A method for synthesizing 2,5-furandicarboxylic acid by highly selective oxidation of 5-hydroxymethylfurfural

Abstract

The invention discloses a method for synthesizing 2,5-furandicarboxylic acid by high selective oxidation of 5-hydroxymethylfurfural. The method includes: subjecting a mixed system comprising a cobalt-based catalyst, 5-hydroxymethylfurfural, a first reductant, and an alkaline reagent to an oxidation reaction to obtain 2,5-furandicarboxylic acid; wherein the cobalt-based catalyst includes a composite carrier and an active metal, and the active metal is loaded on the composite carrier; the active metal includes platinum; the composite carrier includes a first metal element and a second metal element; the loading amount of the active metal in the cobalt-based catalyst is 1 to 10wt%. The synthesis method of the present invention has mild reaction conditions, high utilization rate of hypochlorous acid, and the catalyst can be recycled, which greatly reduces the production cost of the product and has industrial application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and particularly relates to a method for synthesizing 2,5-furandicarboxylic acid by highly selective oxidation of 5-hydroxymethylfurfural. Background Art

[0002] Selective oxidation of 5-hydroxymethylfurfural (HMF) is the main method for synthesizing 2,5-furandicarboxylic acid (FDCA), but due to the high price of raw materials and the lack of batch synthesis process, FDCA has not yet been industrialized. Therefore, efficient catalyst design and catalytic process development are currently hot topics. Compared with homogeneous catalysts, heterogeneous catalysts have significant advantages in solid-liquid separation and catalyst recovery. Precious metal catalysts such as Pd, Au, and Pt can use oxygen or air as oxidants to efficiently oxidize HMF to FDCA at higher temperatures (65-130°C), but the expensive price of the catalyst and the problem of catalyst deactivation limit its large-scale application. Compared with precious metal catalysts, cheap metal oxides such as Cu, Ni, and Co have weaker activity and can effectively catalyze the oxidation of HMF to prepare FDCA under the action of sodium hypochlorite oxidant. However, when synthesizing FDCA from HMF, there are problems such as difficult catalyst separation and recovery, low utilization rate of hypochlorous acid, harsh reaction conditions, and large losses. In summary, the large-scale and low-cost synthesis of FDCA still faces many difficulties. Summary of the invention

[0003] The main purpose of the present invention is to provide a method for synthesizing 2,5-furandicarboxylic acid by highly selective oxidation of 5-hydroxymethylfurfural, so as to overcome the shortcomings of the prior art.

[0004] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0005] One aspect of the present invention provides a method for synthesizing 2,5-furandicarboxylic acid by highly selective oxidation of 5-hydroxymethylfurfural, comprising: subjecting a mixed system comprising a cobalt-based catalyst, 5-hydroxymethylfurfural, a first reducing agent, and an alkaline reagent to an oxidation reaction to obtain 2,5-furandicarboxylic acid;

[0006] The cobalt-based catalyst comprises a composite carrier and an active metal, wherein the active metal is loaded on the composite carrier; the active metal comprises platinum; the composite carrier comprises a first metal element and a second metal element; and the loading amount of the active metal in the cobalt-based catalyst is 1 to 10 wt%.

[0007] Compared with the prior art, the present invention has at least the following beneficial effects:

[0008] 1) The reaction conditions of the present invention are mild, and the reaction can be carried out at room temperature and pressure. Moreover, since the reaction temperature is relatively low, sodium hypochlorite is not easily decomposed, and the utilization rate of hypochlorous acid is high.

[0009] 2) The improvement and optimization of the catalyst in the present invention significantly improves its catalytic oxidation activity and target product selectivity; and the cobalt-based catalyst is easy to recover and has good stability and reusability;

[0010] 3) The target product of the present invention has high selectivity, and a high-purity product can be obtained through a simple post-treatment process, and the refining cost is low;

[0011] 4) The cobalt-based catalyst of the present invention is easy to prepare and to be scaled up, the reaction process and post-treatment operations are simple and convenient, the product has high added value, and has a prospect for industrial application. DETAILED DESCRIPTION

[0012] In view of the problems existing in the above-mentioned prior art, the inventors of the present invention have conducted extensive and in-depth research and have provided a method for synthesizing 2,5-furandicarboxylic acid through high-selective oxidation of 5-hydroxymethylfurfural. The method mainly utilizes the excellent activity and selectivity of the cobalt-based catalyst prepared by the present invention, and can realize the high-selective oxidation of 5-hydroxymethylfurfural to synthesize 2,5-furandicarboxylic acid under normal temperature and pressure conditions. The selectivity of 2,5-furandicarboxylic acid in the reaction solution is greater than 99.95%. After a simple post-treatment process, 2,5-furandicarboxylic acid with a purity of more than 99.99% can be obtained. The present invention has mild reaction conditions, high utilization rate of sodium hypochlorite, and the catalyst can be recycled, which greatly reduces the production cost of the product.

[0013] The technical solution, its implementation process and principle will be further explained as follows.

[0014] As one aspect of the technical solution of the present invention, a method for synthesizing 2,5-furandicarboxylic acid by highly selective oxidation of 5-hydroxymethylfurfural is provided, comprising: subjecting a mixed system comprising a cobalt-based catalyst, 5-hydroxymethylfurfural, a first reducing agent, and an alkaline reagent to an oxidation reaction to obtain 2,5-furandicarboxylic acid;

[0015] The cobalt-based catalyst comprises a composite carrier and an active metal, wherein the active metal is loaded on the composite carrier; the active metal comprises platinum; the composite carrier comprises a first metal element and a second metal element; and the loading amount of the active metal in the cobalt-based catalyst is 1 to 10 wt%.

[0016] In some preferred embodiments, the active metal loading in the cobalt-based catalyst is 5 wt %. The cobalt-based catalyst in this application refers to a metal / support-supported catalyst in which active metal nanoparticles are uniformly supported on the surface of the support.

[0017] In some embodiments, the mass ratio of 5-hydroxymethylfurfural to the cobalt-based catalyst is 1:0.1 to 1:10.

