材料科学
氧气
碳纤维
氧还原反应
还原(数学)
氧还原
化学工程
纳米技术
物理化学
化学
电化学
电极
有机化学
复合材料
复合数
几何学
数学
工程类
作者
Lingbo Zong,Fenghong Lu,Wenjun Zhang,Kaicai Fan,Xin Chen,Bernt Johannessen,Dongchen Qi,Nicholas Bedford,Mark R. Warren,Carlo U. Segre,Porun Liu,Lei Wang,Huijun Zhao
标识
DOI:10.1016/j.ensm.2022.04.016
摘要
Owing to their ultimate mass-catalytic activity, simple active site configuration and readily tunable electronic structures, transition-metal single atoms (SAs) on carbon support have emerged as a new category of electrocatalysts for oxygen reduction reaction (ORR). Here, we exemplify the use of atomically dispersed Mn with N, O heteroatoms-coordinated Mn sites to enhance alkaline ORR performance. A combined sol-gel/carbonization approach is developed to controllably anchor Mn-SAs onto graphitic carbon nanosheets via a hybridized N, O coordination configuration of Mn-(N-C2)2(O-C2)2 (denoted as [email protected]). The obtained [email protected] exhibits superior alkaline ORR electrocatalytic activity with a half-wave potential of 0.88 V vs. RHE in 0.1 M KOH. The rechargeable Zn–air battery assembled using [email protected] air cathode can readily attain a high power density of 177 mW cm−2 with a narrow voltage gap of 0.76 V at 5 mA cm−2. Density functional theory calculations unveil that altering the coordination environment of Mn-SAs from N-coordinated Mn-(N-C2)4 to N-/O-coordinated Mn-(N-C2)2(O-C2)2 alters the d-band electronic structures and regulates the binding strength of ORR intermediates on Mn-SA sites to dramatically reduce the energy barrier and enhance ORR activity. The exemplified hybridization coordination approach in this work would be applicable to alter the electronic structures of other transition-metal SAs for ORR and other reactions.
科研通智能强力驱动
Strongly Powered by AbleSci AI