192 results about "Hydroxymethylfurfural" patented technology

The invention discloses a preparation method of a sulfonic acid type covalent organic framework material and a preparation method of 5-hydroxymethylfurfural. The material is prepared by carrying out covalent condensation reaction on a monomer containing a sulfonic acid group precursor and a connecting ligand of a skeleton through a hot solvent method, and the catalyst has the characteristics of high crystallinity, large specific surface area, ordered pore structure, high sulfonic acid group density and uniform distribution. The preparation method is simple, convenient, efficient, mild in condition and high in yield. Compared with a traditional lewis acid catalyst for preparing 5-hydroxymethylfurfural through fructose dehydration, the material has the advantages of being uniform and adjustable in porosity, higher in active site, capable of promoting fructose hydrolysis and the like, efficient conversion can be achieved, side reactions and product transition polymerization are inhibited, and better industrialization prospects are shown.

The invention relates to the technical field of chemical synthesis, and discloses a method for preparing 2, 5-furandicarboxylic acid, which comprises the following steps: dispersing cobalt nitrate and nickel sulfate into an aqueous solution of polyvinylpyrrolidone at room temperature; adding a sodium borohydride solution to obtain nano colloid; preparing an aqueous suspension of cerium oxide, and adding the aqueous suspension into the nano colloid; centrifugally filtering, and recovering a solid product; washing the solid product; centrifuging, putting solid powder obtained after centrifuging into a drying oven, and drying; and calcining and grinding the solid powder to finally prepare the Co-Ni / CeO2 catalyst. And dissolving 5-hydroxymethylfurfural in water at normal temperature, adding the prepared Co-Ni / CeO2 catalyst and a sodium hypochlorite solution, reacting, and filtering to remove the catalyst, thereby obtaining the 2, 5-furandicarboxylic acid. The method disclosed by the invention has the advantages of no use of strong base, low reaction temperature, short reaction time, few byproducts, greenness and sustainability.

The invention provides a continuous flow preparation method of a CuPd / C catalyst. The method is simple and efficient, and one-step and continuous production can be realized. The method has the core advantages that multi-phase flow is ordered, the mixing efficiency is high, reaction parameters are accurate and adjustable, the repeatability and the automation degree are remarkably superior to those of a traditional impregnation method, and the problems that the traditional method is long in time consumption, low in selectivity, high in operation dependency, uneven in mixing and the like are effectively solved. In addition, catalyst synthesis conditions are screened, and optimal preparation conditions are determined. According to the CuPd / C catalyst prepared by the method, the conversion rate of 2, 5-dimethylfuran prepared from 5-hydroxymethylfurfural can reach 100%, and the selectivity of 2, 5-dimethylfuran can reach 97.5%. Compared with a CuPd / C catalyst prepared by an impregnation method, the yield of 2, 5-dimethylfuran is improved by more than 34.5%, and is superior to most reported catalysts at present. And mechanical operation can avoid personal errors, so that the result is easier to repeat, and the production efficiency is improved.

The invention discloses a liquid chromatography method for measuring 5-hydroxymethylfurfural in a calcium gluconate and sodium chloride injection. The method comprises the following steps: measuring the calcium gluconate and sodium chloride injection as a test solution; weighing 5-hydroxymethylfurfural, and adding water to dilute the 5-hydroxymethylfurfural to form a reference solution; carrying out continuous sample introduction on the liquid chromatograph by using the reference substance solution to obtain a system applicability solution chromatogram; when the chromatogram of the applicable solution of the system meets the standard, measuring the test solution and the reference solution, respectively injecting the test solution and the reference solution into a liquid chromatograph, and recording the chromatograms; the content of 5-hydroxymethylfurfural in the calcium gluconate and sodium chloride injection is obtained through a 5-hydroxymethylfurfural content calculation formula. The method has the advantages of strong specificity, high sensitivity, good precision, strong durability and the like, and can quantitatively detect 5-hydroxymethylfurfural in the calcium gluconate and sodium chloride injection, so that the safety of clinical medication of the calcium gluconate and sodium chloride injection is improved.

