Process for the oxidation of alcohols and aldehydes to acids

Abstract

The present disclosure relates to a method for preparing acid by oxidation of alcohol and aldehyde, comprising: contacting alcohol reactant and aldehyde reactant with a catalyst to perform oxidation reaction in the presence of oxygen; the catalyst is a composite catalytic material, which 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 one or more selected from titanium, boron, zirconium, tin, aluminum, phosphorus and germanium. The aldehyde co-oxidation reaction and the alcohol oxidation reaction can be coupled together to prepare acid under the conditions of oxygen oxidation and composite catalytic material catalysis, high conversion rate and acid selectivity are obtained, and the method has high industrial application value.

Description

TECHNICAL FIELD

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

[0002] Carboxylic acids are important organic compounds, which have a wide range of applications in industry, agriculture, medicine and people's daily life. The oxidation reaction from alcohol to acid is a basic and important chemical reaction in organic chemistry. In the industry and pharmaceutical field, the production of carboxylic acids is often obtained by oxidation method. Therefore, it has good application prospect to find a high-efficiency, low-cost, mild condition, good functional group compatibility and environmentally friendly catalytic oxidation system.

[0003] Traditionally, the synthesis of acid is obtained by using equivalent or excess oxidant to oxidize the corresponding alcohol, such as KMnO4 oxidation, Jone's oxidation and other oxidation methods based on CrO3. The disadvantages of such methods are that the oxidant contains heavy metals, is expensive, pollutes the environment with waste liquid, often requires strong acid, has harsh conditions, requires high equipment, and is not suitable for large-scale industrial production.

[0004] Oxygen is a cheap, clean, high atom economy, environmentally friendly oxidant. Air is a more ideal oxidant, without the need for preparation and transportation, and is safer in industrial production. Currently, the method of realizing the oxidation from alcohol to acid with oxygen as the oxidant is very limited, and is concentrated in the field of noble metal catalysis, and the report of air oxidation is even less. For example, the Heyns oxidation catalyzed by Pt developed in the 1940s, however, the expensive price and the characteristics of easy poisoning of Pt limit the application of Heyns oxidation in industrial production; In 2014, the Ag(NHC) / KOH system was used to realize the oxidation of benzyl alcohol to acid with dry air; Davis et al. reported that Au / H2O interface catalyzed ethanol and glycerol to generate acid; Zhang Zehui et al. reported that the supported magnetic Pd nanocatalyst catalyzed the oxidation of 5-hydroxymethylfurfural with oxygen to generate 2,5-furan dicarboxylic acid; Buffin et al. reported that under Pd catalysis, alcohols can be oxidized to a mixture of carboxylic acids and esters, and benzyl alcohol can be oxidized to a mixture of aldehyde and acid; In 2015, Li Zhaojun group reported that in the AgO2 / IPr system, aldehyde was oxidized to acid by oxygen. Ag, Au, Ru, Pd and other metal-catalyzed oxidation reactions have also been reported, but the substrate limitation is strong, and most of them need nanotechnology or support to achieve. TEMPO can provide a stable oxygen radical, and plays an important role in the process of catalyzing alcohol to aldehyde or ketone with Fe or Cu (Stahl, S. S.; Ryland, B. L. Angew. Chem. Int. Ed. 2014, 53, 8824-8838; Cao, Q.; Dornan, L. M.; Rogan, L.; Hughes, N. L.; Muldoon, M. J. Chem. Commun., 2014, 50, 4524-4543). However, in such systems, the oxidation of alcohol or aldehyde to acid by oxygen has not been reported. SUMMARY

[0005] The purpose of the present disclosure is to provide a method for oxidizing alcohol and aldehyde to acid, which uses a composite catalytic material comprising a framework heteroatom molecular sieve and a metal element dispersed in the intracrystalline of the molecular sieve as a catalyst, couples the co-oxidation of aldehyde with the oxidation of alcohol to acid, and obtains high conversion rate and acid selectivity, which has high industrial application value.

[0006] To achieve the above object, the present disclosure provides a method for preparing acid by oxidation of alcohol and aldehyde, comprising: contacting alcohol reactant and aldehyde reactant with a catalyst in the presence of oxygen to perform oxidation reaction; the catalyst is a composite catalyst material, which 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 the full-silicon molecular sieve framework 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.

[0007] Optionally, the alcohol reactant is selected from one or more of linear alkyl alcohol with carbon atom number of 4-10, branched alkyl alcohol with carbon atom number of 4-10, cycloalkanol with carbon atom number of 4-10 and aryl alcohol with carbon atom number of 7-12;

[0008] Preferably, the alcohol reactant is selected from one or more of 1-butanol, sec-butanol, cyclopentanol, hexanol, 2-methyl-1-butanol, 1-methylcyclopentanol, 2-hexyl-1-octanol, benzyl alcohol, 1-pentanol, 1-pentanol and 2-hexyl-1-octanol;

[0009] The aldehyde reactant is selected from one or more of isobutyraldehyde, isoamyl aldehyde and n-hexanal;

[0010] Preferably, the method further comprises: after mixing the alcohol with the aldehyde reactant, contacting the mixture with the catalyst to perform oxidation reaction; the molar ratio of the alcohol reactant to the aldehyde reactant is 1:(0.01-20); preferably 1:(0.05-10).

