Strontium cobalt oxychlorides: enhanced electrocatalysts for oxygen reduction and evolution reactions.

Cobalt-based layered perovskite oxychlorides Sr2 CoO3 Cl and Sr3 Co2 O5 Cl2 exhibit high oxygen electrocatalytic activity compared to conventional lanthanum cobalt-based perovskite oxides. The enhanced oxygen electrocatalytic activity can be attributed to the upshifted O p-band center relative to the Fermi level caused by the incorporation of chloride anion into oxygen sites.