The invention provides a preparation method for synthesizing 5-hydroxymethylfurfural by catalyzing glucose through a phosphotungstic acid modified molecular sieve catalyst. Organic amine is adopted as a template to synthesize a silicoaluminophosphate (SAPO) molecular sieve, the SAPO molecular sieve subjected to high-temperature activation is adopted as a catalyst, the SAPO molecular sieve and phosphotungstic acid are subjected to composite roasting, a phase transfer catalyst is added into a two-phase medium of an organic solvent and water, glucose is dehydrated and converted into 5-hydroxymethylfurfural (5-HMF), the yield of the 5-HMF is 50% or above, and the selectivity of the 5-HMF exceeds 90%. After the catalyst is recycled for multiple times, the yield of 5-HMF exceeds 40%.

The invention discloses a method for preparing 2, 5-diformyl furan by selectively oxidizing 5-hydroxymethylfurfural, which comprises the following steps of: reacting 5-hydroxymethylfurfural serving as a raw material, air or oxygen serving as an oxidant, nitrate or ferric salt and sodium iodide serving as main active components of a catalyst and DMSO (dimethylsulfoxide) serving as a solvent at the temperature of between 80 and 160 DEG C for a certain time under the condition of normal pressure, and separating a product to obtain the 2, 5-diformyl furan. The ferric salt is ferric nitrate nonahydrate, and the catalyst is 2, 5-diformyl furan. The dosage of the ferric salt is 0 to 0.50 mmol; the use amount of the sodium iodide is 0 to 0.50 mmol. According to the method, DMSO is adopted as a solvent, the used catalyst is cheap and easy to obtain, the yield of 2, 5-diformyl furan can reach 95% at most after the reaction is carried out at 140 DEG C for 20 h, the requirement for equipment is low, and the method is suitable for industrial production.

The invention relates to a process for the production of a mixture of 5-hydroxymethylfurfural and glucose from a feedstock containing fructose in the presence of at least one polar aprotic solvent and of at least one dehydration catalyst, in which process the reaction temperature is less than 90° C.

The invention relates to a spleen-tonifying, appetite-stimulating and digestion-promoting traditional Chinese medicine preparation UPLC detection method and a fingerprint spectrum, and belongs to the technical field of medicine detection. The invention aims to solve the technical problems that the existing quality control method of the spleen-tonifying, appetite-promoting and digestion-promoting pills lacks comprehensive and objective analysis on the spleen-tonifying, appetite-promoting and digestion-promoting pills, and the problems of low precision, poor reproducibility, low efficiency and the like during detection of related components in the prior art are solved. According to the technical scheme, the UPLC detection method is characterized in that a mixed standard substance of gallic acid, 5-hydroxymethylfurfural, chlorogenic acid, sinapine thiocyanate, sinapic acid, hyperoside, 3, 6-dimustard acyl sucrose, hesperidin, naringenin, nobiletin and hesperetin is taken as a contrast, an acetonitrile-0. 1% formic acid aqueous solution is taken as a mobile phase, gradient elution is carried out, and the content of chlorogenic acid in the sample is detected. The qualitative and quantitative detection of the effective components of the spleen-tonifying, appetite-promoting and digestion-promoting pill is realized.

The present invention relates to a metal nitrate hydrate catalyst and a method for preparing 5-hydroxymethylfurfural, using same and, more specifically, may provide: a catalyst which comprises a metal nitrate hydrate and is to prepare 5-hydroxymethylfurfural (HMF) from at least one selected from the group consisting of monosaccharides and disaccharides; and a method for preparing 5-hydroxymethylfurfural (HMF), the method comprising (a) a step of preparing 5-HMF by reaction in the presence of the catalyst from a sugar comprising at least one selected from the group consisting of monosaccharides and disaccharides. The present invention provides high 5-HMF yield and selectivity, biological and process stability, and economic efficiency by using inexpensive monosaccharides and / or disaccharides.

