Carbazole-based porous organic polymer catalysts and catalytic oxidation of 5-hydroxymethylfurfural to furandicarboxylic acid

Abstract

The application discloses a kind of carbazole-based porous organic polymer catalysts for catalytic oxidation 5-hydroxymethylfurfural to prepare furandicarboxylic acid.The method uses carbazole-based porous organic polymer as carrier, through post-loading metal salt, and obtains carbazole-based porous organic polymer supported metal catalyst by high-temperature reduction.The catalyst can efficiently catalyze 5-hydroxymethylfurfural to prepare furandicarboxylic acid, and the conversion rate and selectivity can reach more than 80%.Compared with traditional heterogeneous catalysts, the catalyst has high thermal stability, good catalytic activity, and the active component is not easy to lose, so the service life of the catalyst is long.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical engineering, in particular to a method for preparing furandicarboxylic acid by catalytic oxidation of 5-hydroxymethylfurfural using a carbazolyl porous organic polymer catalyst. BACKGROUND

[0002] There are thousands of downstream derivatives of bio-based new materials, covering a wide range of fields, and having the characteristics of green, environmental friendly, and renewable raw materials. According to the OECD prediction, at least 800 billion US dollars of petrochemical products can be replaced by bio-based products in the next 10 years, and the market gap is nearly 600 billion US dollars.

[0003] The HMF-FDCA-PEF bio-based new material industry chain has attracted more and more attention from the global academic and industrial circles. However, this industry chain is not complete at present, and there are technical bottlenecks, for example, the commercialization technology of HMF-FDCA is not mature enough; the upstream and downstream chains have not realized benign circulation, and a complete industry chain has not been formed. 2,5-furandicarboxylic acid (FDCA) is a very important bio-based platform molecule in this industry chain. From FDCA, it can be prepared into a variety of high value-added chemicals, of which the most attractive application is as a monomer for polyester. 2,5-furandicarboxylic acid has high similarity in structure and chemical properties with traditional petroleum-based terephthalic acid, and therefore can replace or partially replace terephthalic acid to manufacture biomass-based polyester products. The global annual output of polyethylene terephthalate (PET) is as high as 7000 million tons, and even if FDCA can only partially replace PTA, it will also be a huge emerging market. Therefore, developing an efficient HMF oxidation process to prepare FDCA is of great significance for promoting the development of the PEF whole industry chain.

[0004] Carbazolyl porous organic polymer is an important polymer material, which has the characteristics of large specific surface area and high thermal stability, and has great potential as a catalyst carrier. Because the carbazolyl porous organic polymer skeleton has uniformly distributed nitrogen atoms, and the nitrogen atoms have certain interaction with metals. Therefore, the uniformly distributed nitrogen atoms activate the active sites of metal oxides on one hand; on the other hand, reduce the loss of active components in the reaction process. SUMMARY

[0005] In view of the technical problem of high-efficiency catalytic oxidation of 5-hydroxymethylfurfural to prepare furandicarboxylic acid, the carbazolyl porous organic polymer is used as a catalyst carrier, and the carbazolyl porous organic polymer has a large specific surface area, a high nitrogen content, and nitrogen atoms are uniformly distributed in the polymer skeleton, so that the metal active center can be activated and the active center can be stabilized. The carbazolyl porous organic polymer is obtained by polymerization of a carbazolyl monomer, and the polymer material with uniformly distributed nitrogen atoms in a structural unit is obtained. Then, the active components, palladium and manganese, are loaded on the polymer skeleton by a wet impregnation method, and the active and stable supported cobalt-manganese oxide catalyst is obtained by drying and calcining.

[0006] According to the present application, the carbazolyl porous organic polymer supported transition metal oxide catalyst can be prepared by the following method:

[0007] According to the present application, the method uses the carbazolyl porous organic polymer as a carrier, and a metal salt is loaded by post-loading, and a metal catalyst supported by the carbazolyl porous organic polymer is obtained by high-temperature reduction.