[0018] In some preferred embodiments, the mass ratio of 5-hydroxymethylfurfural to the cobalt-based catalyst is 1:0.5.

[0019] In some embodiments, the molar ratio of 5-hydroxymethylfurfural to the alkaline agent is 1:1 to 1:5.

[0020] In some preferred embodiments, the molar ratio of 5-hydroxymethylfurfural to the alkaline agent is 1:2.

[0021] In some embodiments, the concentration of 5-hydroxymethylfurfural in the mixed system is 0.01 to 5 mol / L. The concentration of 5-hydroxymethylfurfural in the mixed system can be independently selected from 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L, 0.3 mol / L, 0.35 mol / L, 0.4 mol / L, 0.45 mol / L, 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 4 mol / L, and 5 mol / L.

[0022] In some preferred embodiments, the concentration of 5-hydroxymethylfurfural in the mixed system is 0.1 mol / L.

[0023] In some embodiments, the oxidation reaction temperature is 15-30°C, and the reaction time is 0.5-2h. The reaction temperature can be independently selected from 15°C, 20°C, 25°C, 30°C, and the reaction time can be independently selected from 0.5h, 1h, 1.5h, 2h.

[0024] In some preferred embodiments, the oxidation reaction is carried out at a temperature of 15°C and for a period of 1 hour.

[0025] In some embodiments, the first reducing agent comprises a sodium hypochlorite solution.

[0026] In some embodiments, the concentration of the sodium hypochlorite solution in the mixed system is 2500-25000 mg / L. The concentration of the sodium hypochlorite solution in the mixed system can be independently selected from 5000 mg / L, 75000 mg / L, 10000 mg / L, 15000 mg / L, 20000 mg / L, 25000 mg / L, 30000 mg / L.

[0027] In some preferred embodiments, the concentration of the sodium hypochlorite solution in the mixed system can be independently selected from 10000 mg / L, 15000 mg / L, 20000 mg / L, and 30000 mg / L.

[0028] In some more preferred embodiments, the concentration of the sodium hypochlorite solution in the mixed system can be independently selected from 30000 mg / L.

[0029] In some embodiments, the alkaline agent includes at least any one of sodium hydroxide, sodium carbonate, sodium bicarbonate, etc., but is not limited thereto.

[0030] In some preferred embodiments, the alkaline agent comprises sodium hydroxide.

[0031] In some embodiments, the first metal element includes Co; the second metal element includes at least any one of Mg, Al, Fe, Ce, Ni, Cr, Cu, Mn, etc., but is not limited thereto.

[0032] In some preferred embodiments, the second metal element includes Mn.

[0033] In some embodiments, the molar ratio of the first metal element to the second metal element is 1:0.1 to 1:0.5.

[0034] In some embodiments, the cobalt-based catalyst is prepared by a reduction-impregnation method.

[0035] In some embodiments, the preparation method of the cobalt-based catalyst comprises: mixing the first metal salt, the second metal salt, and a sodium hydroxide solution, reacting for 0.5N2h, and calcining to obtain the composite carrier;

[0036] reducing the platinum salt compound using a second reducing agent to obtain a solution containing an active metal;

[0037] The composite carrier is immersed in a solution containing active metals for 8 to 10 hours to prepare the cobalt-based catalyst.

[0038] Furthermore, the first metal salt comprises a cobalt salt.

[0039] Furthermore, the first metal salt includes at least any one of cobalt chloride hexahydrate, cobalt sulfate, cobalt nitrate, etc., but is not limited thereto.

[0040] In some embodiments, the calcination temperature is 200-600°C.

[0041] Furthermore, the calcination temperature can be independently selected from 200, 300, 400, 500, 600°C.

[0042] Furthermore, the calcination temperature can be independently selected from 400°C.

[0043] Furthermore, the second metal salt includes at least any one of magnesium salt, aluminum salt, iron salt, cerium salt, nickel salt, copper salt, manganese salt, etc., but is not limited thereto.

[0044] Furthermore, the second metal salt comprises a manganese salt.

[0045] Furthermore, the anions in the second metal salt include at least any one of chloride ions, nitrate ions, sulfate ions, etc., but are not limited thereto.

[0046] Furthermore, the anions in the second metal salt include chloride ions.

[0047] Furthermore, the second reducing agent includes at least any one of NaBH4, Na2SO3, LiAlH4, etc., but is not limited thereto.

[0048] Furthermore, the platinum salt compound includes at least any one of chloroplatinic acid hexahydrate, platinum nitrate, tetraamineplatinum (II) chloride, etc., but is not limited thereto.

[0049] Furthermore, the second metal salt includes at least any one of manganese chloride, manganese nitrate, manganese sulfate, etc., but is not limited thereto.

[0050] Furthermore, the second metal salt comprises manganese chloride.

[0051] Furthermore, the mass ratio of the first metal salt, the second metal salt and sodium hydroxide is 3.22:0.95 to 7.38:12. In the preparation process of the cobalt-based catalyst, NaOH is excessive.

[0052] Furthermore, the mass ratio of the second reducing agent to the platinum salt compound is 1:1.5-3.

[0053] Furthermore, the mass ratio of the second reducing agent to the platinum salt compound is 1:2.2.

[0054] In some more specific embodiments, the method for preparing the cobalt-based catalyst specifically includes:

[0055] (1) dissolving a cobalt salt (i.e., a first metal salt) and a metal M salt (i.e., a second metal salt) in deionized water, slowly adding a sodium hydroxide solution after they are completely dissolved, stirring and reacting for 0.5 to 2 hours, then filtering, washing, roasting, and grinding to obtain a composite carrier;

[0056] (2) reducing the metal element platinum in the chloroplatinic acid solution by mixing the NaBH4 solution and the chloroplatinic acid solution in a mass ratio of 1:2.2 to obtain a solution containing active metal platinum;

[0057] (3) The composite support prepared above is immersed in the reduced active metal platinum solution, fully stirred, immersed for 10 hours, then filtered, washed, and vacuum dried to prepare the cobalt-based catalyst.

