Carbazolyl porous organic matter polymer catalyst and method for preparing furandicarboxylic acid through catalytic oxidation of 5-hydroxymethylfurfural

Abstract

The invention discloses a carbazolyl porous organic polymer catalyst for preparing furandicarboxylic acid through catalytic oxidation of 5-hydroxymethylfurfural. The method comprises the following steps: by taking a carbazolyl porous organic polymer as a carrier, loading a metal salt, and performing high-temperature reduction to obtain the carbazolyl porous organic polymer loaded metal catalyst. The catalyst can efficiently catalyze 5-hydroxymethylfurfural to prepare furandicarboxylic acid, and both the conversion rate and the selectivity can reach 80% or above. Compared with a traditional heterogeneous catalyst, the catalyst has the advantages of high thermal stability, good catalytic activity, difficult loss of active components and long service life.

Description

Technical Field

[0001] The invention relates to the field of chemistry and chemical engineering, in particular to a method for preparing furandicarboxylic acid by catalytic oxidation of 5-hydroxymethylfurfural with a carbazole-based porous organic polymer catalyst. Background Art

[0002] There are thousands of downstream derivatives of bio-based new materials, covering a wide range of fields, and they are green, environmentally friendly, and have renewable raw materials. According to the OECD's forecast, at least $800 billion of petrochemical products can be replaced by bio-based products in the next 10 years, and the market gap is nearly $600 billion.

[0003] The bio-based new material industry chain represented by HMF-FDCA-PEF has attracted more and more attention from the global academic and industrial circles. However, this industry chain is not yet complete and there are technical bottlenecks. For example, the commercialization technology of HMF-FDCA is not yet mature; the upstream and downstream chains have not yet achieved a virtuous cycle and have not yet formed a complete industry chain. 2,5-furandicarboxylic acid (FDCA) is a very important type of bio-based platform molecule in this industry chain. Starting from FDCA, it can prepare a variety of high-value-added chemicals, among which the most attractive application is as a monomer for polyester. 2,5-furandicarboxylic acid has a high degree of similarity with the traditional petroleum-based monomer terephthalic acid in structure and chemical properties, so it can replace or partially replace terephthalic acid to produce biomass-based polyester products. At present, the annual production of polyethylene terephthalate (PET) in the world is as high as 70 million tons. Even if FDCA can only partially replace PTA, it will be a huge emerging market. Therefore, the development of efficient HMF oxidation technology to prepare FDCA is of great significance for promoting the development of the entire PEF industry chain.

[0004] Carbazole-based porous organic polymer is an important polymer material with large specific surface area and high thermal stability. It has great potential as a catalyst carrier. Since there are uniformly distributed nitrogen atoms on the skeleton of carbazole-based porous organic polymer, and nitrogen atoms have certain interactions with metals, the uniformly distributed nitrogen atoms can activate the active sites of metal oxides on the one hand, and reduce the loss of active components during the reaction on the other hand. Summary of the invention

[0005] Aiming at the technical difficulty of preparing furandicarboxylic acid by efficient catalytic oxidation of 5-hydroxymethylfurfural, the present invention uses a carbazole-based porous organic polymer as a catalyst carrier, which can activate metal active centers and stabilize active centers due to its large specific surface area, high nitrogen content, and uniform distribution of nitrogen atoms in the polymer skeleton. The present invention obtains a polymer material with uniformly distributed nitrogen atoms in the structural unit by polymerizing a carbazole-based porous organic polymer, and then supports the active components of palladium, manganese, etc. on the polymer skeleton by a wet impregnation method, and obtains a supported cobalt manganese oxide catalyst with high activity and stability after drying and calcination.

[0006] According to the present invention, the carbazole-based porous organic polymer-supported transition metal oxide catalyst can be prepared according to the following method: According to the present invention, the method uses a carbazole-based porous organic polymer as a carrier, and obtains a metal catalyst supported by the carbazole-based porous organic polymer by post-loading a metal salt and performing high-temperature reduction.

[0007] According to the present invention, it is characterized in that it can be prepared according to the following steps: 1,3,5-tri(9-carbazolyl)benzene is dissolved in an organic solvent, Lewis acid is used as a catalyst, and the mixture is stirred at room temperature for 5-36 h under a nitrogen atmosphere. After the reaction is completed, a carbazolyl porous organic polymer is obtained by suction filtration and vacuum drying.

[0008] According to the present invention, the organic solvent is one or more of chloroform, dichloromethane and dichloroethane.

[0009] According to the present invention, the Lewis acid is one or more of ferric chloride, aluminum chloride and tin tetrachloride.

