双功能
氧还原
氧还原反应
析氧
电催化剂
兴奋剂
化学
双功能催化剂
材料科学
过电位
化学工程
氧气
分解水
电化学
塔菲尔方程
无机化学
催化作用
电极
有机化学
物理化学
光电子学
工程类
作者
Wei Zhang,Keke Mao,Xiao Cheng Zeng
出处
期刊:ACS Sustainable Chemistry & Engineering
[American Chemical Society]
日期:2019-10-14
卷期号:7 (22): 18711-18717
被引量:48
标识
DOI:10.1021/acssuschemeng.9b05393
摘要
Non-platinum-group (NPG) single-metal-atom electrocatalysts with bifunctional catalytic capabilities for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are highly sought for producing sustainable and renewable energy sources. Doping nonmetal atoms next to the active single-metal-atom can be an effective way to further improve the overall catalytic activities. Herein, we report a nonmetal B-doping strategy for enhancing the catalytic activity of the graphene-based single-metal-atom Mn-pyridine-N4-graphene catalysts [named MnN4Bn-G (n = 0–8)] toward ORR and OER. The underlying chemical mechanism for this design is that the B dopant can lower the charge density corresponding to the d-orbital of the Mn atom, thereby weakening the adsorption strength of oxygen intermediates (O/OH/OOH) on the active Mn site, leading to higher ORR electrocatalytic activity. Not only can this doping strategy enhance ORR activity, but it can also retain high OER activity. Our results show that the MnN4B5-G catalyst entails both relatively high onset potential for ORR (Uonset = 0.78 V) and relatively low overpotential for OER (ηover = 0.43 V), rendering it being a compelling oxygen redox bifunctional electrocatalyst. The newly designed single-metal-atom Mn-pyridine-N4-graphene catalysts offer alternative NPG metals and bifunctional catalysts for renewable energy applications.
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