A double logarithmic method for studying the adsorption effects in an irreversible electrochemical process

The adsorption of an electroinactive product greatly influences an irrevers ible electrochemical reaction in three ways, including self-block, self-inh ibition, and self-acceleration, and changes not only the heterogeneous elec tron-transfer rate constant but also the modified formal potential and elec tron-transfer coefficient of the electrochemical reaction. In order to stud y these adsorption effects, a double logarithmic method was suggested to be used in processing the potential-controlled thin layer spectroelectrochemi cal data. The result shows three types of double logarithmic plots for thre e kinds of adsorption effects. These double logarithmic plots can be a diag nostic criterion of the adsorption effects and enable us to determine some thermodynamic and kinetic parameters. The combination of nonlinear regressi on with double logarithmic method is a convenient way to examine the sugges ted mechanism and to extract more information from the limited experimental data. Some examples are given to test the theoretical results. (C) 1999 Th e Electrochemical Society. S0013-4651(98)05-012-5. All rights reserved.