TWC Behaviour of Platinum Supported on High and Low Surface Area Cerium/Zirconium Mixed Oxides

The catalytic activity as TWC of two Pt catalysts supported on one high and one low surface area Ce 0.68 Zr 0.32 O 2 mixed oxide has been investigated. The catalyst behaviour was studied both fresh and after thermal ageing, and correlated to the textural and the Pt dispersion changes. The results show that the catalyst with the highest surface area is not necessarily the catalyst which has the best performances as TWC. The different behaviour of the catalysts has been attributed mainly to differences in the platinum dispersion and/or the reducibility of the samples, both related to the platinum/support interaction.