Effect of surface decoration on the electrochemical performance of La0.43Ca0.37Ti0.94Ni0.06O3-δ perovskite electrodes for solid oxide cells

Solid oxide cells (SOCs) are efficient energy conversion and storage devices. The development of fuel electrodes with high electrochemical activity is very important for the SOCs with high efficiency, power output and durability. In this work, the La 0.43 Ca 0.37 Ti 0.94 Ni 0.06 O 3- δ (LCTN) perovskite-type fuel electrode was successfully decorated with CeO x , FeO x , CoO x and ZnO x nanoparticles (NPs) (donated as LCTN-X, X = Ce, Fe, Co, Zn) by a simple hydrothermal method. Results show that the LCTN-X electrodes are characterized by the large in situ exsolved Ni NPs (35.3 ± 8.7 nm) and a uniform coverage of decorated metal oxide NPs with much smaller sizes: 6.8 ± 3.0 nm for LCTN-Ce, 6.6 ± 2.0 nm for LCTN-Fe, 6.9 ± 2.7 nm for LCTN-Co, and 6.7 ± 1.8 nm for LCTN-Zn after being reduced in H 2 at 800 °C for 2 h. The as-decorated LCTN-X fuel electrodes exhibit better electrochemical activities for CO 2 electrolysis and H 2 oxidation than the pristine LCTN electrode with only in situ exsolved Ni NPs. Microstructure and phase analysis reveals that the enhanced electrochemical performance is mainly due to the decorated metal oxide NPs with increased reactive sites and oxygen vacancy concentrations in the LCTN-X electrodes. The present work demonstrates that the hydrothermal-decoration strategy can be applied in the modification of perovskite-type fuel electrode surface to further enhance the SOC performance.