Method for preparing 2,5-furan dicarboxylic acid by visible-near infrared light catalysis of 5-hydroxymethylfurfural in room temperature normal pressure pure water system

Abstract

The application discloses a method for preparing 2,5-furan dicarboxylic acid by visible-near infrared light catalysis of 5-hydroxymethylfurfural in a room temperature and normal pressure pure water system, and belongs to the technical field of biomass energy. The application realizes efficient upgrading conversion of 5-hydroxymethylfurfural to prepare 2,5-furan dicarboxylic acid in a room temperature and normal pressure pure water system by using a black titanium dioxide catalyst loaded with sub-nano platinum species and taking more than 90% visible-near infrared light in a solar spectrum as driving force, which effectively overcomes the short board that photocatalysis needs to depend on high-energy ultraviolet light, provides a solid foundation for directly using outdoor sunlight for biomass upgrading conversion, avoids dangerous reaction conditions with high risk coefficients such as toxic organic solvents and high temperature and high pressure, and has the advantages of green environmental protection and low energy consumption.

Description

Technical Field

[0001] This invention belongs to the field of biomass energy technology, specifically relating to a method for the up-conversion of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid using visible-near-infrared photocatalysis in a room temperature and atmospheric pressure pure water system. Background Technology

[0002] The production of high-value chemicals and fuels from widely available renewable biomass resources is one of the effective solutions to address the global depletion of fossil fuels and climate change. 5-Hydroxymethylfurfural (HMF) is an important biomass-derived platform compound. As a raw material, it can be used in catalytic oxidation to yield a series of value-added chemicals. Among these, the most valuable product, 2,5-furandicarboxylic acid (FDCA), has a structure similar to terephthalic acid and can serve as a substitute for polyethylene terephthalate (PET) in the manufacture of bio-based polymers and biodegradable plastics. The preparation of FDCA from HMF involves multiple consecutive oxidation steps of alcohol and aldehyde functional groups, representing a typical tandem catalytic reaction. Currently, the oxidation of HMF to FDCA mainly relies on energy-intensive thermocatalytic conversion, typically requiring harsh reaction conditions of high temperature, high pressure, and strong alkali to achieve high FDCA yields. Therefore, developing new catalytic strategies to achieve efficient conversion of HMF to FDCA under mild conditions is of significant practical importance. Photocatalysis, powered by inexhaustible solar energy, offers a promising technological solution for the oxidation of HMF under mild conditions at room temperature and atmospheric pressure. For example, in recent years, researchers have developed photocatalysts based on oxides, sulfides, quantum dots, and MOF / COF materials for upgrading the photocatalytic oxidation of HMF.

[0003] However, most reported photocatalytic HMF oxidation conversion systems currently suffer from technical problems such as requiring strong bases / organic solvents as reaction media, high-pressure oxygen (1-10 MPa), and ultraviolet light, as well as low selectivity for the product FDCA. For example, Chinese invention patent CN109107605A proposes a photocatalytic HMF oxidation system that requires acetonitrile solvent as a medium and hydrochloric acid as a promoter, resulting in a complex system. Chinese invention patent CN116037166A, through the preparation of a Pt-Ov-BiOBr catalyst with a noble metal-semiconductor interface, performs photocatalytic HMF oxidation, but the oxidation product remains at the intermediate 2,5-furandialdehyde, exhibiting very low selectivity for FDCA. The Z-type heterojunction SnIn4S8-ZnIn2S4 catalyst proposed in Chinese invention patent CN117551063A can only achieve the photocatalytic conversion of HMF to the 2,5-furandialdehyde intermediate. Chinese invention patent CN113698373B proposes photocatalytic oxidation of HMF to prepare FDCA using P-type semiconductor Cu2O. However, the reaction is carried out under high-pressure oxygen conditions and requires ultraviolet light. Chinese invention patent CN113351210B provides a Cu-based catalyst and uses it in a photocatalytic water-to-hydrogen-HMF oxidation coupling reaction. While it achieves the conversion of HMF to FDCA, it suffers from low HMF conversion and the need for ultraviolet light. Another example is Chinese invention patent CN106279080B, which proposes photocatalytic preparation of FDCA using HMF. However, this requires high temperatures of 60-90°C, resulting in high energy consumption. Furthermore, it uses oxygen or hydrogen peroxide generated from photocatalytic water splitting as an oxidant for selective oxidation of the reactants. This process could potentially lead to further mineralization of the FDCA product, generating carbon dioxide, which would severely reduce the actual yield of FDCA.

