The liquid phase oxidation of styrene with tungsten modified silica as a catalyst

Adam, Farook and Mohamed Iqbal, Mohammad Anwar (2011) The liquid phase oxidation of styrene with tungsten modified silica as a catalyst. Chemical Engineering Journal, 171 (3). pp. 1379-1386. ISSN 1385-8947

PDF (The liquid phase oxidation of styrene with tungsten modified silica as a catalyst) - Published Version Restricted to Repository staff only Download (717kB) | Request a copy

Abstract

Tungsten was incorporated into silica matrix using sodium silicate from rice husk at pH 10, 7 and 3. These catalysts were labeled as RHW-10, RHW-7 and RHW-3. The pH was found to have a strong influence on the structure of the resulting silica–tungsten species and its catalytic activity. Analysis suggests that the catalysts were composed of isolated [WO4]2− species, isolated tungsten species or low oligomeric tungsten oxide species and crystalline WO3 species. The catalytic activity was tested in the liquid phase oxidation of styrene using H2O2 as oxidant. RHW-3 showed better catalytic activity than RHW-10 and RHW-7 due to its higher tungsten loading. The reaction is proposed to be catalyzed by pertungstic acid like intermediate which was formed upon the interaction of tungsten oxo species (WO) with H2O2. Benzaldehyde was obtained via styrene oxide as the major product with 100% selectivity. RHW-3 could be re-used several times without losing its catalytic activity even though a small amount of tungsten species leached out from the support.

Item Type:	Article (Journal)
Additional Information:	6745/22280
Uncontrolled Keywords:	Tungsten–silica heterogeneous catalyst; Rice husk silica; Sol–gel; Oxidation of styrene; Benzaldehyde
Subjects:	Q Science > QD Chemistry
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Science > Department of Biotechnology
Depositing User:	Dr Mohammad Anwar Mohamed Iqbal
Date Deposited:	17 May 2012 12:06
Last Modified:	20 Jun 2013 14:45
URI:	http://irep.iium.edu.my/id/eprint/22280

Actions (login required)

View Item