Paper SS1-MoM3
Environmental Effects on Morphology of Oxide Supported Gold Nanoparticles

Monday, October 15, 2007, 8:40 am, Room 608

Metal particles deposited on thin oxide films have been shown to be suitable model systems for studying structure-reactivity relationships of metal catalysts. In this paper, the morphology of Au particles deposited on thin FeO(111) and CeO2(111) films at elevated (up to 10 mbar) pressures of H2, CO, O2 and CO+O2 has been examined using in situ STM at room temperature. The Au particles are found to be fairly stable in oxygen and hydrogen environments. However, in CO+O2 (and CO) atmospheres, the destabilization of Au particles located at the step edges occurs leading to the formation of mobile Au species, which migrate across the oxide surface. General problems encountered with high-pressure STM studies will be also discussed, in particular trace impurities of the gas feedstock may play a big role in system behaviour and data interpretation.