塔菲尔方程
双功能
过电位
氧气
催化作用
选择性
析氧
水溶液
金属
共价键
化学
无机化学
金属有机骨架
组合化学
有机化学
电化学
吸附
物理化学
电极
作者
Sijia Liu,Minghao Liu,Xuewen Li,Shuai Yang,Qiyang Miao,Qing Xu,Gaofeng Zeng
摘要
Abstract Metal–organic frameworks and covalent organic frameworks have been widely employed in electrochemical catalysis owing to their designable skeletons, controllable porosities, and well‐defined catalytic centers. However, the poor chemical stability and low electron conductivity limited their activity, and single‐functional sites in these frameworks hindered them to show multifunctional roles in catalytic systems. Herein, we have constructed novel metal organic polymers (Co‐HAT‐CN and Ni‐HAT‐CN) with dual catalytic centers (metal–N 4 and metal–N 2 ) to catalyze oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). By using different metal centers, the catalytic activity and selectivity were well‐tuned. Among them, Co‐HAT‐CN catalyzed the ORR in a 4e − pathway, with a half‐wave potential of 0.8 V versus RHE, while the Ni‐HAT‐CN catalyze ORR in a 2e − pathway with H 2 O 2 selectivity over 90%. Moreover, the Co‐HAT‐CN delivered an overpotential of 350 mV at 10 mA cm −2 with a corresponding Tafel slope of 24 mV dec −1 for OER in a 1.0 M KOH aqueous solution. The experimental results revealed that the activities toward ORR were due to the M–N 4 sites in the frameworks, and both M–N 4 and M–N 2 sites contributed to the OER. This work gives us a new platform to construct bifunctional catalysts.
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