Place-exchange mechanism of Pt (111) oxidation/reduction as observed by synchrotron X-ray scattering
Structural changes in the Pt(111) single crystal surface associated with incipient electrochemical oxidation/reduction were studied by {ital in}{ital situ} synchrotron x-ray reflectivity. It was shown that lifting of Pt atoms of the surface layer occurs, substantiating the long-standing hypothesis of a place-exchange mechanism for solution/metal interface oxidation. It was also shown that, for a charge transfer of {approx_lt}1.7 e{sup -}/Pt atom, the initially flat surface structure could be recovered by electrochemical reduction. In constrast, the surface was irreversibly roughened for amounts of charge transfer exceeding {approx}1.7 e{sup -}/Pt, but the roughening involved only the atoms in the top layer of the original flat surface. A detailed mechanism is proposed for the place-exchange mechanism and the subsequent roughening of the electrode surface.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-31-109-ENG-38
- OSTI ID:
- 399995
- Report Number(s):
- ANL/MSD/CP-90769; CONF-960502-19; ON: DE96014877
- Resource Relation:
- Conference: 189. meeting of the Electrochemical Society (ECS), Los Angeles, CA (United States), 5-10 May 1996; Other Information: PBD: Jul 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Kinetic Monte Carlo Simulations of Electrochemical Oxidation and Reduction of Pt(111)
Place exchange during surface oxidation of platinum