The Open-Circuit Potential of a Polarizable and Reactive Electrode

Abstract

The open-circuit potential (OCP) of a polarizable and reactive electrode is modeled by the combination of the mixed potential theory and the Frumkin effect. The product of surface oxidation reaction alters the electrolyte double layer structures at the interface, which conversely affects the surface reaction rate. Tribo-electrochemical experiments were carried out with a tungsten rotating disc electrode in a series of diluted KIO3 solutions at pH 2.00. The OCP change with time during the passivation of the electrode surface is fitted based on the model. All the fitting results can provide coherent and reasonable physical meanings, and the apparent surface reaction rate of 1.1*10^4 (mol/L)^-1*sec^-1 of the tungsten electrode surface by KIO3 is thus obtained.