Copper electrodissolution in 1 M HCl at low current densities. I. General steady-state study

Anodic oxidation of a copper rotating disk in hydrochloric acid is studied Under;steady-state conditions. At low current densities, a pseudo-Tafel behaviour varying with the speed of the rotating disk is observed. At potentials higher than -0.15 V/SCE, the value of the high frequency resistance,obtained from EIS measurements, increases and does not correspond to the sole resistance of the electrolytic solution. This behaviour is explained by the occurrence of the electroadsorption process. A two step mechanism for copper oxidation is studied with the only assumption of a constant chloride concentration at the interface. Kinetic zone diagrams are:plotted and all the possible limiting kinetic: behaviours of the model are pointed out. Interpretation of the experimental results reveals the limiting form taken by the current density vs potential curves; (C) 1998 Elsevier Science Ltd. All rights reserved.