An olefin wacker oxidation process

Abstract

The present disclosure relates to a method for olefin Wacker oxidation, comprising the following steps: contacting an olefin compound with a catalyst for oxidation reaction in the presence of oxygen; 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 the silicon in the full-silicon molecular sieve framework is replaced by a heteroatom element Q, the heteroatom element Q is one or more selected from titanium, boron, zirconium, tin, aluminum, phosphorus and germanium; using the composite catalytic material for olefin Wacker oxidation reaction, high conversion rate and aldehyde or ketone selectivity can be obtained under mild conditions.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of organic chemical industry, in particular, to an olefin Wacker oxidation method. BACKGROUND

[0002] In organic synthesis, acetaldehyde is a two-carbon reagent, electrophile, and is considered as a synthetic subunit of CH3CH(OH)-, which has original chirality. It is condensed with three parts of formaldehyde to generate pentaerythritol C(CH2OH)4, and reacts with Grignard reagents and organolithium reagents to generate alcohol. In the synthesis of amino acids, acetaldehyde is condensed with cyanide ions and ammonia, and after hydrolysis, alanine can be synthesized. Acetaldehyde can also be used to construct heterocyclic ring systems, such as the reaction of trimeric acetaldehyde with ammonia to generate pyridine derivatives. In addition, acetaldehyde can be used to manufacture acetic acid, ethanol, and ethyl acetate. Pesticide DDT is synthesized from acetaldehyde. Acetaldehyde is chlorinated to generate trichloroacetaldehyde. The hydrate of trichloroacetaldehyde is a sleeping pill. In addition, acetaldehyde can be used to prepare fruit flavors such as orange, orange, apple, apricot, and strawberry, and can also be used to prepare wine, rum, whiskey, and other wine flavors.

[0003] Lower aliphatic ketones have a wide range of uses, and can be used as solvents and intermediates for organic synthesis of medicines, resins, and rubbers. In particular, methyl ketones are used, for example, butanone has the following uses: used as a solvent for cellulose acetate, acrylic resin, alkyd resin, paint, ink, etc., a binder for dyes, a dewaxing agent for lubricating oil, a vulcanization accelerator, etc.; used as a reagent for determining cadmium, copper, and mercury, a standard material for chromatographic analysis, and a solvent for semiconductor lithography; specified as an edible flavor allowed to be used in GB 2760-96, mainly used for preparing cheese, coffee, and banana type flavors; also used as an extraction solvent, butanone is mainly used as a solvent, such as used in the dewaxing of lubricating oil, the coating industry, and various resin solvents, the azeotropic distillation process of the extraction and refining process of vegetable oil, which has the advantages of strong solubility, lower volatility than acetone, and belongs to medium-boiling ketone solvents. Butanone is also an intermediate for the preparation of medicines, dyes, detergents, flavors, antioxidants, and certain catalysts, such as the synthesis of anti-peeling agent methyl ethyl ketone oxime, polymerization catalyst methyl ethyl ketone peroxide, corrosion inhibitor methyl pentynyl alcohol, etc., used as a developer after integrated circuit lithography in the electronics industry; an organic synthesis raw material, which can be used as a solvent; used as a dewaxing agent for lubricating oil in the oil refining industry, and also used in the pharmaceutical, coating, dye, detergent, flavor, and electronics industries; a solvent for liquid ink; used in the manufacture of nail polish in cosmetics, as a low-boiling solvent, which can reduce the viscosity of nail polish, and has fast drying properties.

[0004] The reaction of olefins in aqueous solution under the catalytic action of copper chloride and palladium chloride with air (oxygen) to generate aldehydes or ketones is called Wacker oxidation reaction. It is used in industry to oxidize ethylene to acetaldehyde. However, the catalysts in the past are all homogeneous catalysts, and there are problems in the separation and recovery of the catalyst. SUMMARY

[0005] The purpose of the present disclosure is to provide a method for heterogeneous oxygen oxidation of olefins Wacker oxidation, which uses a composite catalytic material comprising a skeletal heteroatom molecular sieve and a metal element dispersed in the crystal of the molecular sieve, and can obtain high conversion rate and aldehyde or ketone selectivity under mild reaction conditions, and the catalyst is easy to separate and recover.

[0006] In order to achieve the above-mentioned purpose, the present disclosure provides a method for olefin Wacker oxidation, which comprises the following steps:

[0007] contacting the olefin compound with the catalyst in the presence of oxygen to perform an oxidation reaction;

[0008] The catalyst is a composite catalytic material, which comprises a skeletal heteroatom molecular sieve and a metal element M dispersed in the crystal of the molecular sieve; the skeletal heteroatom molecular sieve is a molecular sieve in which at least part of the silicon in the full-silicon molecular sieve skeleton is replaced by a heteroatom element Q, and the heteroatom element Q is one or more selected from titanium, boron, zirconium, tin, aluminum, phosphorus and germanium.

[0009] Optionally, the method further comprises mixing the olefin compound with a solvent before contacting with the catalyst;

[0010] The olefin compound is selected from one or more of aliphatic chain olefins with carbon atom number of 4-20, unsaturated acids containing carbon-carbon double bonds with carbon atom number of 5-20, and unsaturated esters containing carbon-carbon double bonds with carbon atom number of 5-20;

[0011] Preferably, the olefin compound is selected from one or more of 1-hexene, 1-octene, 1-hexene, methyl oleate, methyl linoleate, cyclohexene, cyclooctene, linolenic acid, cycloheptene, 1-dodecene, 1-heptene, oleic acid, 1,5-cyclooctadiene, 1-pentene and 1-nonene;

[0012] The solvent is selected from at least one of N,N-dimethylformamide (DMF) aqueous solution and hydrochloric acid;

[0013] The molar ratio of the olefin compound to the solvent is 1:(50-200), preferably 1:(50-100).

[0014] Optionally, the conditions of the oxidation reaction include: the reaction temperature is 20-100℃, preferably 30-60℃; the time is 1-48h, preferably 2-48h; the oxygen pressure is 0.1-0.5MPa, preferably 0.1-0.3MPa;

[0015] The weight ratio of the catalyst to the olefin compound is 1:(0.5-20), preferably 1:(0.5-10).

[0016] Optionally, the reactor for the oxidation reaction is any one of a tank reactor, a fixed bed reactor, a moving bed reactor, a suspended bed reactor and a slurry bed reactor.

