| AVS 63rd International Symposium & Exhibition | |
| Fundamental Discoveries in Heterogeneous Catalysis Focus Topic | Wednesday Sessions |
| Session HC+SS-WeM |
| Session: | Bridging Gaps in Heterogeneously-catalyzed Reactions |
| Presenter: | Daniel Killelea, Loyola University Chicago |
| Authors: | D.R. Killelea, Loyola University Chicago J. Derouin, Loyola University Chicago R.G. Farber, Loyola University Chicago M.E. Turano, Loyola University Chicago E.V. Iski, The University of Tulsa |
| Correspondent: | Click to Email |
A long-standing challenge in the study of heterogeneously catalyzed reactions on silver surfaces has been the determination of what surface phases are of greatest chemical importance. This is due to the coexistence of several different surface phases on oxidized silver surfaces. A further complication is subsurface oxygen (Osub). Osub are O atoms dissolved into the near surface of a metal, and are expected to alter the surface in terms of chemistry and structure, but these effects have yet to be well characterized. We studied oxidized Ag(111) surfaces after exposure to gas-phase O atoms with a combination of surface science techniques to determine the resultant surface structure; we observed that once 0.1 ML of Osub has formed, the surface dramatically, and uniformly, reconstructs to a striped phase at the expense of all other surface phases. Furthermore, Osub formation is hindered at temperatures above 500 K. We also observed a coexistence of several surface oxides at intermediate deposition temperatures, and the predominance of the p(4x5√3) surface reconstruction at elevated temperatures.