催化作用
碳纤维
三聚氰胺
化学
聚苯胺
氮气
化学工程
活动站点
电化学
无机化学
材料科学
有机化学
聚合物
物理化学
电极
复合材料
工程类
复合数
聚合
作者
Shiva Gupta,Shuai Zhao,Ogechi Ogoke,Ye Lin,Hui Xu,Gang Wu
出处
期刊:Chemsuschem
[Wiley]
日期:2017-01-27
卷期号:10 (4): 774-785
被引量:124
标识
DOI:10.1002/cssc.201601397
摘要
Abstract Structures and morphologies of Fe‐N‐C catalysts are believed to be crucial because of the number of active sites and local bonding structures governing the overall catalyst performance for the oxygen reduction reaction (ORR). However, the knowledge how to rationally design catalysts is still lacking. By combining different nitrogen/carbon precursors, including polyaniline (PANI), dicyandiamide (DCDA), and melamine (MLMN), we aim to tune catalyst morphology and structure to facilitate the ORR. Instead of the commonly studied single precursors, multiple precursors were used during the synthesis; this provides a new opportunity to promote catalyst activity and stability through a likely synergistic effect. The best‐performing Fe‐N‐C catalyst derived from PANI+DCDA is superior to the individual PANI or DCDA‐derived ones. In particular, when compared to the extensively explored PANI‐derived catalysts, the binary precursors have an increased half‐wave potential of 0.83 V and an enhanced electrochemical stability in challenging acidic media, indicating a significantly increased number of active sites and strengthened local bonding structures. Multiple key factors associated with the observed promotion are elucidated, including the optimal pore size distribution, highest electrochemically active surface area, presence of dominant amorphous carbon, and thick graphitic carbon layers with more pyridinic nitrogen edge sites likely bonded with active atomic iron.
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