[0058] The composite support itself is also active, but its activity is poor at low temperatures. The cobalt in the composite support and the doping metal M have a synergistic effect and can improve the performance of the catalyst.

[0059] In some more specific embodiments, the method for highly selectively oxidizing 5-hydroxymethylfurfural to synthesize 2,5-furandicarboxylic acid specifically includes: adding the cobalt-based catalyst, 5-hydroxymethylfurfural, sodium hypochlorite solution, and alkaline reagent into a glass reaction device, stirring and reacting at 15N30°C for 0.5N2h; after the reaction, filtering the catalyst to obtain a reaction stock solution, acidifying to obtain a 2,5-furandicarboxylic acid product, and subsequently obtaining a high-purity 2,5-furandicarboxylic acid product through a simple acetic acid reflux process.

[0060] Furthermore, the oxidation reaction starts when all materials are added, that is, the oxidation reaction starts counting.

[0061] Furthermore, the reaction temperature is raised to a stable reaction temperature by intelligent constant heating.

[0062] Furthermore, the active metal elements in the cobalt-based catalyst are supported on the composite carrier in the form of nanoparticles.

[0063] Furthermore, the oxidation reaction is carried out in a glass reactor.

[0064] Through the synthesis method of the present invention, the selectivity of the 2,5-furandicarboxylic acid is above 99.95%, and the yield of the 2,5-furandicarboxylic acid is above 99%.

[0065] In summary, the present invention utilizes the prepared cobalt-based catalyst with excellent activity and selectivity, can realize the high-selective oxidation synthesis of 2,5-furandicarboxylic acid by 5-hydroxymethylfurfural under normal temperature and pressure conditions, the selectivity of 2,5-furandicarboxylic acid in the reaction solution is greater than 99.95%, the post-treatment process is simple, the purity of the obtained 2,5-furandicarboxylic acid is high, and the refining cost is low; and the utilization rate of hypochlorous acid in the present invention is high, the catalyst can be recycled and reused, the production cost of the product is greatly reduced, and the invention has a prospect of industrial application.

[0066] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with embodiment. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Those skilled in the art can make modifications or equivalent substitutions based on the understanding of the technical scheme of the present invention without departing from the spirit and scope of the technical scheme of the present invention, and all should be included in the protection scope of the present invention.

[0067] If the specific experimental steps or conditions are not specified in the examples, the operations or conditions of the conventional experimental steps described in the literature in this field can be carried out. If the manufacturer is not specified for the reagents or instruments used, they can all be obtained commercially. Exemplarily, the raw materials and catalysts in the embodiments of the present invention are purchased through commercial channels, all purchased from Adamas Group Chemical Reagent Co., Ltd. The test methods all adopt conventional methods, and the instrument settings all adopt the settings recommended by the manufacturer. The composition (purity) analysis method of the product and mother liquor uses Agilent's 1260 high performance liquid chromatograph to analyze the products in the 5-hydroxymethylfurfural synthesis reaction; the test instrument for effective chlorine is Jida Swan detector.

[0068] Example 1

[0069] (1) Preparation of CoO catalyst: 23.8 g of cobalt chloride hexahydrate was dissolved in 200 mL of deionized water. After complete dissolution, 300 mL of 1 mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400° C. for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain a CoO catalyst.

[0070] (2) Oxidation reaction: In a 1L glass reactor, add 337.5mL of water and 4g of sodium hydroxide and stir to dissolve. When the temperature drops below 20°C, add 150mL of NaClO solution (effective chlorine concentration is 100000mg / L), then add 3.15g of CoO catalyst and 12.5mL of HMF reaction solution (HMF concentration is 4mol / L). The temperature in the reactor is controlled at 15°C, and samples are taken every 15 minutes for reaction. After the reaction is completed, filter and separate the catalyst. The reaction solution is analyzed by HPLC and tested for effective chlorine. The analysis results are shown in Table 1.

[0071] Example 2

[0072] (1) Preparation of CoO catalyst: The catalyst is the same as in Example 1

[0073] (2) Oxidation reaction: The reaction temperature in the kettle was changed to 20° C., and the rest was the same as in Example 1. The reaction liquid was analyzed by HPLC. The analysis results are shown in Table 1.

[0074] Example 3

[0075] (1) Preparation of CoO catalyst: The catalyst is the same as in Example 1

[0076] (2) Oxidation reaction: The reaction temperature in the kettle was changed to 25° C., and the rest was the same as in Example 1. The reaction liquid was analyzed by HPLC. The analysis results are shown in Table 1.

[0077] Example 4

[0078] (1) Preparation of CoO catalyst: The catalyst is the same as in Example 1

[0079] (2) Oxidation reaction: The reaction temperature in the kettle was changed to 30° C., and the rest was the same as in Example 1. The reaction liquid was analyzed by HPLC. The analysis results are shown in Table 1.

[0080] Table 1 Preparation of FDCA by oxidation of HMF catalyzed by cobalt oxide at different reaction temperatures

[0081]

[0082] Examples 1-4 show that increasing temperature accelerates the reaction, but it is worth noting that the effective chlorine in NaClO also increases due to temperature decomposition.

[0083] Example 5

[0084] (1) Preparation of 0.1MgCo catalyst: 23.8g of cobalt chloride hexahydrate and 0.95g of magnesium chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400°C for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.1MgCo catalyst. The molar ratio of cobalt to magnesium in the catalyst was 0.1.

[0085] (2) Oxidation reaction: Using 0.1MgCo catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 2.

[0086] Example 6

[0087] (1) Preparation of 0.1AlCo catalyst: 23.8 g of cobalt chloride hexahydrate and 1.33 g of aluminum chloride were dissolved in 200 mL of deionized water. After complete dissolution, 300 mL of 1 mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400° C. for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.1AlCo catalyst. The molar ratio of cobalt to aluminum in the catalyst was 0.1.

[0088] (2) Oxidation reaction: Using 0.1AlCo catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 2.

