Supported TEMPO catalyst containing quaternary ammonium salt structure as well as preparation method and application of supported TEMPO catalyst

Abstract

The invention relates to a supported TEMPO catalyst containing a quaternary ammonium salt structure as well as a preparation method and application of the supported TEMPO catalyst, and belongs to the technical field of catalyst preparation. In order to solve the problem of low mass transfer efficiency of a supported TEMPO catalyst in an Anli oxidation system, the invention provides a supported TEMPO catalyst containing a quaternary ammonium salt structure, which takes crosslinked polystyrene microspheres as a carrier, and the loading capacity of TEMPO is 0.2-0.8 mmol / g. According to the invention, the quaternary ammonium salt is introduced into the supported TEMPO catalyst to improve the combination with the oxidant active component, so that the catalytic activity of the catalyst is improved. Due to the introduction of quaternary ammonium salt, the quaternary ammonium salt has a phase transfer function, so that the mass transfer efficiency of the quaternary ammonium salt in an Anelli oxidation system can be effectively improved, and the catalytic activity of the quaternary ammonium salt is improved. The catalyst is used for selectively oxidizing alcohol into aldehyde or ketone, and has high catalytic activity and high selectivity.

Description

Technical Field

[0001] The invention belongs to the technical field of catalyst preparation, and in particular relates to a supported TEMPO catalyst containing a quaternary ammonium salt structure and a preparation method and application thereof. Background Art

[0002] Carbonyl compounds such as aldehydes and ketones are important intermediates for fine chemicals such as medicines, pesticides, synthetic fragrances, and food additives. They are mainly prepared by selective oxidation of corresponding alcohols, which is also the main method for preparing carbonyl compounds in industry. In the traditional reaction process of alcohol oxidation to aldehydes or ketones, it is usually necessary to use excessive chromium reagents, manganese reagents, or high-valent iodine oxidants. For example, the PCC oxidation method is used to prepare aldehydes or ketones. Chlorochromic acid pyridinium salt is used as an oxidant. Under anhydrous conditions, primary alcohols and secondary alcohols can be oxidized to aldehydes and ketones. Since there is water in the reaction system, the generated aldehydes and ketones will form hydrated aldehydes or hydrated ketones, and then continue to oxidize to obtain carboxylic acids, so anhydrous is required in the reaction system. The PDC oxidation method uses chromium trioxide pyridinium salt as an oxidant to oxidize alcohols to the corresponding aldehydes or ketones. Whether it is the PCC oxidation method or the PDC oxidation method, the system will generate tar, the yield is low, and heavy metal chromium reagents are used. Jones oxidation method, Dess-Martin oxidation method, Swern oxidation method, etc. can all selectively oxidize alcohols to the corresponding aldehydes or ketones. However, these oxidant systems have problems such as heavy metal pollution, difficulty in separation, harsh reaction conditions, high cost, over-oxidation, and environmental pollution. As people pay more attention to environmental friendliness and atomic green economic chemistry, the development of new methods for green and sustainable alcohol selective oxidation reactions has become a widely-watched research direction.

[0003] 2,2,6,6-Tetramethylpiperidin-1-oxyl free radical (TEMPO) is a stable nitroxide free radical compound. The catalytic oxidation system formed by it with oxidants such as sodium hypochlorite and iodophenyl diacetic acid can be used for the selective oxidation of alcohols. Compared with the traditional alcohol selective oxidation method, it has the advantages of high efficiency, high selectivity, mild reaction conditions, etc., and has been widely used in the field of organic synthesis. 2,2,6,6-Tetramethylpiperidinyl N-oxide is a typical piperidine nitroxide free radical. It has the functions of capturing free radicals, quenching singlet oxygen and selective oxidation. It is a very effective oxidation catalyst. In organic synthesis, it is used for the selective oxidation of various alcohols and polyols to aldehydes or ketones, among which primary alcohols are oxidized to aldehydes, secondary alcohols are oxidized to ketones, and deep oxidation to carboxylic acid products has low content and high selectivity.

