Silicotungstic acid modified CeO2 catalyst with high stability for the catalytic combustion of chlorobenzene.

ABSTRACT

The catalysts' redox capacity and surface acidity was important during the catalytic combustion of chlorobenzene (CB). CeO2 showed great attractiveness due to its high oxygen storage capacity. Furthermore, the increase of acidity on the catalyst surface could improve the resistance to the chlorine poisoning. In this work, the silicotungstic (HSiW) modified CeO2 catalysts prepared by four cerium salts and exhibited the different morphologies and catalytic activity. The HSiW modified CeO2 catalyst prepared by Ce(CH3COO)3 (Cat-A) exhibited the best catalytic activity due to its abundant surface weak acid sites, more Ce3+ species and surface adsorption oxygen. The HSiW mainly located on the CeO2 (111) planes of the Cat-A, which was conducive to redox property of CeO2, thus promoting the deep oxidation of CB. Meanwhile the redox ability together with the weak acidity influenced the catalytic efficiency at low temperature. And the redox ability played a major role at high temperature. In addition, the Cat-A still possessed high stability and water resistance and maintained high activity after continuous catalytic oxidation of CB at 235 and 295 °C for 100h, exhibiting the possibility of industrial application.