Sequential Deposition of Copper on Solid Gold (111): A Statistical Model
Abstract
Phase transitions occurring during electrode processes have been studied using a model in which the electrode is a planar wall with sticky adsorption sites. This model is used to explain the underpotential deposition (UPD) of copper on gold (111) in the presence of bisulfate ions. The model assumes that the bisulfate ions form a template for the adsorption of the first 2/3 of a monolayer of copper onto a honeycomb lattice. The centers of the hexagons that form the honeycomb are occupied by the bisulfate. In the absence of copper the bisulfate is desorbed as the electrode becomes more negatively charged, and for that reason the template 'melts' when the fraction of occupied sites drops below a certain critical value, which is estimated using the hard hexagon model of Baxter. We assume strong copper-bisulfate coadsorption, so that in the presence of a sufficiently large amount of Cu the template is reconstructed. Our model explains the qualitative features of the voltammogram, and makes definite predictions for the structure that should be observed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 15, 1993
- Accession Number
- ADA260269
Entities
People
- Dale A. Huckaby
- Lesser Blum
Organizations
- University of Puerto Rico