Biomass derived chemicals: environmentally benign process for oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran by using nano-fibrous Ag-OMS-2-catalyst

Abstract

5-Hydroxymethylfurfural (HMF) will be a major feedstock derived from waste/fresh biomass, which could be converted into a variety of valuable chemicals. The present work deals with an efficient, robust, environmentally benign and selective catalyst for preparation of 2,5-diformylfuran (DFF) from 5-hydroxymethylfurfural (HMF). It was investigated that impregnation of silver in K-OMS-2 (octahedral molecular sieve) improved the activity of the catalyst by decreasing concentration of acidic sites and increasing basic sites which was confirmed by NH₃ and CO₂-TPD results. Silver impregnation also decreases the reduction temperature of K-OMS-2 as confirmed by TPR study. HMF conversion and DFF selectivity were found to be 99 and 100%, respectively. Effects of various kinetic parameters on rate and conversion were studied. The reaction follows pseudo first order kinetics. The energy of activation is 11.54 kcal/mol. Product isolation protocol is discussed to obtain 99.9% of DFF purity. Ag-OMS-2 catalyst exhibits excellent reusability up to sixth run. Since the overall process is environmentally safe, catalyst is reusable and DFF yield is 99%, it is suitable for further industrial exploration.