[0011] Optionally, the conditions of the oxidation reaction include: temperature of 40-100℃, preferably 60-80℃; reaction time of 1-48 hours, preferably 1.5-24 hours; weight ratio of catalyst to alcohol reactant of 0.04-1, preferably 0.1-1; oxygen pressure of 0.1-0.5 MPa, preferably 0.1-0.3 MPa;

[0012] Preferably, the reactor for the oxidation reaction is selected from any one of a tank reactor, a fixed bed reactor, a moving bed reactor, a suspended bed reactor or a slurry bed reactor.

[0013] Optionally, the metal element M is a metal element capable of forming stable oxide aggregates;

[0014] The composite catalyst material has the following XPS characteristics:

[0015] The electron binding energy of the metal element M in the composite catalyst material is denoted as T1;

[0016] The binding energy of the electron of the metal element M in the stable oxide aggregate is denoted as T2,

[0017] T0 defined by the following formula (1) is any value between 0.7 and 1.5 eV;

[0018] T0 = T1 - T2 Formula (1);

[0019] Preferably, T0 is any value between 0.8 and 1.4 eV.

[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 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;

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

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

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

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

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

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

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

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

[0029] When the metal element M is Co, Mn, Fe, Ni or Cu, the binding energy of the electron of the metal element M is the 2p 3 / 2 binding energy of the metal element M; when the metal element M is Pt, the binding energy of the electron of the metal element M is the 4f 7 / 2binding energy of the electron of the metal element M is 3d of the metal element M when the metal element M is Pd 5 / 2 binding energy of the electron of the metal element M is 3d of the metal element M when the metal element M is Pd

[0030] Optionally, in the composite catalytic material, the molar ratio of the skeleton heteroatom element to the silicon element is (0.001-0.045):1, preferably (0.002-0.04):1.

[0031] Optionally, in the composite catalytic material, the molar ratio of the metal element M to the silicon element is (0.001-0.2):1, preferably (0.002-0.17):1.

[0032] 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 average particle size of the metal nanoparticles in the composite material is 0.5-8.5 nm.

[0033] Optionally, the composite catalytic material is prepared by a preparation method comprising the following steps:

[0034] S1, mixing a template agent, a silicon source, a skeleton heteroatom precursor, water, a metal M precursor, a nitrogen-containing ligand, and a silylation reagent to obtain a reaction mixture;

[0035] S2, performing hydrothermal crystallization treatment on the reaction mixture to obtain a crystallization product, and performing calcination treatment on the crystallization product;

[0036] The silylation reagent comprises at least one coordination group complexed with the metal element M.

[0037] Optionally, the binding energy of the electron of the metal element M in the product obtained by performing calcination treatment on the crystallization product is denoted as T3.

[0038] The binding energy of the electron of the metal element M in the product obtained by performing calcination treatment on the crystallization product is denoted as T3.

[0039] The calcination treatment makes T0' defined by the following formula (2) an arbitrary value between 0.4 and 0.8 eV.

[0040] T0'=T3-T4 Formula (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):(0.001~0.045):(5~100):(0.001~0.2):(0.025~0.4); preferably 1:(0.002~1):(0.002~0.04):(5~100):(0.002~0.17):(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] Optionally, 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 Rd 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] Optionally, 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 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] 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 of the structures shown in the following formula (C):

[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 or 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, or metaphosphate; the framework heteroatom is germanium, and the framework heteroatom precursor is selected from one or more of germanium oxide, germanium alkoxides (e.g., germanium ethanol, germanium isopropoxide), 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] 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 11It 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 R 13 R 14 R 15 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 independently selected from any integer from 1 to 18, and the number of carbon atoms of the aromatic group is any integer from 6 to 18;

[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] 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.

[0080] Through the above technical solution, this disclosure provides a method for producing acid by oxidizing alcohols and aldehydes. This method uses a composite catalytic material comprising a framework heteroatom molecular sieve and a metal element M dispersed within the crystals of the molecular sieve as a catalyst. The molecular sieve of this composite catalytic material has a hierarchical porous structure and a large specific surface area, pore volume, and macromolecular substrate reactivity. Furthermore, the metal element nanoparticles have uniform particle size and are uniformly dispersed within the crystals of the hierarchical porous heteroatom framework molecular sieve (e.g., within mesoporous channels). The metal element and the heteroatoms within the framework of this composite catalytic material can play a synergistic catalytic role, further improving the catalytic activity of the composite catalytic material. Under the condition of oxygen presence, the co-oxidation reaction of aldehydes and the oxidation reaction of alcohols can be coupled to produce acid, thus developing a new acid production process route. High conversion rate and acid selectivity can be obtained under relatively mild reaction conditions, which has high industrial application value.