[0017] Optionally, the composite catalytic material has a characteristic peak in the Raman spectrum at a wave number of 950-1200 cm -1 Optionally, the composite catalytic material has a characteristic peak in the Raman spectrum at a wave number of 950-1200 cm

[0018] The composite catalytic material has the following Raman spectrum characteristics:

[0019] The composite catalytic material has a characteristic peak in the Raman spectrum at a wave number of 950-1200 cm -1 Optionally, the composite catalytic material has a characteristic peak in the Raman spectrum at a wave number of 950-1200 cm -1 Optionally, the composite catalytic material has a characteristic peak in the Raman spectrum at a wave number of 950-1200 cm

[0020] T0 defined by the following formula (1) is any value between 0.05 and 0.8:

[0021] T0 = T1 / T2 Formula (1)

[0022] Preferably, T0 is any value between 0.1 and 0.6.

[0023] 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 one or more selected from MFI structure molecular sieve, MEL structure molecular sieve, BEA structure molecular sieve, MCM structure molecular sieve and SBA structure molecular sieve; further preferably one or more of MFI structure molecular sieve, MEL structure molecular sieve and BEA structure molecular sieve.

[0024] The metal element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold, and is preferably palladium.

[0025] Optionally, in the composite catalytic material, the molar ratio of the framework heteroatom element to the silicon element is (0.001-0.05):1, and is preferably (0.002-0.036):1.

[0026] The molar ratio of the metal M element to the silicon element is (0.001-0.25):1, and is preferably (0.002-0.15):1.

[0027] Optionally, the BET specific surface area of the composite catalytic material is 400-800 m 2 / g, the total pore volume is 0.3-0.65 mL / g, the micropore volume is 0.1-0.19 mL / g, the mesopore volume is 0.2-0.46 mL / g, and the metal element M in the composite catalytic material exists in the form of metal nanoparticles, and the average particle size of the metal nanoparticles is 0.5-9 nm.

[0028] Optionally, the catalyst is prepared by a preparation method comprising the following steps:

[0029] S1, mixing a template agent, a silicon source, a framework heteroatom precursor, water, a metal M precursor, a peroxide, and a silylation reagent to obtain a reaction mixture;

[0030] S2, performing hydrothermal crystallization treatment and calcination treatment on the reaction mixture;

[0031] The silylation reagent comprises at least one coordination group complexed with the metal element M.

[0032] Optionally, in step S1, the molar ratio of the silicon source to the template agent to the framework heteroatom precursor to water to the metal element M to the peroxide to the silylation reagent, calculated based on SiO2, is 1:(0.001-1):(0.001-0.05):(5-100):(0.001-0.25):(0.5-10):(0.025-0.4); preferably 1:(0.001-1):(0.002-0.036):(5-100):(0.002-0.15):(0.5-10):(0.025-0.3).

[0033] Optionally, step S1 comprises the following steps:

[0034] a, mixing a template agent, a silicon source, a framework heteroatom precursor, and water to obtain a hydrolysis solution of silicon;

[0035] b, adding a peroxide to an aqueous solution of a metal M precursor to obtain a first mixture; mixing the first mixture with the hydrolysis solution of silicon to obtain a second mixture;

[0036] c, adding a silylation reagent to the second mixture, and mixing to obtain the reaction mixture;

[0037] Preferably, the mixing conditions in step c include stirring at 20-80°C for 0.5-2 hours.

[0038] Optionally, the silicon source is selected from at least one of organic silicon grease, solid silica gel, white carbon black, and silica sol; preferably at least one of organic silicon grease, solid silica gel, and white carbon black;

[0039] Further preferred is an organosilicon ester having the general structure of formula (A) below:

[0040]

[0041] wherein R a , R b , R c , R d are each independently selected from an alkyl group having 1 to 6 carbon atoms, which is a branched or straight chain alkyl group; preferably, R a , R b , R c , R d are 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 preferred, the R a , R b , R c , R d are each independently selected from a methyl group, an ethyl group, a n-propyl group, an i-propyl group, a n-butyl group, a sec-butyl group, an i-butyl group, or a t-butyl group; further preferred, the organosilicon ester is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, and dimethyldiethyl silicate.

[0042] Optionally, the templating agent is an organic base, preferably at least one selected from a quaternary ammonium base, an aliphatic amine, and an aliphatic alcohol amine; further preferred, the templating agent is at least one selected from quaternary ammonium bases having the general structure of formula (B) below:

[0043] wherein R1, R2, R3, and R4 are each independently selected from an alkyl group having 1 to 4 carbon atoms, preferably a straight chain alkyl group having 1 to 4 carbon atoms and a branched alkyl group having 3 to 4 carbon atoms, more preferably R1, R2, R3, and R4 are each independently selected from at least one of a methyl group, an ethyl group, a n-propyl group, an i-propyl group, a n-butyl group, a sec-butyl group, an i-butyl group, and a t-butyl group;

[0044] Further preferred, the molecular sieve in the composite catalytic material is an MFI-type molecular sieve, the templating agent is tetrapropylammonium hydroxide or is a mixture of tetrapropylammonium hydroxide with one or more selected from tetrapropylammonium chloride, tetrapropylammonium bromide; or

[0045] the molecular sieve in the composite catalytic material is an MEL-type molecular sieve, the templating agent is tetrabutylammonium hydroxide or is a mixture of tetrabutylammonium hydroxide with one or more selected from tetrabutylammonium chloride, tetrabutylammonium bromide; or

[0046] The molecular sieve in the composite catalytic material is a Beta-type molecular sieve, and the template is tetraethylammonium hydroxide or a mixture of tetraethylammonium hydroxide and one or more selected from tetraethylammonium chloride and tetraethylammonium bromide.

[0047] Optionally, in step a, the silicon source is an organosilicon grease, and the hydrolysis alcohol-removing treatment is further included after mixing the template, the organosilicon grease, the skeleton heteroatom precursor and water to obtain the hydrolysis solution.

[0048] Optionally, the conditions of the hydrolysis alcohol-removing treatment include stirring and hydrolyzing at 0-95 ℃ for 2-10 hours; preferably stirring and hydrolyzing at 50-95 ℃ for 2-8 hours.

