CATHODIC REDUCTION OF OXYGEN IN WATER AND MEDIA OF LOW IONIC-STRENGTH

Microdisc electrodes have been used to investigate the cathodic reduction of oxygen in purified water and in solutions with small additions of neutral electrolytes. Current-potential responses at Pt, Ag and Au microdiscs all show well formed reduction waves for oxygen. It is shown, however, that the lack of buffering capacity in the media, the high rate of mass transport to/from microelectrodes and the state of oxidation of the cathode surface as well as the uncompensated IR drop all influence the detailed form of the responses.