[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 Co XPS spectrum of the product prepared in Example 1.

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

[0085] Figure 3 SEM images of the product prepared in Example 1.

[0086] Figure 4 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 producing acid by oxidizing alcohols and aldehydes, comprising: contacting alcohol reactants and aldehyde reactants with a catalyst in the presence of oxygen to carry out an oxidation reaction; wherein the catalyst is a composite catalytic material, the composite catalytic material comprising a framework heteroatom molecular sieve and a metal element M dispersed within the crystals of the molecular sieve, wherein the framework heteroatom molecular sieve is a molecular sieve in which at least a portion 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.

[0089] This method employs a composite catalytic material comprising a framework heteroatom molecular sieve and a metal element M dispersed within the crystals of the molecular sieve as the catalyst. The molecular sieve of this composite catalytic material possesses a hierarchical porous structure and a large specific surface area, pore volume, and high reactivity with macromolecular substrates. Furthermore, the metal element nanoparticles are uniformly sized and dispersed within the crystals of the hierarchical porous heteroatom framework molecular sieve (e.g., within mesoporous channels). The metal element and heteroatoms within the framework of this composite catalytic material can play a synergistic catalytic role, further enhancing the catalytic activity of the composite catalytic material. Under oxygen-containing conditions, the co-oxidation of aldehydes and the oxidation of alcohols can be coupled to produce acids, thus developing a new acid production process route. High conversion rates and acid selectivity can be obtained under relatively mild reaction conditions, demonstrating significant industrial application value.

[0090] In one embodiment, the alcohol reactants are selected from one or more of the following: straight-chain alkyl alcohols with 4 to 10 carbon atoms, branched-chain alkyl alcohols with 4 to 10 carbon atoms, cycloalkanols with 4 to 10 carbon atoms, and aryl alcohols with 7 to 12 carbon atoms.

[0091] Preferably, the alcohol reactants are selected from one or more of 1-butanol, sec-butanol, cyclopentanol, hexanol, 2-methyl-1-butanol, 1-methylcyclopentanol, 2-hexyl-1-octanol, benzyl alcohol, 1-pentanol, 1-pentanol and 2-hexyl-1-octanol;

[0092] The aldehyde reactants are selected from one or more of isobutyraldehyde, isovaleraldehyde, and n-hexanal;

[0093] Preferably, the method further includes: mixing the alcohol and the aldehyde reactant, and then contacting them with the catalyst to carry out an oxidation reaction; the molar ratio of the alcohol reactant to the aldehyde reactant is 1:(0.01-20), preferably 1:(0.05-10).

[0094] The aldehyde reactants used in this disclosure may or may not be oxidation products of the alcohol reactants, and can be selected arbitrarily.

[0095] In one embodiment, the conditions for the oxidation reaction include: a temperature of 40–100°C, preferably 60–80°C; a reaction time of 1–48 hours, preferably 1.5–24 hours; a weight ratio of catalyst to alcohol reactant of 0.04–1, preferably 0.1–1; and an oxygen pressure of 0.1–0.5 MPa, preferably 0.1–0.3 MPa.

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

[0097] 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 pores (crystals) of the framework heteroatom molecular sieve. Some metal element nanoparticles may also exist between crystals or on the surface of the molecular sieve. This composite catalytic material exhibits excellent catalytic properties in the oxidation of alcohols and aldehydes to produce acids. Chemical activity; the heteroatom metal sites on the molecular sieve framework and the metal sites of metal element M in the pores (nanoparticles) can also play a synergistic catalytic effect; through in-depth research, the inventors also found that compared with the XPS binding energy of metal element M in the stable oxide aggregate, the XPS binding energy of metal element M introduced into the composite catalytic material of this disclosure has changed, and the heteroatoms in the framework can also affect the XPS binding energy of metal element M in the composite catalytic material. When the change of the XPS chemical binding energy of metal element M in the composite catalytic material compared with the XPS chemical binding energy of metal element M in its stable oxide is within a certain range, the catalytic activity of the composite catalytic material in the oxidation of alcohol and aldehyde to produce acid is further improved.

[0098] In one embodiment, the metal element M is a metal element capable of forming stable oxide aggregates;

[0099] The composite catalytic material exhibits the following XPS characteristics:

[0100] The binding energy of the electrons of the metal element M in the composite catalytic material is denoted as T1;

[0101] The binding energy of the electrons of the metal element M in the stable oxide aggregate is denoted as T2.

