Monodispersed Co in Mesoporous Polyhedrons: Fine-tuning of ZIF-8 Structure with Enhanced Oxygen Reduction Activity
Monodispersed Co in Mesoporous Polyhedrons: Fine-tuning of ZIF-8 Structure with Enhanced Oxygen Reduction Activity
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介孔多面体中的单分散 Co：微调 ZIF-8 结构并增强氧还原活性
DOI：
10.1016/j.electacta.2017.08.091
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发表时间：
2017-10-10
影响因子：
6.6
通讯作者：
Wei, Zidong
中科院分区：
文献类型：
--
作者：
Shah, Syed Shoaib Ahmad;Peng, Lishan;Wei, Zidong
金属有机骨架（MOFs）被认为是一种很有前途的电催化剂。本文报道了一种以Zn/Co-MOFs为骨架的Co-N-C电催化剂的可控合成方法。由于Zn的低沸点，在热解过程中同时发生Zn的消除，导致具有在N-C骨架中均匀分布的Co的非常介孔的组装体。Zn还促进了Co在Zn/Co-MOF中的分散，这有效地阻止了Co在碳化过程中的团聚。结果表明，以Zn/Co-MOF为前驱体，Co含量为22.5%时，合成的Co-N-C催化剂在碱性溶液中具有最好的氧还原活性，其半波电位为0.91Vvs.RHE，电流密度为3.0mA/cm 2，甚至优于商业Pt/C催化剂。高活性和电流密度主要归因于非常良好分散的Co纳米颗粒和介孔性质。(C)2017爱思唯尔有限公司版权所有
Metal organic frameworks (MOFs) have been considered as promising candidates for excellent electrocatalysts. Herein, we report a controllable synthesis of Co-N-C electrocatalysts derived from Zn/Co bimetallic organic frameworks (Zn/Co-MOFs). The elimination of Zn is simultaneously taken place during the pyrolysis due to its low boiling point, resulting in a very mesoporous assembly with homogeneous Co distribution in N-C framework. Zn also facilitates the dispersion of Co in the Zn/Co-MOF, which efficiently hinders the agglomeration of Co during carbonization. The results show that Co-N-C catalysts synthesized from 22.5% Co containing in the Zn/Co-MOF precursor gives the best ORR activity in alkaline solution with its half wave potential of 0.91 V vs. RHE and current density of 3.0 mA/cm(2), which is even better than those of commercial Pt/C catalysts. The high activity and current density are mainly attributed to the extremely well dispersed Co nanoparticles and the mesoporous nature. (C) 2017 Elsevier Ltd. All rights reserved.