电催化剂
材料科学
合金
钴
碳纤维
氮气
氢
铱
芯(光纤)
化学工程
催化作用
电化学
无机化学
兴奋剂
冶金
物理化学
复合数
有机化学
化学
电极
复合材料
光电子学
工程类
作者
Peng Jiang,Jitang Chen,Changlai Wang,Yang Kang,Shipeng Gong,Shuai Liu,Zhiyu Lin,Mengsi Li,Guoliang Xia,Yang Yang,Jianwei Su,Qianwang Chen
标识
DOI:10.1002/adma.201705324
摘要
Abstract Graphene, a 2D material consisting of a single layer of sp 2 ‐hybridized carbon, exhibits inert activity as an electrocatalyst, while the incorporation of heteroatoms (such as N) into the framework can tune its electronic properties. Because of the different electronegativity between N and C atoms, electrons will transfer from C to N in N‐doped graphene nanosheets, changing inert C atoms adjacent to the N‐dopants into active sites. Notwithstanding the achieved progress, its intrinsic activity in acidic media is still far from Pt/C. Here, a facile annealing strategy is adopted for Ir‐doped metal‐organic frameworks to synthesize IrCo nanoalloys encapsulated in N‐doped graphene layers. The highly active electrocatalyst, with remarkably reduced Ir loading (1.56 wt%), achieves an ultralow Tafel slope of 23 mV dec −1 and an overpotential of only 24 mV at a current density of 10 mA cm −2 in 0.5 m sulfuric acid solution. Such superior performance is even superior to the noble‐metal catalyst Pt. Surface structural and computational studies reveal that the superior behavior originates from the decreased Δ G H* for HER induced by the electrons transferred from the alloy core to the graphene layers, which is beneficial for enhancing CH binding.
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