[0089] Example 7

[0090] (1) Preparation of 0.1FeCo catalyst: 23.8 g of cobalt chloride hexahydrate and 1.62 g of ferric chloride were dissolved in 200 mL of deionized water. After complete dissolution, 300 mL of 1 mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400° C. for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.1FeCo catalyst. The molar ratio of cobalt to iron in the catalyst was 0.1.

[0091] (2) Oxidation reaction: Using 0.1 FeCo catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 2.

[0092] Example 8

[0093] (1) Preparation of 0.1CeCo catalyst: 23.8 g of cobalt chloride hexahydrate and 2.46 g of cerium chloride were dissolved in 200 mL of deionized water. After complete dissolution, 300 mL of 1 mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400° C. for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.1CeCo catalyst. The molar ratio of cobalt to cerium in the catalyst was 0.1.

[0094] (2) Oxidation reaction: 0.1CeCo catalyst was used, and the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 2.

[0095] Example 9

[0096] (1) Preparation of 0.1NiCo catalyst: 23.8g of cobalt chloride hexahydrate and 2.38g of nickel chloride hexahydrate were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400°C for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.1NiCo catalyst. The molar ratio of cobalt to nickel in the catalyst was 0.1.

[0097] (2) Oxidation reaction: Using 0.1NiCo catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 2.

[0098] Example 10

[0099] (1) Preparation of 0.1CrCo catalyst: 23.8 g of cobalt chloride hexahydrate and 1.58 g of chromium chloride were dissolved in 200 mL of deionized water. After complete dissolution, 300 mL of 1 mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400° C. for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.1CrCo catalyst. The molar ratio of cobalt to chromium in the catalyst was 0.1.

[0100] (2) Oxidation reaction: Using 0.1CrCo catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 2.

[0101] Embodiment 11

[0102] (1) Preparation of 0.1CuCo catalyst: 23.8 g of cobalt chloride hexahydrate and 1.34 g of cupric chloride were dissolved in 200 mL of deionized water. After complete dissolution, 300 mL of 1 mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400° C. for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.1CuCo catalyst. The molar ratio of cobalt to copper in the catalyst was 0.1.

[0103] (2) Oxidation reaction: Using 0.1 CuCo catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 2.

[0104] Example 12

[0105] (1) Preparation of 0.1MnCo catalyst: 23.8g of cobalt chloride hexahydrate and 1.25g of manganese chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400°C for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.1MnCo catalyst. The molar ratio of cobalt to manganese in the catalyst was 0.1.

[0106] (2) Oxidation reaction: Using 0.1MnCo catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 2.

[0107] Table 2 Preparation of FDCA by cobalt-based oxidation of HMF with different doped metal M

[0108]

[0109]

[0110] From Examples 1 and 5-12, it can be seen that the cobalt-based catalyst with Mn as the doping metal has higher catalytic activity and higher selectivity.

[0111] Embodiment 13

[0112] (1) Preparation of 0.1MnCo-200°C catalyst: The calcination temperature was changed to 200°C, and the rest was the same as in Example 12 to obtain a 0.1MnCo-200°C catalyst.

[0113] (2) Oxidation reaction: Using 0.1MnCo-200°C catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 3.

[0114] Embodiment 14

[0115] (1) Preparation of 0.1MnCo-300°C catalyst: The calcination temperature was changed to 300°C, and the rest was the same as in Example 12 to obtain a 0.1MnCo-300°C catalyst.

[0116] (2) Oxidation reaction: Using 0.1MnCo-300°C catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 3.

[0117] Embodiment 15

[0118] (1) Preparation of 0.1MnCo-500°C catalyst: The calcination temperature was changed to 500°C, and the rest was the same as in Example 12 to obtain a 0.1MnCo-500°C catalyst.

[0119] (2) Oxidation reaction: Using 0.1MnCo-500°C catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 3.

[0120] Example 16

[0121] (1) Preparation of 0.1MnCo-600°C catalyst: The calcination temperature was changed to 600°C, and the rest was the same as in Example 12 to obtain a 0.1MnCo-600°C catalyst.

[0122] (2) Oxidation reaction: Using 0.1MnCo-600°C catalyst, the rest was the same as in Example 5. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 3.

[0123] Examples 13-16 mainly change the calcination temperature of the 0.1MnCo catalyst.

[0124] Table 3 Preparation of FDCA by catalytic oxidation of HMF by 0.1MnCo-X at different calcination temperatures

[0125]

[0126]

[0127] Embodiment 17

[0128] (1) Preparation of 0.1MnCo-N catalyst: 23.8 g of cobalt chloride hexahydrate and 1.79 g of manganese nitrate were dissolved in 200 mL of deionized water. After complete dissolution, 300 mL of 1 mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400° C. for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.1MnCo-N catalyst.

[0129] (2) Oxidation reaction: Using 0.1MnCo-N catalyst, the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 4.

[0130] Embodiment 18

[0131] (1) Preparation of 0.1MnCo-S catalyst: 23.8 g of cobalt chloride hexahydrate and 1.51 g of manganese sulfate were dissolved in 200 mL of deionized water. After complete dissolution, 300 mL of 1 mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400° C. for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.1MnCo-S catalyst.

[0132] (2) Oxidation reaction: Using 0.1MnCo-S catalyst, the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 4.

[0133] Table 4 Preparation of FDCA by oxidation of HMF catalyzed by 0.1MnCo with different manganese sources

[0134]

[0135] It can be seen from Examples 12, 17 and 18 that manganese chloride has a relative advantage when it is the source of manganese salt.

[0136] Embodiment 19

[0137] (1) Preparation of 0.2MnCo catalyst: 23.8 g of cobalt chloride hexahydrate and 2.50 g of manganese chloride were dissolved in 200 mL of deionized water. After complete dissolution, 300 mL of 1 mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400° C. for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.2MnCo catalyst. The molar ratio of cobalt to manganese in the catalyst was 0.2.

[0138] (2) Oxidation reaction: 0.2MnCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 5.

