Comparative study between two methods of resistance compensation in the cyclic voltammetric determination of the standard electrochemical rate constant of dioxygen

Abstract

Cyclic voltammetric behavior of dioxygen reduction to superoxide ion in dimethylformamide in the presence of tetraethylammonium perchlorate as supporting electrolyte at glassy carbon electrode was investigated. Ferrocene as inner standard and positive feedback methods were used for ohmic resistance compensation. The influence of the supporting electrolyte concentration and the use of ferrocene as inner standard are discussed. The first reduction step of dioxygen to superoxide ion was found to be a quasi-reversible process with an average standard rate constant of 1.1 × 10 −2 cm s −1. The Butler-Volmer kinetics were followed within the experimental error by the charge transfer and a mean value of 0.38 was found for the transfer coefficient.