[0004] Commonly used catalytic systems are transition metal / TEMPO, such as Cu / TEMPO, Ru / TEMPO, Fe-TEMPO, bimetallic salt-TEMPO catalytic systems, etc. These metal-involved catalytic reactions will produce certain waste liquids containing metal ions, and the post-treatment of the system is relatively complex. Catalytic systems without the participation of metal ions include NaClO / TEMPO, iodophenyldiacetic acid / TEMPO, hydrogen peroxide / TEMPO, etc. These catalysts are generally homogeneous reactions with high catalytic efficiency and good selectivity. However, as a homogeneous catalyst, TEMPO is difficult to separate and recycle, resulting in increased costs and reduced product purity.

[0005] Supported TEMPO catalysts retain the high activity and selectivity of TEMPO catalysts, and the catalysts are easy to separate and can be reused, which reduces costs and improves product quality. However, supported TEMPO catalysts often have the problem of slow mass transfer during the reaction, resulting in reduced catalytic efficiency. Summary of the invention

[0006] In order to solve the problem of low mass transfer efficiency of supported TEMPO catalysts, the present invention provides a supported TEMPO catalyst containing a quaternary ammonium salt structure and a preparation method and application thereof.

[0007] The technical solution of the present invention:

[0008] A supported TEMPO catalyst containing a quaternary ammonium salt structure, wherein the quaternary ammonium salt has the structural formula:

[0009] R1 and R2 are both alkyl or benzyl, and X is chlorine, bromine or iodine;

[0010] Cross-linked polystyrene microspheres were used as carriers, and the TEMPO loading amount was 0.2-0.8 mmol / g.

[0011] Furthermore, the TEMPO loading is 0.6-0.7 mmol / g.

[0012] A method for preparing a supported TEMPO catalyst containing a quaternary ammonium salt structure comprises the following steps:

[0013] Step 1, drying, freezing, crushing, screening, washing and drying the chloromethylated polystyrene cross-linked microspheres for use as catalyst carriers;

[0014] Step 2, adding amino TEMPO to a first solvent, adding a base and a halogenated alkane or a benzyl halide to the obtained system, heating and reflux under nitrogen protection, after the reaction is completed, washing the system with water, spinning acetonitrile, and extracting with n-hexane to obtain an organic phase, and purifying the organic phase by column chromatography to obtain a 2,2,6,6-tetramethyl-4-(dialkylamino)-1-piperidinyloxy free radical or a 2,2,6,6-tetramethyl-4-(dibenzylamino)-1-piperidinyloxy free radical;

[0015] Step 3, adding the catalyst carrier obtained in step 1 to the second solvent, adding the 2,2,6,6-tetramethyl-4-(dialkylamino)-1-piperidinyloxy free radical or 2,2,6,6-tetramethyl-4-(dibenzylamino)-1-piperidinyloxy free radical obtained in step 2, adding a nucleophilic reaction catalyst, heating and stirring to reflux the reaction, then cooling and filtering, and washing the obtained solid with acetonitrile, water, acetonitrile and dichloromethane in turn, and drying to obtain a supported TEMPO catalyst containing a quaternary ammonium salt structure.

[0016] Furthermore, the crosslinking degree of the chloromethylated polystyrene crosslinked microspheres in step 1 is 4-7%, the chlorine content is 10-20%, and the average particle size is 0.1-0.6 mm.

[0017] Furthermore, the freezing temperature in step 1 is -10 to -25°C, and the pulverization is to pulverize the chloromethylated polystyrene cross-linked microspheres in a low temperature state after freezing.

[0018] Furthermore, the sieving in step 1 is to select crushed particles of 100-200 mesh, the washing is to wash the selected crushed particles with dichloromethane and acetonitrile in sequence, and the drying is to dry at a temperature of 60-120° C. for 6-8 hours.

