One-pot Synthesis Of 2,5-diformylfuran From Fructose Using MOF-derived Metallic Oxide As Bifunctional Catalysts

In recent years,compared to non-renewable fuels and energy,biomass resources have been regarded as potential substitutes for chemical production owing to its advantages of cheapness,abundance and fast regeneration.5-Hydroxymethylfurfural?5-HMF?,a typical biomass platform molecule derived from dehydartion of biomass,has been reported as a potential platform chemical in bulk chemicals,fine industries and polymer chemicals,due to its rich chemical properties.Besides,HMF could further converted to important compounds,including 2,5-diformylfuran?DFF?,which is a potential intermediate in various applications,it can be applied in the synthesis of antifungal agents,pharmaceuticals,and functional polymer.Generally,DFF were synthesized mainly through the aerobic catalytic oxidation of pure 5-HMF,while5-HMF was produced from the dehydration of carbohydrates?fructose or glucose?,the isolation and purification of HMF from the reaction products needs intensive energy,which limited large-scale synthesis of DFF with 5-HMF as the raw material.Hence,with regard to energy and economic considerations,the direct synthesis of DFF from cheap and abundant carbohydrates via HMF as an intermediate is of great significance in both theoretical research and practical application.In this paper,two kinds of MOF-derived mesoporous oxide were prepared,and applied in the one-pot synthesis of 2,5-diformylfuran from fructose,its mainly includes the following two parts:1.The carbon doped WO_x-ZrO₂/C?WZC?were prepared by double-solvent impregnation method through pyrolysis of tungstate immobilized UiO-66 in N₂.The morphology and surface structure of the catalysts have been tested by a series of catalyst characterization.The results show that WZC catalyst has high acidity and suitable oxidation capacity,and showed good activity in the dehydration of 5-HMF from fructose and selective oxidation of 5-HMF to DFF.In the one-pot synthesis of DFF using fructose as raw material,tungsten content,calcination temperature,reaction temperature and time have great influence on the catalytic efficiency.Under optimal reaction conditions,a DFF yield of 70.8%can be obtained from one-pot progress with a 100%conversion of fructose,The catalyst can be recycled and reused without significant loss of activity.2.A zeolite-imidazole type MOF ZIF-67 was used as sacrifice template and sulfur powder as a dopant for the direct synthesis of Co₃O₄/C-S?Co/C-S?through pyrolysis.The materials were characterized by PXRD and TEM etc.The characterization data showed that Co/C-S were distributed evenly without serious aggregation.In the one-pot synthesis of DFF from fructose,the effects of calcination temperature,reaction temperature and reaction time on the yield of DFF were investigated.Under the optimum reaction conditions,the conversion of fructose was100%while the yield of DFF was 78.9%.In addition,the catalyst can be easily separated from the reaction system after the reaction,and reused more than six times without obvious loss of activity.