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

• Published in: Nano-micro letters Vol. 12; no. 1; pp. 116 - 13
• Main Authors: Jia, Yin, Xiong, Xuya, Wang, Danni, Duan, Xinxuan, Sun, Kai, Li, Yajie, Zheng, Lirong, Lin, Wenfeng, Dong, Mingdong, Zhang, Guoxin, Liu, Wen, Sun, Xiaoming
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.12.2020; Springer Nature B.V; SpringerOpen
• Subjects: Atomic dispersion; Binding; Catalytic activity; Charge density; Charge transfer; Chemical reactions; Computer simulation; Density functional theory; Doping; Electronic structure; Engineering; Iron; Iron–nitrogen moiety; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; Nitrogen atoms; Oxygen reduction; Oxygen reduction reactions; Structural analysis; Substrates; Sulfur doping; X ray absorption; Oxygen reduction; Atomic dispersion; Electronic structure; Iron–nitrogen moiety; Sulfur doping
• ISSN: 2311-6706; 2150-5551; 2150-5551
• DOI: 10.1007/s40820-020-00456-8

Highlights Precisely located S doping of atomic Fe-N 4 in Fe(N 3 )(N–C–S) motif was realized. This S doping renders weakened *OH binding and faster charge transfer on Fe-N 4 . Fe-NSC showed excellent oxygen reduction reaction performance with onset potential ~ 1.09 V and half-wave potential ~ 0.92 V. 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(N 3 )(N–C–S). By enabling precisely localized S doping, the electronic structure of Fe-N 4 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-N 4 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-N x moiety.