Effect of reduction–oxidation treatment on the catalytic activity over tin oxide supported platinum catalysts

In precious metal-oxide catalyst system, the support materials strongly affect the catalytic activity. Especially the term of strong metal–support interaction is well known: Tauster et al. reported that partially reducible oxide such as titanium oxide could modify the chemisorption of H2 and CO [S.J. Tauster, S.C. Fung, R.L. Garten, J. Am. Chem. Soc. 100 (1978) 170; S.J. Tauster, S.C. Fung, J. Catal. 55 (1978) 29; S.J. Tauster, S.C. Fung, R.T.K. Baker, J.A. Horsley, Science 211 (1978) 1121.]. It was also demonstrated that this interaction could modify the catalytic activity of precious metals in different reactions. Accordingly, elucidating these phenomena will be the useful guide for the development of new class of active catalysts. Thus, we had focused on the chemical interaction between platinum and oxide and reported several results. Tin oxide supported platinum catalysts were heat-treated under oxidizing or reducing atmospheres at various temperatures, and their catalytic activity for methane combustion and electrochemical oxidation of CO was investigated. The resulting catalysts exhibited the peculiar microstructure and catalytic activity because of the metal–support interaction.