Acknowledgments

Fig, 10. "Visible " 02 evolution overpotentiol on Ni Ys. temperature temperature curve results (Fig. 10). It should be realized that although there is a minimum in the overpotential vs. temperature plot for "visible " evolu-tion, the potential for oxygen evolution continuously decreases with increasing temperature, although at a much slower rate after the temperature of the mini-mum than before. This information can be utilized to screen potential oxygen electrocatalyst materials. Oxygen evolution will be catalyzed on the appropriate conducting oxide stable with respect to oxygen. In addition if the temperature dependence of the oxide formation is known (either calculated from existing thermodynamic data or experimentally determined), the overpotential for oxygen evolution can be deter-mined at any temperature. This can then be used to elucidate the activity at elevated temperatures of various electrocatalysts and associated mechanism changes with minimum high temperature experimenta-tion