Activating Single-Atom Ni Site via First-Shell Si Modulation Boosts Oxygen Reduction Reaction.
Fangqing WangYing LiRui ZhangHui LiuYangyang ZhangXuerong ZhengJun ZhangCong ChenShijian ZhengHuolin L XinPublished in: Small (Weinheim an der Bergstrasse, Germany) (2022)
Atomically dispersed nitrogen-coordinated 3d transition-metal site on carbon support (M-NC) are promising alternatives to Pt group metal-based catalysts toward oxygen reduction reaction (ORR). However, despite the excellent activities of most of M-NC catalysts, such as Fe-NC, Co-NC et al., their durability is far from satisfactory due to Fenton reaction. Herein, this work reports a novel Si-doped Ni-NC catalyst (Ni-SiNC) that possesses high activity and excellent stability. X-ray absorption fine structure and aberration-corrected transmission electron microscopy uncover that the single-atom Ni site is coordinated with one Si atom and three N atoms, constructing Ni-Si 1 N 3 moiety. The Ni-SiNC catalyst exhibits a half-wave potential (E 1/2 ) of 0.866 V versus RHE, with a distinguished long-term durability in alkaline media of only 10 mV negative shift in E 1/2 after 35 000 cycles, which is also validated in Zn-air battery. Density functional theory calculations reveal that the Ni-Si 1 N 3 moiety facilitates ORR kinetics through optimizing the adsorption of intermediates.
Keyphrases
- transition metal
- metal organic framework
- room temperature
- density functional theory
- molecular dynamics
- highly efficient
- electron microscopy
- electron transfer
- high resolution
- ionic liquid
- genome wide
- computed tomography
- dna methylation
- mass spectrometry
- molecular dynamics simulations
- risk assessment
- quantum dots
- reduced graphene oxide
- emergency department
- human health
- contrast enhanced
- electronic health record
- climate change