Sulfonated ionic liquid immobilized SBA-16 as an active solid acid catalyst for the synthesis of biofuel precursor 5-hydroxymethylfurfural from fructose

The catalytic conversion of biomass-derived chemicals to 5-hydroxymethylfurfural (HMF) is of high current interest. In this work, an efficient solid acid catalyst was synthesized by anchoring sulfonic imidazolium-based ionic liquid (IL) over the surface of mercaptopropyl-modified SBA-16 via thiol-ene click reaction. Various characterization techniques exhibited that the mesostructure of SBA-16 was preserved after the immobilization of acidic IL on its surface. The catalytic activity of the synthesized catalyst was evaluated for the dehydration of fructose to HMF. The influence of different reaction parameters on the catalyst efficiency was examined and optimized. A maximum HMF yield of 98% was attained after 30 min of reaction at 120 °C in dimethyl sulfoxide (DMSO) with a catalyst load of 15 mg. Importantly, the catalyst was simply recoverable and can be reused for five successive runs.