电合成
催化作用
氨生产
可逆氢电极
电化学
电催化剂
选择性
产量(工程)
氮气
无机化学
氨
活动站点
材料科学
过渡金属
化学工程
化学
电极
工作电极
物理化学
冶金
有机化学
工程类
作者
Shreya Mukherjee,Xiaoxuan Yang,Weitao Shan,Widitha Samarakoon,Stavros Karakalos,David A. Cullen,Karren L. More,Maoyu Wang,Zhenxing Feng,Guofeng Wang,Gang Wu
出处
期刊:Small methods
[Wiley]
日期:2020-02-05
卷期号:4 (6): 1900821-1900821
被引量:138
标识
DOI:10.1002/smtd.201900821
摘要
Ammonia (NH3) electrosynthesis gains significant attention as NH3 is essentially important for fertilizer production and fuel utilization. However, electrochemical nitrogen reduction reaction (NRR) remains a great challenge because of low activity and poor selectivity. Herein, a new class of atomically dispersed Ni site electrocatalyst is reported, which exhibits the optimal NH3 yield of 115 µg cm−2 h−1 at –0.8 V versus reversible hydrogen electrode (RHE) under neutral conditions. High faradic efficiency of 21 ± 1.9% is achieved at -0.2 V versus RHE under alkaline conditions, although the ammonia yield is lower. The Ni sites are stabilized with nitrogen, which is verified by advanced X-ray absorption spectroscopy and electron microscopy. Density functional theory calculations provide insightful understanding on the possible structure of active sites, relevant reaction pathways, and confirm that the Ni-N3 sites are responsible for the experimentally observed activity and selectivity. Extensive controls strongly suggest that the atomically dispersed NiN3 site-rich catalyst provides more intrinsically active sites than those in N-doped carbon, instead of possible environmental contamination. This work further indicates that single-metal site catalysts with optimal nitrogen coordination is very promising for NRR and indeed improves the scaling relationship of transition metals.
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