Cascade conversion of biomass to furan monomers in the presence of magnetic catalysts

We have studied a novel sustainable approach for the microwave-assisted synthesis of magnetite, involving a simple procedure, the use of a green solvents, short reaction times, good energy efficiency and the absence of any high-boiling stabilizing agent or organic surfactant. The activity of these novel magnetic catalysts, based on Pt, Pd and Ru supported on magnetite, has been tested in the selective oxidation of biomass-derived aqueous 5-hydroxymethylfurfural (HMF) to give valuable monomers such as 2,5-furandicarboxylic acid and 5-hydroxymethyl furoic acid. We examined also the conversion of cellulose and of crude corn stover in a fully heterogeneous process without isolation of intermediate HMF, through a combined process of acid dehydration catalyzed by niobium phosphate and successive catalytic oxidation.