[0102] T0 is defined by the following formula (1) as any value between 0.7 and 1.5 eV;

[0103] T0 = ​​T1 - T2 Equation (1).

[0104] 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 reactivity. 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.

[0105] 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. For example, when the metal M is Co, the stable oxide aggregate is Co3O4 aggregate; when the metal M is Cu, the stable oxide aggregate is CuO.

[0106] In a preferred embodiment, T0 is any value between 0.8 and 1.4 eV. When the T0 of the composite catalytic material is within this range, the composite catalytic material exhibits higher catalytic activity.

[0107] 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.

[0108] In one embodiment, the metallic element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold; preferably, it is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum and copper.

[0109] In one optional embodiment, the metal M is Co, and the stable oxide aggregate is a Co3O4 aggregate;

[0110] In one optional embodiment, the metal M is Mn, and the oxide aggregate is MnO2 aggregate;

[0111] In one optional embodiment, the metal M is Fe, and the oxide aggregate is a Fe2O3 aggregate;

[0112] In one optional embodiment, the metal M is Ni, and the oxide aggregate is a NiO aggregate;

[0113] In one optional embodiment, the metal M is Pd, and the oxide aggregate is a PdO aggregate;

[0114] In one optional embodiment, the metal M is Pt, and the oxide aggregate is a PtO2 aggregate;

[0115] In one optional embodiment, the metal M is Cu, and the oxide aggregate is a CuO aggregate;

[0116] Wherein, when the metal element M is Co, Mn, Fe, Ni or Cu, the electron binding energy of the metal element M is 2p. 3 / 2 The electron binding energy; when the metal element M is Pt, 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.

[0117] In this disclosure, the XPS feature is 2p 3 / 2 Taking the electron as an example, its specific meaning is: 2p represents the 2p orbital, and 3 / 2 represents the spin-orbit coupling quantum number.

[0118] In one embodiment, the molar ratio of the framework heteroatom element to silicon element in the composite catalytic material is (0.001-0.045):1, preferably (0.002-0.04):1;

[0119] The molar ratio of metal M to silicon is (0.001-0.2):1, preferably (0.002-0.17):1.

[0120] In one embodiment, the BET specific surface area of ​​the composite catalytic material is 400–800 m². 2 / g, preferably 420-750m 2The total pore volume is 0.3–0.65 mL / g, preferably 0.325–0.615 mL / g; the micropore volume is 0.1–0.19 mL / g, preferably 0.110–0.175 mL / g; the mesopore volume is 0.2–0.46 mL / g, preferably 0.210–0.455 mL / g; and the average particle size of the metal nanoparticles is 0.5–8.5 nm, preferably 1.0–8.5 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 specific embodiment, the composite catalytic material 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 heteroatom element Q in the skeletal heteroatom precursor is selected from one of titanium, boron, zirconium, tin, aluminum, phosphorus and germanium; the silanizing agent contains at least one coordinating group that complexes 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 2p chromatogram of the metal element M (taking cobalt as an example) in the XPS spectrum of the composite catalytic material obtained after hydrothermal crystallization and calcination showed a higher chromatogram. 3 / 2 The significantly increased electron binding energy indicates an interaction between the metal nanoparticles and the framework heteroatoms (taking titanium as an example) in the composite material obtained after calcination. The inventors investigated the 2p electron binding energy of the metal element M in the composite catalytic material before and after calcination. 3 / 2 The changes in electron binding energy were studied in depth, revealing that T0' (T0' = T3 - T4; T3 is the 2p electron binding energy of the metallic element M in the product obtained by calcining the crystallized product) is... 3 / 2The electron binding energy, T4, is the 2p electron binding energy of the metallic element M in the crystallized product. 3 / 2 The binding energy of electrons is related to the catalytic activity of composite catalytic materials. That is, the interaction between the metal element M and the framework heteroatom Q in the composite catalytic material can further affect the catalytic activity of the composite catalytic material. When T0' is any value between 0.4 and 0.8 eV, the composite catalytic material can obtain high catalytic activity and effectively improve the conversion rate and acid selectivity of aldehydes and alcohols coupled in the aldehyde and alcohol acid production process.

[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 0.4 and 0.8 eV;

[0130] T0' = T3 - T4 Equation (2). The specific types of electrons in the electron binding energy of metallic element M are the same as the types of electrons in the electron binding energy of metallic element M used to calculate T0.

[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):(0.001~0.045):(5~100):(0.001~0.2):(0.025~0.4); preferably 1:(0.002~1):(0.002~0.04):(5~100):(0.002~0.17):(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 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 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; in another optional embodiment, the framework heteroatom is boron, and the framework heteroatom precursor is selected from one or more of boric acid and borate; in yet another optional embodiment, 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. 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; in another optional embodiment, the framework heteroatom is phosphorus, and the framework heteroatom precursor is selected from one or more of orthophosphoric acid, triethylphosphoric acid, and metaphosphate; in yet another optional embodiment, the framework heteroatom is germanium, and the framework heteroatom precursor is selected from one or more of germanium oxide, germanium alkoxides (e.g., germanium ethanol, germanium isopropoxide), germanium chloride, and sodium germanate.

