Composite cathode La0.4Sr0.4TiO3-[delta]- Ce0.8Sm0.2O2-[delta] impregnated with Ni for high-temperature steam electrolysis

Abstract

Composite Ni–SDC (Samaria doped Ceria) cathodes are able to operate in strong reducing atmospheres for steam electrolysis, and composite cathodes based on redox-stable La0.4Sr0.4TiO3 (LSTO) have demonstrated promising performances without the reducing gas flow. However, the electro-catalytic activity of cathodes based on LSTO is insufficient for the efficient electrochemical reduction of steam or carbon oxide. In this work, catalytic-active Ni nanoparticles were loaded on a La0.4Sr0.4TiO3−δ–Ce0.8Sm0.2O2−δ cathode (Ni-loaded LSTO–SDC) via an impregnation method to improve the electrode performances for direct steam electrolysis. The synergetic effect of catalytically-active Ni nanoparticles and the redox-stable LSTO–SDC skeleton contributed to the improved performances and the excellent stability of the cathode for direct steam electrolysis. The current efficiency with a Ni-loaded cathode was enhanced by 3% and 17% compared to the values with a bare LSTO–SDC cathode under 2.0 V of applied voltage at 800 °C with a flow of 3% H2O/5% H2/Ar and 3% H2O/Ar to cathodes, respectively.