Method for preparing 2, 5-furandicarboxylic acid by catalyzing upgrading of 5-hydroxymethylfurfural through visible-near infrared light in pure water system at room temperature and normal pressure

Abstract

The invention discloses a method for preparing 2, 5-furandicarboxylic acid by catalyzing upgrading of 5-hydroxymethylfurfural through visible-near infrared light in a pure water system at room temperature and normal pressure, and belongs to the technical field of biomass energy. According to the method, the preparation of 2, 5-furandicarboxylic acid through efficient upgrading and conversion of 5-hydroxymethylfurfural in a normal-temperature and normal-pressure pure water system is realized through the black titanium dioxide catalyst loaded by sub-nano platinum species by taking 90% or more of visible-near infrared light in a solar spectrum as driving force, so that on one hand, the defect that photocatalysis needs to depend on high-energy ultraviolet light is effectively overcome, and on the other hand, the preparation of 2, 5-furandicarboxylic acid is realized; a solid foundation is provided for biomass upgrading and conversion by directly utilizing outdoor sunlight; on the other hand, toxic organic solvents, high temperature, high pressure and other reaction conditions with high danger coefficients are avoided, and the method has the advantages of being environmentally friendly and low in energy consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass energy, and specifically relates to a method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural under visible-near infrared light catalysis in a pure water system at room temperature and normal pressure. Background Art

[0002] The production of high-value chemicals and fuels from renewable biomass resources that are widely available on Earth is one of the effective solutions to the global depletion of fossil energy and climate change. 5-Hydroxymethylfurfural (HMF) is an important biomass-derived platform compound. It can be used as a raw material to obtain a series of value-added chemicals through catalytic oxidation reactions. Among them, the most valuable 2,5-furandicarboxylic acid (FDCA) product has a similar structure to terephthalic acid and can be used as a substitute for the production of polyethylene terephthalate for the manufacture of bio-based polymers and biodegradable plastics. The process of preparing 2,5-furandicarboxylic acid (FDCA) from 5-hydroxymethylfurfural (HMF) involves multiple consecutive oxidation steps of alcohol and aldehyde functional groups, which is a typical cascade catalytic reaction. At present, the oxidation of HMF to FDCA mainly relies on high-energy thermal catalytic conversion, which usually requires harsh reaction conditions of high temperature, high pressure and strong base to obtain a high FDCA yield. Therefore, it is of great practical significance to develop new catalytic strategies to achieve efficient conversion of HMF to FDCA under mild conditions. Photocatalysis driven by inexhaustible solar energy provides a promising technical solution for HMF oxidation under mild conditions at room temperature and pressure. For example, in recent years, researchers have developed photocatalysts based on oxides, sulfides, quantum dots and MOF / COF materials for HMF photocatalytic oxidation upgrading.

[0003] However, most of the photocatalytic HMF oxidation conversion systems reported so far generally have technical problems such as the need for strong base / organic solvent as reaction medium, high pressure oxygen (1-10 MPa) and ultraviolet light participation, and low selectivity of the product FDCA. For example, the Chinese invention patent with publication number CN109107605A proposes that acetonitrile solvent is required as a medium and hydrochloric acid is used as a promoter to participate in the catalytic reaction in the photocatalytic HMF oxidation system, and the system is complex. The Chinese invention patent with publication number CN116037166A prepares a Pt-Ov-BiOBr catalyst with a noble metal-semiconductor interface to carry out photocatalytic HMF oxidation. The oxidation product stays in the intermediate 2,5-furandicarboxaldehyde, and the selectivity for FDCA is very low. The Z-type heterojunction SnIn4S8-ZnIn2S4 catalyst proposed in the Chinese invention patent with publication number CN117551063A can only realize the photocatalytic HMF conversion to generate 2,5-furandicarboxaldehyde intermediates. The Chinese invention patent with the announcement number CN113698373B proposes to prepare FDCA by photocatalytic HMF oxidation through P-type semiconductor Cu2O, but the reaction is carried out under high-pressure oxygen conditions and requires the participation of ultraviolet light. The Chinese invention patent with the announcement number CN113351210B provides a Cu-based catalyst and uses it in the photocatalytic water hydrogen production-HMF oxidative coupling reaction. Although HMF is converted into FDCA, there are problems such as low HMF conversion rate and the need for ultraviolet light. For example, the Chinese invention patent with the announcement number CN106279080 B proposes to prepare FDCA using HMF photocatalysis, but on the one hand, it needs to be carried out at a high temperature of 60-90°C, and the reaction energy consumption is high; on the other hand, it uses oxygen or hydrogen peroxide produced by photocatalytic decomposition of water as an oxidant to selectively oxidize the reaction materials. This process is likely to lead to further mineralization of the FDCA product to produce carbon dioxide, which will seriously reduce the actual yield of FDCA.

