OXYGEN EVOLUTION AND REDUCTION ON IRIDIUM OXIDE COMPOUNDS

The electrochemical properties of twelve iridium oxide compounds (incl uding pyrochlores, perovskites, fluorites and compounds of another str ucture) were examined with respect to the oxygen-evolution and the oxy gen-reduction reactions. Steady-state current-potential curves were me asured in 45% KOH. In addition, the kinetic properties and the electri cal conductivity of four iridium oxide pyrochlores were investigated. All twelve compounds have a moderate to high catalytic activity for th e oxygen-evolution reaction, and a somewhat loweractivity for the oxyg en-reduction reaction. Pb-2(PbxIr2-x)O-7-gamma and Nd3IrO7 showed the highest activity towards both reactions.