Vacancy Defects Inductive Effect of Asymmetrically Coordinated Single-Atom Fe―N3S1 Active Sites for Robust Electrocatalytic Oxygen Reduction with High Turnover Frequency and Mass Activity

作者：Zhao, Yilin; Chen, Hsiao-Chien; Ma, Xuelu; Li, Jiaye; Yuan, Qing; Zhang, Peng; Wang, Minmin; Li, Junxi; Li, Min; Wang, Shifu; Guo, Han; Hu, Ruanbo; Tu, Kun-Hua; Zhu, Wei; Li, Xuning; Yang, Xuan; Pan, Yuan^*

来源：Advanced Materials, 2024, 36(11): e2308243-e2308243.

DOI：10.1002/adma.202308243

• controllable synthesis
• electrocatalysis
• oxygen reduction reaction
• single-atom catalyst

The development of facile, efficient synthesis method to construct low-cost and high-performance single-atom catalysts (SACs) for oxygen reduction reaction (ORR) is extremely important, yet still challenging. Herein, an atomically dispersed N, S co-doped carbon with abundant vacancy defects (NSC-vd) anchored Fe single atoms (SAs) is reported and a vacancy defects inductive effect is proposed for promoting electrocatalytic ORR. The optimized catalyst featured of stable Fe & horbar;N3S1 active sites exhibits excellent ORR activity with high turnover frequency and mass activity. In situ Raman, attenuated total reflectance surface enhanced infrared absorption spectroscopy reveal the Fe & horbar;N3S1 active sites exhibit different kinetic mechanisms in acidic and alkaline solutions. Operando X-ray absorption spectra reveal the ORR activity of Fe SAs/NSC-vd catalyst in different electrolyte is closely related to the coordination structure. Theoretical calculation reveals the upshifted d band center of Fe & horbar;N3S1 active sites facilitates the adsorption of O-2 and accelerates the kinetics process of *OH reduction. The abundant vacancy defects around the Fe & horbar;N3S1 active sites balance the OOH* formation and *OH reduction, thus synergetically promoting the electrocatalytic ORR process.

• 单位
  中国石油大学（华东）; 华中科技大学; 中国矿业大学（北京）; 重质油国家重点实验室; 中国科学院; 长春大学; 中国科学院大连化学物理研究所; 有机无机复合材料国家重点实验室; 北京化工大学; 催化基础国家重点实验室