Surface restructuring of Pt films on Au stepped surfaces: effects on catalytic behaviour.

In this paper, the reconstruction of Pt films deposited on stepped Au(hkl) surfaces belonging to the [n(111) × (110)] family of planes has been studied. Pt films were deposited using the galvanic displacement procedure of a pre-deposited Cu monolayer. We experimentally found that the Pt film deposition onto Au(hkl) surfaces is not fully epitaxial suggesting an atomic arrangement different from the underlying substrate. Additionally, we found that even though voltammetric profiles are not much different from those reported in the literature for Pt single crystals having the same crystallographic orientation, there is a reconstruction of the Pt layers on all Pt/Au(hkl) surfaces upon CO adsorption/oxidation as indicated by comparing the active areas of the Pt films before and after stripping. Additional FTIR in situ experiments on ethanol oxidation confirm that film reconstruction affects the reaction by product yield modification.