[0049] Optionally, in step S1, the skeleton heteroatom precursor includes at least one of an organic skeleton heteroatom precursor and an inorganic skeleton heteroatom precursor; the inorganic skeleton heteroatom precursor is at least one selected from chlorides, nitrates and sulfates of the heteroatom element Q; the inorganic skeleton heteroatom precursor is an organic acid ester containing the heteroatom element Q, and is at least one selected from structures shown in the following formula (C):

[0050]

[0051] wherein R5, R6, R7 and R8 are each selected from alkyl groups having 1-6 carbon atoms, preferably linear alkyl groups having 1-4 carbon atoms and branched alkyl groups having 3-6 carbon atoms, and further preferably R5, R6, R7 and R8 are each selected from linear alkyl groups having 2-4 carbon atoms and branched alkyl groups having 2-4 carbon atoms;

[0052] Optionally, R5, R6, R7 and R8 are each selected from one of methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, i-butyl, t-butyl, i-pentyl, hexyl or i-hexyl; preferably each independently selected from one of ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, i-butyl or t-butyl;

[0053] Preferably, the framework heteroatom is titanium, 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, the framework heteroatom precursor is selected from one or more of boric acid and boric acid salts; the framework heteroatom is tin, the framework heteroatom precursor is selected from one or more of tin halide, stannous halide, stannous sulfate, stannic sulfate, stannic acid salts, stannous acid salts, stannic nitrate, stannic oxide and stannous oxide; the framework heteroatom is aluminum, the framework heteroatom precursor is selected from one or more of sodium metaaluminate, aluminum sulfate, boehmite, metallic aluminum, aluminum nitrate, aluminum isopropoxide and aluminum hydroxide; the framework heteroatom is phosphorus, the framework heteroatom precursor is selected from one or more of orthophosphoric acid, triethyl phosphonic acid and metaphosphoric acid salts; the framework heteroatom is germanium, the framework heteroatom precursor is selected from one or more of germanic oxide, germanic alcoholate, germanic chloride and sodium germanate.

[0054] Optionally, in step S1, the metal M precursor is one or more of inorganic metal compounds and organic metal compounds; the inorganic metal compound is a water-soluble inorganic salt of the metal element M; the water-soluble inorganic salt of the metal element M is selected from one or more of chloride, hydrated chloride, sulfate, hydrated sulfate and nitrate of the metal element M; the organic metal compound is an organic ligand compound of the metal element M; preferably the metal M precursor is a water-soluble inorganic salt of the metal element M.

[0055] The metal element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold, and is preferably palladium.

[0056] Preferably, the metal M precursor is in the form of an aqueous solution of the metal M precursor, and the molar ratio of the metal element M to water in the aqueous solution of the metal M precursor is 1:(50-500).

[0057] Optionally, in step S1, the peroxide is selected from one or more of hydrogen peroxide and organic peroxide; preferably the organic peroxide includes one or more of cumene hydroperoxide, ethylbenzene hydroperoxide and tert-butyl hydroperoxide.

[0058] Optionally, in step S1, the silylating agent has a general formula of R9Si(R 10 )(R 11 )R 12 , wherein R9, R 10 , R 11 , R 12 are each independently halogen, alkyl, alkoxy, aryl, thiol or amine, and R9, R 10 , R 11 , R 12at least one of the alkyl group, the alkoxy group, the aryl group, the mercapto group and the amine group is independently selected from the group consisting of alkyl group, alkoxy group, aryl group, mercapto group and amine group, and the number of carbon atoms of the alkyl group, the alkoxy group, the mercapto group and the amine group is independently 1-18, and the number of carbon atoms of the aryl group is 6-18;

[0059] Preferably, the silanization agent is selected from one or more of dimethyldichlorosilane, N-phenyl-3-aminopropyltrimethoxysilane, phenyltrimethoxysilane, 1,7-dichlorooctylmethyltetrasiloxane, hexadecyltrimethoxysilane, octyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane; further preferably at least one of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

[0060] Optionally, in step S2, the hydrothermal crystallization treatment is performed under autogenous pressure, and 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℃.

[0061] Optionally, the calcination treatment is performed at a calcination temperature of 400-900℃ for a calcination time of 1-16 hours; preferably, the calcination temperature is 400-800℃ and the calcination time is 2-8 hours.

[0062] By the above technical solution, the present disclosure provides a method for olefin Wacker oxidation, which performs a heterogeneous oxidation reaction using oxygen as an oxidant, and uses a composite catalytic material comprising a framework heteroatom molecular sieve and a metal element dispersed in the intracrystalline of the molecular sieve. The molecular sieve of the composite catalytic material has a large specific surface area, pore volume and reaction activity, and the metal nanoparticles have a high dispersion degree in the molecular sieve. The heteroatom Q in the framework of the molecular sieve and the metal element M outside the framework can achieve a synergistic catalytic effect, and high conversion of olefin and high selectivity of aldehyde or ketone can be obtained under mild conditions. The present disclosure adopts.

[0063] Other features and advantages of the present disclosure will be described in detail in the following specific embodiments section. BRIEF DESCRIPTION OF DRAWINGS

[0064] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and together with the specific embodiments below, serve to explain the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings:

[0065] Figure 1 A Raman spectrum of the product prepared in Example 1 at 532 nm was prepared.

[0066] Figure 2 Ti XPS pattern of the product prepared in Example 1.

[0067] Figure 3 Raman spectrum of 532 nm of the conventional all-silica molecular sieve.

[0068] Figure 4 XRD pattern of the product prepared in Example 1.

[0069] Figure 5 SEM pattern of the product prepared in Example 1. DETAILED DESCRIPTION

[0070] The specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present disclosure, and are not intended to limit the present disclosure.

[0071] The present disclosure provides a method for olefin Wacker oxidation, which comprises the following steps:

[0072] contacting an olefin compound with a catalyst in the presence of oxygen to perform an oxidation reaction;

[0073] The catalyst is a composite catalytic material, which comprises a skeletal heteroatom molecular sieve and a metal element M dispersed in the intracrystalline of the molecular sieve; the skeletal heteroatom molecular sieve is a molecular sieve in which at least part of the silicon in the all-silica molecular sieve skeleton is replaced by a heteroatom element Q, and the heteroatom element Q is one or more selected from titanium, boron, zirconium, tin, aluminum, phosphorus and germanium.

[0074] The inventors of the present disclosure unexpectedly found that, by using metal nanoparticles and molecular sieve composite catalytic material as a catalyst, the oxidation reaction rate of olefin by oxygen can be effectively improved, the reaction time can be shortened, and high conversion rate of olefin and high selectivity of aldehyde and ketone can be achieved under relatively mild conditions.

[0075] It is known in the art that, in the Wacker oxidation reaction of olefins, according to the different structures of the olefin compound, the following three reaction equations can be used to prepare aldehyde or ketone:

[0076]

[0077] In one embodiment, the method further comprises: mixing the olefin compound with a solvent before contacting with the catalyst.