[0004] It is evident that the rational and efficient utilization of solar energy for biomass upgrading and conversion is of great significance for alleviating the global energy crisis and environmental problems. Therefore, there is an urgent need to develop catalytic systems that can utilize visible light under mild conditions to achieve efficient HMF conversion and highly selective FDCA generation. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for the preparation of 2,5-furandicarboxylic acid by up-catalysis of 5-hydroxymethylfurfural in a room temperature and atmospheric pressure pure water system, so as to solve the technical problems of the prior art that it requires ultraviolet light or high temperature assistance, low selectivity of FDCA product, and low reaction conversion rate.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] One objective of this invention is to provide a method for the efficient upgrading of HMF to FDCA in a room-temperature and atmospheric-pressure pure water system. The invention discloses a method for the photocatalytic upgrading of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid in a room-temperature and atmospheric-pressure pure water system using visible-near-infrared photocatalysis. The method includes: under visible-near-infrared irradiation, in a room-temperature and atmospheric-pressure pure water system, photocatalytic conversion of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid using a black titanium dioxide catalyst supported on sub-nanometer platinum species.

[0008] Preferably, the method includes: stirring the reactant 5-hydroxymethylfurfural and sub-nano platinum species-supported black titanium dioxide catalyst evenly with water as solvent at room temperature and normal pressure; then reacting for 1-10 h under visible-near infrared light irradiation, separating the reaction liquid, and obtaining 2,5-furandicarboxylic acid.

[0009] More preferably, the mass ratio of 5-hydroxymethylfurfural to sub-nanoplatinum species-supported black titanium dioxide catalyst is (0.1-1000):1;

[0010] During the reaction, the reactant 5-hydroxymethylfurfural was prepared into a 1-200 mM reaction solution with water;

[0011] More preferably, the reactant 5-hydroxymethylfurfural is prepared into a 20 mM reaction solution with water.

[0012] Preferably, the ratio of water to reactant 5-hydroxymethylfurfural is (10 - 1000) mL: (12.6 - 1260) mg.

[0013] Preferably, the stirring time is 0.5-5 h.

[0014] Preferably, the wavelength range of the visible-near infrared light is 400-1000 nm;

[0015] More preferably, the wavelength of the visible-near infrared light is 400 nm or 500 nm.

[0016] The optimized specific operating procedure is as follows: a certain volume of deionized water is added to a double-layer quartz photocatalytic reactor, and then the sub-nanometer platinum species-supported black titanium dioxide catalyst and the reactant 5-hydroxymethylfurfural are added and stirred at room temperature for a certain period of time; cooling water is circulated through the outer layer of the double-layer quartz photocatalytic reactor and the temperature of the cooling water 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; after reacting for a period of time under normal pressure, the reaction solution is taken out and centrifuged to obtain a transparent reaction solution without catalyst; the content of 2,5-furandicarboxylic acid product is analyzed by high performance liquid chromatography.

[0017] The volume of deionized water is added according to the reactant ratio, and the conductivity of pure water should be less than 0.1 µS / cm; the mass ratio of sub-nanometer platinum species-supported black titanium dioxide catalyst to reactant 5-hydroxymethylfurfural is 1:(0.1-1000); the HMF solution concentration is 1 mM-200 mM; the stirring time at room temperature is 0.5-5 h; the cooling water temperature range is 15-35℃; 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 atmospheric pressure, i.e., 0.1013 MPa; the photocatalytic reaction time is 1-10 h; and the purity of the product 2,5-furandicarboxylic acid is 95%-99.9%.

