The Catalytic Oxidation of Short-chain Alkane VOCs Using Metal Oxide Modified Titania Supported Palladium Catalysts

摘要

The activity of a palladium/titania catalyst for propane oxidation has been promoted by the addition of varying loadings of tungsten by impregnation. The addition of WO_x to the Pd/TiO_2 catalysts led to a significant increase in the activity for propane oxidation. The improved activity of tungsten-promoted Pd/TiO_2 catalysts has been related to the presence of vacant sites at the interface between the WO_x species and the PdO nanoparticles, generating new sites where propane molecules can be adsorbed and oxidized by oxygen species from the adjacent palladium sites. Additionally, for the tungsten promoted Pd/TiO_2 catalysts the catalytic activity increases with increasing tungsten loading. This has been explained in terms of the PdO particle size, which increases with the tungsten loading and is a structure sensitive reaction. These catalysts have demonstrated high activity for short chain alkane oxidation and they are now worthy of further study for their wider applications for VOC abatement. Next steps in this work will focus on the activity of these catalysts for the total oxidation of a wider range of hydrocarbons and other VOCs. We also plan to probe the efficiency of destruction of VOC mixtures and assess longer term catalyst stability.