Hydrogen-bonded organic framework material for catalyzing oxidative conversion of hmf and preparation method and application thereof
By constructing a highly stable hydrogen-bonded organic framework material and combining photocatalysis and biocatalysis cascades, the stability and solvent toxicity issues of the HMF ring cleavage pathway were solved, enabling a highly efficient one-pot two-step conversion of HMF into high-value chemicals.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUAIYIN TEACHERS COLLEGE
- Filing Date
- 2026-03-12
- Publication Date
- 2026-06-12
AI Technical Summary
In existing technologies, the ring cleavage pathway of HMF has not been fully developed, the photocatalyst has poor stability, the solvent has high toxicity, and it is difficult to achieve a complete one-pot two-step conversion of HMF into high-value chemicals.
A highly stable hydrogen-bonded organic framework material is constructed using dual ligands. The oxidation conversion of HMF is achieved through a cascade of photocatalysis and biocatalysis. The framework is constructed using charged hydrogen bonds and π-π stacking, and combined with photo-whole-cell and photo-enzyme catalytic pathways to avoid solvent toxicity and achieve efficient conversion.
The highly selective oxidative conversion of HMF was achieved, with a maleic acid yield of 53.18%, an L-Ala conversion rate of >99%, and a DMM yield of 99.69%. Under mild conditions, a one-pot two-step conversion of HMF to high-value chemicals was realized, which is in line with the principles of green chemistry.
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Abstract
Description
Technical Field
[0001] This invention relates to a hydrogen-bonded organic framework material for catalyzing the oxidation and conversion of HMF, its preparation method and application, belonging to the fields of high-value utilization of biomass, preparation of hydrogen-bonded organic framework materials and photo-biocatalysis technology. Background Technology
[0002] Biomass, as a renewable resource, has its derivative 5-hydroxymethylfurfural (HMF) as a key platform molecule for building future chemical systems. Current catalytic conversion of HMF mainly focuses on acyclic cracking pathways (such as the synthesis of derivatives like FDCA, DFF, and BHMF), achieving breakthroughs in the field of biodegradable plastics. However, the cyclic cracking pathway of HMF can overcome the furan ring limitation to generate high-value chemicals such as fuel additives and amino acids, but this pathway has not yet been fully explored.
[0003] While photocatalysis offers new opportunities for HMF oxidation as a green strategy, current research still focuses on acyclic cleavage products. Cyclic cleavage requires a photocatalyst to simultaneously drive the oxidation reaction and ring breaking, involving complex electron transfer and molecular rearrangement mechanisms, significantly increasing the design difficulty. For example, although Jia and Si reported in 2020 that the photocatalytic oxidation of furfural achieved an 89% yield of maleic anhydride, the research object was simple furfural without hydroxymethyl groups, and the product was a solid anhydride requiring additional hydrolysis. The strong oxidizing persulfate residue further deactivated the biocatalyst, making it unsuitable for cascade conversion. Currently, only Qi's group has achieved a 55% conversion rate of HMF to maleic acid using ferric chloride (III) photocatalyst through a chlorine radical mechanism, but this method suffers from high solvent toxicity, uncontrollable side reactions, and an unclear substrate mineralization mechanism.
[0004] Hydrogen-bonded organic frameworks (HOFs) have emerged as promising photocatalysts due to their metal-free nature and biocompatibility. However, conventional HOFs suffer from poor stability and are easily dissolved and deactivated in reaction media. More importantly, the photocatalytic products require further biocatalytic conversion into high-value chemicals (such as DMM or L-alanine), but solvents (such as tert-butanol, LC4) are often unsuitable. 50 =3.5 g / L) and oxidant (H2O2) are highly toxic to biocatalysts. Existing systems mostly focus on single products (such as FDCA or BHMF), and a complete one-pot two-step route of HMF→maleic acid→L-alanine / dimethyl maleate has not yet been achieved. In addition, HOFs have been reported mainly for gas adsorption or CO2 reduction (such as the PCN series), and their application in the photocatalytic ring-opening oxidation of HMF lacks systematic research. Moreover, the synthesis of these materials often requires high temperature and high pressure conditions, and their ability to regulate reactive oxygen species (ROS) is insufficient.