[0139] Embodiment 20

[0140] (1) Preparation of 0.3MnCo catalyst: 23.8 g of cobalt chloride hexahydrate and 3.75 g of manganese chloride were dissolved in 200 mL of deionized water. After complete dissolution, 300 mL of 1 mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400° C. for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.3MnCo catalyst. The molar ratio of cobalt to manganese in the catalyst was 0.3.

[0141] (2) Oxidation reaction: 0.3MnCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 5.

[0142] Embodiment 21

[0143] (1) Preparation of 0.4MnCo catalyst: 23.8g of cobalt chloride hexahydrate and 5.00g of manganese chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400°C for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.4MnCo catalyst. The molar ratio of cobalt to manganese in the catalyst was 0.4.

[0144] (2) Oxidation reaction: 0.4MnCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 5.

[0145] Embodiment 22

[0146] (1) Preparation of 0.5MnCo catalyst: 23.8g of cobalt chloride hexahydrate and 6.25g of manganese chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added dropwise. After the addition was complete, the mixture was stirred for reaction for 0.5 hour, then filtered, washed three times with pure water, and then calcined at 400°C for 5 hours. The mixture was taken out, ground and sieved (100-150 mesh) to obtain 0.5MnCo catalyst. The molar ratio of cobalt to manganese in the catalyst was 0.5.

[0147] (2) Oxidation reaction: 0.5MnCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 5.

[0148] Table 5 Preparation of FDCA by oxidation of HMF catalyzed by xMnCo with different cobalt-manganese ratios

[0149]

[0150]

[0151] Through Examples 12 and 19-22, it is clear that the optimal molar ratio of cobalt to manganese is 0.3.

[0152] Embodiment 23

[0153] (1) Preparation of 1Pt / 0.3MnCo catalyst: 0.3MnCo catalyst was used, and the preparation method was the same as that in Example 21. The Pt active component was loaded by the reduction-impregnation method. 0.0836g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36°C. Then 0.1832g of sodium borohydride was dissolved in 10mL of ice-water solution and quickly injected into the three-necked flask. The solution was quickly stirred and reacted at this temperature for 3h. After the reaction was completed, 3.15g of 0.3MnCo was added and immersed in the above-mentioned reduced metal platinum solution. After fully stirring for 0.5h, the stirring was stopped immediately, and the mixture was immersed for 10h. The mixed solution was filtered, and the precipitate was repeatedly washed until the filtrate was neutral. The 1Pt / 0.3MnCo catalyst was obtained by vacuum drying for 12h. The loading amount of Pt in the cobalt-based catalyst was 1%.

[0154] (2) Oxidation reaction: 1Pt / 0.3MnCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 6.

[0155] Embodiment 24

[0156] (1) Preparation of 3Pt / 0.3MnCo catalyst: 0.3MnCo catalyst was used, and the preparation method was the same as that in Example 21. The Pt active component was loaded by the reduction-impregnation method. 0.2509g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36°C. Then 0.5497g of sodium borohydride was dissolved in 30mL of ice-water solution and quickly injected into the three-necked flask. The solution was quickly stirred and reacted at this temperature for 3h. After the reaction was completed, 3.15g of 0.3MnCo was added and immersed in the above-mentioned reduced metal platinum solution. After fully stirring for 0.5h, the stirring was stopped immediately, and the mixture was immersed for 10h. The mixed solution was filtered, and the precipitate was repeatedly washed until the filtrate was neutral. The 3Pt / 0.3MnCo catalyst was obtained by vacuum drying for 12h. The loading amount of Pt in the cobalt-based catalyst was 3%.

[0157] (2) Oxidation reaction: 3Pt / 0.3MnCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 6.

[0158] Embodiment 25

[0159] (1) Preparation of 5Pt / 0.3MnCo catalyst: 0.3MnCo catalyst was used, and the preparation method was the same as that in Example 21. The Pt active component was loaded by the reduction-impregnation method. 0.4181g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mmL pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36°C. Then 0.9162g of sodium borohydride was dissolved in 50mL of ice water solution and quickly injected into the three-necked flask. The solution was quickly stirred and reacted at this temperature for 3h. After the reaction was completed, 3.15g of 0.3MnCo was added and immersed in the above-mentioned reduced metal platinum solution. After fully stirring for 0.5h, the stirring was stopped immediately, and the mixture was immersed for 10h. The mixed solution was filtered, and the precipitate was repeatedly washed until the filtrate was neutral. The 5Pt / 0.3MnCo catalyst was obtained by vacuum drying for 12h. The loading amount of Pt in the cobalt-based catalyst was 5%.

[0160] (2) Oxidation reaction: 5Pt / 0.3MnCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 6.

[0161] Embodiment 26

[0162] (1) Preparation of 7Pt / 0.3MnCo catalyst: 0.3MnCo catalyst was used, and the preparation method was the same as that in Example 21. The Pt active component was loaded by the reduction-impregnation method. 0.5853g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36°C. Then 1.2826g of sodium borohydride was dissolved in 70mL of ice-water solution and quickly injected into the three-necked flask. The solution was quickly stirred and reacted at this temperature for 3h. After the reaction was completed, 3.15g of 0.3MnCo was added and immersed in the above-mentioned reduced metal platinum solution. After fully stirring for 0.5h, the stirring was stopped immediately, and the mixture was immersed for 10h. The mixed solution was filtered, and the precipitate was repeatedly washed until the filtrate was neutral. The 7Pt / 0.3MnCo catalyst was obtained by vacuum drying for 12h. The loading amount of Pt in the cobalt-based catalyst was 7%.

[0163] (2) Oxidation reaction: 7Pt / 0.3MnCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 6.

[0164] Embodiment 27

[0165] (1) Preparation of 10Pt / 0.3MnCo catalyst: 0.3MnCo catalyst was used, and the preparation method was the same as that of Example 21. The Pt active component was loaded by the reduction-impregnation method. 0.8362g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36°C. Then 1.8324g of sodium borohydride was dissolved in 100mL of ice-water solution, then quickly injected into the three-necked flask, and the solution was quickly stirred and reacted at this temperature for 3h. After the reaction was completed, 3.15g of 0.3MnCo was added and immersed in the above-mentioned reduced metal platinum solution. After fully stirring for 0.5h, the stirring was stopped immediately, and the mixture was immersed for 10h. The mixed solution was filtered, and the precipitate was repeatedly washed until the filtrate was neutral. It was vacuum dried for 12h to obtain the 10Pt / 0.3MnCo catalyst. The loading amount of Pt in the cobalt-based catalyst was 10%.

