A Study of Bismuth Ruthenate as an Electrocatalyst for Bifunctional Air Electrodes

The electrode kinetics of oxygen reduction and evolution on Ru, and electrodes were studied in 0.1 M . The transport and current shielding properties of the rotating ring‐disk electrode technique were used to obtain the kinetic variables as well as to determine the stability of these electrodes. Relatively high catalytic activity for reduction was observed on an Ru electrode. The catalytic activity of Ru was considerably reduced on the surface modified by "irreversibly adsorbed" Bi. The inhibition of reduction was accompanied by a change in the reaction mechanism from a predominately direct "four‐electron pathway," characteristic for reduction on pure Ru, to a significant branching of the reaction to the "peroxide pathway" on the electrode. exhibited low catalytic activity for reduction and relatively high activity for peroxide decomposition and/or reduction. Although less active for oxygen evolution than either Ru or electrodes, the electrode is more stable during evolution than either of these electrodes, with no dissolution products detected at the ring electrode.