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 (i_mix) 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.