(750d) Furfuryl Alcohol Dehydration over Metal Oxides (TiO2, Al2O3 and Nb2O5) supported WO3 Catalysts

The conversion of lignocellulosic biomass into fuels has been investigated as a result of increasing demand for petroleum oil and environmental concerns. Furfuryl alcohol (FA), which is produced from furfural derived from a selective dehydration of xylose, is an attractive intermediate chemical for the production of template chemicals, such as levulinic acid and alkyl levulinate and FA polymer. Under acid condition, FA can be converted to FA oligomers through intermolecular dehydration. Previously we found the use of bulk tungsten oxide was very similar to strong homogeneous acid, such as sulfuric acid. It was known that the interaction of a catalytic active component, such as WO₃, with a metal oxide support can dramatically alter the molecular and electronic structural and catalytic properties of the supported catalytic active component. In the present study, a series of supported WO₃ catalysts were synthesized on TiO₂, Al₂O₃, and Nb₂O₅ supports by incipient wetness impregnation method. The monolayer coverage and the molecular structures of the supported tungsten oxide were determined with in-situ Raman. Two significant parameters, the tungsten oxide coverage (W/nm²) (loading effect) and the specific metal oxides support (support effect), were carefully examined during liquid phase FA dehydration reaction under mild experimental conditions, 100^oC and ambient pressure, for 3 hours. The specific metal oxide support was found to significantly affect the relative catalytic activity of the surface WO_x species to that of the crystalline WO₃ particles.