[0018] Based on the above objectives, this invention provides a highly active catalyst for achieving visible-near-infrared photocatalytic HMF upgrade conversion. The technical solution adopted is to synthesize a black titanium dioxide catalyst supported on sub-nanometer platinum species via a "wet impregnation-high temperature calcination" method.

[0019] Preferably, the sub-nanometer platinum species-supported black titanium dioxide catalyst is prepared by the following method:

[0020] A chloroplatinic acid aqueous solution was stirred and mixed with black titanium dioxide solid powder at room temperature and thoroughly impregnated for a period of time to obtain a mixture. After evaporating the solvent, the mixture was calcined at high temperature in an inert or reducing gas atmosphere for a certain period of time to obtain a sub-nanometer platinum species supported black titanium dioxide catalyst.

[0021] More preferably, the mass ratio of chloroplatinic acid to black titanium dioxide solid powder is (0.1-10):100; and the impregnation time is 0.5-5 h.

[0022] More preferably, argon, nitrogen, hydrogen, or a mixture of hydrogen and argon is selected as the reaction atmosphere.

[0023] More preferably, the high-temperature calcination temperature is 200-400 ℃, and the calcination time is 1-10 h.

[0024] The optimized specific operation scheme is as follows: stir and mix the aqueous solution of chloroplatinic acid and the solid powder of black titanium dioxide at room temperature and impregnate it for a period of time; after evaporating the solvent, place the mixture of chloroplatinic acid and black titanium dioxide in a tube furnace and calcine it at high temperature for a certain time in an inert or reducing gas atmosphere to obtain a black titanium dioxide catalyst supported on sub-nanometer platinum species.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention provides a method for the photocatalytic conversion of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid using a room-temperature, atmospheric-pressure pure water system in the visible-near-infrared range. Utilizing a black titanium dioxide catalyst supported on sub-nanometer platinum species, and driven by over 90% of the visible-near-infrared spectrum of sunlight, this method achieves highly efficient conversion of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid in a room-temperature, atmospheric-pressure pure water system. This method effectively overcomes the limitation of photocatalysis relying on high-energy ultraviolet light, providing a solid foundation for the direct utilization of outdoor sunlight for biomass conversion. Furthermore, it avoids the high-risk reaction conditions of toxic organic solvents and high temperatures and pressures, offering advantages such as being environmentally friendly and having low energy consumption. Experimental results confirm that the selectivity for the target product is 99.9%, and the TOF value for 2,5-furandicarboxylic acid production can reach 50 mol / L. FDCA mol Pt -1 h -1 This study achieved the best yield level reported to date for thermocatalytic systems involving high temperature, high pressure, and strong alkali, providing a strong research foundation for the large-scale application of photocatalytic HMF conversion to FDCA.

[0027] Furthermore, this invention selects a black titanium dioxide catalyst supported on sub-nanometer platinum species. This catalyst uses sub-nanometer platinum species as catalytic active centers and is loaded onto the surface of black titanium dioxide using a "wet impregnation-high temperature calcination" method. By rationally controlling the geometric / electronic structure of the sub-nanometer platinum species, the effective adsorption and activation ability of the catalytic centers for aldehyde and alcohol functional groups in the reactant 5-hydroxymethylfurfural molecule is enhanced. Using black titanium dioxide as a light-absorbing center, the catalyst can effectively utilize visible-infrared light, thereby achieving efficient upgrading of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid through visible-near-infrared photocatalysis in a room temperature, atmospheric pressure, and pure water system. Attached Figure Description

[0028] Figure 1 HADDF-STEM image of black TiO2 loaded with sub-nanometer platinum species;

