Irreversible inactivation of initial redox form in surface electrode mechanism: Theoretical aspects in square-wave voltammetry

Various redox species frequently undergo irreversible inactivation under specific chemical conditions. This study explores square-wave voltammetry to examine the electrochemical behavior of lipophilic redox systems classified within the family of surface electrode mechanisms. The theoretical analysis considers an initial redox form that simultaneously undergoes an electrochemical transformation and an irreversible chemical inactivation reaction. The study presents a detailed tabulation of distinctive voltammetric patterns, assisting readers to accurately identify this electrode mechanism and distinguish it from the film loss in the square-wave voltammetry of surface-confined redox systems. The extensive collection of simulated voltammograms in this work offers insight into establishing diagnostic criteria for recognizing this mechanism. Additionally, several suitable approaches for determining the kinetics of the dual processes involved in the electrochemical mechanism are proposed. These findings are expected to help experimentalists studying metal and alloy inactivation, as well as protein-film voltammetry (PFV), to accurately characterize the considered electrode mechanism. Given the unique features of this mechanism, experimental protocols should incorporate the use of a flow-through electrochemical cell for voltammetric measurements.