Determination of the kinetic parameters of the oxygen reduction reaction using the rotating ring-disk electrode

A general scheme of oxygen reduction is given and analysis of the disk—ring measurements is performed. Expressions for the diagnostic criteria for such a scheme have been derived and their implications are discussed. The existence of superoxide and oxygen ions and the interaction of the series and direct paths have been assumed in postulating the scheme. Also, all the electrochemical reactions involved only one-electron exchange. The possibilities and limitations of the disk-ring measurements in the mechanistic study of oxygen reduction are discussed together with a re-evaluation of some well-accepted criteria which are shown to be misleading. New definitions and terminology for different pathways of O2 reduction are proposed.