Electrochimica Acta, Vol.265, 638-650, 2018
Double pulse voltammetric study of the IT-CeqC mechanism underlying the oxygen reduction and hydrogen evolution reactions at liquid/liquid interfaces
A theoretical study of the IT-CeqC mechanism (ion transfer followed by a chemical equilibrium and a subsequent chemical reaction) is presented at liquid vertical bar liquid macrointerfaces by using the double pulse electrochemical techniques reverse pulse voltammetry (RPV), double pulse chronoamperometry and differential double pulse voltammetry (DDPV). These techniques have proven to be very powerful for the characterization and identification of homogeneous kinetics coupled to the charge transfer, with high sensitivity and reduced capacitive and background effects. From the general analytical expressions here deduced, interesting limiting cases and eccentric behaviours are revealed. Methodologies and tools are given for the extraction of the chemical kinetics and thermodynamics on the basis of the analysis of the RPV limiting current, RPV cross potential and DDPV peak potential. The results can be valuable for the investigation of outstanding processes such as the oxygen reduction reaction (ORR) and the hydrogen evolution reaction (HER), the voltammetry of which can be described in a first approach by the IT-CeqC mechanism. (C) 2018 Elsevier Ltd. All rights reserved.