Evaluating the ozone cleaning treatment in shape-controlled Pt nanoparticles: Evidences of atomic surface disordering

The application of shape-controlled Pt nanoparticles is rapidly increasing mainly because surface reactivity is, for many cases, structure sensitive. Shape control is generally obtained by using capping agents which finally cover the surface. However, for many applications these adsorbed molecules have to be effectively removed. For this purpose UV/ozone has been recently proposed. However, although this methodology was shown to be effective for cleaning, its effects over the catalyst surface structure are still unclear. In this paper the effect of UV/ozone cleaning treatment on uncapped/clean shaped-controlled Pt nanoparticles is evaluated. The results demonstrate that this procedure strongly perturbs the surface structure of the nanoparticles, significantly modifying their catalytic properties, but without altering their size and shape. (C) 2011 Elsevier B.V. All rights reserved.