The application discloses a low-foam acid zinc plating additive and a preparation process thereof, and belongs to the technical field of electroplating additives. The additive comprises a low-foam softener and a water-based brightener. The low-foam softener comprises the following raw materials in percentage by mass: polyethylene imine 0.8-1.2%, monododecyl phosphate potassium 0.03-0.06%, water-soluble polyether amine 0.2-0.6%, and the balance is water. The water-based brightener comprises the following raw materials: 5-hydroxymethyl furfural 0.6-1.2%, L-cysteine salt 0.2-0.4%, 4-amino-2(1H) pyrimidinone 0.1-0.15%, sodium salicylate 0.05-0.1%, citric acid 1-1.5%, alpha-ketoglutaric acid 0.3-0.5%, isoascorbic acid 0.2-0.4%, and the balance is water. The application optimizes the components in the additive, prepares a water-based formula, and the components are uniformly dispersed, the foam amount is low, and the plating layer quality is good.

A synthesis method of 2,5-dihydroxymethyl tetrahydrofuran, comprising: 5-hydroxymethyl furfural is contacted with hydrogen after a plasma generator in the presence of a non-noble metal catalyst to generate 2,5-dihydroxymethyl tetrahydrofuran. The present application uses 5-hydroxymethyl furfural (5-HMF) as raw material, and synthesizes DHMTHF by hydrogen plasma coupling non-noble metal catalyst. The method of the present application does not need to use noble metal, utilizes the high reactivity of excited state particles in hydrogen plasma, reduces the reaction pressure and reaction temperature, and the plasma has the effect of dispersing the catalyst active metal again. The whole reaction process has the characteristics of relatively mild reaction conditions, low hydrogen consumption, high selectivity of target product, simple process, good stability of catalyst, low cost of catalyst, etc.

The invention provides a method for preparing 2, 5-diformyl furan by catalyzing fructose by using an ionic liquid and a vanadium complex, which comprises the following steps: carrying out dehydration reaction by using the fructose as a raw material and the ionic liquid as a reaction solvent and a catalyst to obtain 5-hydroxymethylfurfural, then adding a V / HCP-AQ catalyst, and carrying out oxidation reaction on the 5-hydroxymethylfurfural in an oxygen atmosphere to obtain the 2, 5-diformyl furan. And 3, 5-diformyl furan is obtained. According to the method, the ionic liquid is adopted to replace DMSO to serve as a fructose dehydration and oxidation solvent, ethyl acetate is added into a reaction system for extraction after the reaction is finished, the product 2, 5-diformyl furan can be obtained, and the problem that the product is difficult to separate in the process of preparing the 2, 5-diformyl furan through the fructose one-pot method under a traditional catalytic system is solved.

Process for the production of 5-hydroxymethyl-2-furancarboxylic acid (HMFA), wherein 5-hydroxymethylfurfural (HMF), which is present in an aqueous solution, is oxidized to obtain 5-hydroxymethyl-2-furancarboxylic acid (HMFA) by treatment with an NAD(P)+-dependent aldehyde dehydrogenase in vitro with NAD(P)H being formed; after said oxidation step the NAD(P)H formed during the oxidation is enzymatically regenerated with an oxidoreductase back to NAD(P)+, and a keto compound is used as a cosubstrate of the oxidoreductase.

The invention discloses a method for preparing 2, 5-furandicarboxaldehyde based on photocatalytic oxidation of BiVO4 / Cs2AgBiBr6 with a wavelength of 440 to 450 nm. The specific method comprises the following steps: preparing a perovskite photocatalytic material BiVO4 / Cs2AgBiBr6; the prepared BiVO4 / Cs2AgBiBr6 is added into a 5-hydroxymethylfurfural (HMF) anhydrous acetonitrile solution, and a photocatalytic oxidation experiment is carried out under the condition of an LED lamp with the wavelength of 440-450 nm. According to the technical process, HMF can be efficiently converted to synthesize 2, 5-furandicarboxaldehyde (DFF), reaction conditions are mild, operation is easy, the method is a cheap and efficient DFF preparation method, reference is provided for renewable biomass resource conversion, and the method has important significance on development of novel renewable energy sources.

