Selective transformation of biomass-derived 5-hydroxymethylfurfural into 2,5-dihydroxymethylfuran via catalytic transfer hydrogenation over magnetic zirconium hydroxides

An economical and effective approach for the selective transformation of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-dihydroxymethylfuran (DHMF) was developed by catalytic transfer hydrogenation over various magnetic zirconium hydroxides (MZHs). As expected, MZH with a moderate Zr/Fe molar ratio of 2 displayed the highest catalytic activity, resulting in 98.4% HMF conversion and 89.6% DHMF yield at 150 °C for 5 h in the presence of 2-butanol that simultaneously acted as the hydrogen donor and reaction solvent, which was ascribed to its appropriate specific surface area, pore size and acid-base content. Moreover, a plausible reaction mechanism for the catalytic transfer hydrogenation of HMF into DHMF over MHZ(Zr/Fe=2) was also proposed, in which the basic hydroxyl groups with the aid of acidic zirconium metal centers were considered to be responsible for the pivotal hydride transfer via a six-membered ring structure.