TUNGSTEN-OXIDE MODIFIED SILICA-TITANIA OXIDATIVE-ACIDIC BIFUNCTIONAL CATALYST FOR DIOL SYNTHESIS

Oxidative-acidic bifunctional catalysts of tungsten oxide modified silica-titania, xW/TiO2-SiO2 (x=1, 5, 10 wt%) were successfully synthesized and characterized. Both XRD and UV-Vis analyses results indicated presence of WO3 phase in samples with higher dopant amount. It also revealed tetrahedral Ti and octahedral coordinated existed as the dominant species in the samples. FTIR analysis suggested formation of Si-O-W in the tungsten oxide modified samples. The catalytic performance of the samples was evaluated via consecutive transformation of 1-octene to 1,2-octanediol through the conversion of 1,2-epoxyoctane using aqueous H2O2 as oxidant. While TiO2-SiO2 and 1W/TiO2-SiO2 showed no catalytic activity in yielding diol, samples 5W/TiO2-SiO2 and 10W/TiO2-SiO2 exhibited bifunctional catalytic activity. It has been demonstrated that sample 10W/TiO2-SiO2 was the best oxidative-acidic bifuntional catalyst which produced 321 mu mol 1,2-epoxyoctane and 51 mu mol 1,2-octanediol after 24 h reaction. (C) 2016 Penerbit UTM Press. All rights reserved