[0005] In summary, developing novel HOF materials that combine high stability, high efficiency in photocatalytic activity, and biocompatibility to achieve HMF photocatalytic conversion and photo-biological cascade conversion is the core path to overcome the bottlenecks of low selectivity in ring cleavage, complex processes, and poor sustainability. Summary of the Invention
[0006] The purpose of this invention is to provide a hydrogen-bonded organic framework material for catalytic HMF oxidation and conversion, its preparation method and application. This hydrogen-bonded organic framework material has excellent stability, can be used for HMF photocatalytic ring-opening oxidation, and can be cascaded with biocatalysis to achieve one-pot two-step HMF conversion.
[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0008] A method for preparing a hydrogen-bonded organic framework material that catalyzes the oxidation and conversion of HMF involves mixing a deprotonated pyrene carboxylic acid derivative solution with a methanetetrabenzamide tetrahydrochloride solution, allowing it to stand in the dark, and then centrifuging, washing, and freeze-drying the mixture.
[0009] Preferably, in the pyrene carboxylic acid derivative solution, the pyrene carboxylic acid derivative is 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetra(phenylethynyl)benzoic acid;
[0010] In the solution of methanetetrabenzamide tetrahydrochloride, methanetetrabenzamide tetrahydrochloride is 4,4',4'',4'''-methanetetrabenzamide tetrahydrochloride.
[0011] Preferably, the concentration of the pyrene carboxylic acid derivative solution is 2-5 mg / mL;
[0012] The concentration of the methanetetrabenzamide tetrahydrochloride solution is 2-4 mg / mL;
[0013] The molar ratio of pyrene carboxylic acid derivative in the pyrene carboxylic acid derivative solution to that in the methane tetrabenzamide tetrahydrochloride solution is (0.5-10):1.
[0014] Preferably, the reagent used for deprotonation of the pyrene carboxylic acid derivative solution is an aqueous solution of tetrabutylammonium hydroxide (35-50 wt.%).
[0015] The molar ratio of tetrabutylammonium hydroxide in the aqueous solution to pyrene carboxylic acid derivative in the solution is (5-15):1.
[0016] Preferably, the time for keeping the container in the dark is 10-15 hours.
[0017] A hydrogen-bonded organic framework material that catalyzes the oxidative conversion of HMF is prepared by any of the methods described above.
[0018] The application of the aforementioned hydrogen-bonded organic framework material in the photocatalytic preparation of maleic acid from HMF involves mixing the solvent, the hydrogen-bonded organic framework material, HMF, and hydrogen peroxide, and then performing a photocatalytic reaction at room temperature.
[0019] Preferably, the solvent is ethyl acetate or tert-butanol; the wavelength of the light source used for photocatalysis is 100-450 nm; the concentration of hydrogen peroxide is 25-35 wt%, and the amount used is 0.05-0.15 times the volume of the solvent.
[0020] The above-mentioned hydrogen-bonded organic framework materials are used in the photo-whole-cell cascade catalytic synthesis of L-alanine from HMF.
[0021] The above-mentioned hydrogen-bonded organic framework materials are used in the photo-enzyme cascade catalytic synthesis of dimethyl maleate from HMF.