[0158] 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.

[0159] The metallic element M is selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum, copper and gold; preferably selected from one or more of manganese, iron, cobalt, nickel, palladium, platinum and copper.

[0160] 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).

[0161] 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.

[0162] 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).

[0163] R9(NH2) n Formula (D);

[0164] 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.

[0165] (HOR 10 ) m NH (3m) Equation (E);

[0166] 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;

[0167] (HOOCR 11 ) x NH (3x) Formula (F);

[0168] Where R 11It 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.

[0169] In a further preferred embodiment, the nitrogen-containing ligand is selected from one or more of ethylamine, ethylenediamine, ethanolamine, and ethylenediaminetetraacetic acid.

[0170] In one embodiment, 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 R 13 R 14 R 15 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 independently selected from any integer from 1 to 18, preferably from any integer from 1 to 12; the number of carbon atoms of the aromatic group can be any integer from 6 to 18, preferably from any integer from 6 to 12.

[0171] 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.

[0172] 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.

[0173] 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.

[0174] 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.

[0175] The method for producing acids by oxidizing alcohols and aldehydes disclosed herein can achieve an alcohol conversion rate of over 95% and a carboxylic acid selectivity of over 99% under relatively mild reaction conditions (e.g., 60°C).

[0176] 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.

[0177] 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°.

[0178] 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.

[0179] The scanning electron microscope (SEM) images of the samples were obtained using a Hitachi S4800 high-resolution cold field emission scanning electron microscope.

[0180] 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.

[0181] The cobalt nitrate used in the following embodiments of this disclosure is cobalt nitrate hexahydrate.

[0182] Preparation Example 1

[0183] (1) 1.63 g of 25.05% by weight tetrapropylammonium hydroxide (TPAOH, 0.002 mol) aqueous solution, 20.8 g of tetraethyl silicate (0.1 mol), 0.170 g of tetrabutyl titanate (0.0005 mol) and 9 g of water (0.5 mol) were added sequentially into a 500 mL beaker, placed on a magnetic stirrer with heating and stirring functions and mixed evenly. The mixture was stirred at 80 °C for 4 hours, and the evaporated water was replenished periodically to obtain a colorless and transparent silica gel solution.

[0184] (2) Stir 0.3g of cobalt nitrate hexahydrate (0.001mol) and 1.8g (0.1mol) of water evenly, then add 0.0005mol of ethylenediamine and mix the cobalt aqueous solution with the silicon hydrolysis solution obtained in step (1);

[0185] (3) Add 0.64 g of N-phenyl-3-aminopropyltrimethoxysilane (PHAPTMS) to the mixture in step (2) and stir for 0.5 hours;

[0186] (4) The mixture obtained in step (3) was transferred to a stainless steel sealed reactor and crystallized at 170℃ for 28 hours to obtain a sample. The sample was filtered, washed, dried at 120℃ for 6 hours, and then calcined in a muffle furnace at 550℃ for 6 hours to prepare the composite catalytic material product, denoted as C-1. The XPS diagram of the metal element Co of C-1 is shown below. Figure 1 As shown. The Ti XPS spectrum of C-1 is as follows. Figure 2 As shown, a 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 C-1 is shown below. Figure 3 As shown, the product prepared in this embodiment has a regular shape and uniform size. The XRD pattern of C-1 is shown below. Figure 4 As shown, XRD analysis indicates that it has an MFI structure.

[0187] The BET specific surface area, total pore volume, micropore volume, mesopore volume, and average particle size of the metal nanoparticles contained in the composite material of C-1 are listed in Table 2.

[0188] Comparative Preparation Example 1

[0189] Prepared according to the method of Preparation Example 1, except that no silanizing agent was added, and the resulting product was denoted as DC-1.

[0190] Comparative Preparation Example 2

[0191] 0.03 g of cobalt nitrate hexahydrate and 0.18 g of water were stirred until homogeneous to obtain an aqueous solution of cobalt. Then, 10.2 g of alumina support (purchased from Innochem, catalog number A17263) was added, and the mixture was stirred for 4 hours. The solvent was then evaporated to dryness. The solid was collected and dried at 110 °C for 6 hours, followed by calcination in a muffle furnace at 550 °C for 6 hours. The resulting product was designated DC-2.