[0078] In one embodiment, the olefin compound is selected from one or more of aliphatic alkenes having carbon atoms number of 4-20, unsaturated acids having carbon-carbon double bond with carbon atoms number of 5-20 and unsaturated esters having carbon-carbon double bond with carbon atoms number of 5-20;

[0079] In one preferred embodiment, the olefin compound is selected from one or more of 1-hexene, 1-octene, 1-hexene, methyl oleate, methyl linoleate, cyclohexene, cyclooctene, linolenic acid, cycloheptene, 1-dodecene, 1-heptene, oleic acid, 1,5-cyclooctadiene, 1-pentene and 1-nonene;

[0080] In one embodiment, the solvent is selected from at least one of aqueous N,N-dimethylformamide (DMF) and hydrochloric acid;

[0081] The molar ratio of the olefin compound to the solvent is 1:(50-200), preferably 1:(50-100).

[0082] In one embodiment, the conditions of the oxidation reaction include: reaction temperature of 20-100°C, preferably 30-60°C; time of 1-48h, preferably 2-48h; oxygen pressure of 0.1-0.5MPa, preferably 0.1-0.3MPa;

[0083] The weight ratio of the catalyst to the olefin compound is 1:(0.5-20), preferably 1:(0.5-10).

[0084] Optionally, the reactor for the oxidation reaction is any one of a tank reactor, a fixed bed reactor, a moving bed reactor, a suspended bed reactor and a slurry bed reactor.

[0085] The present inventors surprisingly found, through a large number of experiments, that by introducing a heteroatom precursor, a metal M precursor, a peroxide and a silylating agent (containing at least one coordination group complexed with the metal element M) into the reaction raw materials of a crystalline synthetic molecular sieve, and then performing hydrothermal crystallization treatment and calcination treatment, a heteroatom can be introduced into the molecular sieve framework, and the framework heteroatom molecular sieve of the composite catalytic material has a hierarchical pore structure (micropore and mesopore), a large specific surface area and pore volume, and metal oxide nanoparticles with a high degree of uniformity and uniform dispersion in the pore channel of the framework heteroatom molecular sieve, and a certain amount of metal M nanoparticles also exist on the surface of the pore channel; the metal sites of the heteroatom on the molecular sieve framework and the metal sites (nanoparticles) of the metal element M in the pore channel can also have a synergistic catalytic effect, further improving the catalytic activity in the oxidation reaction; the present inventors further found that, compared with the Raman spectrum at 532 nm of the framework heteroatom molecular sieve not containing the metal element M, the metal-stable oxide and the all-silicon molecular sieve not containing a heteroatom, the Raman spectrum at 532 nm of the composite catalytic material obtained after the introduction of the metal element M has a new characteristic peak in the range of 950-1200 cm -1 , which is obviously stronger than the peak in the range of 950-1200 cm -1 of the Raman spectrum at 532 nm of the pure all-silicon molecular sieve, due to the interaction between the introduced metal element and the silicon in the molecular sieve. The pure all-silicon molecular sieve can be obtained by general commercial purchase or by a known preparation method.

[0086] In a preferred embodiment, the Raman spectrum at 532 nm of the composite catalytic material has a characteristic peak in the range of 950-1200 cm -1 .

[0087] The molecular sieve of the composite catalytic material has a hierarchical pore structure and a large specific surface area, pore volume and macromolecular substrate reactivity; and the metal oxide nanoparticles have a uniform particle size and are uniformly dispersed in the mesopore channel of the hierarchical pore heteroatom framework molecular sieve. There is an obvious interaction between the metal element of the metal oxide particles and the heteroatom in the framework, and after the introduction of the heteroatom into the molecular sieve framework, the two metal sites in the composite catalytic material can have a synergistic catalytic effect, effectively improving the catalytic activity of the composite catalytic material for macromolecular substrates.

[0088] The present inventors further studied the relationship between the characteristic peak in the range of 950-1200 cm -1 and the catalytic activity of the composite catalytic material, and found that, in the Raman spectrum at 532 nm of the composite catalytic material, the characteristic peak in the range of 950-1200 cm -1the intensity of the highest peak (T1) in the range of 360-380 cm -1 The ratio of the intensity of the highest peak (T1) in the range of 360-380 cm

[0089] In a preferred embodiment, T0 is any value between 0.1 and 0.6. When T0 of the composite catalytic material is within this range, the composite catalytic material has higher catalytic activity.

[0090] In an embodiment, the framework heteroatom molecular sieve in the composite catalytic material is one or more of MFI structure molecular sieve (such as S-1), MEL structure molecular sieve (such as S-2), BEA structure molecular sieve (such as Beta), MWW structure molecular sieve (such as MCM-22), two-dimensional hexagonal structure molecular sieve (such as MCM-41, SBA-15), MOR structure molecular sieve (such as MOR), TUN structure molecular sieve (such as TUN), and other structure silicon molecular sieve (such as ZSM-48, MCM-48); preferably 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; further preferably one or more of MFI structure molecular sieve, MEL structure molecular sieve, and BEA structure molecular sieve, such as one of S-1, S-2, and Beta; further preferably MFI structure molecular sieve, such as S-1.

[0091] In an embodiment, the metal element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper, and gold, preferably palladium.

[0092] In an embodiment, the molar ratio of the framework heteroatom element to the silicon element in the composite catalytic material is (0.001-0.05):1, preferably (0.002-0.036):1.

[0093] The molar ratio of the metal M element to the silicon element is (0.001-0.25):1, preferably (0.002-0.15):1.

[0094] In an embodiment, the BET specific surface area of the composite catalytic material is 400-800 m 2 / g, the total pore volume is 0.3-0.65 mL / g, the micropore volume is 0.1-0.19 mL / g, the mesopore volume is 0.2-0.46 mL / g, and the metal element M in the composite catalytic material exists in the form of metal nanoparticles, and the average particle size of the metal nanoparticles is 0.5-9 nm. The composite catalytic material in the present disclosure has a hierarchical pore structure, which is beneficial to catalyzing reactions of reaction substrates of different sizes, especially catalyzing reactions of macromolecular substrates.

[0095] In an embodiment, the catalyst is prepared by a preparation method comprising the following steps:

[0096] S1, mixing a template agent, a silicon source, a framework heteroatom precursor, water, a metal M precursor, a peroxide, and a silylating agent to obtain a reaction mixture;

[0097] S2, performing hydrothermal crystallization treatment and calcination treatment on the reaction mixture;

[0098] Preferably, the silylating agent comprises at least one coordination group complexed with the metal element M.