[0004] It can be seen that the rational and efficient use of solar energy for biomass upgrading and conversion is of great significance to alleviating the global energy crisis and environmental problems. Therefore, it is urgent to develop a catalytic system that can use visible light to achieve efficient conversion of HMF and highly selective generation of FDCA under mild conditions. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a method for upgrading 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid by visible-near-infrared photocatalysis in a pure water system at room temperature and normal pressure, so as to solve the technical problems that the prior art needs to rely on ultraviolet light or high temperature assistance, the product FDCA selectivity is low, and the reaction conversion rate is low.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: One of the purposes of the present invention is to provide a method for efficiently upgrading HMF in a pure water system at room temperature and pressure to prepare FDCA. A method for upgrading 5-hydroxymethylfurfural to prepare 2,5-furandicarboxylic acid by visible-near-infrared photocatalysis in a pure water system at room temperature and pressure is disclosed. The method comprises: under visible-near-infrared light, in a pure water system at room temperature and pressure, photocatalytically converting 5-hydroxymethylfurfural to prepare 2,5-furandicarboxylic acid by a sub-nanometer platinum species-loaded black titanium dioxide catalyst.

[0007] Preferably, the method comprises: at room temperature and normal pressure, using water as solvent, uniformly stirring the reactants 5-hydroxymethylfurfural and a sub-nanometer platinum species-loaded black titanium dioxide catalyst; then reacting for 1-10 hours under visible-near infrared light irradiation, separating the reaction liquid, and obtaining 2,5-furandicarboxylic acid.

[0008] Further preferably, the mass ratio of 5-hydroxymethylfurfural and sub-nanometer platinum species-supported black titanium dioxide catalyst is (0.1-1000): 1; During the reaction, the reactant 5-hydroxymethylfurfural is prepared into a 1-200 mM reaction solution with water; More preferably, the reactant 5-hydroxymethylfurfural is prepared into a 20 mM reaction solution with water.

[0009] Preferably, the ratio of water to the reactant 5-hydroxymethylfurfural is (10 - 1000) mL: (12.6 -1260) mg.

[0010] Preferably, the stirring time is 0.5-5 h.

[0011] Preferably, the wavelength range of visible-near infrared light is 400-1000 nm; Further preferably, the wavelength of the visible-near infrared light is 400 nm or 500 nm.

[0012] The optimized specific operation plan is as follows: a certain volume of deionized water is added to a double-layer quartz photocatalytic reactor, and then a sub-nano platinum species-loaded black titanium dioxide catalyst and a reactant 5-hydroxymethylfurfural are placed therein, and stirred at room temperature for a certain period of time; cooling water is introduced into the outer layer of the double-layer quartz photocatalytic reactor, and the cooling water temperature is kept constant within a certain range, a 300W xenon lamp light source with a filter is turned on to irradiate the top of the quartz photocatalyst, and after reacting for a period of time at normal pressure, the reaction liquid is taken out and centrifuged to obtain a transparent reaction liquid without a catalyst, and the content of the 2,5-furandicarboxylic acid product is analyzed by high performance liquid chromatography.

