Catalysis Letters, Vol.145, No.4, 1080-1088, 2015
Polyethylene Glycol-400-Functionalized Dicationic Acidic Ionic Liquids for Highly Efficient Conversion of Fructose into 5-Hydroxymethylfurfural
A variety of polyethylene glycol-400-functionalized dicationic acidic ionic liquids (ILs) (PEG(400)-DAILs) were synthesized and tested in the dehydration of fructose. Among these catalysts, hydrogen sulfate anion-based ILs showed the higher catalytic performance in the conversion of fructose. The highest HMF yield of 96.5 % with 100 % consumption of fructose were obtained after 60 min at 110 A degrees C. The effects of catalyst concentration, reaction time, reaction temperature, and solvents were systematically investigated. In addition, the generality of the catalysts was examined by processing inulin and sucrose to HMF with yield of 71.9 and 52.1 % under certain conditions, respectively. PEG(400)-DAILs possess modified physicochemical properties such as low viscosity, strong hydrophilicity and hydrogen bonding with sugars so as to improve activity for the dehydration of fructose into HMF. The used IL catalyst could be separated and recycled repeatedly without significant loss of catalytic activity. The research emphasizes preparation of the novel catalysts combining polymers with functionalized ILs for conversion of renewable biomass.