[0192] Comparative preparation example 3

[0193] 0.03 g of cobalt nitrate hexahydrate and 0.18 g of water were stirred until homogeneous to obtain an aqueous solution of cobalt. Then, 6 g of titanium-silicon MFI molecular sieve support was added, and the mixture was stirred for 4 hours. The solvent was then evaporated. The solid was collected and dried at 110 °C for 6 hours, followed by calcination in a muffle furnace at 550 °C for 6 hours. The resulting product was designated DC-3.

[0194] The titanium-silicon MFI molecular sieve carrier is prepared according to Preparation Example 1. The difference between Preparation Example 1 and Preparation Example 1 is that step (2) is not performed, that is, cobalt nitrate hexahydrate and ethylenediamine are not added in the molecular sieve synthesis. The rest of the process is the same as Preparation Example 1.

[0195] Preparation Examples 2-9

[0196] Products C-2 to C-9 were prepared according to the method in Example 1, and their proportions, synthesis conditions, and results are listed in Table 1. Other conditions and procedures are the same as in Example 1.

[0197] Example 10

[0198] Cobalt-containing hierarchical porous β-zeolite was prepared by referring to the method in Example 1, but with changes to the formulation and template agent. Tetraethylammonium hydroxide (TEAOH) was used as the template agent. The resulting product was designated C-10. The formulation, synthesis conditions, and results are shown in Table 1. The XRD pattern of C-10 is shown below. Figure 3 As shown, XRD analysis indicates that it has a β-zeolite structure.

[0199] Preparation Example 11

[0200] This embodiment prepared a cobalt-containing hierarchical porous MEL molecular sieve, following the method of Example 1, but with changes to the formulation and template agent. The template agent used was tetrabutylammonium hydroxide (TBAOH). The resulting product was designated C-11. Its formulation, synthesis conditions, and results are shown in Table 1. The XRD pattern of C-11 is shown below. Figure 4 As shown, XRD analysis indicates that it has a MEL molecular sieve structure.

[0201] Preparation Example 12

[0202] The corresponding product was prepared according to the method of Preparation Example 1. The proportions, synthesis conditions, and results are shown in Table 1. Other conditions and operations were the same as in Preparation Example 1, and the obtained product was designated as C-12. The hydrothermal crystallization temperature was 120℃, the hydrothermal crystallization time was 6 days, and the calcination temperature was 870℃, the calcination time was 9 hours.

[0203] 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.

[0204] Table 1

[0205]

[0206] In Table 1, TPAOH is tetrapropylammonium hydroxide, TPABr is tetrapropylammonium bromide, TBAOH is tetrabutylammonium hydroxide, and TEAOH is tetraethylammonium hydroxide; PHAPTMS is N-phenyl-3-aminopropyltrimethoxysilane, APTES is 3-aminopropyltriethoxysilane, KH792 is silane coupling agent KH792 (a bisamino functional group silane, N-aminoethyl-γ-aminopropyltrimethoxysilane); and EDTA is ethylenediaminetetraacetic acid. The reagents used in this disclosure can be obtained through conventional purchasing channels.

[0207] Table 2

[0208]

[0209] 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.

[0210] As shown in Table 2, compared with DC-1 prepared by Comparative Example 1 (without adding silanizing reagent), the present invention adds silanizing reagent during the preparation process, and the prepared C1 to C12 have higher mesopore volumes, indicating that the method provided in this disclosure can effectively expand the pores of molecular sieves.

[0211] Furthermore, compared with DC-1 to DC-3, the composite catalytic materials C-1 to C-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.

[0212] Reaction Examples

[0213] This is used to illustrate the reaction effects of the method for producing acid by oxidizing alcohols and aldehydes provided in this disclosure.

[0214] The catalysts prepared in the above examples and comparative examples were used to catalyze the oxidation of alcohols. 1 mmol of alcohol (see Table 3 for specific alcohols) was mixed with 0.1 mmol of isobutyraldehyde solvent (the molar ratio of alcohol to aldehyde was 10:1), and then 50 mg of catalyst was contacted in a slurry bed reactor. The contact temperature was 60 °C, the contact time was 6 h, and the oxygen pressure was 0.1 MPa. The results are shown in Table 3 below.

[0215] The distribution of the obtained products was determined using an HP-5 capillary column (30m × 0.25mm) on an Agilent 6890N chromatograph.

[0216] Alcohol conversion rate (%) = (number of moles of alcohol involved in the reaction / number of moles of alcohol added) × 100%.

[0217] Carboxylic acid selectivity (%) = number of moles of carboxylic acid / number of moles of alcohol participating in the reaction × 100%.

[0218] Wherein, the number of moles of alcohol participating in the reaction = the number of moles of alcohol fed into the reaction mixture - the number of moles of alcohol remaining in the reaction mixture.

