An oxygen evolution catalyst of the formula: Sr2MCoO5 where M=Al, Ga wherein M is bonded with four oxygen atoms to form a tetrahedron. The catalyst is operated at a potential of less than 1.58 volts vs. RHE at a current density of 50 μA/cm2 for a pH of 7-13. The catalyst is operated at a potential of less than 1.55 volts vs. RHE at a current density of 50 μA/cm2 and a pH of 13. The oxygen evolution catalyst of the formula: Sr2GaCoO5 wherein the catalyst is operated at a potential of less than 1.53 volts vs. RHE at a current density of 50 μA/cm2 and a pH of 7. The oxygen evolution catalyst of formula: Sr2GaCoO5 wherein the catalyst maintains a current within 94% after 300 minutes at a potential of 1.645 volts vs. RHE wherein the current is greater than 1 milliamp and a pH of 7.