Giving physical insight into the Butler–Volmer model of electrode kinetics: Part 2 – Nonlinear solvation effects on the voltammetry of heterogeneous electron transfer processes

Electrochemical and spectroscopic experiments have shown the weaknesses of the symmetric Marcus–Hush model to model electrode processes, which is likely related to “asymmetric” oxidation and reduction processes. In a previous paper (M.C. Henstridge, E. Laborda, Y. Wang, D. Suwatchara, N. Rees, A. Molina, F. Martínez-Ortiz, R.G. Compton, J. Electroanal. Chem. 672 (2012) 45) the effects arising from different vibrational force constants have been considered, and in the present work we focus on those associated with solvent reorganization. fects of different solvent frequencies in the oxidized and reduced forms are analyzed for the Gibbs energy surface, the oxidation/reduction rate constants and the voltammetry of solution-phase and surface-bound redox systems. Criteria to assess these effects by electrochemical experiments are given based on the analysis of the value of the Butler–Volmer transfer coefficient.