[0219] Table 3

[0220]

[0221] In this disclosure, the T2 value of the stable oxide aggregate of metal element Co, Co3O4, is 781.25 eV; the T2 value of the stable oxide aggregate of manganese, MnO2, is 642.10 eV; the T2 value of the stable oxide aggregate of metal element copper, CuO, is 933.60 eV; and the T2 value of the stable oxide aggregate of iron, Fe2O3, is 710.80 eV.

[0222] Comparative Example 1

[0223] The oxidation reaction was carried out according to the method of reaction example 1 using catalyst C-1, except that catalyst C-1 was replaced with the noble metal catalyst Au / CeO2, otherwise it was the same as the reaction example using catalyst C-1. The reaction results were: alcohol conversion rate 83.1%; aldehyde conversion rate 85.7%; acid selectivity 96.1%.

[0224] The noble metal catalyst Au / CeO2 was obtained according to the method disclosed in the literature C. April, et al. / Journal of Catalysis, 264 (2009), 44–53.

[0225] Based on the data in Table 3 and the reaction results of Comparative Example 1, it can be seen that compared with the catalysts DC-1 (without pore expansion), DC-2 (with alumina as the support), and DC-3 (with titanium silicate MFI molecular sieve as the support, cobalt is supported by impregnation and calcination, and no silanizing reagent is added during preparation) prepared in Comparative Examples 1-3, and the noble metal catalyst Au / CeO2 used in Comparative Example 1, the composite catalysts C-1 to C-12 prepared in the present disclosure exhibit higher catalytic activity in the oxidation of alcohols and aldehydes to produce acids, resulting in higher conversion rates of alcohols and aldehydes and higher selectivity for carboxylic acids.

[0226] 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 containing cobalt 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 4 below.

[0227] Table 4

[0228] Catalyst [T0’ / eV] C-1 0.51 C-5 0.40 C-6 0.57 C-8 0.71 C-10 0.45 C-11 0.42 DC-1 0.01 DC-2 0.03 DC-3 0.04

[0229] According to Table 4 and the test data in Table 3, compared with Comparative Examples 1-3, the T0' obtained by using cobalt as the metal element nanoparticles in Examples 1-11 is 0.4-0.8 eV, which has higher cyclooctene conversion rate, isobutyraldehyde conversion rate and epoxycyclooctene selectivity.

[0230] Reaction Examples 2-4

[0231] The oxidation process for acid production, as described in Example 1, using C-3 as a catalyst and cyclopentanol as the alcohol reactant (aldehyde reactants are listed in Table 5 below), was employed. The reaction effects under different oxidation conditions were tested, and the specific reaction conditions and results are listed in Table 5 below. The catalyst dosage was 50 mg in all cases.

[0232] Table 5

[0233]

[0234] As shown in Table 5, the method provided in this disclosure is applicable to the oxidation reactions of a variety of alcohols and aldehydes (e.g., isovaleraldehyde in reaction example 2), and has a wide range of applications.

[0235] Compared with C-3 as the catalyst in Reaction Example 1, which uses C-3 as the catalyst, Reaction Example 1, with a reaction temperature range of 60-80℃, showed better oxidation reaction effect, higher conversion rate of alcohols and aldehydes, and higher selectivity of carboxylic acids.

[0236] Compared with Reaction Example 1, which used C-3 as the catalyst, Reaction Example 1 had a better oxidation reaction effect with a catalyst-to-alcohol reactant weight ratio in the range of 0.1 to 1, resulting in higher conversion rates of alcohols and aldehydes and higher selectivity of carboxylic acids.

[0237] 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.

[0238] 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.

[0239] 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 producing acids by oxidizing alcohols and aldehydes, characterized in that, Includes the following steps: In the presence of oxygen, alcohols and aldehydes are brought into contact with a catalyst to undergo an oxidation reaction. The alcohol reactants are selected from one or more of 1-butanol, sec-butanol, cyclopentanol, hexanol, 2-methyl-1-butanol, 1-methylcyclopentanol, benzyl alcohol, 1-pentanol, and 2-hexyl-1-octanol; The aldehyde reactants are isobutyraldehyde and / or isovaleraldehyde; The catalyst is a composite catalytic material, which includes a framework heteroatom molecular sieve and a metal element M dispersed in the crystal 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. The heteroatom element Q is selected from one or more 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 binding energy of the electrons of the metal element M in the composite catalytic material is denoted as T1; The binding energy of the electrons of the metal element M in the stable oxide aggregate is denoted as T2. T0 is defined by the following formula (1) as any value between 0.7 and 1.5 eV; T0 = ​​T1 - T2 (1); The composite catalytic material is prepared by a method including 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 method further includes: mixing the alcohol reactant and the aldehyde reactant, and then contacting them with the catalyst to carry out an oxidation reaction; the molar ratio of the alcohol reactant to the aldehyde reactant is 1:(0.01~20).

3. The method according to claim 2, characterized in that, The molar ratio of the alcohol reactant to the aldehyde reactant is 1:(0.05~10).

