Single Cobalt Atoms with Precise N-Coordination as Superior Oxygen Reduction Reaction Catalysts
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- 作者：Peiqun Yin ; Tao Yao ; Prof. Yuen Wu ; Lirong Zheng ; Yue Lin ; Wei Liu ; Huanxin Ju ; Junfa Zhu ; Xun Hong ; Zhaoxiang Deng ; Gang Zhou ; Shiqiang Wei and Prof. Yadong Li
- 刊名：Angewandte Chemie
- 出版年：2016
- 出版时间：August 26, 2016
- 年：2016
- 卷：128
- 期：36
- 页码：10958-10963
- 全文大小：2369K
- ISSN：1521-3757
文摘
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.