Kanglei Pang, Chang Long, Jiayin Yuan
The catalyst-electrolyte interface (CEI) fundamentally plays a vital role in governing the activity and kinetics of electrochemical reactions relevant to chemical manufacturing, energy devices, and other applications. However, state-of-the-art observations of the CEI reveal structural evolution during reactions, leading to challenges in elucidating the true structure-performance relationships and thereby hindering the rational design of high-performance catalytic systems for emerging applications. This perspective highlights advances in operando X-ray spectroscopies that enable a mechanistic understanding of dynamic CEI across electronic-, atomic-, and nanoscale levels. We highlight the challenges and opportunities regarding X-ray spectroscopies for understanding, predictive design, and durability engineering of the CEI in heterogeneous electrocatalysis.