[0029] Figure 2 EXAFS image of black TiO2 loaded with sub-nanometer platinum species;

[0030] Figure 3 The curves showing the time-dependent changes in HMF conversion and FDCA yield of black TiO2 supported on sub-nanometer platinum species under visible light catalysis;

[0031] Figure 4 HPLC product distribution at different times;

[0032] Figure 5 Performance diagram of HMF-to-FDCA conversion using photocatalysis at different wavelengths;

[0033] Figure 6 The performance graph of the catalyst after 10 cycles;

[0034] Figure 7 The time-varying curves for HMF conversion (left) and FDCA formation (right) at different HMF aqueous solution concentrations. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] The present invention will now be described in further detail with reference to the accompanying drawings:

[0038] This invention discloses a method for the efficient upgrading of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid via visible-near-infrared photocatalysis in a room-temperature, atmospheric-pressure pure water system. The method comprises: first, using sub-nanometer platinum species as the catalytic active center, loading them onto the surface of black titanium dioxide via a "wet impregnation-high-temperature calcination" method to prepare a sub-nanometer platinum species-supported black titanium dioxide catalyst; second, under visible-near-infrared irradiation in a room-temperature, atmospheric-pressure pure water system, catalyzing the efficient upgrading of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid via the sub-nanometer platinum species-supported black titanium dioxide catalyst.

[0039] Specifically, the method of the present invention includes the following steps:

[0040] Step 1) To prepare a sub-nanometer platinum species-supported black titanium dioxide catalyst, an aqueous solution of chloroplatinic acid and solid black titanium dioxide powder were stirred and mixed at room temperature and thoroughly impregnated for a period of time. After the solvent was evaporated, the mixture of chloroplatinic acid and black titanium dioxide was placed in a tube furnace and calcined at high temperature for a certain time in an inert or reducing gas atmosphere to obtain the sub-nanometer platinum species-supported black titanium dioxide catalyst.

[0041] Preferably, the mass ratio of chloroplatinic acid to black titanium dioxide is (0.1-10):100; the impregnation time is 0.5-5 h; the inert or reducing gas atmosphere is argon, nitrogen, hydrogen, or a hydrogen-argon mixture; the high-temperature calcination temperature is 200-400℃, and the calcination time is 1-10 h.

[0042] 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 CN110813280A.

[0043] Step 2): Add a certain volume of deionized water to the double-layer quartz photocatalytic reactor, then add the sub-nanometer platinum species-supported black titanium dioxide catalyst and the reactant 5-hydroxymethylfurfural, and stir at room temperature for a certain time; circulate cooling water through the outer layer of the double-layer quartz photocatalytic reactor, keep the cooling water temperature constant within a certain range, turn on a 300W xenon lamp light source with a filter to irradiate the top of the quartz photocatalyst, and after reacting for a period of time under normal pressure, take out the reaction solution and centrifuge to obtain a transparent reaction solution without catalyst, and analyze the content of 2,5-furandicarboxylic acid product by high performance liquid chromatography.

[0044] Preferably, the volume of the deionized water is 5-1000 ml, and the conductivity of the pure water should be less than 0.1 µS / cm; the mass ratio of the sub-nanometer platinum species-supported black titanium dioxide catalyst to the reactant 5-hydroxymethylfurfural is 1:(0.1-1000); the HMF solution concentration is 1 mM-200 mM; the stirring time at room temperature is 0.5-5 h; the cooling water temperature range is 15-35℃; the filter wavelength range is 400-1000 nm; the atmosphere for the photocatalytic reaction of 5-hydroxymethylfurfural is air or oxygen, and the gas pressure is atmospheric pressure, i.e., 0.1013 MPa; the photocatalytic reaction time is 1-10 h; and the purity of the product 2,5-furandicarboxylic acid is 95%-99.9%.

