Atomically Dispersed Fe-N4 Modified with Precisely Located S for Highly Efficient Oxygen Reduction

Nano-Micro Letters

Lirong Zheng¹  Wenfeng Lin²  Mingdong Dong³  Xuya Xiong³  Danni Wang⁴  Guoxin Zhang⁴  Yajie Li⁵  Wen Liu⁵  Xiaoming Sun⁵  Xinxuan Duan⁵  Yin Jia⁵  Kai Sun⁵ 

[1] Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences;Department of Chemical Engineering, Loughborough University;Interdisciplinary Nanoscience Center (INANO), Sino-Danish Center for Education and Research (SDC), Aarhus University;Shandong University of Science and Technology, Electrical Engineering and Automation;State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology;

关键词: Atomic dispersion;    Iron–nitrogen moiety;    Electronic structure;    Sulfur doping;    Oxygen reduction;   

DOI  :  10.1007/s40820-020-00456-8

来源: DOAJ

【 摘 要 】

Abstract Immobilizing metal atoms by multiple nitrogen atoms has triggered exceptional catalytic activity toward many critical electrochemical reactions due to their merits of highly unsaturated coordination and strong metal-substrate interaction. Herein, atomically dispersed Fe-NC material with precise sulfur modification to Fe periphery (termed as Fe-NSC) was synthesized, X-ray absorption near edge structure analysis confirmed the central Fe atom being stabilized in a specific configuration of Fe(N3)(N–C–S). By enabling precisely localized S doping, the electronic structure of Fe-N4 moiety could be mediated, leading to the beneficial adjustment of absorption/desorption properties of reactant/intermediate on Fe center. Density functional theory simulation suggested that more negative charge density would be localized over Fe-N4 moiety after S doping, allowing weakened binding capability to *OH intermediates and faster charge transfer from Fe center to O species. Electrochemical measurements revealed that the Fe-NSC sample exhibited significantly enhanced oxygen reduction reaction performance compared to the S-free Fe-NC material (termed as Fe-NC), showing an excellent onset potential of 1.09 V and half-wave potential of 0.92 V in 0.1 M KOH. Our work may enlighten relevant studies regarding to accessing improvement on the catalytic performance of atomically dispersed M-NC materials by managing precisely tuned local environments of M-Nx moiety.

【 授权许可】

Unknown