DERIVATIZATION OF SURFACES AND SELF-INHIBITION IN IRREVERSIBLE ELECTROCHEMICAL REACTIONS - CYCLIC VOLTAMMETRY AND PREPARATIVE-SCALE ELECTROLYSIS

Self-inhibition of irreversible electrochemical reactions is discussed under the assumption that the portion of the surface that is covered by the adsorbing or electrode-derivatizing species blocks the electrode reaction completely. The decrease in the cyclic voltammetric current upon repetitive cycling and the peak characteristics during the first cycle are described as a function of a single dimensionless parameter that is a measure of the competition between the surface and solution reactions and of the matching between the diffusion flux of the substrate and the area occupied by the inhibiting species. The time dependence for the growth of the inhibiting film in preparative-scale electrolysis is also established. Possible extensions of the model in terms of the reaction scheme and the inhibition mechanism are discussed.