[0013] The volume of the deionized water is added according to the ratio of the reactants, and the conductivity of the pure water should be lower than 0.1µs / cm; the mass ratio of the subnanometer platinum species-loaded black titanium dioxide catalyst to the reactant 5-hydroxymethylfurfural is 1: (0.1-1000); the concentration of the HMF solution is 1 mM-200 mM; the stirring time at room temperature is 0.5-5 h; the cooling water temperature range is 15-35°C; the filter wavelength range is 400-1000 nm; the atmosphere for the photocatalytic 5-hydroxymethylfurfural reaction is air or oxygen, and the gas pressure is normal pressure, i.e. 0.1013MPa; the photocatalytic reaction time is 1-10 h; the purity of the product 2,5-furandicarboxylic acid is 95%-99.9%.

[0014] Based on the above purpose, the present invention provides a highly active catalyst to achieve visible-near infrared photocatalytic HMF upgrading conversion. The technical scheme adopted is: synthesizing sub-nanometer platinum species-loaded black titanium dioxide catalyst by "wet impregnation-high temperature calcination" method.

[0015] Preferably, the sub-nanometer platinum species-supported black titanium dioxide catalyst is prepared according to the following method: The chloroplatinic acid aqueous solution and the black titanium dioxide solid powder are stirred and mixed at room temperature, and fully immersed for a period of time to obtain a mixture; after evaporating the solvent, the mixture is calcined at a high temperature in an inert or reducing gas atmosphere for a certain period of time to obtain a sub-nanometer platinum species-loaded black titanium dioxide catalyst.

[0016] Further preferably, the mass ratio of chloroplatinic acid to black titanium dioxide solid powder is (0.1-10):100; and the immersion time is 0.5-5 h.

[0017] More preferably, argon, nitrogen, hydrogen or a hydrogen-argon mixture is selected as the reaction atmosphere.

[0018] More preferably, the high temperature calcination temperature is 200-400° C., and the calcination time is 1-10 h.

[0019] The optimized specific operation plan is: stir and mix the chloroplatinic acid aqueous solution and the black titanium dioxide solid powder at room temperature, and fully immerse them for a period of time; after evaporating the solvent, place the mixture of chloroplatinic acid and black titanium dioxide in a tubular furnace, and calcine at high temperature for a certain period of time in an inert or reducing gas atmosphere to obtain a sub-nanometer platinum species-loaded black titanium dioxide catalyst.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method for upgrading 5-hydroxymethylfurfural to prepare 2,5-furandicarboxylic acid by visible-near-infrared photocatalysis in a pure water system at room temperature and pressure. The method uses a black titanium dioxide catalyst loaded with sub-nanometer platinum species and more than 90% of visible-near-infrared light in the solar spectrum as a driving force to achieve efficient upgrading and conversion of 5-hydroxymethylfurfural to prepare 2,5-furandicarboxylic acid in a pure water system at room temperature and pressure. On the one hand, it effectively overcomes the shortcoming that photocatalysis needs to rely on high-energy ultraviolet light, and provides a solid foundation for directly using outdoor sunlight to upgrade and convert biomass; on the other hand, it avoids toxic organic solvents and high-risk reaction conditions such as high temperature and high pressure, and has the advantages of being green, environmentally friendly and having low energy consumption. The present invention has been confirmed by experimental results data that the selectivity for the target product is 99.9%, and the production TOF value of 2,5-furandicarboxylic acid can reach 50 mol FDCA mol Pt -1 h -1 , reaching the optimal yield level reported so far for thermal catalytic systems involving high temperature, high pressure and strong base, providing a strong research basis for the large-scale application of photocatalytic HMF conversion to FDCA.

