Presentation Information
[1B07]Oxidation of Silver and Rhodium surfaces
*Dan Killelea1 (1. Department of Chemistry, Loyola University Chicago)
Understanding the interaction of oxygen with transition metal surfaces is important in many areas including corrosion and catalysis. Of interest to us is the formation and chemistry of subsurface oxygen (Osub); oxygen atoms dissolved in the near-surface region of catalytically active metals. We seek to understand how incorporation of Osub into the selvedge alters the surface structure and chemistry and use ultra-high vacuum (UHV) based surface science techniques to characterize Ag and Rh surfaces after exposure to atomic oxygen (AO) to obtain O coverages in excess of 1 ML. We have found that the surface temperature during deposition is an important factor for the formation of Osub and the consequent surface structures. Rh surfaces are significantly more reactive towards CO oxidation when Osub is present. This enhanced reactivity is located at the interface between the less reactive RhO2 oxide and O-covered metallic Rh. This leads to question – what are the microscopic steps the reagents take in a surface-catalyzed oxidation reaction?