Effect of electrochemical pretreatment on catalytic activity of bismuth ruthenate electrodes for oxygen evolution in alkaline solution.

The catalytic activity of a film-type bismuth ruthenate electrode for oxygen evolution was greatly enhanced by the electrochemical pretreatment, including potential holding and cycling. On the other hand, any appreciable enhancement in catalytic activity was not observed for a pellet-type bismuth ruthenate electrode. Such an pretreatment effect was explained on the basis of the participation of higher valence Ru species in the oxygen evolution reaction, rather than the increase of surface area.