Metal–Organic‐Framework‐Derived Hybrid Carbon Nanocages as a Bifunctional Electrocatalyst for Oxygen Reduction and Evolution |
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Authors: | Shaohong Liu Zhiyu Wang Si Zhou Fengjiao Yu Mengzhou Yu Chang‐Yang Chiang Wuzong Zhou Jijun Zhao Jieshan Qiu |
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Affiliation: | 1. State Key Lab of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian, China;2. Education Ministry Key Lab of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian, China;3. School of Chemistry, University of St Andrews, UK;4. School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an, China |
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Abstract: | The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are cornerstone reactions for many renewable energy technologies. Developing cheap yet durable substitutes of precious‐metal catalysts, especially the bifunctional electrocatalysts with high activity for both ORR and OER reactions and their streamlined coupling process, are highly desirable to reduce the processing cost and complexity of renewable energy systems. Here, a facile strategy is reported for synthesizing double‐shelled hybrid nanocages with outer shells of Co‐N‐doped graphitic carbon (Co‐NGC) and inner shells of N‐doped microporous carbon (NC) by templating against core–shell metal–organic frameworks. The double‐shelled NC@Co‐NGC nanocages well integrate the high activity of Co‐NGC shells into the robust NC hollow framework with enhanced diffusion kinetics, exhibiting superior electrocatalytic properties to Pt and RuO2 as a bifunctional electrocatalyst for ORR and OER, and hold a promise as efficient air electrode catalysts in Zn–air batteries. First‐principles calculations reveal that the high catalytic activities of Co‐NGC shells are due to the synergistic electron transfer and redistribution between the Co nanoparticles, the graphitic carbon, and the doped N species. Strong yet favorable adsorption of an OOH* intermediate on the high density of uncoordinated hollow‐site C atoms with respect to the Co lattice in the Co‐NGC structure is a vital rate‐determining step to achieve excellent bifunctional electrocatalytic activity. |
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Keywords: | bifunctional electrocatalyst first‐principles calculation hollow nanostructure metal– organic frameworks oxygen electrocatalysis |
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