[0021] Furthermore, the present invention selects a black titanium dioxide catalyst loaded with sub-nanometer platinum species. The catalyst uses sub-nanometer platinum species as the catalytic active center, and is loaded on the surface of black titanium dioxide by the method of "wet impregnation-high temperature calcination". By reasonably regulating the geometric / electronic structure of the sub-nanometer platinum species, the effective adsorption and activation ability of the catalytic center for the aldehyde and alcohol functional groups in the reactant 5-hydroxymethylfurfural molecule is improved; using black titanium dioxide as the light absorption center, the catalyst effectively utilizes light in the visible-infrared region, thereby realizing the visible-near-infrared photocatalytic upgrading of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid in a pure water system at room temperature and normal pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 HADDF-STEM image of black TiO2 loaded with sub-nanometer platinum species; Figure 2 This is the EXAFS graph of black TiO2 loaded with sub-nanometer platinum species; Figure 3 The curves of HMF conversion rate and FDCA yield over time under sub-nanometer platinum species-loaded black TiO2 visible light catalysis; Figure 4 The HPLC product distribution diagram at different times; Figure 5 Performance diagram of photocatalytic HMF upgrading and conversion to FDCA at different wavelengths; Figure 6 This is the performance diagram of the catalyst after 10 cycles; Figure 7The time curves of HMF conversion (left) and FDCA generation (right) at different HMF aqueous solution concentrations. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings: The present invention discloses a method for efficiently upgrading 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid by visible-near-infrared light catalysis in a pure water system at room temperature and atmospheric pressure, comprising: firstly, using a sub-nanometer platinum species as a catalytic active center, and loading it on a black titanium dioxide surface by a "wet impregnation-high temperature calcination" method to prepare a sub-nanometer platinum species-loaded black titanium dioxide catalyst; secondly, under visible-near-infrared light, in a pure water system at room temperature and atmospheric pressure, catalyzing the efficient upgrading and conversion of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid by the sub-nanometer platinum species-loaded black titanium dioxide catalyst.

[0026] Specifically, the above method of the present invention comprises the following steps: Step 1) prepares a sub-nanometer platinum species-loaded black titanium dioxide catalyst, stirs and mixes a chloroplatinic acid aqueous solution and a black titanium dioxide solid powder at room temperature, and fully immerses for a period of time; after evaporating the solvent, the mixture of chloroplatinic acid and black titanium dioxide is placed in a tubular furnace, and calcined at a high temperature for a certain period of time in an inert or reducing gas atmosphere to obtain a sub-nanometer platinum species-loaded black titanium dioxide catalyst.

[0027] Preferably, the mass ratio of chloroplatinic acid to black titanium dioxide is (0.1-10):100; the immersion time is 0.5-5 h; the inert or reducing gas atmosphere is argon, nitrogen, hydrogen, or a mixture of hydrogen and argon; the high-temperature calcination temperature is 200-400° C., and the calcination time is 1-10 h.

[0028] Preferably, the sub-nanometer platinum species-supported black titanium dioxide catalyst described in step 1) can also be prepared according to the method disclosed in Chinese patent application with publication number CN110813280A.

[0029] Step 2), adding a certain volume of deionized water into a double-layer quartz photocatalytic reactor, then putting a sub-nanometer platinum species-loaded black titanium dioxide catalyst and a reactant 5-hydroxymethylfurfural therein, and stirring at room temperature for a certain period of time; passing cooling water into the outer layer of the double-layer quartz photocatalytic reactor, keeping the cooling water temperature constant within a certain range, turning on a 300W xenon lamp light source with a filter to irradiate the top of the quartz photocatalyst, reacting for a period of time under normal pressure, taking out the reaction liquid and centrifuging to obtain a transparent reaction liquid without a catalyst, and analyzing the content of the 2,5-furandicarboxylic acid product by high performance liquid chromatography.

[0030] Preferably, the volume of the deionized water is 5-1000 ml, and the conductivity of pure water should be lower than 0.1µs / cm; the mass ratio of the subnanometer platinum species-loaded black titanium dioxide catalyst to the reactant 5-hydroxymethylfurfural is 1: (0.1-1000); the concentration of the HMF solution is 1 mM-200 mM; the stirring time at room temperature is 0.5-5 h; the cooling water temperature range is 15-35°C; the filter wavelength range is 400-1000 nm; the atmosphere for the photocatalytic 5-hydroxymethylfurfural reaction is air or oxygen, and the gas pressure is normal pressure, i.e. 0.1013MPa; the photocatalytic reaction time is 1-10 h; the purity of the product 2,5-furandicarboxylic acid is 95%-99.9%.

