THE EFFECT OF CHLORIDE ON THE UNDERPOTENTIAL DEPOSITION OF COPPER ON PT(111) - AES, LEED, RRDE, AND X-RAY SCATTERING STUDIES

摘要

The details of the underpotential deposition (UPD) of Cu on Pt(111) in the presence of Cl- were re-examined using a combination of familiar ex-situ techniques (AES/LEED) and new in-situ techniques, anomalous surface X-ray scattering (SXS) and Cu2+ flux measurements using a rotating ring disk configuration with the Pt(111) single crystal as the disk electrode. In combination these techniques show definitively that Cu UPD occurs in a two step process, the first being the formation of a Cu-Cl adlattice having a bi-layer structure similar to the (111) plane of CuCl, the second being the formation of a pseudomorphic Cu monolayer covered with a Cl adlayer. The latter appears to have a structure similar to the structure of Cl adsorbed on Cu(111) to saturation in UHV. References: 30