Cyclic voltammetry in weakly supported media: The reduction of the cobaltocenium cation in acetonitrile – Comparison between theory and experiment

Experimental cyclic voltammetry at a hemispherical mercury microelectrode in acetonitrile solution, containing 3 mM cobaltocenium hexafluorophosphate and different concentrations of supporting electrolyte, is compared with theoretical simulations using the Nernst–Planck–Poisson system of equations, without the assumption of electroneutrality, and is found in to be in good agreement. Deviations from diffusion-only theory are analyzed in terms of migration and potential drop in the solution as a function of the concentration of supporting electrolyte. We are unaware of previous reports in which non-steady-state cyclic voltammetry without supporting electrolyte has been quantitatively and fully simulated, so this work opens up a new area for voltammetry.