[0166] (2) Oxidation reaction: 10Pt / 0.3MnCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 6.

[0167] Table 6 Preparation of FDCA by oxidation of HMF catalyzed by xPt / 0.3MnCo with different Pt loadings

[0168]

[0169]

[0170] Through Examples 23-27, it is clear that the optimal loading amount of Pt in the cobalt-based catalyst is 5%.

[0171] Embodiment 28

[0172] The catalyst stability test was carried out using the 5Pt / 0.3MnCo catalyst in Example 25 as a typical representative.

[0173] The specific steps are as follows:

[0174] (1) Filtering with a 0.45 μm organic filter membrane to recover the 5Pt / 0.3MnCo catalyst;

[0175] (2) Oxidation reaction: Same as Example 1, the difference in the number of recycling cycles and catalyst performance is shown in Table 7 below.

[0176] Table 7 Catalyst cycle stability test

[0177]

[0178] The reaction solution obtained in Example 25 was used as a typical example to purify FDCA.

[0179] The specific steps are as follows:

[0180] (1) Use a 0.45 μm organic microporous filter membrane to filter out the catalyst.

[0181] (2) The solution from step (1) after the catalyst is filtered out is transferred to a 5 L flask, and concentrated hydrochloric acid is added dropwise under stirring until the pH is 1.0. The process temperature is controlled at 25°C.

[0182] (3) Filter the FDCA obtained in step (2), wash it with water once with stirring, filter the washing liquid, and dry the obtained FDCA in a 55° C. forced air oven.

[0183] (4) The completely dried FDCA obtained in the filtering step (3) was dissolved in 60 mL of acetic acid, refluxed at 110° C. for 1 h, then cooled to room temperature, the acetic acid was filtered, and the obtained FDCA was placed in a 55° C. forced air oven for drying.

[0184] (5) The FDCA solid obtained in step (4) is analyzed by HPLC to obtain a high-purity FDCA product of 99.99% with a yield of 99%.

[0185] Embodiment 29

[0186] (1) Preparation of 5Pt / 0.3MgCo catalyst: Preparation of 0.3MgCo catalyst: 23.8g of cobalt chloride hexahydrate and 2.85g of magnesium chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added. After the addition was complete, the mixture was stirred for 0.5 hours, filtered, washed three times with pure water, and then calcined at 400℃ for 5 hours. The mixture was taken out and ground and sieved (100-150 mesh) to obtain 0.3MgCo catalyst. Pt active component was loaded by reduction-impregnation method. 0.4181g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36℃. Then 0.9162g of sodium borohydride was dissolved in 50mL of ice water solution and quickly injected into the three-necked flask. The solution was stirred quickly and reacted at this temperature for 3h. After the reaction is completed, 3.15 g of 0.3MgCo is added and immersed in the above-mentioned reduced metal platinum solution. After being fully stirred for 0.5 h, stirring is stopped immediately, and the mixture is immersed for 10 h. The mixed solution is filtered, and the precipitate is washed repeatedly until the filtrate is neutral. It is vacuum dried for 12 h to obtain a 5Pt / 0.3MgCo catalyst.

[0187] (2) Oxidation reaction: 5Pt / 0.3MgCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 8.

[0188] Embodiment 30

[0189] (1) Preparation of 5Pt / 0.3AlCo catalyst: Using 0.3AlCo catalyst: 23.8g of cobalt chloride hexahydrate and 3.99g of aluminum chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added. After the addition was complete, the mixture was stirred for 0.5 hours, filtered, washed three times with pure water, and then calcined at 400℃ for 5 hours. The mixture was taken out and ground and sieved (100-150 mesh) to obtain 0.3AlCo catalyst. Pt active component was loaded by reduction-impregnation method. 0.4181g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36℃. Then 0.9162g of sodium borohydride was dissolved in 50mL of ice water solution and quickly injected into the three-necked flask. The solution was stirred quickly and reacted at this temperature for 3h. After the reaction is completed, 3.15 g of 0.3AlCo is added and immersed in the above-mentioned reduced metal platinum solution. After being fully stirred for 0.5 h, stirring is stopped immediately, and the mixture is immersed for 10 h. The mixed solution is filtered, and the precipitate is washed repeatedly until the filtrate is neutral. It is vacuum dried for 12 h to obtain a 5Pt / 0.3A1Co catalyst.

[0190] (2) Oxidation reaction: 5Pt / 0.3A1Co catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 8.

[0191] Embodiment 31

[0192] (1) Preparation of 5Ptt0.3FeCo catalyst: Using 0.3FeCo catalyst: 23.8g of cobalt chloride hexahydrate and 4.86g of ferric chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added. After the addition was completed, the mixture was stirred for 0.5 hours, then filtered, washed three times with pure water, and then calcined at 400℃ for 5 hours. The mixture was taken out and ground and sieved (100-150 mesh) to obtain 0.3FeCo catalyst. Pt active component was loaded by reduction-impregnation method. 0.4181g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36℃. Then 0.9162g of sodium borohydride was dissolved in 50mL of ice water solution and quickly injected into the three-necked flask. The solution was stirred quickly and reacted at this temperature for 3h. After the reaction is completed, 3.15 g of 0.3FeCo is added and immersed in the above-mentioned reduced metal platinum solution. After being fully stirred for 0.5 h, stirring is stopped and the mixture is immersed for 10 h. The mixed solution is filtered and the precipitate is washed repeatedly until the filtrate is neutral. The 5Pt / 0.3FeCo catalyst is obtained by vacuum drying for 12 h.

[0193] (2) Oxidation reaction: 5P / / 0.3FeCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 8.

