Redox catalysis. Theory for a Nernstian reaction coupled to an irreversible reaction

Abstract

An electrochemical model based on the Wagner–Traud additivity principle has been used to predict the kinetics of catalysis of a redox reaction involving a Nernstian reduction reaction (Ox1+n1 e–→ Red1) coupled to an irreversible oxidation reaction (Red2→ Ox2+n2 e–). The mixture current (imix) flowing through a redox catalyst may be diffusion-controlled, partly diffusion-controlled or activation-controlled depending upon the mixture potential adopted by the redox catalyst. Kinetic equations are derived for each of these cases and predictions are made about the mixture current as a function of [Ox1], [Red1], catalyst surface area and temperature. In addition,xs a general method for reconstructing [Ox1]vs. time decay curves is described.