characterized in that, In step S2, the conditions for the hydrothermal crystallization treatment include: being carried out under autogenous pressure, a hydrothermal crystallization time of 0.5 to 5 days, and a hydrothermal crystallization temperature of 150 to 200°C. The conditions for the roasting treatment include: a roasting temperature of 400~800℃ and a roasting time of 2~8 hours.

Images