Investigation of the elimination of VOC mixtures over a Pd-loaded V-doped TiO₂ support

The removal of a butanone-toluene mixture over Pd/5%V-TiO₂ and Pd/TiO₂ catalysts has been investigated. The V-doped sample showed a higher performance in the oxidation of butanone and also a butanone-toluene mixture, which was attributed to competition between oxygen species and VOCs on vanadium adsorption sites. However in the presence of both VOCs, Pd/5%V-TiO ₂ showed a higher performance than in the elimination of butanone alone. An operando DRIFT experiment coupled with a mass spectrometer revealed that both VOCs compete in terms of adsorption on the surface of the catalyst. However, toluene adsorption is decreased by MEK, meaning that the latter oxidizes more easily into its by-products, whose combustion causes variations in the surface temperature of the catalyst, thus enhancing the oxidation of toluene molecules present in the gaseous stream.