Cathodic polarization of strontium-doped lanthanum ferrite in proton-conducting solid oxide fuel cell

The cathodic polarization of strontium-doped lanthanum ferrite, La 1− x Sr x FeO 3−α, was studied in the hydrogen–oxygen fuel cell using proton-conducting SrCe 0.95Yb 0.05O 3−α as an electrolyte. The overpotential of La 0.7Sr 0.3FeO 3−α cathode was smaller than those of other perovskite-type oxides such as La 0.7Sr 0.3MnO 3−α and La 0.7Sr 0.3CoO 3−α, and platinum at 773–973 K. The best cathodic performance was obtained for La 0.7Sr 0.3FeO 3−α heat-treated at 1173 K. The cathode resistance of La 0.7Sr 0.3FeO 3−α was independent of pO 2 while that of sputtered platinum was proportional to pO 2 −1/4.