Progress on X-ray Absorption Spectroscopy for the Characterization of Perovskite-Type Oxide Electrocatalysts

The phases and electronic structures of perovskite oxides can be rationally designed to meet the requirements of different electrochemical reactions. Therefore, perovskite-type oxides as functional materials have attracted considerable research interest in energy conversion and storage systems. Advancing energy devices requires a fundamental and deep understanding of precatalysts and corresponding reaction mechanisms, such as the key intermediates and the real active species under working conditions. X-ray absorption spectroscopy (XAS) supported by synchrotron radiation is a powerful tool used to capture the electronic structures and local environments of electrocatalysts. In this review, recent advances regarding the application of XAS for the characterization of perovskite-type oxide electrocatalysts are summarized. Special attention is given to the recently developed advanced operando XAS techniques to uncover the reaction mechanism on the surface. The collected information reveals not only the dynamic nature of perovskite oxides and structural and chemical changes during the reactions but also the important role of perovskite-type oxides as promising candidates for electrocatalysts. Finally, emerging opportunities and some current challenges facing the development of high-performance perovskite oxides and perspectives on future techniques are discussed.