Functionalized ionic liquids supported on silica as mild and effective heterogeneous catalysts for dehydration of biomass to furan derivatives

Abstract

A series of functional ionic liquid supported silica nanoparticles with different acidity (ILs/SiO2) have been prepared by covalent bonds using novel, non-toxic ethanol as solvent. Compared with using toluene or acetonitrile as solvent in traditional prepared method, the process represents a green, environmental friendly route to synthesize supported functional ionic liquid catalysts (SFILCs). These SFILCs, with the benefits of ionic liquid and the advantages of immobilization, were first systematically utilized in biomass dehydration reactions and proved to be efficient heterogeneous catalysts for the preparation of furan derivatives from various carbohydrates. However, the supported dual acidic functional ionic liquid catalyst (3-sulfobutyl-1-(3-propyltriethoxysilane) imidazolium hydrogen sulfate) was found to be more active and selective than other ILs/SiO2 and the conversion of fructose, glucose, xylose, sucrose, cellobiose was up to 99, 96, 94, 76 and 99%. Moreover, the reducing sugar (TRS) yield of microcrystalline cellulose dehydration was up to 77%.