Catalysis of the electrochemical processes on solid oxide fuel cell cathodes

Three methods of lowering the activation energy of the oxygen reduction reaction at solid oxide fuel cell (SOFC) cathodes are reported: (i) addition of highly dispersed noble metals (less than or equal to 0.1 mg/cm(2)) at the La0.84Sr0.16MnO3 cathode/yttria stabilized zirconia (YSZ) electrolyte interface; (ii) partial substitution of manganese by cobalt in La0.79Sr0.16MnO3 cathodes, and (iii) combination of (i) and (ii). In the presence of palladium, the apparent activation energy, E(2), of the oxygen reduction reaction is decreased from 2.2 eV (La0.84Sr0.16MnO3 without catalyst) to 1.4 eV. A similar effect is observed, when manganese is substituted by 20 mol% Co (La0.79Sr0.16Mn0.80Co0.20O3), where E(a) approximate to 0.9 eV is obtained. In the presence of palladium, with the substitution of manganese by cobalt (method (iii)), no further improvement is achieved.