[0031] Example 1 Weigh 0.1g of black titanium dioxide, put it into a round-bottom flask and add 20ml of water, stir for 30 min; then add 5ml of 0.2mg / ml chloroplatinic acid aqueous solution dropwise, the mass ratio of chloroplatinic acid to black titanium dioxide is 1:100, stir for 2h, evaporate the solvent with a rotary evaporator, obtain a mixture of chloroplatinic acid and black titanium dioxide and transfer it to a quartz boat, put it in a tube furnace and calcine it at 300℃ in an argon atmosphere for 2h, wash and dry, and obtain a sub-nanometer platinum species-loaded black titanium dioxide catalyst. The morphology and structure of the platinum species were characterized by spherical aberration electron microscopy and synchrotron radiation. Results are shown in Figure 1 , Figure 2 .from Figure 1It can be seen that subnanometer platinum species are evenly distributed on the surface of black titanium dioxide, and the size of the platinum species is about 0.8-1.0 nm. Figure 2 It can be seen that each platinum atom in the platinum species is coordinated with 2-3 surrounding oxygen atoms, and there is a weak Pt-Pt interaction, which proves the sub-nanostructure of the platinum species.

[0032] Weigh 20 mg of sub-nano platinum species-loaded black titanium dioxide catalyst, add 100 ml of 20 mM HMF pure water solution, transfer the mixed reaction solution to a 150 ml double-layer quartz photocatalytic reactor, put in a magnet and stir; connect the double-layer quartz catalytic reactor to circulating cooling water, and keep the cooling water temperature constant at 25°C. Use a 300W xenon lamp with a 400 nm filter to irradiate the top of the quartz reactor for 8 h, take out 1 ml of the reaction solution, centrifuge to obtain the supernatant, and use HPLC to analyze the product (the results are shown in Figure 4 According to the results of liquid chromatography, the conversion rate of HMF was 100% and the yield of FDCA was 99.9% (the results are shown in Figure 3 as shown).

[0033] Example 2 Weigh 0.1g of black titanium dioxide, put it into a round-bottom flask and add 20 ml of water, stir for 30 min; then add 5ml of 0.2mg / ml chloroplatinic acid aqueous solution dropwise, the mass ratio of chloroplatinic acid to black titanium dioxide is 1:100, stir for 2 h, evaporate the solvent with a rotary evaporator, obtain a solid powder mixed with chloroplatinate and black titanium dioxide and transfer it to a quartz boat, put it in a tube furnace and calcine it at 300℃ for 2h in an argon atmosphere, wash and dry it to obtain a sub-nanometer platinum species-loaded black titanium dioxide catalyst. Weigh 20 mg of sub-nanometer platinum species-loaded black titanium dioxide catalyst, add 100 ml of 20 mM HMF pure aqueous solution, transfer this mixed reaction solution to a 150 ml double-layer quartz photocatalytic reactor, put in a magnet and stir; connect the double-layer quartz catalytic reactor to the circulating cooling water, and keep the cooling water temperature constant at 25℃. A 300 W xenon lamp with 500 nm, 600 nm, 800 nm and 1000 nm filters was used to irradiate the top of the quartz reactor for 8 h, respectively. 1 ml of the reaction solution was taken out and centrifuged to obtain the supernatant, and the product was analyzed by HPLC. According to the liquid chromatography results, at 500 nm, the conversion rate of HMF was 100%, and the yield of FDCA was 99.9%; at 600 nm, the conversion rate of HMF was 100%, and the yield of FDCA was 90%; at 800 nm, the conversion rate of HMF was 90%, and the yield of FDCA was 78%; at 1000 nm, the conversion rate of HMF was 60%, and the yield of FDCA was 50%.

