Spatiotemporal patterns during electrodissolution of a metal ring: three-dimensional simulations

Spatiotemporal patterns that appear during the electrodissolution of a meta l that exhibits passivity are simulated by a two-variable model in a three- dimensional geometry with a point like reference electrode. The dynamical v ariables of the model are the potential drop across the electric double lay er and the proton concentration in front of the working electrode surface. The simulations elucidate the role of the geometry of the electrode arrange ment in an electrochemical cell and of experimental parameters in the evolu tion of patterns like rotating waves on a ring electrode, spatially homogen eous oscillations or a non-uniform stationary state including transitions b etween them. The prevalence of a specific spatiotemporal pattern is control led by the interplay of positive and negative long-range coupling of sites on the electrode through the electric field. The model is of a general char acter and does not take into account the specific kinetics of a given metal . (C) 2001 Elsevier Science B.V. All rights reserved.