Resolving Dynamic Behavior of Electrocatalysts via Advances of Operando X-Ray Absorption Spectroscopies: Potential Artifacts and Practical Guidelines

Abstract

Although numerous techniques are developed to enable real-time understanding of dynamic interactions at the solid–liquid interface during electrochemical reactions, further progress in the development of these methods over the last several decades has faced challenges. With the rapid development of high-brilliance synchrotron sources, operando X-ray spectroscopies have become increasingly popular for revealing interfacial features and catalytic mechanisms in electrocatalysis. Nevertheless, the resulting spectra are highly sensitive to factors such as X-ray radiation, reaction environment, and acquisition procedures, all of which may potentially introduce artifacts that are often overlooked, leading to misinterpretations of electrocatalytic behaviors. In this perspective, several emerging hard X-ray spectroscopies used in electrocatalysis research are reviewed, highlighting their electronic transition processes, detection modes, and functional complementarity. Significantly, based on a case study of operando X-ray absorption spectroscopy at various beamlines, potential artifacts generated by X-ray irradiation are systematically investigated through photon-flux density-, dose-, and time-dependent studies of typical copper electrocatalysts. Accordingly, a practical protocol for conducting reliable X-ray spectroscopic measurements in operando electrocatalytic studies to minimize potential artifacts that can affect the resulting X-ray spectra, thereby ensuring accurate interpretation and a deeper understanding of interfacial interactions and electrocatalytic mechanisms, is established.