Electrochemical Impedance of Oxygen Reduction in Acidic Solution at Silver-Modified Glassy Carbon Electrode

The electro-reduction of oxygen on silver-modified glassy carbon electrode (Ag/GC) in acidic solution at different potentials was studied by ac-impedance spectroscopy. The influence of the electrode potential on impedance of oxygen reduction reaction is studied and a mathematical model was put forward to quantitative account for the impedance behavior of oxygen reduction. At potentials higher than -0.4 V/Ag-AgCl, a pseudo inductive behavior is observed. The conditions required for this behavior are delineated with the use of the impedance model.