Rest Potentials in the Platinum-Oxygen-Acid System

The rest potential of a platinum bead electrode in oxygen‐stirred acid solution was investigated as a function of the p H, the partial pressure of oxygen, and the history of electrode preparation. It is believed that the theoretical equilibrium oxygen potential, +1.229v vs . N.H.E., cannot be obtained in any known system because all known electronic conductors interact with oxygen. One observes, then, a mixed potential. Such systems are not at equilibrium but in a steady‐state condition. Evidence for the understanding of the nature of the potential‐determining reactions in this system are presented.