title: Single Cobalt Atoms with Precise N-Coordination as Superior Oxygen Reduction Reaction Catalysts.
abstract: A new strategy for achieving stable Co single atoms (SAs) on nitrogen-doped porous carbon with high metal loading over 4 wt % is reported. The strategy is based on a pyrolysis process of predesigned bimetallic Zn/Co metal-organic frameworks, during which Co can be reduced by carbonization of the organic linker and Zn is selectively evaporated away at high temperatures above 800 °C. The spherical aberration correction electron microscopy and extended X-ray absorption fine structure measurements both confirm the atomic dispersion of Co atoms stabilized by as-generated N-doped porous carbon. Surprisingly, the obtained Co-Nx single sites exhibit superior ORR performance with a half-wave potential (0.881 V) that is more positive than commercial Pt/C (0.811 V) and most reported non-precious metal catalysts. Durability tests revealed that the Co single atoms exhibit outstanding chemical stability during electrocatalysis and thermal stability that resists sintering at 900 °C. Our findings open up a new routine for general and practical synthesis of a variety of materials bearing single atoms, which could facilitate new discoveries at the atomic scale in condensed materials.
authors.affiliation: Department of Chemistry and Center of Advanced Nanocatalysis, (CAN-USTC)University of Science and Technology of China, Hefei, Anhui, 230026, China.|Department of Chemistry and Collaborative Innovation Center for Nanomaterial Science and Engineering, Tsinghua University, Beijing, 100084, China.
authors.forename: Peiqun
authors.initials: P
authors.lastname: Yin
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui Province, 230026, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yao
authors.affiliation: Department of Chemistry and Center of Advanced Nanocatalysis, (CAN-USTC)University of Science and Technology of China, Hefei, Anhui, 230026, China. yuenwu@ustc.edu.cn.|Department of Chemistry and Collaborative Innovation Center for Nanomaterial Science and Engineering, Tsinghua University, Beijing, 100084, China. yuenwu@ustc.edu.cn.
authors.forename: Yuen
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Institute of High Energy Physics, Beijing, 100029, China.
authors.forename: Lirong
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui Province, 230026, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui Province, 230026, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui Province, 230026, China.
authors.forename: Huanxin
authors.initials: H
authors.lastname: Ju
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui Province, 230026, China.
authors.forename: Junfa
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Chemistry and Center of Advanced Nanocatalysis, (CAN-USTC)University of Science and Technology of China, Hefei, Anhui, 230026, China.|Department of Chemistry and Collaborative Innovation Center for Nanomaterial Science and Engineering, Tsinghua University, Beijing, 100084, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Hong
authors.forename: Zhaoxiang
authors.initials: Z
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui Province, 230026, China.
authors.forename: Shiqiang
authors.initials: S
authors.lastname: Wei
authors.affiliation: Department of Chemistry and Center of Advanced Nanocatalysis, (CAN-USTC)University of Science and Technology of China, Hefei, Anhui, 230026, China. ydli@mail.tsinghua.edu.cn.|Department of Chemistry and Collaborative Innovation Center for Nanomaterial Science and Engineering, Tsinghua University, Beijing, 100084, China. ydli@mail.tsinghua.edu.cn.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Li
keywords: coordination control; metal single atoms; metal-organic frameworks; oxygen reduction reaction