[0194] Embodiment 32

[0195] (1) Preparation of 5Pt / t / 0.3CeCo catalyst: Using 0.3CeCo catalyst: 23.8g of cobalt chloride hexahydrate and 7.38g of cerium chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added. After the addition was complete, the mixture was stirred for 0.5 hours, filtered, washed three times with pure water, and then calcined at 400℃ for 5 hours. The mixture was taken out and ground and sieved (100-150 mesh) to obtain 0.3CeCo catalyst. Pt active component was loaded by reduction-impregnation method. 0.4181g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36℃. Then 0.9162g of sodium borohydride was dissolved in 50mL of ice water solution and quickly injected into the three-necked flask. The solution was stirred quickly and reacted at this temperature for 3h. After the reaction is completed, 3.15 g of 0.3CeCo is added and immersed in the above-mentioned reduced metal platinum solution. After being fully stirred for 0.5 h, stirring is stopped immediately, and the mixture is immersed for 10 h. The mixed solution is filtered, and the precipitate is washed repeatedly until the filtrate is neutral. It is vacuum dried for 12 h to obtain a 5Pt / 0.3CeCo catalyst.

[0196] (2) Oxidation reaction: 5Pt / 0.3CeCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 8.

[0197] Embodiment 33

[0198] (1) Preparation of 5Pt / 0.3NiCo catalyst: Using 0.3NiCo catalyst, 23.8g of cobalt chloride hexahydrate and 7.14g of cerium chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added. After the addition was complete, the mixture was stirred for 0.5 hours, filtered, washed three times with pure water, and then calcined at 400°C for 5 hours. The mixture was taken out and ground and sieved (100-150 mesh) to obtain 0.3NiCo catalyst. Pt active component was loaded by reduction-impregnation method. 0.4181g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36°C. Then 0.9162g of sodium borohydride was dissolved in 50mL of ice water solution and quickly injected into the three-necked flask. The solution was stirred quickly and reacted at this temperature for 3h. After the reaction is completed, 3.15 g of 0.3NiCo is added and immersed in the above-mentioned reduced metal platinum solution. After being fully stirred for 0.5 h, stirring is stopped immediately, and the mixture is immersed for 10 h. The mixed solution is filtered, and the precipitate is washed repeatedly until the filtrate is neutral. It is vacuum dried for 12 h to obtain a 5Pt / 0.3NiCo catalyst.

[0199] (2) Oxidation reaction: 5Pt / 0.3NiCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 8.

[0200] Embodiment 34

[0201] (1) Preparation of 5Pt / 0.3CrCo catalyst: Using 0.3CrCo catalyst, 23.8g of cobalt chloride hexahydrate and 4.74g of chromium chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added. After the addition was complete, the mixture was stirred for 0.5 hours, filtered, washed three times with pure water, and then calcined at 400℃ for 5 hours. The mixture was taken out and ground and sieved (100-150 mesh) to obtain 0.3CrCo catalyst. Pt active component was loaded by reduction-impregnation method. 0.4181g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mmL three-necked flask and placed in a water bath at 36℃. Then 0.9162g of sodium borohydride was dissolved in 50mL of ice water solution and quickly injected into the three-necked flask. The solution was stirred quickly and reacted at this temperature for 3h. After the reaction is completed, 3.15 g of 0.3CrCo is added and immersed in the above-mentioned reduced metal platinum solution. After being fully stirred for 0.5 h, stirring is stopped immediately, and the mixture is immersed for 10 h. The mixed solution is filtered, and the precipitate is washed repeatedly until the filtrate is neutral. It is vacuum dried for 12 h to obtain a 5Pt / 0.3CrCo catalyst.

[0202] (2) Oxidation reaction: 5Pt / 0.3CrCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 8.

[0203] Embodiment 35

[0204] (1) Preparation of 5Ptt0.3CuCo catalyst: Using 0.3CuCo catalyst: 23.8g of cobalt chloride hexahydrate and 4.02g of copper chloride were dissolved in 200mL of deionized water. After complete dissolution, 300mL of 1mol / L NaOH solution was slowly added. After the addition was complete, the mixture was stirred for 0.5 hours, then filtered, washed three times with pure water, and then calcined at 400℃ for 5 hours. The mixture was taken out and ground and sieved (100-150 mesh) to obtain 0.3CuCo catalyst. Pt active component was loaded by reduction-impregnation method. 0.4181g of chloroplatinic acid hexahydrate was weighed and dissolved in 50mL of pure water, then transferred to a 250mL three-necked flask and placed in a water bath at 36℃. Then 0.9162g of sodium borohydride was dissolved in 50mL of ice water solution and quickly injected into the three-necked flask. The solution was stirred quickly and reacted at this temperature for 3h. After the reaction is completed, 3.15 g of 0.3CuCo is added and immersed in the above-mentioned reduced metal platinum solution. After being fully stirred for 0.5 h, stirring is stopped immediately, and the mixture is immersed for 10 h. The mixed solution is filtered, and the precipitate is washed repeatedly until the filtrate is neutral. It is vacuum dried for 12 h to obtain a 5Pt / t / 0.3CuCo catalyst.

[0205] (2) Oxidation reaction: 5Pt / t / 0.3CuCo catalyst was used, and the rest was the same as in Example 1. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 8.

[0206] Table 85 Ptt0.3MCo catalytic oxidation of HMF to prepare FDCA

[0207]

[0208]

[0209] Embodiment 36

[0210] (1) Preparation of 5Pt / 0.3MnCo catalyst: The preparation method is the same as Example 25.

[0211] (2) Oxidation reaction: 5Pt / 0.3MnCo catalyst was used, the reaction temperature was 20°C, and the rest was the same as in Example 25. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 9.

[0212] Embodiment 37

[0213] (1) Preparation of 5Pt / 0.3MnCo catalyst: The preparation method is the same as Example 25.

[0214] (2) Oxidation reaction: 5Pt / 0.3MnCo catalyst was used, the reaction temperature was 25°C, and the rest was the same as in Example 25. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 9.

