双功能
催化作用
析氧
材料科学
熔盐
锌
解吸
化学工程
碳纤维
纳米技术
电极
化学
电化学
无机化学
有机化学
物理化学
吸附
冶金
复合材料
工程类
复合数
作者
Kun Wang,Zhenjiang Lu,Jing Lei,Zhaoyang Liu,Yizhao Li,Yali Cao
出处
期刊:ACS Nano
[American Chemical Society]
日期:2022-07-26
卷期号:16 (8): 11944-11956
被引量:76
标识
DOI:10.1021/acsnano.2c01748
摘要
Achieving full utilization of active sites and optimization of the electronic structure of metal centers is the key to improving the intrinsic activity of single-atom catalysts (SACs) but still remains a challenge to date. Herein, a versatile molten salt-assisted pyrolysis strategy was developed to construct ultrathin, porous carbon nanosheets supported Co SACs. Molten salts are capable of inducing the formation of a Co single-atom and porous graphene-like carbon, which facilitates full exposure of the active center and simultaneously endows the Co SACs with abundant defective Co-N4 configurations. The reported Co SACs deliver an excellent bifunctional activity and good stability for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Moreover, metal-air batteries (MABs) assembled with the Co SACs as air electrode also deliver excellent performance with high power densities of 160 mW·cm-2, large capacities of 760 mAh·g-1, and superior long-term charge/discharge stability, outperforming those of commercial Pt/C+RuO2. DFT theoretical calculation results show that the defects in the second coordination shell (CS) of Co SACs promote desorption of the OH* intermediate for the ORR and facilitate deprotonation of OH* for the OER, which can serve as the favorable active site for oxygen bifunctional catalysts. Our work provides an efficient strategy for the preparation of SACs with fully exposed active centers and optimized electronic structures.
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