ELECTROCHEMISTRY OF NICKEL-OXIDE ELECTRODE .V. SELF-PASSIVATION EFFECTS IN OXYGEN-EVOLUTION KINETICS

Potentiostatic studies on the oxygen-evolution reaction at nickel and oxidized nickel surfaces reveal inhibition effects (self-passivation) analogous to those found in anodic organic oxidations at the noble metals. Here, however, the inhibiting species, surface oxides, are directly involved in the over-all reaction itself. Similar effects are shown to arise at platinum in alkaline solutions and comparative experiments are also reported for silver, where easily distinguishable states of surface oxidation can be related to the oxygen-evolution kinetics at oxidized silver surfaces. A kinetic theory of the self-inhibition effects is presented in general terms for various supposed oxidation states of the surface region of the electrode interphase. © 1969.