[0022] The beneficial effects of this invention are as follows: A highly stable framework was constructed using dual ligands (charged hydrogen bonds + π-π stacking), which was observed by SEM to be a micron-sized single crystal with excellent thermal stability (49.57% residual weight at 800℃). It was then used for the first time in the photocatalytic ring-opening oxidation of HMF, breaking through the selectivity bottleneck. H2O2 inhibits the ·OH mineralization pathway and enhances ·O2 mineralization. - The ring-opening activity, through the HGRT mechanism, enables precise ROS regulation, avoiding excessive oxidation and achieving an MA yield of 53.18%. In the cascade catalytic compatibility design, the photocatalytic-whole-cell pathway, with a 5% photocatalytic solution addition ratio to avoid solvent toxicity, achieves an L-Ala conversion rate >99%. The photocatalytic-enzyme pathway, utilizing a heterogeneous n-hexane system, overcomes substrate solubility limitations, achieving a DMM yield of 99.69%. The cascade system is compatible with both photocatalysis and biocatalysis, employing a one-pot, two-step conversion to avoid intermediate separation losses; it operates under mild conditions (ambient temperature and pressure), requires no precious metals, and conforms to green chemistry principles. Attached Figure Description
[0023] Figure 1 SEM images of HOF-M; Figure 2 TGA spectral analysis of HOF-M; Figure 3 TGA spectral analysis of HOF-B5; Figure 4 The photocurrent response spectrum of HOF-M; Figure 5 The fluorescence intensity (PL) spectrum of HOF-M is shown. Figure 6 Liquid phase diagram showing the yield of maleic acid under HOF-M photocatalysis (ethyl acetate solvent); Figure 7Liquid phase diagram showing the yield of maleic acid under HOF-M photocatalysis (tert-butanol solvent); Figure 8 The yield of alanine synthesis in HOF-M photo-whole-cell coupled catalysis is shown in the figure. Figure 9 The graph shows the yield of dimethyl maleate synthesized by HOF-M photo-enzyme-linked catalysis. Detailed Implementation
[0024] Comparative Example 1: Preparation of HOF-B5.
[0025] 6 mg of 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetra(phenylethynyl)benzoic acid was dissolved in 3 mL of DMF. The solution was heated in a water bath at 90 °C for 20 min, and stirred at 200 rpm until completely dissolved. The solution was then filtered while hot, and 6 mL of ethanol solution was added while hot. After shaking well, the solution was allowed to stand in the dark for 30 min, and then washed once by centrifugation with ethanol. Finally, the solution was washed three times by centrifugation with water and dried in a freeze dryer to obtain a red powder material, namely the hydrogen-bonded organic framework material HOF-B5.
[0026] Example 1: Preparation of HOF-M material.
[0027] 8 mg of 4,4',4'',4'''-methanetetrabenzamide tetrahydrochloride and 3 mL of water were added to a 10 mL centrifuge tube to dissolve the ligand and obtain a clear solution A. 9.82 mg of 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetra(phenylethynyl)benzoic acid and 3 mL of water were added to a 10 mL centrifuge tube and ultrasonically dispersed. 0.082 mL of tetrabutylammonium hydroxide aqueous solution (40 wt.%) was added to deprotonate the ligand (after shaking or stirring and allowing to stand). The solution was then filtered to obtain a clear orange-red solution B. The clear orange-red solution B was added dropwise to solution A to mix the reaction system thoroughly. After standing in the dark for 12 h, the mixture was centrifuged, washed (with water), and lyophilized to obtain an orange-red powder, namely the ultrastable hydrogen-bonded organic framework material HOF-M.
[0028] Figure 1 The image shows a HOF-M SEM image, which reveals that the material exhibits uniform micron-sized tetragonal prism-shaped single-crystal aggregates with sharp edges and smooth surfaces.
[0029] Figure 2 TGA spectral analysis of HOF-M Figure 3 The TGA spectral analysis of HOF-B5 shows that there are significant differences in the weight loss process and kinetic behavior between the two. HOF-M has better thermal stability (residual weight at 800℃: 49.57% vs. 38.4% (HOF-B5)) and better structural durability under photocatalytic high-temperature environment.
[0030] Figure 4 The photocurrent response spectrum of HOF-M shows a significant photocurrent response, indicating that electrons are rapidly generated and form a current during illumination. Comparison reveals that the photocurrent density of HOF-M is greater than that of HOF-B5, suggesting that HOF-M has a higher electron-hole separation efficiency, thereby enhancing its photocatalytic activity.
[0031] Figure 5 The fluorescence intensity spectrum of HOF-M is shown in the figure. It can be seen from the figure that the fluorescence intensity of HOF-M is lower than that of HOF-B5, which proves that the recombination rate of photogenerated electrons and holes is greatly reduced after recombination with amidine salt, thus improving the photocatalytic efficiency.
