Patent ID: 7803348

Claim:
An oxygen reduction catalyst comprising a compound represented by Formula 1-1: Sr 3−x A 1+x Co 4−y B y O 10.5−z (1-1) wherein −0.6≦x≦1.0; 0≦y≦3; and −1.5≦z≦0.5; wherein A represents an element of the group consisting of Eu, Gd, Tb, Dy, Ho, and Y; wherein B represents an element of the group consisting of Fe, Ga, Cu, Ni, Mn, and Cr; and wherein said compound further comprises a crystal structure comprising a plurality of layers of corner-shared octahedra, wherein each of said layers is separated by an oxygen-deficient layer, wherein said oxygen-deficient layers comprise tetra cyclic units of corner-shared tetrahedra CoO 4 with an additional oxygen atom.