This invention discloses a titanium dioxide core-shell structured photocatalyst supported on metal particles. The catalyst is obtained by calcining titanium-based metal-organic framework material MIL-125(Ti) as a precursor, after introducing metal components, tannic acid, and metal coordination. Titanium oxide forms the core structure, and a carbon layer coating the surface forms the shell structure, supporting metal particles. During preparation, the preparation conditions can be optimized by controlling the concentration of metal ions, the concentration of tannic acid, and the pH of the tannic acid coordination system. This photocatalyst exhibits high catalytic activity, target product selectivity, and cycle stability in the photocatalytic oxidation conversion of biomass derivatives. It is suitable for the selective oxidation of biomass platform compounds such as 5-hydroxymethylfurfural to prepare high-value-added products. Furthermore, the preparation method is simple, the raw materials are widely available, and it is suitable for catalytic conversion applications under visible light conditions, demonstrating good application prospects and promotional value.

The invention provides a preparation method of a cobalt-ruthenium double-site catalyst and application of the cobalt-ruthenium double-site catalyst in synthesis of 2, 5-furandicarboxylic acid. A lignin-based cobalt-ruthenium double-site catalyst is utilized, oxygen or air is used as an oxidizing agent, and high-selectivity conversion of 5-hydroxymethylfurfural into 2, 5-furandicarboxylic acid is realized. According to the catalyst, lignin rich in functional groups serves as a raw material, cobalt ions are anchored through nitrogen doping and metal coordination technologies to achieve uniform dispersion of Co monatomic atoms, and then controllable loading of Ru sub-nanoclusters is achieved through an impregnation method. The double-site catalyst has excellent performance at normal temperature and normal pressure (the HMF conversion rate is greater than 95%, and the FDCA yield is greater than 90%), and is superior to the traditional and conventional single-component catalyst. The catalyst used in the invention is green, environment-friendly and recoverable, solves the problems of harsh reaction conditions, high cost and low environmental friendliness of the existing system, and provides key support for industrialization of biomass-based chemicals.

The present application relates to the field of electrochemistry, and discloses a kind of side chain containing TEMPO conductive polymer and its preparation method and application.2,5-diformylfuran is prepared by using 5-hydroxymethylfurfural as raw material, and there are problems of catalyst recovery and separation difficulty with product. In order to solve the above technical problems, the small molecule catalyst TEMPO is connected to the conductive polymer, and the conductive polymer obtained by connection realizes heterogeneous electrochemical catalytic oxidation of 5-hydroxymethylfurfural to generate 2,5-diformylfuran. The conductive polymer is used as the catalyst for the electrocatalytic oxidation of 5-hydroxymethylfurfural to prepare 2,5-diformylfuran, which avoids the problem of difficult separation of catalyst and product, and has the characteristics of high reaction rate and high product yield.

The application discloses a method for detecting 5-hydroxymethylfurfural in a compatibility experiment of hydrocortisone sodium succinate for injection and glucose injection by HPLC. The 5-hydroxymethylfurfural is a degradation impurity of glucose. The detection method comprises the following steps: (1) preparation of a control sample solution; (2) preparation of a test sample solution; (3) chromatographic conditions; a mobile phase A is 8mmol / L potassium dihydrogen phosphate solution (pH value is adjusted to 5.0-5.1 by using 8mmol / L potassium hydrogen phosphate solution, and the solution is prepared freshly before use); a mobile phase B is methanol, gradient elution is carried out; a detection wavelength is 284nm; a column temperature is 40 DEG C; a flow rate is 1.4-1.6mL / min; and a chromatographic column is C 18 ; the application can effectively detect the content of 5-hydroxymethylfurfural, and has strong specificity and high sensitivity.

