Efficient dehydration of fructose into 5-hydroxymethylfurfural in aqueous medium over silica-included heteropolyacids

The dehydration of fructose in aqueous and biphasic system was studied using heteropolyacids, immobilized in silica, as catalyst. The catalysts were characterized by ICP-AES, nitrogen sorption, NH3TPD, TEM, FT-IR, XRD, and TGA. The effect of different parameters, such as reaction temperature, reaction time, catalyst loading and volume ratio of water with methyl isobutyl ketone (MIBK) was studied. Silica included tungstosilisic acid (HSiW) was found to function as an efficient catalyst for the transformation of fructose into 5-hydroxymethylfurfural in aqueous phase. Addition of MIBK into the reaction system can increase both of fructose conversion and HMF selectivity. Besides, MIBK showed a positive effect in increasing the stability of the catalyst by suppressing the formation and deposition of humins over catalyst surface. After the third catalysis cycles, a stabilization of the catalytic activity was observed. (C) 2016 Elsevier Ltd. All rights reserved.