Rolando Guidelli et al.Pure and Applied Chemistry, 2014Volume 86, Issue 2, pp 259–262
The transfer coefficient α is a quantity that is commonly employed in the kinetic investigation of electrode processes. An unambiguous definition of the transfer coefficient, independent of any mechanistic consideration and exclusively based on experimental data, is proposed. The cathodic transfer coefficient αc is defined as –(RT/F)(dln|jc|/dE), where jc is the cathodic current density corrected for any changes in the reactant concentration on the electrode surface with respect to its bulk value, E is the applied electric potential, and R, T, and F have their usual significance. The anodic transfer coefficient αa is defined similarly, by simply replacing jc with the anodic current density and the minus sign with the plus sign. This recommendation aims at clarifying and improving the definition of the transfer coefficient reported in the 3rd edition of the IUPAC Green Book.
A detailed assessment in the form of an IUPAC Technical Report is published directly preceding the recommendations; see Pure and Applied Chemistry, 2014, Volume 86, Issue 2, pp. 245–258; http://dx.doi.org/10.1515/pac-2014-5026