The construction method of the HPLC characteristic chromatogram of the coked medicated leaven medicinal material, decoction pieces and standard decoction and the determination method of the adenine content provided by the invention comprise the following steps: extracting a test raw material with 30% methanol to obtain a to-be-detected solution; determining the liquid to be detected by adopting HPLC (High Performance Liquid Chromatography) to obtain HPLC characteristic chromatograms of the coked medicated leaven medicinal material, decoction pieces and standard decoction; preparation of a reference substance solution: respectively taking uracil, adenine and 5-hydroxymethylfurfural reference substances, and dissolving the reference substances with a solvent to obtain the reference substance solution of the reference substances; the HPLC conditions are as follows: a chromatographic column is a C18 column; a mobile phase A is an acetonitrile solution, a mobile phase B is a 0.1% phosphoric acid aqueous solution, and gradient elution is carried out. According to the method, a high performance liquid chromatography method is adopted, an acetonitrile-0. 1% phosphoric acid solution is selected as a mobile phase for gradient elution, uracil, adenine and 5-hydroxymethylfurfural are taken as reference substances, and the HPLC characteristic chromatogram method for the coked medicated leaven medicinal material, decoction pieces and standard decoction is established. And more and more scientific technical means are provided for controlling the medicinal quality of the coked medicated leaven medicinal material, decoction pieces and standard decoction.

This invention provides a method for simultaneously detecting 17 heat-processing hazards in 4 categories, comprising: adding n-hexane to the sample, mixing thoroughly, discarding the n-hexane phase, extracting acrylamide, 5-hydroxymethylfurfural, and free heterocyclic amines using dimethyl ketone and ultrasound-assisted extraction, collecting the supernatant, and purifying it; simultaneously transferring the precipitate to another tube, reducing it with sodium tetrahydroborate, hydrolyzing it with hydrochloric acid to release bound heterocyclic amines and late-stage glycosylation products, and performing UPLC-MS / MS analysis. This invention is the first to propose a two-step extraction method for simultaneously determining 17 heat-processing hazards in 4 categories within 7 minutes using UPLC-MS / MS. The accuracy, precision, detection limit, quantitation limit, and recovery rate of the method were verified, and all test indicators met the requirements. This method is applicable to the determination of heat-processing hazards in four types of food matrices: high starch, high protein, high fat, and high sugar.

The application discloses a kind of biochar catalyst and its preparation method and application in catalyzing 5-hydroxymethylfurfural oxidation preparation 2,5-furan dicarboxylic acid.The preparation method comprises the following steps: after mixing trehalose with zinc chloride and potassium chloride, carbonization is pyrolyzed under inert atmosphere to obtain biochar catalyst.The application utilizes efficient, low-cost, renewable catalyst to efficiently catalyze HMF to selectively generate DFF in the presence of potassium hydrogen peroxymonosulfate composite salt, and has the advantages of low catalyst cost, high product yield, high product selectivity, mild reaction conditions, low production cost, no security risks and environmental friendliness.

The application provides a 5-hydroxymethylfurfural recognition aptamer and application, wherein the 5-hydroxymethylfurfural recognition aptamer comprises the following nucleotide sequence: 5'-GGGAGGACAGATACGGTGGGA-3'. The 5-hydroxymethylfurfural recognition aptamer provided by the application comprises good dose-dependent detection capability for 5-hydroxymethylfurfural, can rapidly realize accurate detection of 5-hydroxymethylfurfural in food, and has high detection convenience and does not need to rely on large and precise instruments.

