Dynamic active sites behind Cu-based electrocatalysts: Original or restructuring-induced catalytic activity

Abstract

Structural dynamics in electrocatalysts under operating conditions, including restructuring, dissolution/redeposition, and single-site-to-cluster transitions, are commonly observed phenomena but are often poorly understood. Cu-based catalysts, entailing single-atom catalysts (SACs), molecular catalysts, and nanostructured catalysts, have shown promise in key electrochemical reactions such as CO₂ reduction, NO₃⁻ reduction, and C–N coupling and are particularly prone to structural changes as they carry out these reactions. While the fully accurate prediction of restructuring-induced activity remains an ongoing challenge, this review offers a comprehensive analysis of Cu-based catalysts, focusing on the dynamic behavior of Cu active sites, which can undergo structural changes during electrocatalytic reactions, thereby impacting catalytic performance and selectivity. Taking insights from advanced in situ/operando techniques, such as X-ray absorption spectroscopy (XAS), this study identifies and evaluates a set of Cu-based electrocatalysts under electrocatalytic reduction reactions and distinguishes the dynamic active sites between original and restructuring-induced forms.