[0019] Further, in step 2, the first solvent is acetonitrile or tetrahydrofuran, the amount of the first solvent added is 2 to 20 times the mass of amino TEMPO, the base is anhydrous potassium carbonate, sodium hydroxide or sodium tert-butoxide, the amount of the base added is 0.7 to 2 times the amount of amino TEMPO substance, and the halogenated alkane is a halogenated C1-C 16 The normal or isomeric alkane, the benzyl halide is benzyl chloride, benzyl bromide or benzyl iodide, and the amount of the halogenated alkane or benzyl halide added is 3.5 to 5 times the amount of the amino TEMPO substance.

[0020] Furthermore, in step 2, the first solvent is acetonitrile, and the amount of the first solvent added is 5 to 15 times the mass of amino-TEMPO.

[0021] Furthermore, the temperature of the heating reflux in step 2 is 60 to 100° C., and the time of the heating reflux is 6 to 24 hours.

[0022] Furthermore, the temperature of the heating reflux in step 2 is 81° C., and the time of the heating reflux is 8 to 14 hours.

[0023] Furthermore, in step three, the second solvent is one of acetonitrile, acetone, dichloromethane, dichloroethane, dimethylformamide or dimethylacetamide, and the amount of the second solvent added is 20 to 50 times the mass of the catalyst support; the amount of the 2,2,6,6-tetramethyl-4-(dibutylamino)-1-piperidinyloxy free radical added is 0.5 to 2 times the mass of the catalyst support.

[0024] Furthermore, in step three, the second solvent is acetonitrile, and the added amount of the 2,2,6,6-tetramethyl-4-(dibutylamino)-1-piperidinyloxy free radical is 0.9 to 1.1 times the mass of the catalyst carrier.

[0025] Furthermore, the nucleophilic reaction catalyst is DMAP, the amount of the nucleophilic reaction catalyst added is 0.01 to 0.2 times the mass of the catalyst carrier, the temperature of the heating, stirring and reflux is 70 to 81° C., and the time of the heating, stirring and reflux is 10 to 20 hours.

[0026] Furthermore, the amount of the nucleophilic reaction catalyst added is 0.1 to 0.2 times the mass of the catalyst carrier, and the heating, stirring and reflux time is 15 to 18 hours.

[0027] The invention discloses an application of a supported TEMPO catalyst containing a quaternary ammonium salt structure in catalyzing the selective oxidation of alcohols to aldehydes or ketones.

[0028] Beneficial effects of the present invention:

[0029] The present invention provides a method for preparing a cross-linked polystyrene chloride ball-supported TEMPO catalyst containing a quaternary ammonium salt structure, wherein the quaternary ammonium salt is introduced into the supported TEMPO catalyst, and the cationic properties of the quaternary ammonium salt are used to interact with the anion or polar part of the oxidant through electrostatic or hydrogen bonding, thereby enhancing the binding strength between the catalyst and the active component of the oxidant. This enhanced interaction helps to improve the ClO - The transfer efficiency from the aqueous phase to the organic phase increases, the hydrophilicity of the surface is increased, thereby improving the interaction between the catalyst and the solvent, effectively improving its mass transfer efficiency in the Anelli oxidation system, thereby improving its catalytic activity. The supported catalyst can also be used in a fixed bed reaction device to achieve continuous oxidation of fatty alcohols or benzyl alcohol.

[0030] The supported TEMPO catalyst prepared by the present invention has a specific surface area greater than 15m 2 / g, has strong solvent resistance and cyclic stability, and has no obvious decrease in catalytic effect after repeated use for 5 times. The supported TEMPO catalyst prepared by the present invention is used for selective oxidation of alcohol to aldehyde or ketone, has high catalytic activity and high selectivity, can be separated by filtering, and can be recycled. The production process is simplified, the cost is reduced, and it is beneficial to environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The reaction equations of step 2 and step 3 of the supported TEMPO catalyst containing a quaternary ammonium salt structure in Example 1;

[0032] Figure 2 The infrared spectrum of the supported TEMPO catalyst containing a quaternary ammonium salt structure in Example 1;

[0033] Figure 3 This is a thermogravimetric curve of the supported TEMPO catalyst containing a quaternary ammonium salt structure in Example 1. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described below in conjunction with the embodiments, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention shall be included in the protection scope of the present invention. The process equipment or devices not specifically noted in the following embodiments are all conventional equipment or devices in the art. If not specifically specified, the raw materials used in the embodiments of the present invention can be obtained commercially; if not specifically specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0035] Example 1

[0036] This embodiment provides a supported TEMPO catalyst containing a quaternary ammonium salt structure and a preparation method thereof.

