Electrocatalytic Behavior of Perovskite-Related Cobaltites and Nickelates in Alkaline Media
Dense ceramic anodes of perovskite-type La1-x-ySrxCo1-zAlzO3-δ ( x = 0.45-0.70; y = 0- 0.05; z = 0-0.20) and K2NiF4-type La2Ni1-xMexO4+δ (Me = Co, Cu; x = 0-0.20), synthesized by the glycine-nitrate technique, were assessed for oxygen evolution in alkaline media. The lowest overpotentials are observed for (La0.3Sr0.7)0.97CoO3-δ, which exhibits a significant oxygen deficiency in combination with high conductivity associated with the A-site cation nonstoichiometry compensation mechanism via Co4+ formation. Perovskite-type cobaltite anodes are essentially stable in alkaline solutions, whilst La2NiO4-based electrodes exhibit degradation at the potentials where the oxygen evolution occurs, probably due to the electrochemical oxygen intercalation in the lattice.
Paula Maria Vilarinho
S. K. Poznyak et al., "Electrocatalytic Behavior of Perovskite-Related Cobaltites and Nickelates in Alkaline Media", Materials Science Forum, Vols. 514-516, pp. 1391-1395, 2006