Tan, Hui-YingHui-YingTanLin, Sheng-ChihSheng-ChihLinWang, JialiJialiWangChen, Jui-HsienJui-HsienChenChang, Chia-JuiChia-JuiChangHou, Cheng-HungCheng-HungHouShyue, Jing-JongJing-JongShyueKuo, Tsung-RongTsung-RongKuoHAO MING CHEN2024-01-152024-01-152023-12-1300027863https://scholars.lib.ntu.edu.tw/handle/123456789/638489Single-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-C3N4 and zeolitic imidazolate framework (ZIF) substrates. Cu SACs supported on g-C3N4 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-C3N4, 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.en[SDGs]SDG7journal article10.1021/jacs.3c10707380406692-s2.0-85179615291https://api.elsevier.com/content/abstract/scopus_id/85179615291