[0010] According to the present invention, the preparation method comprises the steps of: 1) Add 1%-10 wt% of metal salt to the carbazole-based porous organic polymer, add ethanol, stir at 20-60°C and soak overnight; 2) After the impregnation, the ethanol is removed and the catalyst is reduced in a hydrogen atmosphere at 250-400° C. for 2-5 h to obtain the polycarbazole-based catalyst.

[0011] According to the present invention, the metal salt includes one or more of cobalt acetate, cobalt nitrate, manganese acetate, manganese sulfate, palladium chloride and palladium nitrate.

[0012] According to the invention, the invention can be applied to the reaction of preparing furandicarboxylic acid by oxidation of 5-hydroxymethylfurfural.

[0013] A catalyst for preparing furandicarboxylic acid by catalytic oxidation of 5-hydroxymethylfurfural, comprising a catalyst prepared by the method described.

[0014] A method for preparing furandicarboxylic acid by catalytic oxidation of 5-hydroxymethylfurfural comprises the following steps: adding a solvent to a carbazole-based porous organic polymer catalyst and 5-hydroxymethylfurfural to mix evenly, and subjecting the mixture to a high-temperature and high-pressure oxidation reaction to obtain furandicarboxylic acid.

[0015] The solvent is selected from any one of acetonitrile, furan and dichloromethane; the high temperature and high pressure oxidation reaction refers to the reaction at 60-150° C. and a reaction oxygen pressure of 0.1-2.0 MPa for 1-12 h.

[0016] The amount of the carbazole-based porous organic polymer catalyst is 0.1-100% of the mass of 5-hydroxymethylfurfural.

[0017] Beneficial effects of the present invention: 1. The carbazole-based porous organic polymer carrier has a higher specific surface area and is easier to load active components.

[0018] 2. Due to the presence of a large number of nitrogen atoms in the skeleton, the interaction between the catalyst and the metal stabilizes the active center. The catalyst has good reusability and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the TEM characterization image of material A obtained in Example 1.

[0020] Figure 2 This is the nitrogen adsorption-desorption curve of material A obtained in Example 1. DETAILED DESCRIPTION

[0021] The method provided by the present invention is described in detail below in conjunction with embodiments, but the present invention is not limited in any form.

[0022] Example 1 Preparation of Material A 1) Weigh 2.0 g of ferric chloride, replace with nitrogen, add 60 ml of anhydrous chloroform, and then add 0.8 g of 1,3,5-tri(9-carbazolyl)benzene. Stir for 36 h at room temperature, and obtain the carbazolyl porous organic polymer by suction filtration and drying.

[0023] 2) Weigh 0.8 g of carbazole-based porous organic polymer, add 500 mg of cobalt acetate tetrahydrate, add 5 ml of ethanol, and stir at 40°C for 24 h.

[0024] 3) After the impregnation, the ethanol was removed by a rotary evaporator, dried in an oven at 80°C for 12 h, and reduced in a tube furnace at 300°C for 3 h to obtain material A.

[0025] TEM electron microscope images show that the catalyst has abundant amorphous pore structures, which is conducive to the entry and exit of reaction substrates; Figure 1 This is the TEM image of material A obtained in Example 1.

[0026] From the N2 adsorption-desorption curve of material A, it can be calculated that its specific surface area is as high as 500 m 2 / g, and its adsorption-desorption curve is not closed, indicating that in addition to the microporous structure, there are also abundant multi-level pore structures; Figure 2 This is the nitrogen adsorption-desorption curve of material A obtained in Example 1.

[0027] Example 2 Preparation of Material BE The preparation method of material BE is the same as that of material A, except for the selection of metal salt, loading amount and calcination temperature. The obtained materials are listed in Table 1.

[0028] Table 1 Metal salts, loadings and calcination temperatures used in materials BE

[0029] Example 3 30 mg of the synthesized catalyst A and 1.2 g of HMF were added to a high-pressure reactor, 10 ml of acetonitrile was used as the reaction solvent, the oxygen pressure was 1.2 MPa, the reaction temperature was 130°C, and the reaction was carried out for 6 h. After the reaction was completed and the temperature was lowered to room temperature, the HMF conversion rate was 90% and the selectivity of furandicarboxylic acid was 82% by high-performance liquid chromatography.

[0030] Example 4 40 mg of the synthesized catalyst B and 1 g of HMF were added to a high-pressure reactor, 20 ml of acetonitrile was used as the reaction solvent, the oxygen pressure was 0.8 MPa, the reaction temperature was 150 °C, and the reaction was carried out for 10 h. After the reaction was completed and the temperature was lowered to room temperature, the HMF conversion rate was 90% and the selectivity of furandicarboxylic acid was 88% by high-performance liquid chromatography.

