Reversibly Adapting Configuration in Atomic Catalysts Enables Efficient Oxygen Electroreduction
Hui‐Ying Tan, Sheng‐Chih Lin, Jiali Wang, Jui-Hsien Chen, Chia-Jui Chang, Cheng‐Hung Hou, Jing‐Jong Shyue, Tsung‐Rong Kuo, Hao Ming Chen
Abstract
Single-atom catalysts (SACs) featuring M–N–C moieties have garnered significant attention as efficient electrocatalysts for the oxygen reduction reaction (ORR). However, the role of the dynamic M–N configuration of SACs induced by the derived frameworks under applied ORR potentials remains poorly understood. Herein, we conduct a comprehensive investigation using multiple operando techniques to assess the dynamic configurations of Cu SACs under various microstructural interface (MSI) regulations by anchoring atomic Cu on g-C 3 N 4 and zeolitic imidazolate framework (ZIF) substrates. Cu SACs supported on g-C 3 N 4 exhibit symmetric Cu–N configurations characterized by a reversibly adaptive nature under operational conditions, which leads to their excellent ORR catalytic activity. In contrast, the Cu–N configuration in ZIF-derived Cu SACs undergoes irreversible structural changes during the ORR process, in which the elongated Cu–N pair is unstable and breaks during the ORR, acting as a competing reaction against the ORR and resulting in high overpotential requirements. Crucially, operando time-resolved X-ray absorption spectroscopy (TR-XAS) and Raman results unequivocally reveal the reversibly adapting properties of the local Cu–N configuration in atomic Cu-anchored g-C 3 N 4, which have been overlooked in numerous literatures. All findings provide valuable insights into the potential-driven characteristics of atomic electrocatalysts during target reactions and offer a systematic approach to study atomic electrocatalysts and their corresponding catalytic behaviors.