MOF‐Based Metal‐Doping‐Induced Synthesis of Hierarchical Porous CuN/C Oxygen Reduction Electrocatalysts for Zn–Air Batteries |
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| Authors: | Qingxue Lai Junjie Zhu Yingxuan Zhao Yanyu Liang Jianping He Junhong Chen |
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| Affiliation: | 1. Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, P. R. China;2. Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing, P. R. China;3. Department of Mechanical Engineering, University of Wisconsin‐Milwaukee, Milwaukee, WI, USA |
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| Abstract: | A transition‐metal–nitrogen/carbon (TM–N/C, TM = Fe, Co, Ni, etc.) system is a popular, nonprecious‐metal oxygen reduction reaction (ORR) electrocatalyst for fuel cell and metal–air battery applications. However, there remains a lack of comprehensive understanding about the ORR electrocatalytic mechanism on these catalysts, especially the roles of different forms of metal species on electrocatalytic performance. Here, a novel Cu?N/C ORR electrocatalyst with a hybrid Cu coordination site is successfully fabricated with a simple but efficient metal–organic‐framework‐based, metal‐doping‐induced synthesis strategy. By directly pyrolyzing Cu‐doped zeolitic‐imidazolate‐framework‐8 polyhedrons, the obtained Cu?N/C catalyst can achieve a high specific surface area of 1182 m2 g?1 with a refined hierarchical porous structure and a high surface N content of 11.05 at%. Moreover, regulating the Cu loading can efficiently tune the states of Cu(II) and Cu0, resulting in the successful construction of a highly active hybrid coordination site of N?Cu(II)?Cu0 in derived Cu?N/C catalysts. As a result, the optimized 25% Cu?N/C catalyst possesses a high ORR activity and stability in 0.1 m KOH solution, as well as excellent performance and stability in a Zn–air battery. |
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| Keywords: | Cu N/C catalysts hybrid coordination sites metal– organic frameworks oxygen reduction Zn– air batteries |
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