Comprehensive investigation of the biomass derived furfuryl alcohol oligomer formation over tungsten oxide catalysts

The feasibility of using tungsten oxide catalysts for furfuryl alcohol (FA) oligomerization reaction was investigated in the liquid phase at 100 degrees C and ambient pressure. Five dimers (2,2'-difurylmethane, 2-(2-fulylmethyl)-5-methylfuran, difurfuryl ether, 4-furfuryl-2-pentenoic acid gamma-lactone, 5-fufuryl-furfuryl alcohol) and two timers (2,5-difurfurylfuran and 2,2'-(furylmethylene)bis(5-methylfuran)) were observed in GC and GC/MS, while Infrared (IR) and Raman spectroscopy provided the co-existence of conjugated diene and diketone molecular structures, respectively. It was observed that C-9-C-15 oligomers' selectivity decreased as the reaction time increased. Ether bridge and terminal alcohol are dominant FA dimers which are very similar to sulfuric acid (homogeneous catalysis) catalyzed dehydration/condensation reaction of FA. (C) 2015 Elsevier B.V. All rights reserved.