[0099] The present disclosure introduces a heteroatom precursor into a reaction mixture for synthesizing a molecular sieve, and the heteroatom mainly enters the framework of the molecular sieve during crystallization. The present disclosure also introduces a metal element precursor, a peroxide, and a silylating agent into the reaction mixture, wherein the peroxide can be complexed with metal M ions to play a role in fixing and dispersing the metal element; and the coordination group of the silylating agent complexed with the metal plays a role in fixing and dispersing the metal element, and the space layering effect of the alkyl chain plays a pore-expanding effect; so that a framework heteroatom molecular sieve with a hierarchical pore structure is finally prepared, and metal M oxide nanoparticles can also be uniformly dispersed in the mesopore channels of the hierarchical pore framework heteroatom molecular sieve.

[0100] In an embodiment, the molar ratio of the silicon source to the template agent to the framework heteroatom precursor to water to the metal element M to the peroxide to the silylating agent in step S1 is 1:(0.001-1):(0.001-0.05):(5-100):(0.001-0.25):(0.5-10):(0.025-0.4), preferably 1:(0.001-1):(0.002-0.036):(5-100):(0.002-0.15):(0.5-10):(0.025-0.3), calculated based on SiO2.

[0101] Specifically, the water used in step S1 can be water commonly used in the synthesis of molecular sieves, and preferably deionized water to avoid the introduction of heteroatoms.

[0102] In a preferred embodiment, step S1 comprises the following steps:

[0103] a. mixing a template agent, a silicon source, a framework heteroatom precursor and water to obtain a hydrolytic solution of silicon;

[0104] b. adding a peroxide to an aqueous solution of a metal M precursor to obtain a first mixture; mixing the first mixture with the hydrolytic solution of silicon to obtain a second mixture;

[0105] c. adding a silylating agent to the second mixture, and mixing to obtain the reaction mixture;

[0106] Preferably, the conditions of mixing in step c. comprise stirring at 20-80 °C for 0.5-2 hours.

[0107] In one embodiment, the silicon source is selected from at least one of an organosilicon grease, a solid silica gel, fumed silica and a silica sol; preferably at least one of an organosilicon grease, a solid silica gel and fumed silica.

[0108] Further preferably, the organosilicon grease has the general structure shown in formula (A) below:

[0109]

[0110] wherein R a , R b , R c , R d are each independently selected from an alkyl group having 1-6 carbon atoms, the alkyl group being a branched or straight chain alkyl group; preferably, R a , R b , R c , R d are each independently selected from a straight chain alkyl group having 1-4 carbon atoms or a branched alkyl group having 3-4 carbon atoms; further preferably, the R a , R b , R c , R d are each independently selected from a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group or a tert-butyl group.

[0111] In one preferred embodiment, the organosilicon grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate and dimethyldiethyl silicate.

[0112] According to the present disclosure, 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. Among them, 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 in NH3 with an aliphatic hydrocarbon group (such as an alkyl group); and the aliphatic alcohol amine can be a compound formed by replacing at least one hydrogen in various NH3 with an aliphatic group containing a hydroxyl group (such as an alkyl group).

[0113] In a further preferred embodiment, the template agent is at least one selected from quaternary ammonium bases of the structure represented by the following formula (B):

[0114] wherein R1, R2, R3 and R4 are each selected from at least one of alkyl groups having 1-4 carbon atoms, preferably linear alkyl groups having 1-4 carbon atoms and branched alkyl groups having 3-4 carbon atoms, and 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.

[0115] 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

[0116] In another preferred embodiment, the molecular sieve in the composite catalytic material is an 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

[0117] 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.

[0118] In an embodiment, in step a, the silicon source is an organosilicon fat, and the hydrolysis alcohol-removing treatment is further included after mixing the template agent, the organosilicon fat, the framework heteroatom precursor and water to obtain the hydrolysis solution.

[0119] The conditions of the hydrolysis alcohol-removing treatment include stirring hydrolysis at 0-95°C for 2-10 hours, and preferably stirring hydrolysis at 50-95°C for 2-8 hours; wherein the mass content of alcohol produced by hydrolysis of the organosilicon source in the hydrolysis solution is 10 ppm or less.

[0120] According to the present disclosure, the optional range of the kind of metal precursor is wide, and any substance containing the metal element (for example, a compound containing a metal element and / or a metal element) can achieve the purpose of the present disclosure.

[0121] In one embodiment, in step S1, the skeleton heteroatom precursor includes at least one of an organic skeleton heteroatom precursor and an inorganic skeleton heteroatom precursor; the inorganic skeleton heteroatom precursor is at least one of a chloride, a nitrate or a sulfate of the heteroatom element; the inorganic skeleton heteroatom precursor is an organic acid ester containing the heteroatom element, and is selected from at least one of the structures shown in the following formula (C):

[0122]

[0123] wherein R5, R6, R7and R8are each selected from an alkyl group having 1-6 carbon atoms, preferably a linear alkyl group having 1-4 carbon atoms and a branched alkyl group having 3-6 carbon atoms, further preferably R5, R6, R7and R8are each selected from a linear alkyl group having 2-4 carbon atoms and a branched alkyl group having 2-4 carbon atoms;

[0124] Optionally, R5, R6, R7and R8are each selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, isoamyl, hexyl or isohexyl; preferably each independently selected from one of ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl;

[0125] In an optional embodiment, the skeleton heteroatom is titanium, and the skeleton heteroatom precursor is selected from one or more of titanium tetrachloride, titanium sulfate, titanium nitrate, tetraethyl titanate, tetrapropyl titanate and tetrabutyl titanate;

[0126] In an optional embodiment, the skeleton heteroatom is boron, and the skeleton heteroatom precursor is selected from one or more of boric acid and a boric acid salt;

[0127] In an optional embodiment, the skeleton heteroatom is tin, and the skeleton heteroatom precursor is selected from one or more of a tin halide, a stannous halide, stannous sulfate, stannic sulfate, a stannate, a stannite, stannic nitrate, stannic oxide and stannous oxide;

[0128] In an optional embodiment, the skeleton heteroatom is aluminum, and the skeleton heteroatom precursor is selected from one or more of sodium metaaluminate, aluminum sulfate, boehmite, metallic aluminum, aluminum nitrate, aluminum isopropoxide and aluminum hydroxide;

[0129] In an optional embodiment, the skeleton heteroatom is phosphorus, and the skeleton heteroatom precursor is selected from one or more of orthophosphoric acid, triethyl phosphonic acid and a metaphosphate.

