Development of a thermally stable Pt catalyst by redispersion between CeO(2) and Al(2)O(3)

For catalytic systems consisting of Pt as the active component and CeO(2)–Al(2)O(3) as the support material, the metal–support interaction between the Pt and CeO(2) components is widely applied to inhibit aggregation of Pt species and thus enhance the thermal stability of the catalyst. In this work, a highly thermostable Pt catalyst was prepared by modifying the synthesis procedure for conventional Pt/CeO(2)/Al(2)O(3) (Pt/Ce/Al) catalyst, that is, the CeO(2) component was introduced after deposition of Pt on Al(2)O(3). The obtained CeO(2)/Pt/Al(2)O(3) (Ce/Pt/Al) catalyst exhibits significantly different aging behavior. During the hydrothermal aging process, redispersion of Pt species from the surface of Al(2)O(3) to the surface of CeO(2) occurs, resulting in a stronger metal–support interaction between Pt and CeO(2). Thus, the formed Pt–O–Ce bond could act as an anchor to retard aggregation of Pt species and help Pt species stay at a more oxidative state. Consequently, excellent reduction capability and superior three-way catalytic performance are acquired by Ce/Pt/Al-a after hydrothermal aging treatment.