Abstract: A cathode for oxygen reduction in a fuel cell is formed from a host matrix including at least one transition metal element which is structurally modified by the incorporation of at least one modifier element to enhance its catalytic properties. The catalytic body is based on a disordered non-equilibrium material designed to have a high density of catalytically active sites, resistance to poisoning and long operating life. Modifier elements, such as La, Al, K, Cs, Na, Li, C, and O structurally modify the local chemical environments of a host matrix including one or more transition elements such as Mn, Co and Ni to form the catalytic materials of the cathode. The improved, low overvoltage, catalytic materials of the cathode of the present invention increase operating efficiencies of fuel cells employing such cathodes. The catalytic materials can be deposited as a layer on the surface of a porous electrode substrate to form a gas diffusion cathode or can be formed as a gas diffusion electrode.