[0130] 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.

[0131] 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.

[0132] The metallic element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold, preferably palladium;

[0133] 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).

[0134] In one embodiment, in step S1, the peroxide is selected from one or more of hydrogen peroxide or organic peroxides; preferably, the organic peroxide includes one or more of cumene hydroperoxide, ethylbenzene hydroperoxide, and tert-butyl hydroperoxide.

[0135] In one embodiment, in step S1, the silanizing agent has the general formula R9Si(R 10 (R) 11 )R 12 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 12 At least one of them is an alkyl, alkoxy, aromatic, mercapto, or amino group; the number of carbon atoms of the alkyl, alkoxy, mercapto, and amino groups is 1 to 18, preferably 1 to 12; the number of carbon atoms of the aromatic group can be 6 to 18, preferably 6 to 12.

[0136] Preferably, the silanization agent is selected from one or more of dimethyldichlorosilane, N-phenyl-3-aminopropyltrimethoxysilane, phenyltrimethoxysilane, 1,7-dichlorooctylmethyltetrasiloxane, hexadecyltrimethoxysilane, octyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane; further preferably at least one of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane.

[0137] In the present disclosure, different silanization agents can be selected for different metal elements M, for example, when the metal element M is Co, the silanization 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 silanization agent is at least one of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane and 3-mercaptobutyltrimethoxysilane.

[0138] In one embodiment, in step S2, the hydrothermal crystallization treatment is performed under autogenous pressure, the hydrothermal crystallization time is 0.5-10 days, and the hydrothermal crystallization temperature is 110-200°C; preferably, the hydrothermal crystallization time is 0.5-5 days, and the hydrothermal crystallization temperature is 150-200°C.

[0139] In one embodiment, in step S2, the calcination treatment is performed at a calcination temperature of 400-900°C for a calcination time of 1-16 hours; preferably, the calcination temperature is 400-800°C, and the calcination time is 2-8 hours.

[0140] In the present disclosure, the sample is subjected to Raman characterization on a LabRAM HR UV-NIR confocal microscope Raman spectrometer, and the test conditions are as follows: room temperature, normal pressure, laser wavelength 532 nm, and the spectral acquisition range is 170-1200 cm -1 .

[0141] The XPS characterization of the sample is performed on an ESCALAB 250 X-ray photoelectron spectrometer, monochromatic Al Kα X-ray, energy 1486.6 eV, power 150 W, and the nuclear potential is corrected by using the C1s peak (284.8 eV) of the contaminating carbon.

[0142] The scanning electron microscope picture SEM of the sample is obtained on a Hitachi S4800 high-resolution cold field emission scanning electron microscope.

[0143] The transmission electron microscope (TEM) picture of the sample was obtained on a FEI Tecnai G2 F20 S-TWIN transmission electron microscope. The average particle size of the metal oxide nanoparticles was obtained according to the TEM electron microscope test.

[0144] X-ray diffraction (XRD) phase diagram determination of the sample was performed on a Siemens D5005 X-ray diffractometer, with a Kα (Cu) ray source, and a test range 2θ of 0.5°-70°.

[0145] The total specific surface area and total pore volume of the sample were determined according to the ASTM D4222-98 standard method on an ASAP 245 static nitrogen adsorption instrument of Micromeritics. The adsorption isotherm and desorption isotherm determination of the sample by low-temperature nitrogen adsorption was performed according to the ASTM D4222-98 standard method.

[0146] Preparation Example 1

[0147] (1) 1.6 g of a 25.05 wt% tetrapropylammonium hydroxide (TPAOH) aqueous solution, 20.8 g of tetraethyl silicate, 0.17 g of tetrabutyl titanate, and 9 g of water were sequentially added to a 500 mL beaker, placed on a magnetic stirrer with heating and stirring functions, mixed uniformly, and stirred at 80°C for 2 hours, with the evaporation of water being supplemented in a timely manner, to obtain a colorless transparent silica gel solution;

[0148] (2) 0.177 g of palladium chloride (0.001 mol) and 1.8 g of water were stirred uniformly, 0.0005 mol of H2O2 was added, and the metal aqueous solution was mixed with the hydrolysis solution of silicon obtained in step (1);

[0149] (3) 0.56 g of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane (silane coupling agent kh-792) was added to the mixture of step (2), and stirred for 0.5 hours;

[0150] (4) The mixture obtained in step (3) was transferred to a stainless steel sealed autoclave, and crystallized at 170°C for 28 hours to obtain a sample. The obtained sample was filtered, washed, dried at 120°C for 6 hours, and then calcined at 600°C in a muffle furnace for 6 hours, to obtain a metal nanoparticle and molecular sieve composite catalytic material product, which is recorded as CAT-1.

[0151] The 532 nm Raman spectrum of the sample CAT-1 is shown in Figure 1 , Figure 1 which shows a spectrum peak at a wave number of 1080 cm -1 , and a spectrum peak at a wave number of 950-1200 cm -1The intensity T1 of the highest peak in the range is 62.5, and the wave number is 360-380 cm -1 The intensity T2 of the highest peak in the range is 125, and T0 is 0.5.

[0152] The Ti XPS spectrum of sample CAT-1 is shown in Figure 1, and there is a peak of skeletal Ti at the position of 459.88 eV, which proves that Ti heteroatom is successfully introduced into the skeleton in the obtained product. Figure 2 The Ti XPS spectrum of sample CAT-1 is shown in Figure 1, and there is a peak of skeletal Ti at the position of 459.88 eV, which proves that Ti heteroatom is successfully introduced into the skeleton in the obtained product.

[0153] The BET specific surface area, total pore volume, micropore volume, mesopore volume, and particle size of metal nanoparticles of sample CAT-1 are shown in Table 2.

[0154] Preparation of Comparative Example 1

[0155] Preparation according to the method of Example 1, except that no silanization reagent is added, and the obtained product is denoted as DCAT-1.

[0156] Preparation of Comparative Example 2

[0157] 0.177 g of palladium chloride and 18 g of water are stirred to obtain an aqueous solution of metal. Then 10.2 g of alumina carrier (Innochem product number A17263) is added, stirred for 4 h, the solvent is evaporated, and the solid is collected and dried at 110°C for 6 hours, and then calcined in a muffle furnace at 550°C for 6 hours; the obtained product is denoted as DCAT-2.

