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- Title
Atomically Dispersed Fe-N<sub>4</sub> Modified with Precisely Located S for Highly Efficient Oxygen Reduction.
- 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
- Abstract
Highlights: Precisely located S doping of atomic Fe-N4 in Fe(N3)(N–C–S) motif was realized. This S doping renders weakened *OH binding and faster charge transfer on Fe-N4. 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(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.
- Subjects
X-ray absorption near edge structure; OXYGEN reduction; MOIETIES (Chemistry); CHARGE transfer
- Publication
Nano-Micro Letters, 2020, Vol 12, Issue 1, pN.PAG
- ISSN
2311-6706
- Publication type
Article
- DOI
10.1007/s40820-020-00456-8