Activation of Pt/SnO2 catalyst for catalytic oxidation of volatile organic compounds

The catalytic combustion of toluene over tin oxide-supported metal catalysts (Pt/SnO2, Pd/SnO2, Ru/SnO2, and Rh/SnO2) was studied. As a result, the Pt/SnO2 catalyst exhibited the highest activity. The activity of Pt/SnO2 catalyst is expected to originate from the strong chemical interaction between platinum and tin oxide. The correlation between the nano-structure and catalytic activity in the oxidation of ethyl acetate was investigated for the Pt/SnO2 catalysts treated under a reducing or an oxidative atmosphere. For the transmission electron microscopy image of the as-calcined Pt/SnO2 catalyst, the fine particles composed of platinum species was highly dispersed on the surface of SnO2 support. After the reduction treatment at 400 °C, the peculiar core–shell structure was formed. It is noted that the particles with this structure disappeared by the reoxidation treatment in air, and the redispersion of nano-particles was confirmed. The particles with the core–shell structure were observed again after the second reduction treatment for the reoxidized catalyst. The catalytic activities of ethyl acetate combustion over Pt/SnO2 catalysts were deteriorated and activated, corresponding to the nano-structural changes induced by the reduction–oxidation treatments.