[0045] Example 1

[0046] 0.1 g of black titanium dioxide was weighed and placed in a round-bottom flask with 20 ml of water. The mixture was stirred for 30 min. Then, 5 ml of a 0.2 mg / ml aqueous solution of chloroplatinic acid was added dropwise (the mass ratio of chloroplatinic acid to black titanium dioxide was 1:100). The mixture was stirred for 2 h, and the solvent was evaporated to dryness using a rotary evaporator to obtain a mixture of chloroplatinic acid and black titanium dioxide. This mixture was then transferred to a quartz boat and calcined in a tube furnace at 300 °C under an argon atmosphere for 2 h. After washing and drying, a black titanium dioxide catalyst supported on sub-nanometer platinum species was obtained. The morphology and structure of the platinum species were characterized using aberration-corrected electron microscopy and synchrotron radiation. (See attached results). Figure 1 , Figure 2 .from Figure 1 It can be seen that the sub-nanometer platinum species are uniformly 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 is known 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-nano structure of the platinum species.

[0047] Weigh 20 mg of sub-nano platinum species-supported black titanium dioxide catalyst and add it to 100 ml of 20 mM HMF pure water solution. Transfer this mixed reaction solution to a 150 ml double-layer quartz photocatalytic reactor, place a magnetic stir bar, and stir. Connect the double-layer quartz photocatalytic reactor to circulating cooling water to maintain a constant cooling water temperature of 25°C. Irradiate the top of the quartz reactor with a 300W xenon lamp with a 400 nm filter for 8 h. Take out 1 ml of the reaction solution, centrifuge to obtain the supernatant, and analyze the product by HPLC (results are shown in the figure). Figure 4 As shown); according to the liquid chromatography results, the conversion rate of HMF was 100%, and the yield of FDCA was 99.9% (results are shown in the figure). Figure 3 (As shown).

[0048] Example 2

[0049] Weigh 0.1 g of black titanium dioxide, place it in a round-bottom flask, add 20 ml of water, and stir for 30 min. Then, add 5 ml of 0.2 mg / ml chloroplatinic acid aqueous solution dropwise (the mass ratio of chloroplatinic acid to black titanium dioxide is 1:100), stir for 2 h, and evaporate the solvent using a rotary evaporator to obtain a solid powder mixture of chloroplatinate and black titanium dioxide. Transfer the powder to a quartz boat, place it in a tube furnace, and calcine it at 300 °C for 2 h under an argon atmosphere. Wash and dry to obtain a sub-nanometer platinum species-supported black titanium dioxide catalyst. Weigh 20 mg of the sub-nanometer platinum species-supported black titanium dioxide catalyst, add 100 ml of 20 mM HMF pure aqueous solution, and transfer this mixed reaction solution to a 150 ml double-layer quartz photocatalytic reactor. Place a magnetic stirrer and stir. Connect the double-layer quartz photocatalytic reactor to circulating cooling water to maintain a constant cooling water temperature of 25 °C. The quartz reactor was irradiated with a 300 W xenon lamp equipped with filters of 500 nm, 600 nm, 800 nm, and 1000 nm for 8 h. One ml of the reaction solution was collected, centrifuged to obtain the supernatant, and the products were analyzed by HPLC. According to the HPLC 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%; and at 1000 nm, the conversion rate of HMF was 60% and the yield of FDCA was 50%.

[0050] See results Figure 5 ,from Figure 5 It is known that the efficient conversion of HMF-FDCA can be achieved using visible-near infrared light at 400 nm, 500 nm, 600 nm, 800 nm and 1000 nm by black titanium dioxide catalyst supported on sub-nanometer platinum species.

