Investigation of the Redispersion of Pt Nanoparticles on Polyhedral Ceria Nanoparticles.

Redispersion of platinum nanoparticles (Pt NPs) on ceria is an important route for catalyst regeneration and antisintering. Here, we investigate the redispersion of Pt on ceria nanoparticles with defined surface planes including cubes ({100}) and octahedra ({111}). It is observed that Pt redispersion takes place only on ceria cubes in an alternating oxidation and reduction atmosphere. A quicker alternation rate is beneficial for such redispersion. On the basis of our experimental results and understandings toward this process, we proposed that the redispersion takes place at the moment of alternation of oxidation and reduction.