Analysis of Simulated Reversible Cyclic Voltammetric Responses for a Charged Redox Species in the Absence of Added Electrolyte

Abstract

We present an analysis of simulated cyclic voltammetric responses of a dissolved redox salt with no added supporting electrolyte. The redox system of interest is a reversible one electron transfer: AzA + e = BzA-1. Only the charged, oxidized species AzA and counterion XzX are initially present in solution (analogous systems where the reduced species and counterion are initially present are not explicitly discussed); their relative concentrations are dictated by zA, zX, and the constraint of electroneutrality (systems where zA = 0 or 1 are not considered). Cyclic voltammetric responses are simulated assuming Nernst−Planck transport, and electroneutrality with perfect IR compensation (easily simulated but experimentally unattainable) and with partial IR compensation. Simulations assuming perfect compensation allow us to elucidate the change in the resistance, Rref, between the working and reference electrodes effected by changes in the depletion layer during the course of the cyclic voltammetric perturbati...