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Negative Pressure Pyrolysis Induced Highly Accessible Single Sites Dispersed on 3D Graphene Frameworks for Enhanced Oxygen Reduction
Author(s) -
Zhou Huang,
Yang Tong,
Kou Zongkui,
Shen Lei,
Zhao Yafei,
Wang Zhiyuan,
Wang Xiaoqian,
Yang Zhenkun,
Du Junyi,
Xu Jie,
Chen Min,
Tian Lin,
Guo Wenxin,
Wang Qiuping,
Lv Hongwei,
Chen Wenxing,
Hong Xun,
Luo Jun,
He Daping,
Wu Yuen
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202009700
Subject(s) - overpotential , graphene , pyrolysis , materials science , carbon fibers , cleavage (geology) , mesoporous material , metal organic framework , oxygen reduction , metal , chemical engineering , oxygen , transmission electron microscopy , nanotechnology , catalysis , chemistry , composite material , electrode , organic chemistry , adsorption , fracture (geology) , composite number , engineering , metallurgy , electrochemistry
Herein, we report a negative pressure pyrolysis to access dense single metal sites (Co, Fe, Ni etc.) with high accessibility dispersed on three‐dimensional (3D) graphene frameworks (GFs), during which the differential pressure between inside and outside of metal–organic frameworks (MOFs) promotes the cleavage of the derived carbon layers and gradual expansion of mesopores. In situ transmission electron microscopy and Brunauer–Emmett–Teller tests reveal that the formed 3D GFs possess an enhanced mesoporosity and external surface area, which greatly favor the mass transport and utilization of metal sites. This contributes to an excellent oxygen reduction reaction (ORR) activity (half‐wave potential of 0.901 V vs. RHE). Theoretical calculations verify that selective carbon cleavage near Co centers can efficiently lower the overall ORR theoretical overpotential in comparison with intact atomic configuration.