[0158] Preparation of Comparative Example 3

[0159] 0.177 g of palladium chloride and 18 g of water are stirred to obtain an aqueous solution of metal, and then 6 g of titanium-silicon MFI molecular sieve carrier is added, stirred for 4 h, the solvent is evaporated, and the solid is collected and dried at 110°C for 6 hours, and then calcined in a muffle furnace at 550°C for 6 hours; the obtained product is denoted as DCAT-3. The titanium-silicon MFI molecular sieve carrier is prepared according to Preparation Example 1, except that step (2) is not performed, i.e. no palladium chloride and H2O2 are added in the synthesis of the molecular sieve, and the rest of the process is the same as that of Preparation Example 1.

[0160] Preparation of Examples 2-9

[0161] The corresponding products are prepared according to the method of Preparation Example 1, and the obtained products are denoted as CAT-2 to CAT-9, the ratios and synthesis conditions and results of which are shown in Table 1.

[0162] Preparation of Example 10

[0163] A palladium-containing hierarchical pore β molecular sieve is prepared according to the method of Preparation Example 1, and the ratio and template agent are changed, and the obtained product is denoted as CAT-10, and the template agent used is tetraethylammonium hydroxide (TEAOH), and the ratio and synthesis conditions and results of which are shown in Table 1.

[0164] Preparation Example 11

[0165] The preparation of the palladium-containing hierarchical pore MEL molecular sieve was carried out according to the method of Preparation Example 1, the ratio was changed, and the template was changed. The obtained product is denoted as CAT-11, and the template used is tetrabutylammonium hydroxide (TBAOH). The ratio and the synthesis conditions and results are shown in Table 1.

[0166] Preparation Example 12

[0167] The corresponding product was prepared according to the method of Preparation Example 1, and the ratio and the synthesis conditions and results are shown in Table 1. The other conditions and operations refer to Preparation Example 1, and the obtained product is denoted as CAT-12.

[0168] The BET specific surface area, total pore volume, micropore volume and mesopore volume of the products obtained in the above examples and comparative examples, and the average particle size of the metal nanoparticles in the composite material are shown in Table 2 below.

[0169] Table 1

[0170]

[0171]

[0172] In Table 1, cobalt nitrate is 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 (diamino functional silane, N-aminoethyl-γ-aminopropyltrimethoxysilane). CHP is cumene hydroperoxide, TBHP is tert-butyl hydroperoxide, and EBHP is ethylbenzene peroxide. The reagents used in the present disclosure can be obtained through conventional purchase channels.

[0173] Table 2

[0174]

[0175]

[0176] The pores with a diameter less than 2 nm are micropores, and the pores with a diameter between 2 nm and 50 nm are mesopores.

[0177] As can be seen from Table 2, compared with Comparative Example 1 (without adding silanization reagent), the products obtained by adding silanization reagent in the preparation process of Examples 1-12 of the present disclosure have higher mesopore volume, indicating that the method provided by the present disclosure can effectively expand the pores of the molecular sieve.

[0178] And compared with DCAT-1~DCAT-3, the composite catalytic material CAT-1~CAT-12 provided by the present disclosure can simultaneously have a large mesopore volume, a large specific surface area, and a smaller metal nanoparticle particle size, indicating that the metal nanoparticles in the composite catalytic material obtained by the present disclosure have a lower aggregation degree and a higher dispersion degree.

[0179] Reaction Example 1

[0180] To illustrate the effect of the olefin Wacker oxidation reaction provided by the present disclosure.

[0181] The catalysts prepared in the above preparation examples and comparative examples were used to catalyze the oxidation of olefins with oxygen. 1 mmol of an olefin compound (see Table 3 below for specific substances) was mixed with a DMF aqueous solution (0.032 mol DMF, 0.046 mol H2O, n(DMF):n(H2O) = 7) and contacted with 50 mg of the catalyst in a slurry bed reactor, while the reactor was connected to an oxygen balloon at a pressure of 0.1 MPa. The contact temperature was 30°C, and the contact time was 12 h. The results are shown in Table 3 below.

[0182] The product distribution was determined on an Agilent 6890N chromatograph using an HP-5 capillary column (30 m x 0.25 mm).

[0183] Olefin conversion rate (%) = moles of olefin participating in the reaction / moles of olefin added x 100%.

[0184] Aldehyde or ketone selectivity (%) = moles of aldehyde or ketone / moles of olefin participating in the reaction x 100%.

[0185] The moles of olefin participating in the reaction = moles of olefin fed - moles of olefin remaining in the obtained reaction mixture.

[0186] Table 3

[0187]

[0188] It can be seen that compared with the catalysts DCAT-1~DCAT3, the catalysts CAT-1~CAT12 prepared according to the method of the present disclosure have a TO of 0.05~0.8, have higher catalytic activity, and have higher olefin conversion rate and aldehyde or ketone selectivity.

[0189] Comparing Preparation Examples 1~11 with Preparation Example 12, the composite catalytic material prepared in Preparation Examples 1~11 has a TO of 0.1~0.6, has better catalytic effect in the olefin Wacker oxidation reaction, and has higher olefin conversion rate and aldehyde or ketone selectivity.

[0190] Reaction Comparative Example 1

[0191] 1-decene was subjected to Wacker oxidation reaction in aqueous solution in the presence of copper chloride and palladium chloride, specifically, 1-decene was subjected to Wacker oxidation reaction in the presence of 10 mol% (based on 1-decene) PdCl2 and 100 mol% CuCl under 1 atm O2 atmosphere in DMF solution (n(DMF):n(H2O) = 7) at room temperature for 24 hours.

[0192] The reaction result was that the yield of 2-decanone was 65% to 73%.

[0193] According to Reaction Example 1 and Reaction Comparative Example 1, it can be seen that the catalyst prepared according to the method of the present disclosure has higher catalytic activity compared with the traditional homogeneous catalyst.

[0194] Reaction Example 2

[0195] The method of using CAT-2 as catalyst and methyl oleate as raw material was used to test the reaction effect under different oxidation reaction conditions, and the specific reaction conditions and reaction results are listed in Table 4 below. In the following table, the mass of the catalyst is 50 mg.

[0196] Table 4

[0197]

[0198] According to Table 4, it can be seen that the catalytic effect of CAT-2 obtained in Reaction Example 2 and Reaction Example 1 is compared, and the oxidation reaction effect is better when the reaction temperature in Reaction Example 1 is in the range of 30-60℃, or the weight ratio of the catalyst to the olefin compound is in the range of 1:(0.5-10).

[0199] The preferred embodiments of the present disclosure are described in detail above in combination with the drawings, but the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0200] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combination manners are not described again in the present disclosure.