[0037] The preparation method of this embodiment specifically comprises the following steps:

[0038] Step 1, drying commercial chloromethylated polystyrene cross-linked microspheres with an average particle size of 0.6 mm and a cross-linking degree of 7% and freezing them to -25°C, then crushing the chloromethylated polystyrene cross-linked microspheres with a high-speed crusher at low temperature, sieving and selecting 100-200 mesh part of the crushed particles, washing them with appropriate amounts of dichloromethane and acetonitrile in turn, and then drying them at 80°C for 8 hours, and using them as catalyst carriers for standby use;

[0039] Step 2: Add 5.03 g of amino TEMPO to a 100 ml reaction bottle, add 50 g of acetonitrile, add 4.05 g of anhydrous potassium carbonate and 21.49 g of n-butane iodide to the obtained system, heat to 80 ° C under nitrogen protection, and reflux for 10 hours. After the reaction is completed, the system is washed with water, spun dry with acetonitrile, and extracted with n-hexane to obtain an organic phase. The organic phase is purified by column chromatography to obtain 6.76 g of a red oily liquid, which is 2,2,6,6-tetramethyl-4-(dibutylamino)amino-1-piperidinyloxy free radical;

[0040] Step 3: Add 7.26 g of the catalyst carrier obtained in step 1 to a 250 ml reaction bottle, add 70 g of acetonitrile, add 3.0 g of 2,2,6,6-tetramethyl-4-(dibutylamino)-1-piperidinyloxy free radical obtained in step 2, add 0.6 g of nucleophilic reaction catalyst 4-dimethylaminopyridine DMAP, heat to 80 ° C, stir and reflux for 16 hours, then cool and filter, wash the obtained solid with acetonitrile, water, acetonitrile and dichloromethane in turn, and obtain 8.04 g of supported TEMPO catalyst containing quaternary ammonium salt structure after drying. The quaternary ammonium salt structure is:

[0041] R1 is n-butyl, R2 is n-butyl, X is chlorine, and the TEMPO loading is 0.39 mmol / g.

[0042] The catalytic performance of the supported TEMPO catalyst containing a quaternary ammonium salt structure obtained in this example, the catalyst carrier obtained in step 1, the cross-linked polystyrene chloride ball powder before loading, and TEMPO were evaluated:

[0043] Weigh 3.25g of benzyl alcohol and place it in a 250ml three-necked flask, then add 30g of acetonitrile and 0.77g of different catalysts, stir and heat to 30°C, then add 30ml of sodium hypochlorite aqueous solution, take samples at regular intervals, and analyze by liquid chromatography. The analysis conditions are C18 chromatographic column, mobile phase is 20% acetonitrile, 80% water, and detection wavelength is 254nm.

[0044] After reacting for 40 minutes, the supported TEMPO catalyst system containing a quaternary ammonium salt structure obtained in this example had a benzyl alcohol content of 0.79%, a benzoic acid content of 0.02%, and a benzaldehyde content of 99.19%.

[0045] After reacting for 40 minutes, the catalyst carrier obtained in step 1 - the cross-linked polystyrene chloride ball powder system before loading had a benzyl alcohol content of 58.37%, a benzoic acid content of 0.02%, and a benzaldehyde content of 41.61%.

[0046] After 40 minutes of reaction, the benzyl alcohol content of the TEMPO system was 0.983%, the benzoic acid content was 0.064%, and the benzaldehyde content was 98.953%.