This invention discloses a method for preparing and purifying 5-hydroxymethylfurfural crystals. The method involves reacting a sugar source and an acid catalyst in a first solvent to obtain a reaction solution containing crude 5-hydroxymethylfurfural. The solution is then purified according to the following steps: the first solvent is removed by rotary evaporation, and a second solvent is added in the presence of water for extraction. The resulting organic phase is then subjected to rotary evaporation to remove the second solvent. Water and activated carbon are added to the concentrate for decolorization, followed by filtration. The first solvent is a water-soluble solvent, and the second solvent is a water-insoluble nonpolar solvent. The resulting filtrate is then subjected to rotary evaporation and freeze-drying to remove moisture. The dried crystals are then separated by column chromatography to obtain high-purity 5-hydroxymethylfurfural crystals. This method features a simple reaction system, mild reaction conditions, and lower processing costs, providing a new solution for the preparation and purification of 5-hydroxymethylfurfural crystals.

The invention relates to the technical field of cables, and provides a high-flame-retardant low-voltage power cable which sequentially comprises a conductor, an insulating layer and a sheath layer from inside to outside. The sheath layer is prepared from the following raw material components in parts by weight: 85 parts of ethylene-vinyl acetate copolymer, 65-75 parts of polyethylene, 30-40 parts of silicone rubber, 50-60 parts of a flame retardant, 3-5 parts of an activating agent, 2-4 parts of a lubricating agent, 2-4 parts of a vulcanizing agent, 1-3 parts of a vulcanizing aid and 1-3 parts of an antioxidant; the flame retardant is prepared from the following raw material components in parts by weight: 7 to 8 parts of 5-hydroxymethylfurfural, 3 to 4 parts of phenylguanidine carbonate and 40 to 50 parts of ammonium polyphosphate. According to the technical scheme, the problem of insufficient flame retardance of the sheath layer in the prior art is solved.

The invention relates to a method for producing 5-hydroxymethyl-2-furancarboxylic acid (HMFA), wherein 5-hydroxymethylfurfural (HMF), which is present in an aqueous solution, is oxidized in order to form 5-hydroxymethyl-2-furancarboxylic acid (HMFA) by means of a treatment using an NAD(P)+-dependent aldehyde dehydrogenase in vitro, thereby forming NAD(P)H, after which the NAD(P)H formed during the oxidation process is enzymatically regenerated using an NAD(P)H oxidase in order to form NAD(P)+. The method is characterized in that the NAD(P)H oxidase comprises an amino acid sequence selected from the group consisting of: i) an amino acid sequence which has an identity of at least 80% to SEQ ID No. 14, SEQ ID No. 16, or SEQ ID No. 18, ii) an amino acid sequence encoded by a nucleic acid which has an identity of at least 80% to SEQ ID No. 13, SEQ ID No. 15, or SEQ ID No. 17, and iii) an amino acid sequence encoded by a nucleic acid which, under stringent conditions, binds to a nucleic acid molecule having the nucleic acid sequence SEQ ID No. 13, SEQ ID No. 15, or SEQ ID No. 17.

The invention discloses a Ni3S2 / Ni (OH) 2 / metal phthalocyanine heterojunction self-supporting electrocatalyst as well as a preparation method and application thereof. According to the catalyst, foamed nickel serves as a substrate and a nickel source, a Ni3S2 / Ni (OH) 2 nanosheet array precursor grows in situ through one-step hydrothermal, metal phthalocyanine is loaded through solvothermal, and the Ni3S2 / Ni (OH) 2 / metal phthalocyanine composite electrode material with a multistage heterogeneous interface is formed. The material can be used for preparing 2, 5-furandicarboxylic acid (FDCA) through efficient electro-catalysis of deep oxidation of 5-hydroxymethylfurfural (HMF) in an alkaline solution at room temperature; the metal phthalocyanine molecular catalyst and the nickel-based composite material are combined for preparing the self-supporting electrode for the first time, efficient and high-selectivity total oxidation of HMF is achieved in an alkaline environment, the structure avoids using a binder, the conductivity, the structural stability and the active site exposure degree are enhanced, and industrial large-scale preparation is facilitated.