[0051] Example 3

[0052] Weigh 0.1 g of black titanium dioxide, place it in a round-bottom flask, add 20 ml of water, and stir for 30 min. Then, add 5 ml of 0.2 mg / ml chloroplatinic acid aqueous solution dropwise (the mass ratio of chloroplatinic acid to black titanium dioxide is 1:100), stir for 2 h, and evaporate the solvent using a rotary evaporator to obtain a solid powder mixture of chloroplatinate and black titanium dioxide. Transfer the powder to a quartz boat, place it in a tube furnace, and calcine it at 300 °C under an argon atmosphere for 2 h. Wash and dry to obtain a sub-nanometer platinum species-supported black titanium dioxide catalyst. Weigh 20 mg of the sub-nanometer platinum species-supported black titanium dioxide catalyst, add 100 ml of 20 mM HMF pure aqueous solution, and transfer this mixed reaction solution to a 150 ml double-layer quartz photocatalytic reactor. Place a magnetic stirrer and stir. Connect the double-layer quartz photocatalytic reactor to circulating cooling water to maintain a constant cooling water temperature of 25 °C. The quartz reactor was irradiated with a 300 W xenon lamp equipped with a 400 nm filter for 8 h. 1 ml of the reaction solution was collected, centrifuged to obtain the supernatant, and the product was analyzed by HPLC. The catalyst was recovered, washed, dried, and then placed in a fresh 20 mM HMF aqueous solution for catalyst cycle performance testing. Experimental results are shown below. Figure 6 Even after 10 cycles of 8-hour catalytic reactions, the catalyst still maintains 100% HMF conversion and 99.9% FDCA yield.

[0053] Example 4

[0054] Weigh 0.1 g of black titanium dioxide, place it in a round-bottom flask, add 20 ml of water, and stir for 30 min. Then, add 5 ml of 0.2 mg / ml chloroplatinic acid aqueous solution dropwise (the mass ratio of chloroplatinic acid to black titanium dioxide is 1:100), stir for 2 h, and evaporate the solvent using a rotary evaporator to obtain a solid powder mixture of chloroplatinate and black titanium dioxide. Transfer the powder to a quartz boat, place it in a tube furnace, and calcine it at 300 °C for 2 h under an argon atmosphere. Wash and dry to obtain a sub-nanometer platinum species-supported black titanium dioxide catalyst. Weigh 20 mg of the sub-nanometer platinum species-supported black titanium dioxide catalyst and conduct catalytic reactions with different concentrations of HMF aqueous solutions (5 mM, 10 mM, 20 mM, 40 mM). Transfer this mixed reaction solution to a 150 ml double-layer quartz photocatalytic reactor, add a magnetic stir bar, and stir. Connect the double-layer quartz photocatalytic reactor to circulating cooling water to maintain a constant cooling water temperature of 25 °C. The quartz reactor was irradiated with a 300 W xenon lamp equipped with a 400 nm filter for 8 h. 1 ml of the reaction solution was collected, centrifuged to obtain the supernatant, and the product was analyzed by HPLC. Experimental results are shown below. Figure 7At an HMF concentration of 5 mM, the HMF conversion reached 100% in 2 h and the FDCA yield reached 99.9% in 6 h; at 10 mM, the HMF conversion reached 99.9% in 3 h and the FDCA yield reached 99.9% in 6 h; at 20 mM, the HMF conversion reached 100% in 4 h and the FDCA yield reached 99.9% in 8 h; and at 40 mM, the HMF conversion reached 100% in 4 h and the FDCA yield reached 60% in 8 h.

[0055] The preparation of 2,5-furandicarboxylic acid (FDCA) from 5-hydroxymethylfurfural (HMF) involves multiple consecutive oxidation steps of alcohol and aldehyde functional groups, constituting a typical tandem catalytic reaction. High FDCA yields are typically achieved under harsh reaction conditions of high temperature, high pressure, and strong alkali. This invention addresses this by constructing sub-nanometer platinum species catalytic active centers and regulating the geometry / electronic structure of these platinum species to enable excellent catalytic oxidation of the alcohol and aldehyde functional groups of 5-hydroxymethylfurfural, rapidly converting it to 2,5-furandicarboxylic acid. Furthermore, black titanium dioxide serves as the catalytic light-absorbing center, fully utilizing visible-near-infrared light for the catalytic reaction. In summary, the black titanium dioxide support provides the driving force for the photocatalytic oxidation of HMF, while the sub-nanometer platinum species provide specific catalytic sites for the multi-step tandem reaction in the preparation of FDCA from HMF.

