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Edge‐Rich Fe−N 4 Active Sites in Defective Carbon for Oxygen Reduction Catalysis
Author(s) -
Wang Xin,
Jia Yi,
Mao Xin,
Liu Daobin,
He Wenxiang,
Li Jia,
Liu Jianguo,
Yan Xuecheng,
Chen Jun,
Song Li,
Du Aijun,
Yao Xiangdong
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202000966
Subject(s) - catalysis , materials science , redistribution (election) , oxygen reduction reaction , carbon fibers , density functional theory , electrocatalyst , oxygen , active site , nanotechnology , nitrogen , chemical engineering , chemistry , computational chemistry , electrode , organic chemistry , composite material , politics , political science , law , electrochemistry , engineering , composite number
Abstract Controllably constructing nitrogen‐modified divacancies (ND) in carbon substrates to immobilize atomic Fe species and unveiling the advantageous configuration is still challenging, but indispensable for attaining optimal Fe−N−C catalysts for the oxygen reduction reaction (ORR). Herein, a fundamental investigation of unfolding intrinsically superior edge‐ND trapped atomic Fe motifs (e‐ND−Fe) relative to an intact center model (c‐ND−Fe) in ORR electrocatalysis is reported. Density functional theory calculations reveal that local electronic redistribution and bandgap shrinkage for e‐ND−Fe endow it with a lower free‐energy barrier toward direct four‐electron ORR. Inspired by this, a series of atomic Fe catalysts with adjustable ND−Fe coordination are synthesized, which verify that ORR performance highly depends on the concentration of e‐ND−Fe species. Remarkably, the best e‐ND−Fe catalyst delivers a favorable kinetic current density and halfwave potential that can be comparable to benchmark Pt−C under acidic conditions. This work will guide to develop highly active atomic metal catalysts through rational defect engineering.