Abstract:
Zirconia-alumina mixed oxide supported phosphotungstic acid catalysts were synthesized and characterized by various techniques. The surface-and bulk properties of the catalysts were examined by Xray diffraction, BET surface area, ammonia-TPD, TPR, P-31 MAS NMR and FTIR techniques. The prepared catalysts were evaluated for liquid phase epoxidation of trans-stilbene using tert-butylhydroperoxide as an oxidant. Among all the promoted catalyst, 25 wt.% phosphotungstic acid impregnated zirconia-alumina mixed oxide showed 46% conversion and 89% of selectivity towards trans-stilbene oxide formation. (C) 2009 Published by Elsevier B.V.