4. The method according to claim 1, characterized in that, The conditions for the oxidation reaction include: a temperature of 40~100℃; a reaction time of 1~48 hours; a weight ratio of catalyst to alcohol reactant of 0.04~1; and an oxygen pressure of 0.1~0.5MPa.

5. The method according to claim 4, characterized in that, The conditions for the oxidation reaction include: a temperature of 60-80°C; a reaction time of 1.5-24 hours; a weight ratio of catalyst to alcohol reactant of 0.1-1; and an oxygen pressure of 0.1-0.3 MPa.

6. The method according to claim 1, characterized in that, The reactor for the oxidation reaction is selected from any one of the following: a batch reactor, a fixed-bed reactor, a moving-bed reactor, a suspended-bed reactor, or a slurry-bed reactor.

7. The method according to claim 1, characterized in that, The T0 mentioned is any value between 0.8 and 1.4 eV.

8. 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.

9. 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.

10. The method according to claim 9, 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.

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

12. The method according to claim 1, characterized in that, In the composite catalytic material, the molar ratio of framework heteroatom elements to silicon elements is (0.001~0.045):1; The molar ratio of metal M to silicon is (0.001~0.2):

1.

13. The method according to claim 12, characterized in that, In the composite catalytic material, the molar ratio of the framework heteroatom elements to silicon elements is (0.002~0.04):

1.

14. The method according to claim 12, characterized in that, The molar ratio of metallic element M to silicon is (0.002~0.17):

1.

15. The method according to claim 1, characterized in that, The composite catalytic material has a BET specific surface area of ​​400~800 m². 2 / g, with a total pore volume of 0.3~0.65mL / g, a micropore volume of 0.1~0.19mL / g, and a mesopore volume of 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 0.5~8.5nm.

16. The method according to claim 1, characterized in that, The binding energy of the metal element M in the product obtained by calcining the crystallized product is denoted as T3. The binding energy of the electrons 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 0.4 and 0.8 eV; T0' = T3-T4 (2).

17. 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): (0.001~0.045): (5~100): (0.001~0.2): (0.025~0.4).

18. The method according to claim 17, 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): (0.002~0.04): (5~100): (0.002~0.17): (0.025~0.3).

19. 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.

20. 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.

21. 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.

22. The method according to claim 21, characterized in that, The silicon source is selected from at least one of organosilicon grease, solid silica gel, and precipitated silica.

23. The method according to claim 22, 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.

24. The method according to claim 23, 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.

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

26. The method according to claim 23, characterized in that, The silicone grease is selected from one or more of tetramethyl silicate, tetraethyl silicate, tetrabutyl silicate, and dimethyl diethyl silicone grease.

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

28. The method according to claim 27, characterized in that, The template agent is selected from at least one of quaternary ammonium bases, aliphatic amines, and aliphatic alcoholic amines.

29. The method according to claim 28, 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.

30. The method according to claim 29, 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.

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

32. The method according to claim 29, 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.

33. 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.

34. The method according to claim 33, characterized in that, The conditions for the hydrolysis and alcohol removal treatment include: stirring and hydrolyzing at 50~95℃ for 2~8 hours.

35. 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.

36. The method according to claim 35, 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.

37. The method according to claim 35, 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.

38. The method according to claim 35, 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.

39. The method according to claim 38, 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.

40. The method according to claim 35, characterized in that, When 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; when the framework heteroatom is boron, the framework heteroatom precursor is selected from one or more of boric acid and borate; when the framework heteroatom is tin, 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.

41. 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.

42. The method according to claim 41, characterized in that, The precursor of metal M is a water-soluble inorganic salt of the metal element M.

43. The method according to claim 41, 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).

44. 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.

45. The method according to claim 44, 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.

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

47. The method according to claim 46, 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.

48. The method according to claim 45, 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.

49. The method according to claim 48, characterized in that, When n is 2, R9 is one of methylene, ethylene, n-propylene, n-butylene, n-pentylene, and n-hexylene.

50. The method according to claim 45, characterized in that, R 10 It is one of methylene, ethylene, n-propylene, and n-butylene.

51. The method according to claim 45, characterized in that, R 11 It is one of methylene, ethylene, n-propylene, and n-butylene.

52. The method according to claim 45, characterized in that, The nitrogen-containing ligand is selected from one or more of ethylamine, ethylenediamine, ethanolamine, and ethylenediaminetetraacetic acid.

53. 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 number of carbon atoms of the alkyl, alkoxy and amino groups is independently selected from any integer from 1 to 18, and the number of carbon atoms of the aromatic group is any integer from 6 to 18.

54. The method according to claim 53, 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.

55. The method according to claim 54, characterized in that, At least one of N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane.

56. 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.

57. The method according to claim 56, characterized in that, 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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