When an Encapsulating Oxide Layer Promotes Reaction on Noble Metals: Dewetting and In situ Formation of an Inverted FeOx/Pt Catalyst

An ultra-thin FeO(111) film grown on Pt(111) is found to exhibit a much higher rate of CO oxidation at stoichiometric CO:O-2 ratios than the clean Pt(111) surface. This unexpected result is rationalized on the basis of reaction induced dewetting of the oxide film, ultimately resulting in highly dispersed FeOx nanoparticles on Pt(111). The effect may have a strong impact on the catalytic properties of the noble metal particles encapsulated by the reducible oxide support as a result of strong metal-support interaction.