[0032] Example 2: HOF-M photocatalytic oxidation of HMF to generate maleic acid.
[0033] Photocatalytic oxidation of HMF to prepare maleic acid (ethyl acetate solvent). 1.8 mL of ethyl acetate, 2 mg of HOF-M, 32 mM HMF (final concentration in the reaction system), and 0.2 mL of 30% hydrogen peroxide were mixed and transferred to a 10 mL quartz photocatalytic tube. The photocatalytic reaction was carried out at room temperature (approximately 25 °C) using a 420 nm LED light source for 6 hours. After the reaction, the reaction solution was centrifuged, the supernatant was collected, and the product was analyzed using high-performance liquid chromatography (HPLC).
[0034] Photocatalytic oxidation of HMF to prepare maleic acid (tert-butanol solvent). 1.8 mL of tert-butanol, 2 mg of HOF-M, 32 mM HMF (final concentration in the reaction system), and 0.2 mL of 30% hydrogen peroxide were mixed and transferred to a 10 mL quartz photocatalytic tube. The photocatalytic reaction was carried out at room temperature (approximately 25°C) using a 420 nm LED light source for 6 hours. After the reaction, the reaction solution was centrifuged, the supernatant was collected, and the product was analyzed using high-performance liquid chromatography (HPLC).
[0035] Analysis of the maleic acid synthesis reaction mixture: An Aminex® HPX-87H Column (300 × 7.8 mm) was used. The mobile phase was 10 mM H2SO4 solution and acetonitrile (95:5 v / v). The flow rate was 0.6 mL / min, the column temperature was 30 °C, the detection wavelength was 223 nm, and the injection volume was 10 µL.
[0036] Figure 6 The figure shows the liquid phase diagram of maleic acid yield under HOF-M photocatalysis (ethyl acetate solvent). As can be seen from the figure, HOF-M photocatalysis can achieve highly selective oxidation and ring-opening of HMF to generate maleic acid.
[0037] Figure 7The figure shows the liquid phase diagram of maleic acid yield under HOF-M photocatalysis (tert-butanol solvent). As can be seen from the figure, HOF-M photocatalysis can achieve highly selective oxidation and ring-opening of HMF to generate maleic acid.
[0038] Example 3: HOF-M photo-whole-cell cascade catalysis of HMF to synthesize L-alanine.
[0039] In a 10 mL reaction system, a bacterial culture (E. coli BL21-ΔfumA / fumC-T7 / AspA) with OD600=80 and a photocatalytic product (ethyl acetate system) HMF-MA mixture (5% v / v) were added, and the reaction was carried out at 37 °C in a shaker at 200 rpm. A certain amount of the reaction solution was taken, heated in a boiling water bath for 10 minutes, and then centrifuged (13,000 rpm, 3 minutes). 500 µL of the supernatant was taken, and 250 µL of 1 mol / L triethylamine-acetonitrile solution (14:86, v / v) and 250 µL of 0.1 mol / L PITC-acetonitrile solution (1:83, v / v) were added sequentially. After mixing, the mixture was reacted in the dark for 1 hour. The reaction was terminated by adding 700 µL of n-hexane, and the mixture was mixed and allowed to stand for separation. The lower layer was collected, filtered through a 0.22 µm filter, and analyzed by HPLC.
[0040] Analysis of the alanine synthesis reaction mixture: A Zorbax Eclipse Plus C18 column (4.6 mm × 250 mm, 5 µm, Agilent) was used. Mobile phase A was 80% (v / v) acetonitrile solution, and mobile phase B was 97% (v / v) 0.1 mol·L⁻¹ sodium hydroxide solution. -1 A mixed solution of sodium acetate and 3% (v / v) acetonitrile was used; the flow rate was 0.6 mL / min, the column temperature was 40℃, the detection wavelength was 254 nm, and the injection volume was 10 μL. The gradient elution conditions were: 0–35 min, mobile phase B decreased from 95% to 65%; 35–40 min, mobile phase B increased from 65% to 95%; 40–45 min, the concentration of mobile phase B remained constant.
