ATR-SEIRAS for Single-Atom Electrocatalysis

Abstract

Single-atom catalysts (SACs) represent a revolutionary paradigm in heterogeneous catalysis and display exceptional atom utilization efficiency with well-defined active sites. These distinctive characteristics position SACs as pivotal materials for advancing electrochemical energy conversion and storage technologies. The active center atoms are typically anchored by coordination with oxygen (O), nitrogen (N), and other functional groups on the surface of the supports. When precisely anchored onto tailored supports, these isolated active centers offer considerable promise for enhanced catalytic activity and selectivity. Nevertheless, the inherent complexity of the multistep proton-coupled electron transfer processes in electrochemical energy conversion and storage systems presents major challenges for the mechanistic elucidation and rational design of catalytic architectures to optimize reaction kinetics. Recent advancements in in situ/operando characterizations, most notably attenuated total reflection–surface-enhanced infrared absorption spectroscopy (ATR–SEIRAS), have greatly stimulated SACs research. ATR–SEIRAS amplifies the vibrational signal at the interface, enabling real-time tracking of transient interfacial species at submonolayer concentrations. Moreover, it simultaneously captures the dynamic structural evolution of single-atom motifs during the catalytic cycles.