PNNL

Abstract

We report on the reactivity of a FeO(111) monolayer grown on Pt(111) toward aliphatic alcohols. Using a combination of temperature programmed desorption, infrared reflection-absorption spectroscopy, and scanning tunneling microscopy techniques we show that the alcohols dissociate primarily at FeO(111) step edges and their oxidation leads to the removal of the FeO(111) film. Upon annealing, FeO(111) lattice oxygen is incorporated into the reaction products and reduced iron left behind dissolves into the underlying Pt(111) substrate. Ethanol is employed in a more detailed spectroscopic study to follow the reaction products and surface intermediates as the removal of FeO(111) proceeds. The ethoxy species formed upon dissociative adsorption of ethanol at the FeO(111) step edges undergo partial oxidation to acetaldehyde and a complete oxidation to CO and H2O. Other products, CH4 and H2, associated with the reactions occurring on Pt(111) are also observed as the bare Pt(111) surface appears. A similar etching process was also observed for n-decane.