Complete oxidation of toluene over supported palladium catalysts: Effect of support

The catalytic oxidation of toluene was carried out to investigate the effect of the support on the properties and performance of a supported palladium catalyst (1 wt% loading). γ-Al₂O₃, SiO₂ and TiO₂ were used as supports. The properties of the prepared catalysts were characterized by XRD, BET, PT, TPD, TPR, XPS and FE-TEM analyses. The experimental results showed that the order of catalytic performance was 1 wt% Pd/TiO₂ > 1 wt% Pd/SiO₂ > 1 wt%Pd/γ-Al₂O₃. A strong interaction between the palladium and support was found, which affected the palladium surface concentration and particle size. The higher catalytic activity of the Pd/TiO₂ catalyst was attributed to the higher palladium surface concentration and larger particle size.