Homogeneous redox catalysis of multielectron electrochemical reactions. Part I. Competition between heterogeneous and homogeneous electron transfer

Abstract

Homogeneous redox catalysis of two-electron electrochemical reactions involves the competition between two pathways, where the second electron is transferred either from the electrode surface (ECE), or from the active form of the catalyst in the solution (SET). The problem is discussed in the context of linear sweep voltammetry and the outcome of the competition is described quantitatively as a function of the various experimental parameters, concentrations, sweep rates and characteristic rate constants. The reduction of haloaromatics in the benzene and pyridine series, mediated by aromatic and heteroaromatic anion radicals in dimethylformamide, is taken as an experimental example illustrating the procedures derived from the theory. © 1985.