Oxygen Evolution on La1 − x Sr x Fe1 − y Co y O 3 Series Oxides

series oxides with perovskite‐type structure were synthesized and were examined as the electrode for the oxygen evolution reaction in alkaline solution. The oxides except for , , and their neighbors were suitable for the electrode with respect to high conductivity. The catalytic activity for the oxygen evolution reaction increases along the direction from to in composition. It is concluded that the following two conditions are desirable for the perovskite‐type oxide with high catalytic activity for the oxygen evolution reaction: ( i ) the oxide has a broad band and ( ii ) the transition metal cation in the oxide exists as the higher oxidation state. In addition, it was found that the catalytic activity of is the highest in the oxides prepared in this study.