[0041] Figure 8 The figure shows the yield of alanine synthesis in HOF-M photo-whole-cell cascade catalysis. As can be seen from the figure, HOF-M photo-whole-cell cascade catalysis of HMF efficiently synthesized L-alanine.
[0042] Example 4: HOF-M photo-enzyme cascade catalysis of HMF to synthesize dimethyl maleate.
[0043] The photocatalytic product HMF-MA mixture (tert-butanol system) was volatilized, and an equal volume of n-hexane, methanol (molar ratio, methanol:maleic acid = 64:1) and 100 mg of lipase were added. The mixture was reacted at 60 °C in a shaker at 200 rpm for 6 h. A certain amount of the reaction solution was filtered through a 0.22 µm filter and then analyzed by HPLC.
[0044] Analysis of the reaction mixture for the synthesis of dimethyl maleate: A Zorbax Eclipse Plus C18 column (4.6 mm × 250 mm, 5 µm, Agilent) was used. The mobile phase was 0.1% formic acid aqueous solution / acetonitrile (40:60, v / v). The flow rate was 1 mL / min, the column temperature was 30 °C, the detection wavelength was 220 nm, and the injection volume was 10 μL.
[0045] Figure 9 The graph shows the conversion rate of HMF to dimethyl maleate catalyzed by HOF-M photo-enzyme cascade. As can be seen from the graph, HOF-M photo-enzyme cascade catalysis can achieve efficient synthesis of dimethyl maleate from HMF.
Claims
1. A method for preparing a hydrogen-bonded organic framework material that catalyzes the oxidative conversion of HMF, characterized in that, It is obtained by mixing a deprotonated pyrene carboxylic acid derivative solution with a methanetetrabenzamide tetrahydrochloride solution, allowing it to stand in the dark, and then centrifuging, washing, and freeze-drying.
2. The method for preparing the hydrogen-bonded organic framework material according to claim 1, characterized in that, In the solution of the pyrene carboxylic acid derivative, the pyrene carboxylic acid derivative is 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetra(phenylethynyl)benzoic acid; In the solution of methanetetrabenzamide tetrahydrochloride, methanetetrabenzamide tetrahydrochloride is 4,4',4'',4'''-methanetetrabenzamide tetrahydrochloride.
3. The method for preparing hydrogen-bonded organic framework materials according to claim 2, characterized in that, The molar ratio of pyrene carboxylic acid derivative in the pyrene carboxylic acid derivative solution to that in the methane tetrabenzamide tetrahydrochloride solution is (0.5-10):
1.
4. The method for preparing the hydrogen-bonded organic framework material according to claim 2, characterized in that, The reagent used for deprotonation of the pyrene carboxylic acid derivative solution was an aqueous solution of tetrabutylammonium hydroxide; The molar ratio of tetrabutylammonium hydroxide in the aqueous solution to pyrene carboxylic acid derivative in the solution is (5-15):
1.
5. The method for preparing the hydrogen-bonded organic framework material according to claim 1, characterized in that, The product should be kept in the dark for 10-15 hours.
6. A hydrogen-bonded organic framework material for catalyzing the oxidative conversion of HMF, characterized in that, Prepared by the method described in any one of claims 1-5.
7. The application of the hydrogen-bonded organic framework material according to claim 6 in the photocatalytic preparation of maleic acid using HMF, characterized in that, It involves mixing a solvent, a hydrogen-bonded organic framework material, HMF, and hydrogen peroxide, and then performing a photocatalytic reaction at room temperature.
8. The application according to claim 7, characterized in that, The solvent is ethyl acetate or tert-butanol; the wavelength of the light source used for photocatalysis is 100-450nm; the concentration of hydrogen peroxide is 25-35wt%, and the amount used is 0.05-0.15 times the volume of the solvent.
9. The application of the hydrogen-bonded organic framework material according to claim 6 in the photo-whole-cell cascade catalytic synthesis of L-alanine from HMF.
10. The application of the hydrogen-bonded organic framework material of claim 6 in the photo-enzyme cascade catalytic synthesis of dimethyl maleate from HMF.