Influence of the nature of the conduction band of transition metal oxides on catalytic activity for oxygen reduction

Abstract

Catalytic activities for oxygen reduction of some transition metal oxides with metallic conductivity such as LaTiO 3, SrFeO 3, SrVO 3, SrRuO 3, V 0.2Ti 1.8O 3 and La 1-xSr xMnO 3 were investigated, and they as well as the activities of other oxides reported already were compared with the nature of their conduction bands. It was found that the catalytic activity of oxides having a σ * conduction band was high. The conclusion is drawn that in order for a transition metal oxide to have a high catalytic activity, (1) it must have a σ * band and (2) the band must contain electrons. This conclusion will be useful to predict the catalytic activity for oxygen reduction of transition metal oxides.