Metal dissolution partial charge transfer

D. Vanmaekelbeigh and B. H. Eme, Coupled partial charge-transfer steps in the anodic dissolution of metals, J. Electrochem. Soc. 7546 2488 (1999). 

The anodic partial reaction also involves a charge transfer at the interface because a metal atom loses electrons. It then dissolves in the solution as a hydrated or complexed ion and diffuses towards the bulk. In the vicinity of the metal surface, the concentration generated by dissolution therefore often exceeds that of the bulk electrolyte. Once the solubility threshold is reached, solid reaction products begin to precipitate and form a porous film. Alternatively, under certain conditions, metal ions do not dissolve at all but form a thin compact oxide layer, called passive film. The properties of the passive film then determine the rate of corrosion of the underlying metal (Chapter 6). 

If charge transfer is rate limiting, the Butler-Volmer equation (35) described the current-potential relationship of each partial reaction. With the overvoltage of the metal dissolution reaction, r j = - reduction reaction, rjg... 

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