[0047] Figure 2 The infrared spectrum of the supported TEMPO catalyst containing quaternary ammonium salt structure is shown in Figure 1. The tertiary amine is the first blue curve, the quaternary ammonium salt is the second red curve, and the polystyrene chloride ball is the third black curve. It can be seen from the picture that the polystyrene chloride ball has a wavelength of 1265 cm -1 and 680cm -1 There is an obvious absorption peak of CH2Cl at 1350cm -1 There is an obvious absorption peak of NO free radicals, indicating that the catalyst is loaded on the carrier.

[0048] Figure 3 This is the thermogravimetric curve of the supported TEMPO catalyst containing a quaternary ammonium salt structure. It can be seen from the picture that the supported groups begin to decompose at around 250°C, and the polystyrene skeleton begins to decompose at 400°C.

[0049] Example 2

[0050] This embodiment provides a supported TEMPO catalyst containing a quaternary ammonium salt structure and a preparation method thereof.

[0051] The preparation method of this embodiment specifically comprises the following steps:

[0052] Step 1, drying commercial chloromethylated polystyrene cross-linked microspheres with an average particle size of 0.6 mm and a cross-linking degree of 7% and freezing them to -25°C, then crushing the chloromethylated polystyrene cross-linked microspheres with a high-speed crusher at low temperature, sieving and selecting 100-200 mesh part of the crushed particles, washing them with appropriate amounts of dichloromethane and acetonitrile in turn, and then drying them at 80°C for 8 hours, and using them as catalyst carriers for standby use;

[0053] Step 2: Add 4.17 g of amino TEMPO to a 100 ml reaction bottle, add 40 g of acetonitrile, add 3.35 g of anhydrous potassium carbonate and 16.68 g of benzyl bromide to the obtained system, heat to 80 ° C under nitrogen protection, and reflux for 10 hours. After the reaction is completed, the system is washed with water, spin-dried with acetonitrile, and extracted with n-hexane to obtain an organic phase. The organic phase is purified by column chromatography to obtain 5.45 g of a red solid, which is 2,2,6,6-tetramethyl-4-(dibenzylamino)-1-piperidinyloxy free radical;

[0054] Step 3: Add 7.02g of the catalyst carrier obtained in step 1 to a 250ml reaction bottle, add 70g of acetonitrile, add 5.45g of the 2,2,6,6-tetramethyl-4-(dibenzylamino)-1-piperidinyloxy free radical obtained in step 2, add 0.6g of nucleophilic reaction catalyst 4-dimethylaminopyridine DMAP, heat to 80°C, stir and reflux for 16h, then cool and filter, wash the obtained solid with acetonitrile, water, acetonitrile and dichloromethane in turn, and obtain 8.17g of supported TEMPO catalyst containing quaternary ammonium salt structure after drying, and the quaternary ammonium salt structure is:

[0055] R1 is benzyl, R2 is benzyl, X is chlorine, and the TEMPO loading is 0.40 mmol / g.

[0056] Example 3

[0057] This embodiment provides a supported TEMPO catalyst containing a quaternary ammonium salt structure and a preparation method thereof.

[0058] The preparation method of this embodiment specifically comprises the following steps:

[0059] Step 1, drying commercial chloromethylated polystyrene cross-linked microspheres with an average particle size of 0.6 mm and a cross-linking degree of 7% and freezing them to -25°C, then crushing the chloromethylated polystyrene cross-linked microspheres with a high-speed crusher at low temperature, sieving and selecting 100-200 mesh part of the crushed particles, washing them with appropriate amounts of dichloromethane and acetonitrile in turn, and then drying them at 80°C for 8 hours, and using them as catalyst carriers for standby use;

[0060] Step 2: Add 5.00 g of amino TEMPO to a 100 ml reaction bottle, add 50 g of acetonitrile, add 3.05 g of sodium tert-butoxide and 21.51 g of isobutyl iodide to the obtained system, heat to 80 ° C under nitrogen protection, and reflux for 10 hours. After the reaction is completed, the system is washed with water, spin-dried with acetonitrile, and extracted with n-hexane to obtain an organic phase. The organic phase is purified by column chromatography to obtain 6.97 g of a red oily liquid, which is 2,2,6,6-tetramethyl-4-(diisobutylamino)-1-piperidinyloxy free radical;

