Complex spatiotemporal antiphase oscillations during electrodissolution of a metal disk electrode: Model calculations

Pattern formation in electrochemical systems depends sensitively on the relative arrangement of the electrodes. We present simulations of spatiotemporal patterns during the electrodissolution of a metal disk electrode in which the reference electrode is located on the axis of the disk and close to the metal working electrode. This geometry introduces a strong but asymmetric negative feedback which tends to destabilize the homogeneous potential distribution. We demonstrate that the feedback gives rise to a variety of complex antiphase-type patterns. Some of these patterns have been observed in experiments; others present novel manifestations of dynamic instabilities in electrochemical systems.