[0034] Results Figure 5 ,from Figure 5 It can be seen that the black titanium dioxide catalyst loaded with sub-nanometer platinum species can achieve efficient conversion of HMF-FDCA using visible-near-infrared light of 400 nm, 500 nm, 600 nm, 800 nm and 1000 nm.

[0035] Example 3 Weigh 0.1g of black titanium dioxide, put it into a round-bottom flask and add 20 ml of water, stir for 30 min; then add 5ml of 0.2mg / ml chloroplatinic acid aqueous solution dropwise, the mass ratio of chloroplatinic acid to black titanium dioxide is 1:100, stir for 2h, evaporate the solvent with a rotary evaporator, obtain a solid powder mixed with chloroplatinate and black titanium dioxide and transfer it to a quartz boat, put it in a tube furnace and calcine it at 300℃ in an argon atmosphere for 2h, wash and dry it to obtain a sub-nanometer platinum species-loaded black titanium dioxide catalyst. Weigh 20 mg of sub-nanometer platinum species-loaded black titanium dioxide catalyst, add 100 ml of 20 mM HMF pure aqueous solution, transfer this mixed reaction solution to a 150 ml double-layer quartz photocatalytic reactor, put in a magnet and stir; connect the double-layer quartz catalytic reactor to the circulating cooling water, and keep the cooling water temperature constant at 25℃. A 300 W xenon lamp with a 400 nm filter was used to irradiate the top of the quartz reactor for 8 h. 1 ml of the reaction solution was taken out and centrifuged to obtain the supernatant, and the product was analyzed by HPLC. The catalyst after the reaction was recovered, washed and dried, and then placed in a fresh 20 mM HMF aqueous solution for catalyst cycle performance testing. The experimental results can be found in Figure 6 , the catalyst can still maintain 100% HMF conversion and 99.9% FDCA yield after 10 8-h catalytic reactions.

[0036] Example 4 Weigh 0.1g black titanium dioxide, put it into a round-bottom flask and add 20ml water, stir for 30min; then add 5ml 0.2mg / ml chloroplatinic acid aqueous solution dropwise, the mass ratio of chloroplatinic acid to black titanium dioxide is 1:100, stir for 2h, evaporate the solvent with a rotary evaporator, obtain a solid powder mixed with chloroplatinate and black titanium dioxide and transfer it to a quartz boat, put it into a tube furnace and calcine it at 300℃ in an argon atmosphere for 2h, wash and dry it, and obtain a sub-nanometer platinum species-loaded black titanium dioxide catalyst. Weigh 20mg of sub-nanometer platinum species-loaded black titanium dioxide catalyst, carry out catalytic reaction of different concentrations of HMF aqueous solution (5mM, 10mM, 20mM, 40mM), transfer this mixed reaction solution to a 150ml double-layer quartz photocatalytic reactor, put in a magnet and stir; connect the double-layer quartz catalytic reactor to circulating cooling water, and keep the cooling water temperature constant at 25℃. A 300 W xenon lamp with a 400 nm filter was used to irradiate the top of the quartz reactor for 8 h. 1 ml of the reaction solution was taken out and centrifuged to obtain the supernatant. The product was analyzed by HPLC. The experimental results are shown in Figure 7 When the HMF concentration was 5 mM, the HMF conversion rate reached 100% in 2 h, and the FDCA yield reached 99.9% in 6 h; when the HMF concentration was 10 mM, the HMF conversion rate reached 99.9% in 3 h, and the FDCA yield reached 99.9% in 6 h; when the HMF concentration was 20 mM, the HMF conversion rate reached 100% in 4 h, and the FDCA yield reached 99.9% in 8 h; when the HMF concentration was 40 mM, the HMF conversion rate reached 100% in 4 h, and the FDCA yield reached 60% in 8 h.

