Trapping Platinum on Ceria: Role of Surface Facets

Supported platinum catalysts are used in the automotive industry for the oxidation of CO, hydrocarbons, and NOx. Dispersed Pt provides active sites for these reactions to occur. During the use of these catalyst, high temperatures will cause Pt to become volatile and sinter, forming large particles which will lead to a loss of catalytic activity. The study of Pt sintering has been of high priority for the automotive industry along with mechanisms that will reduce the effect of sintering. Developing an understanding of how supports can hinder sintering of Pt will lead to the preparation of more robust catalysts. A promising support for Pt is CeO2. Altering the synthesis of CeO2 can allow for different nanoshapes to be formed which lead to different surface facets being exposed. The three types of nanoshaped CeO2 synthesized for the catalyst are polyhedra, rods, and cubes, which expose different surface facets. The polyhedra produced expose primarily the (111) and (100) facet while rods expose (111) and cubes expose the (100). These three CeO2 nanoshapes will be tested to discover if one surface facet is able to trap Pt in a dispersed form after aging at high temperature.