Journal of Electroanalytical Chemistry, Vol.681, 96-102, 2012
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. Martinez-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. The effects 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. (C) 2012 Elsevier B.V. All rights reserved.
Keywords:Electrode kinetics;Nonlinear solvation;Matyushov model;Marcus-Hush model;Solvent force constants