[0061] Step 3: Add 7.00 g of the catalyst carrier obtained in step 1 to a 250 ml reaction bottle, add 70 g of acetonitrile, add 3.0 g of 2,2,6,6-tetramethyl-4-(diisobutylamino)-1-piperidinyloxy free radical obtained in step 2, add 0.6 g of nucleophilic reaction catalyst 4-dimethylaminopyridine DMAP, heat to 80 ° C, stir and reflux for 16 hours, then cool and filter, wash the obtained solid with acetonitrile, water, acetonitrile and dichloromethane in turn, and obtain 8.86 g of supported TEMPO catalyst containing a quaternary ammonium salt structure after drying. The quaternary ammonium salt structure is

[0062] R1 is isobutyl, R2 is isobutyl, X is chlorine, and the TEMPO loading is 0.67 mmol / g.

[0063] Example 4

[0064] This embodiment provides a supported TEMPO catalyst containing a quaternary ammonium salt structure and a preparation method thereof.

[0065] The preparation method of this embodiment specifically comprises the following steps:

[0066] Step 1, drying commercial chloromethylated polystyrene cross-linked microspheres with an average particle size of 0.6 mm and a cross-linking degree of 7% and freezing them to -25°C, then crushing the chloromethylated polystyrene cross-linked microspheres with a high-speed crusher at low temperature, sieving and selecting 100-200 mesh part of the crushed particles, washing them with appropriate amounts of dichloromethane and acetonitrile in turn, and then drying them at 80°C for 8 hours, and using them as catalyst carriers for standby use;

[0067] Step 2: Add 5.11 g of amino TEMPO to a 100 ml reaction bottle, add 50 g of acetonitrile, add 1.68 g of potassium hydroxide and 27.12 g of n-heptane iodide to the obtained system, heat to 80 ° C under nitrogen protection, and reflux for 10 hours. After the reaction is completed, the system is washed with water, acetonitrile is spin-dried, and n-hexane is extracted to obtain an organic phase. The organic phase is purified by column chromatography to obtain 7.12 g of a red solid, which is 2,2,6,6-tetramethyl-4-(diheptylamino)-1-piperidinyloxy free radical;

[0068] Step 3: Add 7.03 g of the catalyst carrier obtained in step 1 to a 250 ml reaction bottle, add 70 g of acetonitrile, add 4.2 g of the 2,2,6,6-tetramethyl-4-(diheptylamino)-1-piperidinyloxy free radical obtained in step 2, add 0.6 g of nucleophilic reaction catalyst 4-dimethylaminopyridine DMAP, heat to 80 ° C, stir and reflux for 16 hours, then cool and filter, wash the obtained solid with acetonitrile, water, acetonitrile and dichloromethane in turn, and obtain 7.89 g of supported TEMPO catalyst containing a quaternary ammonium salt structure after drying. The quaternary ammonium salt structure is R1 is n-heptyl, R2 is n-heptyl, X is chlorine (in the embodiment, R1 and R2 should be specific alkyl groups corresponding to the halogenated alkane used), and the TEMPO loading is 0.30 mmol / g.

Claims

1. A supported TEMPO catalyst containing a quaternary ammonium salt structure, characterized in that: The quaternary ammonium salt structural formula is: R1 and R2 are both alkyl or benzyl, and X is chlorine, bromine or iodine; Cross-linked polystyrene microspheres were used as carriers, and the TEMPO loading amount was 0.2-0.8 mmol / g.