[0215] Embodiment 38

[0216] (1) Preparation of 5Pt / 0.3MnCo catalyst: The preparation method is the same as Example 25.

[0217] (2) Oxidation reaction: 5Pt / 0.3MnCo catalyst was used, the reaction temperature was 30°C, and the rest was the same as in Example 25. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 9.

[0218] Embodiment 39

[0219] (1) Preparation of 5Pt / 0.3MnCo catalyst: The preparation method is the same as Example 25.

[0220] (2) Oxidation reaction: 5Pt / 0.3MnCo catalyst was used, the reaction temperature was 35°C, and the rest was the same as in Example 25. The reaction solution was analyzed by HPLC. The analysis results are shown in Table 9.

[0221] Table 9 Preparation of FDCA by catalytic oxidation of HMF by 5Pt / 0.3MnCo at different temperatures

[0222]

[0223]

[0224] Embodiment 40

[0225] (1) Preparation of 5Pt / 0.3MnCo catalyst: The preparation method is the same as Example 25.

[0226] (2) Oxidation reaction: Using 5Pt / 0.3MnCo catalyst, the reaction times were set to 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, and 3 h, respectively. The rest was the same as in Example 25. The reaction solution was analyzed by HPLC and tested for effective chlorine. The analysis results are shown in Table 10.

[0227] Table 10 Preparation of FDCA by 5Pt / 0.3MnCo catalytic oxidation of HMF at different times

[0228]

[0229] The various aspects, embodiments, features and examples of the present invention should be considered as illustrative in all aspects and are not intended to limit the present invention, the scope of the present invention is defined only by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

[0230] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0231] Although the present invention has been described with reference to illustrative embodiments, it will be appreciated by those skilled in the art that various other changes, omissions and / or additions may be made without departing from the spirit and scope of the present invention and that the elements of the embodiments may be replaced by substantial equivalents. In addition, many modifications may be made without departing from the scope of the present invention to adapt specific circumstances or materials to the teachings of the present invention. Therefore, it is not intended herein to limit the present invention to the disclosed specific embodiments for performing the present invention, but it is intended that the present invention will include all embodiments within the scope of the appended claims. In addition, unless specifically stated, any use of the terms first, second, etc. does not indicate any order or importance, but rather uses the terms first, second, etc. to distinguish one element from another.

Claims

1. A method for synthesizing 2,5-furandicarboxylic acid by highly selective oxidation of 5-hydroxymethylfurfural, characterized in that: A mixed system including a cobalt-based catalyst, 5-hydroxymethylfurfural, a first reducing agent, and an alkaline reagent is subjected to an oxidation reaction to obtain 2,5-furandicarboxylic acid; The cobalt-based catalyst comprises a composite carrier and an active metal, wherein the active metal is loaded on the composite carrier; the active metal comprises platinum; the composite carrier comprises a first metal element and a second metal element; and the loading amount of the active metal in the cobalt-based catalyst is 1 to 10 wt%.

2. The method according to claim 1, characterized in that: The mass ratio of 5-hydroxymethylfurfural to the cobalt-based catalyst is 1:0.1 to 1:10; And / or, the molar ratio of 5-hydroxymethylfurfural to the alkaline agent is 1:1 to 1:5; And / or, the concentration of 5-hydroxymethylfurfural in the mixed system is 0.01-5 mol / L.

3. The method according to claim 1, characterized in that: The temperature of the oxidation reaction is 15-30° C. and the time is 0.5-2 h.

4. The method according to claim 1, characterized in that: The first reducing agent includes a sodium hypochlorite solution; Preferably, the concentration of the sodium hypochlorite solution in the mixed system is 2500-25000 mg / L; And / or, the alkaline reagent includes at least any one of sodium hydroxide, sodium carbonate, and sodium bicarbonate; Preferably, the alkaline agent comprises sodium hydroxide.

5. The method according to claim 1, characterized in that: The first metal element includes Co; the second metal element includes at least any one of Mg, Al, Fe, Ce, Ni, Cr, Cu, and Mn; Preferably, the second metal element includes Mn; And / or, the molar ratio of the first metal element to the second metal element is 1:0.1 to 1:0.

5.

6. The method according to claim 1, characterized in that: The selectivity of the 2,5-furandicarboxylic acid is above 99.95%, and the yield of the 2,5-furandicarboxylic acid is above 99%.

7. The method according to claim 1, characterized in that: The cobalt-based catalyst is prepared by a reduction-impregnation method.

8. The method according to claim 1 or 7, characterized in that: The preparation method of the cobalt-based catalyst comprises: mixing a first metal salt, a second metal salt and a sodium hydroxide solution, and reacting for 0.5 to 2 hours to obtain the composite carrier; reducing the platinum salt compound using a second reducing agent to obtain a solution containing an active metal; The composite carrier is immersed in a solution containing active metals for 8 to 10 hours to prepare the cobalt-based catalyst.

9. The method according to claim 8, characterized in that: The first metal salt comprises a cobalt salt; Preferably, the first metal salt includes at least any one of cobalt chloride hexahydrate, cobalt sulfate, and cobalt nitrate; And / or, the second metal salt includes at least any one of magnesium salt, aluminum salt, iron salt, cerium salt, nickel salt, copper salt, and manganese salt; Preferably, the second metal salt comprises a manganese salt; And / or, the anions in the second metal salt include at least any one of chloride ions, nitrate ions, and sulfate ions; Preferably, the anion in the second metal salt comprises chloride ion; And / or, the second reducing agent includes at least any one of NaBH4, Na2SO3, and LiAlH4; And / or, the platinum salt compound includes at least any one of chloroplatinic acid hexahydrate, platinum nitrate, and tetraamineplatinum (II) chloride.

10. The method according to claim 9, characterized in that: The second metal salt includes at least any one of manganese chloride, manganese nitrate, and manganese sulfate; Preferably, the second metal salt comprises manganese chloride; And / or, the mass ratio of the first metal salt, the second metal salt, and sodium hydroxide is 3.22:0.95 to 7.38:12; And / or, the mass ratio of the second reducing agent to the platinum salt compound is 1:1.5-3.

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