Peiqun Yin1,2, Tao Yao3, Yuen Wu1,2, Lirong Zheng4, Yue Lin3, Wei Liu3, Huanxin Ju3, Junfa Zhu3, Xun Hong1,2, Zhaoxiang Deng, Gang Zhou5, Shiqiang Wei3, Yadong Li1,2
1Department of Chemistry and Center of Advanced Nanocatalysis (CAN-USTC)University of Science and Technology of China Hefei Anhui 230026 China
2Department of Chemistry and Collaborative Innovation Center for Nanomaterial Science and Engineering, Tsinghua University, Beijing 100084, China
3Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei Anhui Province 230026 China
4Institute of High Energy Physics Beijing 100029 China
5State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
Tóm tắt
AbstractA 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.