[0201] In addition, various different embodiments of the present disclosure can also be combined in any manner, as long as it does not deviate from the idea of the present disclosure, and it should also be considered as disclosed by the present disclosure.

Claims

1. A method for Wacker oxidation of olefins, characterized in that, The method includes the following steps: In the presence of oxygen, olefin compounds are brought into contact with a catalyst to undergo an oxidation reaction; 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 or more of titanium, boron, zirconium, tin, aluminum, phosphorus and germanium. 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, MCM structure molecular sieve, SBA structure molecular sieve, MOR structure molecular sieve and TUN structure molecular sieve. The metallic element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold; In the composite catalytic material, the molar ratio of the framework heteroatom element to silicon element is (0.001~0.05):1; the molar ratio of the metal M element to silicon element is (0.001~0.25):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 peroxide to the aqueous solution of metal M precursor to obtain a first mixture; mix the first mixture with the silicon hydrolysis solution to obtain a second mixture; c. Add the silanizing agent to the second mixture and mix to obtain a reaction mixture; S2. The reaction mixture is subjected to hydrothermal crystallization and 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 method further includes: mixing the olefin compound with a solvent and then contacting it with the catalyst; The olefin compounds are selected from one or more of the following: aliphatic chain alkenes with 4 to 20 carbon atoms, unsaturated acids with 5 to 20 carbon atoms containing carbon-carbon double bonds, and unsaturated esters with 5 to 20 carbon atoms containing carbon-carbon double bonds; or The olefin compound is selected from one or more of cyclohexene, cyclooctene, cycloheptene, and 1,5-cyclooctadiene.

3. The method according to claim 2, characterized in that, The olefin compounds are selected from one or more of 1-octene, 1-hexene, methyl oleate, methyl linoleate, linolenic acid, 1-dodecene, 1-heptene, oleic acid, 1-pentene, and 1-nonene; The solvent is selected from at least one of N,N-dimethylformamide (DMF) aqueous solution and hydrochloric acid; The molar ratio of the olefin compound to the solvent is 1:(50-200).

4. The method according to claim 3, characterized in that, The molar ratio of the olefin compound to the solvent is 1:(50-100).

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:(0.5-20).

6. The method according to claim 5, characterized in that, The conditions for the oxidation reaction include: a reaction temperature of 30-60℃; a reaction time of 2-48 hours; and an oxygen pressure of 0.1-0.3 MPa. The weight ratio of the catalyst to the olefin compound is 1:(0.5-10).

7. The method according to claim 1, characterized in that, The reactor for the oxidation reaction can be any one of a batch reactor, a fixed-bed reactor, a moving-bed reactor, a suspended-bed reactor, and a slurry-bed reactor.

8. The method according to claim 1, characterized in that, The composite catalytic material exhibits a Raman spectrum at 532 nm with wavenumbers ranging from 950 to 1200 cm⁻¹. -1 Characteristic peaks exist within the range; The composite catalytic material exhibits the following Raman spectral characteristics: The Raman spectrum of the composite catalytic material at 532 nm has a wavenumber of 950-1200 cm⁻¹. -1 The intensity of the highest peak within the range is denoted as T1; the wavenumber is 360~380cm. -1 The intensity of the highest peak within the range is denoted as T2. T0 is defined as any value between 0.05 and 0.8 in the following formula (1); T0 = ​​T1 / T2 (Equation 1) 9. The method according to claim 8, characterized in that, T0 is any value between 0.1 and 0.

6.

10. The method according to claim 1, characterized in that, The framework heteroatom molecules in the composite catalytic material are screened from one or more of the following: MFI structure molecular sieves, MEL structure molecular sieves, and BEA structure molecular sieves.

11. The method according to claim 10, characterized in that, The framework heteroatom molecular sieve in the composite catalytic material is one or more of MFI structure molecular sieve, MEL structure molecular sieve and BEA structure molecular sieve; The metallic element M is palladium.

12. 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 (0.002~0.036):1; The molar ratio of metallic element M to silicon is (0.002~0.15):

1.

13. 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 0.5~9nm.

14. The method according to claim 1, characterized in that, 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: peroxide: silanizing agent is 1: (0.001~1): (0.001~0.05): (5~100): (0.001~0.25): (0.5~10): (0.025~0.4).

15. The method according to claim 14, characterized in that, 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: peroxide: silanizing agent is 1: (0.001~1): (0.002~0.036): (5~100): (0.002~0.15): (0.5~10): (0.025~0.3).

16. The method according to claim 1, characterized in that, The mixing conditions in step c include stirring at 20~80℃ for 0.5~2 hours.

17. 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.

18. The method according to claim 17, characterized in that, The silicon source is selected from at least one of organosilicon grease, solid silica gel, and precipitated silica.

19. The method according to claim 18, 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.

20. The method according to claim 19, 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.

21. The method according to claim 20, 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.

22. The method according to claim 19, characterized in that, The silicone grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, and dimethyl diethyl silicone grease.

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

24. The method according to claim 23, characterized in that, The template agent is selected from at least one of quaternary ammonium bases, aliphatic amines, and aliphatic alcoholic amines.

25. The method according to claim 24, 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.

26. The method according to claim 25, 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.

27. The method according to claim 26, 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.

28. The method according to claim 1, 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.

29. 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.

30. The method according to claim 29, characterized in that, The conditions for the hydrolysis and alcohol removal treatment include: stirring and hydrolyzing at 50~95℃ for 2~8 hours.

31. 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.

32. The method according to claim 31, 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.

33. The method according to claim 32, 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.

34. The method according to claim 31, 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.

35. The method according to claim 34, 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.

36. The method according to claim 1, characterized in that, 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.

37. 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.

38. The method according to claim 1, characterized in that, The precursor of metal M is a water-soluble inorganic salt of the metal element M; The metallic element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper, and gold.

39. The method according to claim 38, characterized in that, The metallic element M is palladium; 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).

40. The method according to claim 1, characterized in that, In step S1, the peroxide is selected from one or more of hydrogen peroxide or organic peroxides.

41. The method according to claim 40, characterized in that, The organic peroxides include one or more of cumene hydroperoxide, ethylbenzene hydroperoxide, and tert-butyl hydroperoxide.

42. The method according to claim 1, characterized in that, In step S1, the general formula of the silanizing agent is R9Si(R 10 (R) 11 )R 12 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 12 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.

43. The method according to claim 42, characterized in that, 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.

44. The method according to claim 43, characterized in that, The silanizing agent is at least one of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

45. 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.

46. ​​The method according to claim 45, 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.

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