Promoting the Segregation of Sr2+ from the Perovskite Oxygen Catalyst La0.5Sr0.5Co3−δ via Quenching

Abstract

The microstructure of the surface plays a crucial role in determining the efficacy of high-temperature oxygen catalysts. In this study, we conducted a comprehensive investigation into the impact of quenching on the crystal structure, surface topology, and oxygen-catalyzing capabilities of La0.5Sr0.5CoO3−δ (LSC). Our findings revealed that quenching can notably promote the segregation of SrO on the surface of the classical perovskite-based high-temperature oxygen catalyst LSC. This phenomenon can be attributed to the introduction of a significant number of chemical defects within the LSC bulk during the catalytic process, thereby endowing it with sufficient stress and electrostatic forces to drive Sr2+ toward the catalyst’s surface. This finding could simplify the removal of inert segregation layers on the surface of perovskite-based high-temperature oxygen catalysts. The electrochemical analysis results demonstrate that the quenching process can markedly improve the long-term operational stability of LSC but can bring a decrease in catalytic activity.