[0056] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for the preparation of 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural via visible-near-infrared photocatalysis in a pure water system at room temperature and atmospheric pressure, characterized in that... include: Under visible-near-infrared light irradiation, in a pure water system at room temperature and atmospheric pressure, 2,5-furandicarboxylic acid was prepared by photocatalytic conversion of 5-hydroxymethylfurfural using a black titanium dioxide catalyst supported on sub-nanometer platinum species. The sub-nanometer platinum species-supported black titanium dioxide catalyst was prepared by the following method: A chloroplatinic acid aqueous solution was stirred and mixed with black titanium dioxide solid powder at room temperature and thoroughly impregnated for a period of time to obtain a mixture. After evaporating the solvent, the mixture was calcined at high temperature in an inert or reducing gas atmosphere for a certain period of time to obtain a sub-nanometer platinum species supported black titanium dioxide catalyst.

2. The method for preparing 2,5-furandicarboxylic acid from a room temperature, atmospheric pressure pure water system using visible-near-infrared photocatalysis according to claim 1, characterized in that... include: Under normal temperature and pressure conditions, 5-hydroxymethylfurfural and sub-nano platinum species-supported black titanium dioxide catalyst were stirred evenly with water as solvent; then, the reaction was carried out for 1-10 h under visible-near infrared light irradiation, and the reaction solution was separated to obtain 2,5-furandicarboxylic acid.

3. The method for preparing 2,5-furandicarboxylic acid from a room temperature, atmospheric pressure pure water system using visible-near-infrared photocatalysis according to claim 2, is characterized in that... The mass ratio of 5-hydroxymethylfurfural to sub-nanoplatinum 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.

4. The method for preparing 2,5-furandicarboxylic acid from a room temperature, atmospheric pressure pure water system using visible-near-infrared photocatalysis according to claim 3, characterized in that... During the reaction, the reactant 5-hydroxymethylfurfural was prepared into a 20 mM reaction solution with water.

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

6. The method for preparing 2,5-furandicarboxylic acid from a room temperature, atmospheric pressure pure water system using visible-near-infrared photocatalysis according to claim 2, is characterized in that... The stirring time is 0.5-5 hours.

7. The method for preparing 2,5-furandicarboxylic acid from a room temperature, atmospheric pressure pure water system using visible-near-infrared photocatalysis according to claim 2, characterized in that... The wavelength range of visible-near infrared light is 400-1000 nm.

8. The method for preparing 2,5-furandicarboxylic acid from a room temperature, atmospheric pressure pure water system using visible-near-infrared photocatalysis according to claim 7, characterized in that... The wavelength of visible-near infrared light is 400 nm or 500 nm.

9. The method for preparing 2,5-furandicarboxylic acid from a room temperature, atmospheric pressure pure water system using visible-near-infrared photocatalysis according to claim 1, characterized in that... The mass ratio of chloroplatinic acid to black titanium dioxide solid powder is (0.1-10):100; the impregnation time is 0.5-5 h.

10. The method for preparing 2,5-furandicarboxylic acid from a room temperature, atmospheric pressure pure water system using visible-near-infrared photocatalysis according to claim 1, characterized in that... Argon, nitrogen, hydrogen, or a mixture of hydrogen and argon can be selected as the reaction atmosphere.

11. The method for preparing 2,5-furandicarboxylic acid from a room temperature, atmospheric pressure pure water system using visible-near-infrared photocatalysis according to claim 1, characterized in that... The high-temperature calcination temperature is 200-400 ℃, and the calcination time is 1-10 h.

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