[0008] According to the present application, it can be prepared by the following steps:

[0009] The 1,3,5-tris(9-carbazolyl)benzene is dissolved in an organic solvent, a Lewis acid is used as a catalyst, and stirring is performed at room temperature under a nitrogen atmosphere for 5-36 h. After the reaction is completed, the carbazolyl porous organic polymer is obtained by suction filtration and vacuum drying.

[0010] According to the present application, the organic solvent is one or more of chloroform, dichloromethane, and dichloroethane.

[0011] According to the present application, the Lewis acid is one or more of ferric chloride, aluminum chloride, and tin tetrachloride.

[0012] According to the present application, the preparation method comprises the following steps:

[0013] 1) The carbazolyl porous organic polymer is added with 1%-10 wt% of a metal salt, ethanol is added, and stirring is performed under the condition of 20-60°C, and then impregnation is performed overnight;

[0014] 2) After the impregnation is completed, the ethanol is removed, and reduction is performed at 250-400°C under a hydrogen atmosphere for 2-5 h to obtain the polycarbazolyl catalyst.

[0015] According to the present application, the metal salt comprises one or more of cobalt acetate, cobalt nitrate, manganese acetate, manganese sulfate, palladium chloride, and palladium nitrate.

[0016] According to the present application, it can be applied in the reaction of 5-hydroxymethylfurfural oxidation to prepare furandicarboxylic acid.

[0017] A catalyst for catalytic oxidation of 5-hydroxymethylfurfural to prepare furandicarboxylic acid, comprising a catalyst prepared by the method.

[0018] A method for catalytic oxidation of 5-hydroxymethylfurfural to prepare furandicarboxylic acid, wherein a carbazole-based porous organic polymer catalyst is mixed with 5-hydroxymethylfurfural in a solvent, and then furandicarboxylic acid is obtained through high-temperature and high-pressure oxidation reaction.

[0019] The solvent is selected from any one of acetonitrile, furan and dichloromethane; the high-temperature and high-pressure oxidation reaction refers to a reaction under the conditions of 60-150 DEG C, 0.1-2.0 MPa of oxygen pressure and 1-12 h.

[0020] The amount of the carbazole-based porous organic polymer catalyst is 0.1-100 % of the mass of 5-hydroxymethylfurfural.

[0021] The present application has the following beneficial effects:

[0022] 1. The carbazole-based porous organic polymer carrier has a higher specific surface area and is easier to load active components.

[0023] 2. Due to the presence of a large number of nitrogen atoms in the skeleton, the interaction with metals plays a role in stabilizing the active center. The catalyst has good reusability and long service life. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A TEM characterization graph of material A obtained in Example 1.

[0025] Figure 2 A nitrogen adsorption-desorption curve of material A obtained in Example 1. DETAILED DESCRIPTION

[0026] The method provided by the present application is described in detail below in combination with examples, but does not limit the present application in any form.

[0027] Example 1

[0028] Preparation of material A

[0029] 1) 2.0 g of iron chloride is weighed, replaced with nitrogen, added with 60 ml of anhydrous chloroform, and then 0.8 g of 1,3,5-tris (9-carbazolyl) benzene is added, stirred at room temperature for 36 h, and then a carbazole-based porous organic polymer is obtained through suction filtration and drying.

[0030] 2) 0.8 g of the carbazole-based porous organic polymer is weighed, 500 mg of cobalt acetate tetrahydrate is added, 5 ml of ethanol is added, and then stirred at 40 DEG C for 24 h.

[0031] 3) After the impregnation, the ethanol was removed by 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.

[0032] TEM pictures show that the catalyst has abundant amorphous pore structure, which is beneficial to the access of the reaction substrate; Figure 1 TEM picture of material A obtained from Example 1.

[0033] The specific surface area of material A is as high as 500 m 2 / g calculated from the N2adsorption-desorption curve, and the adsorption-desorption curve is not closed, indicating that there is abundant hierarchical pore structure in addition to the microporous structure; Figure 2 N2adsorption-desorption curve of material A obtained from Example 1.