2. A method for preparing a supported TEMPO catalyst containing a quaternary ammonium salt structure as claimed in claim 1, characterized in that: The steps include: Step 1, drying, freezing, crushing, screening, washing and drying the chloromethylated polystyrene cross-linked microspheres for use as catalyst carriers; Step 2, adding amino TEMPO to a first solvent, adding a base and a halogenated alkane or a benzyl halide to the obtained system, heating and reflux under nitrogen protection, after the reaction is completed, washing the system with water, spinning acetonitrile, and extracting with n-hexane to obtain an organic phase, and purifying the organic phase by column chromatography to obtain a 2,2,6,6-tetramethyl-4-(dialkylamino)-1-piperidinyloxy free radical or a 2,2,6,6-tetramethyl-4-(dibenzylamino)-1-piperidinyloxy free radical; Step 3, adding the catalyst carrier obtained in step 1 to the second solvent, adding the 2,2,6,6-tetramethyl-4-(dialkylamino)-1-piperidinyloxy free radical or 2,2,6,6-tetramethyl-4-(dibenzylamino)-1-piperidinyloxy free radical obtained in step 2, adding a nucleophilic reaction catalyst, heating and stirring to reflux the reaction, then cooling and filtering, and washing the obtained solid with acetonitrile, water, acetonitrile and dichloromethane in turn, and drying to obtain a supported TEMPO catalyst containing a quaternary ammonium salt structure.

3. The preparation method of the supported TEMPO catalyst containing quaternary ammonium salt structure according to claim 2, characterized in that, The cross-linking degree of the chloromethylated polystyrene cross-linked microspheres in step 1 is 4-7%, the chlorine content is 10-20%, and the average particle size is 0.1-0.6 mm.

4. The preparation method of the supported TEMPO catalyst containing quaternary ammonium salt structure according to claim 2, characterized in that, The freezing temperature in step 1 is -10 to -25°C, and the crushing is to crush the chloromethylated polystyrene cross-linked microspheres in a low-temperature state after freezing.

5. The preparation method of the supported TEMPO catalyst containing quaternary ammonium salt structure according to claim 2, characterized in that, The sieving in step 1 is to sieve out crushed particles of 100 to 200 meshes, the washing is to wash the sieved crushed particles with dichloromethane and acetonitrile in sequence, and the drying is to dry at a temperature of 60 to 120° C. for 6 to 8 hours.

6. The preparation method of the supported TEMPO catalyst containing quaternary ammonium salt structure according to claim 2, characterized in that, Step 2: The first solvent is acetonitrile or tetrahydrofuran, and the amount of the first solvent added is 2 to 20 times the mass of amino TEMPO; the base is anhydrous potassium carbonate, sodium hydroxide or sodium tert-butoxide, and the amount of the base added is 0.7 to 2 times the amount of amino TEMPO substance; the halogenated alkane is a halogenated C1-C 16 The normal or isomeric alkane, the benzyl halide is benzyl chloride, benzyl bromide or benzyl iodide, and the amount of the halogenated alkane or benzyl halide added is 3.5 to 5 times the amount of the amino TEMPO substance.

7. The preparation method of the supported TEMPO catalyst containing quaternary ammonium salt structure according to claim 2, characterized in that, The temperature of the heating reflux in step 2 is 60-100° C., and the time of the heating reflux is 6-24 hours.

8. The preparation method of the supported TEMPO catalyst containing quaternary ammonium salt structure according to claim 2, characterized in that, Step 3: The second solvent is one of acetonitrile, acetone, dichloromethane, dichloroethane, dimethylformamide or dimethylacetamide, and the amount of the second solvent added is 20 to 50 times the mass of the catalyst support; the amount of the 2,2,6,6-tetramethyl-4-(dibutylamino)-1-piperidinyloxy free radical added is 0.5 to 2 times the mass of the catalyst support.

9. The preparation method of the supported TEMPO catalyst containing quaternary ammonium salt structure according to claim 2, characterized in that, The nucleophilic reaction catalyst is DMAP, the amount of the nucleophilic reaction catalyst added is 0.01 to 0.2 times the mass of the catalyst carrier, the temperature of the heating, stirring and reflux is 70 to 81° C., and the time of the heating, stirring and reflux is 10 to 20 hours.

10. Use of the supported TEMPO catalyst containing a quaternary ammonium salt structure as claimed in claim 1 in catalyzing the selective oxidation of alcohols to aldehydes or ketones.

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