Catalytic Conversion Of Bio-Based Platform Chemicals Based On Photo-Enzyme Catalysis Systems

Photo-enzyme coupled reaction systems,which are modeled on natural photosynthesis,have shown great potential for development due to the driven by inexhaustible solar energy and combines the advantages of mild reaction conditions and high selectivity of bio-enzyme catalysis.In order to expand the range of substrates and reaction pathways for conventional photo-enzyme-catalyzed reactions,this study constructed efficient photo-enzyme catalysis systems by the photo-regeneration of NADH and the photocatalytic production of H₂O₂.And they were used for the reduction and oxidation reactions of bio-based platform chemicals,respectively.Firstly,ZnIn₂S₄,a metal sulfide with large specific surface area and suitable energy band structure,was prepared as the photocatalyst.The complex of noble metal element rhodium[M]was used as the electron mediator and L-ascorbic acid as the hole sacrificial agent.Upon visible light irradiation,the yield of NADH regeneration was as high as 90.2±3.28%under the conditions of 1.0 mg m L^-1of ZnIn₂S₄,1.0 m M of NAD⁺,and 100 m M of L-ascorbic acid.Further coupling with alcohol dehydrogenase ensured a high selectively of furfuryl alcohol（79.4±1.95%）from bio-based furfural at room temperature and pressure.Secondly,to address the problems of low electron transfer and utilization in the conventional photo-enzyme coupling system,artificially assembled nanoparticle ZnIn₂S₄/PDA@poly/[M]/NAD⁺was prepared by assembling a polydopamine（PDA）layer containing electron mediator[M]and coenzyme NAD⁺functionalized polymer on the surface of the base photocatalyst ZnIn₂S₄.The modification of PDA not only enhanced the absorption of visible light by ZnIn₂S₄and formed a Z-scheme electron transfer mechanism to effectively inhibit the compounding behavior of photogenerated electron-hole pairs,but also realized the immobilization of[M]and NAD⁺to shorten the electron transfer distance,constituting an effective intra-and intermolecular electron transfer pathway.These ensembles enhance the separation,transfer,and utilization of electrons.The yield of NADH regeneration of 80.7±1.43%was obtained under visible light irradiation,and CO₂was successfully converted to 116.7±11.8μM methanol after coupling with the multi-enzyme-mediated cascade reaction,which was 1.79 times higher than that of the free system.Finally,a novel photo-enzyme-coupled"one-pot"reaction route for the selective oxidation of 2,5-furandicarboxylic acid（FDCA）from2,5-diformylfuran（DFF）was constructed for the first time,using2-ethylanthraquinone as the photocatalyst to produce H₂O₂in tandem with lipase.The effects of photocatalyst concentration,light power,oxygen supplementation,and different volume ratios of tert-butanol/ethanol mixture as the electron donor on the photocatalytic production of H₂O₂were investigated,and it was determined that the optimized photocatalyst dosage was 2 mg m L^-1,the light power was 7 W,and the volume ratio of tert-butanol/ethanol was 9:1 under the condition of air blown in.A mixmum H₂O₂concentration of 154.0±17.2 m M was obtained,and all the DFF could be converted with a FDCA yield of 82.1±7.51%after 120 h of reaction.