[0037] The process of preparing 2,5-furandicarboxylic acid (FDCA) from 5-hydroxymethylfurfural (HMF) involves multiple consecutive oxidation steps of alcohol and aldehyde functional groups, which is a typical tandem catalytic reaction; usually, a high FDCA yield can be obtained under harsh reaction conditions of high temperature, high pressure and strong base. The present invention constructs a sub-nanometer platinum species catalytic active center and regulates the geometric / electronic structure of the platinum species, so that it has excellent catalytic oxidation ability for the alcohol and aldehyde functional groups of 5-hydroxymethylfurfural, and can quickly convert 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid; black titanium dioxide is used as a catalytic light absorption center, and visible-near infrared light can be fully utilized for catalytic reactions. In short, the carrier black titanium dioxide provides a driving force for the photocatalytic oxidation of HMF, and the sub-nanometer platinum species provide specific catalytic sites for the multi-step tandem reaction of HMF to prepare FDCA.

[0038] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural under visible-near infrared light catalysis in pure water system at room temperature and pressure, characterized in that: include: Under visible-near infrared light, 2,5-furandicarboxylic acid was prepared by photocatalytic conversion of 5-hydroxymethylfurfural over subnanometer platinum species-supported black titanium dioxide catalyst in a pure water system at room temperature and atmospheric pressure.

2. The method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural using visible-near infrared photocatalysis in pure water system at room temperature and pressure according to claim 1, characterized in that: include: At room temperature and normal pressure, with water as solvent, the reactant 5-hydroxymethylfurfural and the sub-nanometer platinum species-loaded black titanium dioxide catalyst are stirred evenly; then, under visible-near infrared light irradiation, the reaction is carried out for 1-10 hours, and the reaction liquid is separated to obtain 2,5-furandicarboxylic acid.

3. The method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural using visible-near infrared photocatalysis in pure water system at room temperature and pressure according to claim 2, characterized in that: The mass ratio of 5-hydroxymethylfurfural and sub-nanometer platinum species supported black titanium dioxide catalyst is (0.1-1000): 1; During the reaction, the reactant 5-hydroxymethylfurfural is prepared into a 1-200 mM reaction solution with water; Preferably, the reactant 5-hydroxymethylfurfural is prepared into a 20 mM reaction solution with water.

4. The method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural using visible-near infrared photocatalysis in pure water system at room temperature and pressure according to claim 2, characterized in that: The ratio of water to reactant 5-hydroxymethylfurfural is (10 - 1000) mL: (12.6 -1260) mg.

5. The method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural under visible-near infrared light catalysis in pure water system at room temperature and pressure according to claim 2, characterized in that: The stirring time is 0.5-5 h.

6. The method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural under visible-near infrared light catalysis in pure water system at room temperature and pressure according to claim 2, characterized in that: The wavelength range of visible-near infrared light is 400-1000 nm; Preferably, the wavelength of the visible-near infrared light is 400 nm or 500 nm.

7. The method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural under visible-near infrared light catalysis in pure water system at room temperature and pressure according to any one of claims 1 to 6, characterized in that: The sub-nanometer platinum species-loaded black titanium dioxide catalyst is prepared according to the following method: The chloroplatinic acid aqueous solution and the black titanium dioxide solid powder are stirred and mixed at room temperature, and fully immersed for a period of time to obtain a mixture; after evaporating the solvent, the mixture is calcined at a high temperature in an inert or reducing gas atmosphere for a certain period of time to obtain a sub-nanometer platinum species-loaded black titanium dioxide catalyst.

8. The method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural under visible-near infrared light catalysis in pure water system at room temperature and pressure according to claim 7, characterized in that: The mass ratio of chloroplatinic acid to black titanium dioxide solid powder is (0.1-10):100; the immersion time is 0.5-5 h.

9. The method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural under visible-near infrared light catalysis in pure water system at room temperature and pressure according to claim 7, characterized in that: Argon, nitrogen, hydrogen or a mixture of hydrogen and argon is selected as the reaction atmosphere.

10. The method for preparing 2,5-furandicarboxylic acid by upgrading 5-hydroxymethylfurfural under visible-near infrared light catalysis in pure water system at room temperature and pressure according to claim 7, characterized in that: The high temperature calcination temperature is 200-400 °C, and the calcination time is 1-10 h.

Images