Nuances of the voltammetry of homogeneous multi-electron molecular catalysts: an analytical theory for two-electron catalysis

Abstract

A wide range of cases of homogeneous two-electron molecular catalysts of electrochemical reactions, as a paradigm of multi-electron catalysis, are investigated in voltammetry through a novel and rigorous analytical theory. Simple expressions are deduced for the current-potential response at static and rotating macroelectrodes in all possible situations in terms of catalytically active pathway(s), rate constant(s) and formal potentials of the electron transfers. Criteria and procedures have been proposed to identify the true catalytic states and pathways. The results reveal fundamental differences in the voltammetry of multi-electron catalysts with respect to that of mono-electron ones (EC’ mechanism), specifically with regard to the impact of mass transport on the features of the signal and on the accessibility to pure kinetic conditions.