The invention discloses a preparation method of an amphiphilic bifunctional solid acid catalyst for synthesis of 5-hydroxymethylfurfural. The preparation method comprises the following steps: synthesizing a hafnium phosphate solid diacid catalyst, coating the surface of the hafnium phosphate solid diacid catalyst with silicon oxide to construct a core-shell composite structure, and then carrying out surface hydrophobization modification by adopting a vapor deposition method. The prepared catalyst has certain water-oil amphipathy, keeps good Lewis / Bronsted acidity, crystal structure and pore characteristics, can be used as a catalyst and a stabilizer at the same time, and promotes formation of a stable water-in-oil Pickering emulsion in a water-organic two-phase solvent system. According to the system, the mass transfer interface area between water and organic phases is remarkably increased, the liquid-liquid interface extraction efficiency of the 5-hydroxymethylfurfural is enhanced, side reactions of sugar / 5-hydroxymethylfurfural in a water phase are reduced, the selectivity and yield of the 5-hydroxymethylfurfural prepared through glucose catalytic conversion are improved, and the method is suitable for industrial production. Meanwhile, the hydrothermal stability and the reusability of the solid acid catalyst are remarkably improved.

The invention provides a method for preparing 2, 5-furandicarboxylic acid from 5-hydroxymethylfurfural, and belongs to the field of chemistry and chemical engineering. The method comprises the following steps: uniformly mixing a 5-hydroxymethylfurfural solution and an alkali solution, adding a first catalyst, a second catalyst, an auxiliary agent and an oxidizing agent, and carrying out oxidation reaction to generate 2, 5-furandicarboxylic acid. The method is simple to operate and mild in condition, the yield of the 2, 5-furandicarboxylic acid is as high as 95.4%, the reaction does not need a high-pressure environment, the reaction can be carried out in air, the requirement on the pressure resistance of equipment is reduced, the production cost of FDCA is reduced, and the method has a good industrial application prospect.

The invention discloses a preparation method of a 2, 5-furandicarboxylic acid (FDCA)-based ligand modified nickel hydroxide catalyst (FDCA-Ni (OH) 2) and an application of the catalyst in the electrocatalytic oxidation of an FDCA precursor. The catalyst uses FDCA (target product) as a ligand to modify nickel hydroxide, and is used for electrocatalytic oxidation of FDCA precursors (including but not limited to 2, 5-dimethylolfuran, BHMF, 5-hydroxymethylfurfural, HMF, 5-hydroxymethyl-2-furancarboxylic acid, HMFCA, 2, 5-diformyl furan, DFF, 5-formyl-2-furancarboxylic acid, FFCA) into FDCA. The method is low in raw material cost, simple in process and mild in condition, and the prepared catalyst is excellent in performance, has remarkable economic value and is suitable for large-scale application of preparing FDCA through electro-catalytic oxidation of the FDCA precursor.

An ion-pair-bound homogeneous catalytic system, and a method for synthesizing 5-hydroxymethylfurfural. The homogeneous catalytic system comprises a quaternary ammonium salt, a homogeneous acid and water. The method comprises: mixing fructose with an ion-pair-bound homogeneous catalytic system to form a homogeneous catalytic reaction system; reacting the homogeneous catalytic reaction system under reduced pressure, and after the completion of the reaction, adding a quenching agent to quench the reaction; extracting the obtained reaction mixture; and then respectively separating 5-hydroxymethylfurfural and the ion-pair-bound homogeneous catalytic system from a light phase and a heavy phase formed after the extraction. The reaction can achieve the simple, safe and efficient synthesis of 5-hydroxymethylfurfural under mild conditions; the conversion rate of the raw material fructose is high; the yield of the target product, i.e., 5-hydroxymethylfurfural, is high; and the separation operation can be conveniently conducted. Moreover, the used ion-pair-bound homogeneous catalytic system that is formed from a quaternary ammonium salt, a homogeneous acid and water is convenient to recover and reuse. Therefore, the method is environmentally friendly and economical, and has broad application prospects.