[0031] Example 5 15 mg of the synthesized catalyst C and 0.8 g of HMF were added to a high-pressure reactor, 10 ml of acetonitrile was used as the reaction solvent, the oxygen pressure was 0.5 MPa, the reaction temperature was 130 °C, and the reaction was carried out for 4 h. After the reaction was completed and the temperature was lowered to room temperature, the HMF conversion rate was 99% and the selectivity of furandicarboxylic acid was 75% by high-performance liquid chromatography.

[0032] Example 6 60 mg of the synthesized catalyst D and 1.0 g of HMF were added to a high-pressure reactor, 15 ml of acetonitrile was used as the reaction solvent, the oxygen pressure was 1.2 MPa, the reaction temperature was 80 °C, and the reaction was carried out for 6 h. After the reaction was completed and the temperature was lowered to room temperature, the HMF conversion rate was 91% and the selectivity of furandicarboxylic acid was 82% by high-performance liquid chromatography.

[0033] Example 7 30 mg of the synthesized catalyst E and 1.2 g of HMF were added to a high-pressure reactor, 20 ml of acetonitrile was used as the reaction solvent, the oxygen pressure was 2.0 MPa, the reaction temperature was 100 °C, and the reaction was carried out for 10 h. After the reaction was completed and the temperature was lowered to room temperature, the HMF conversion rate was 95% and the selectivity of furandicarboxylic acid was 87% by high-performance liquid chromatography.

Claims

1. A method for preparing a carbazole-based porous organic polymer catalyst, characterized in that: The carbazole-based porous organic polymer is used as a carrier, a metal salt is loaded later, and a metal catalyst loaded on the carbazole-based porous organic polymer is obtained through high-temperature reduction.

2. The method for preparing a carbazole-based porous organic polymer catalyst according to claim 1, characterized in that: The carbazole-based porous organic polymer support was prepared according to the following steps: 1,3,5-tri(9-carbazolyl)benzene is dissolved in an organic solvent, Lewis acid is used as a catalyst, and the mixture is stirred at room temperature for 5-36 h under a nitrogen atmosphere. After the reaction is completed, a carbazolyl porous organic polymer is obtained by suction filtration and vacuum drying.

3. The method for preparing the carbazole-based porous organic polymer catalyst according to claim 2, characterized in that: The organic solvent is one or more of chloroform, dichloromethane and dichloroethane.

4. The method for preparing the carbazole-based porous organic polymer catalyst according to claim 2, characterized in that: The Lewis acid is one or more of ferric chloride, aluminum chloride and tin tetrachloride.

5. The method for preparing the carbazole-based porous organic polymer catalyst according to claim 1, characterized in that: The preparation method is as follows: (1) Add 1%-10 wt% of metal salt to a carbazole-based porous organic polymer, add ethanol, stir at 20-60°C and soak overnight; (2) After the impregnation, the ethanol is removed and the catalyst is reduced in a hydrogen atmosphere at 250-400°C for 2-5 h to obtain a carbazole-based porous organic polymer catalyst.

6. The method for preparing the carbazole-based porous organic polymer catalyst according to claim 5, characterized in that: The metal salt includes one or more of cobalt acetate, cobalt nitrate, manganese acetate, manganese sulfate, palladium chloride and palladium nitrate.

7. A catalyst for catalytic oxidation of 5-hydroxymethylfurfural to prepare furandicarboxylic acid, characterized in that: The invention comprises a catalyst prepared by the method according to any one of claims 1 to 6.

8. A method for preparing furandicarboxylic acid by catalytic oxidation of 5-hydroxymethylfurfural, characterized in that: The carbazole-based porous organic polymer catalyst and 5-hydroxymethylfurfural are mixed evenly by adding a solvent, and then subjected to a high-temperature and high-pressure oxidation reaction to obtain furandicarboxylic acid.

9. The method for preparing furandicarboxylic acid by catalytic oxidation of 5-hydroxymethylfurfural according to claim 8, characterized in that: The solvent is selected from any one of acetonitrile, furan and dichloromethane; the high temperature and high pressure oxidation reaction refers to the reaction at 60-150° C. and a reaction oxygen pressure of 0.1-2.0 MPa for 1-12 h.

10. The method for preparing furandicarboxylic acid by catalytic oxidation of 5-hydroxymethylfurfural according to claim 8, characterized in that: The amount of the carbazole-based porous organic polymer catalyst is 0.1-100% of the mass of 5-hydroxymethylfurfural.

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