[0034] Preparation of materials B-E of Example 2

[0035] The preparation method of materials B-E is the same as that of material A, except that the selection of metal salt, loading amount and calcination temperature, and the obtained materials are listed in Table 1.

[0036] Table 1 Metal salt, loading amount and calcination temperature used for materials B-E

[0037]

[0038] Example 3

[0039] 30 mg of synthesized catalyst A and 1.2 g of HMF were added to a high-pressure reaction kettle, 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 reduced to room temperature, the HMF conversion rate was 90% and the furan dicarboxylic acid selectivity was 82% by using high-performance liquid chromatography analysis method.

[0040] Example 4

[0041] 40 mg of synthesized catalyst B and 1 g of HMF were added to a high-pressure reaction kettle, 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 reduced to room temperature, the HMF conversion rate was 90% and the furan dicarboxylic acid selectivity was 88% by using high-performance liquid chromatography analysis method.

[0042] Example 5

[0043] Synthesized 15 mg of catalyst C and 0.8 g of HMF were added to a high-pressure reaction kettle, 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 time was 4 h. After the reaction was completed and the temperature was reduced to room temperature, the HMF conversion rate was 99% and the furandicarboxylic acid selectivity was 75% by using high-performance liquid chromatography analysis method.

[0044] Example 6

[0045] Synthesized 60 mg of catalyst D and 1.0 g of HMF were added to a high-pressure reaction kettle, 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 time was 6 h. After the reaction was completed and the temperature was reduced to room temperature, the HMF conversion rate was 91% and the furandicarboxylic acid selectivity was 82% by using high-performance liquid chromatography analysis method.

[0046] Example 7

[0047] Synthesized 30 mg of catalyst E and 1.2 g of HMF were added to a high-pressure reaction kettle, 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 time was 10 h. After the reaction was completed and the temperature was reduced to room temperature, the HMF conversion rate was 95% and the furandicarboxylic acid selectivity was 87% by using high-performance liquid chromatography analysis method.

Claims

1. A method for preparing furanyl dicarboxylic acid by catalytic oxidation of 5-hydroxymethylfurfural, characterized in that, Carbazole-based porous organic polymer catalyst and 5-hydroxymethylfurfural were mixed evenly with a solvent and then subjected to high temperature and high pressure oxidation reaction to obtain furan dicarboxylic acid; The preparation method of carbazole-based porous organic polymer catalyst is to use carbazole-based porous organic polymer as support, and then load metal salt and reduce it at high temperature to obtain metal catalyst supported on carbazole-based porous organic polymer. The carbazole-based porous organic polymer support was prepared according to the following steps: 1,3,5-tris(9-carbazole)benzene was dissolved in an organic solvent and stirred at room temperature for 5-36 h under a nitrogen atmosphere using a Lewis acid as a catalyst. After the reaction was completed, carbazole-based porous organic polymers were obtained by filtration and vacuum drying.

2. The method according to claim 1, characterized in that, The organic solvent is one or more of chloroform, dichloromethane, and dichloroethane.

3. The method according to claim 1, characterized in that, The Lewis acid is one or more of ferric chloride, aluminum chloride, and tin tetrachloride.

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

5. The method according to claim 4, characterized in that, The metal salts mentioned include one or more of cobalt acetate, cobalt nitrate, manganese acetate, manganese sulfate, palladium chloride, and palladium nitrate.

6. The method according to claim 1, characterized in that, The solvent is selected from any one of acetonitrile, furan, and dichloromethane.

7. The method according to claim 1, characterized in that, The aforementioned high-temperature and high-pressure oxidation reaction refers to a reaction at 60-150℃ and a reaction oxygen pressure of 0.1-2.0 MPa for 1-12 hours.

8. The method according to claim 1, characterized in that, The amount of the carbazole-based porous organic polymer catalyst used is 0.1-100% of the mass of 5-hydroxymethylfurfural.

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