ANODIC-DISSOLUTION OF METALS UNDER MASS-TRANSPORT CONTROL

This paper is focussed on anodic dissolution processes controlled by m ass transport. After the recall of the results obtained for a classic redox system, four examples are discussed: (i) iron dissolution in sul phuric acid for which a liquid layer of high visosity is formed at the interface; (ii) copper dissolution in hydrochloric acid and (iii) in phosphate acid, where in both solutions a solid salt layer is existing at the electrode surface; and (iv) nickel dissolution in sulphate aci d media, where a very high Schmidt number is involved in the mass tran sport. On the basis of the analysis of steady-state results and electr ohydrodynamic impedance, it is evidenced that each system needs a part icular description.