Catalysts for composite cathodes of protonic ceramic fuel cells

Unlike oxygen ion-conducting fuel cells (OCFCs), protonic ceramic fuel cells (PCFCs) generate steam at the cathodes. Many different catalysts have been developed for OCFC anodes; therefore, in this work, potential catalysts for steam-generating cathodes of PCFCs were investigated. The steam generation reaction at the PCFC cathode can be enhanced by the use of suitable cathodic catalysts. PCFCs with composite cathodes comprising (La,Sr)FeO3 and Y-doped Ba(Ce,Zr)O-3 were fabricated by infiltrating small amounts of alkali oxides into the composite as cathodic reaction catalysts. The results obtained from symmetric half-cells demonstrated that lithium oxide catalysts significantly improve the cathodic performance. A plausible mechanism for the enhancement in the cathode reaction is also proposed.