Fe Isolated Single Atoms on S, N Codoped Carbon by Copolymer Pyrolysis Strategy for Highly Efficient Oxygen Reduction Reaction.
Heteroatom-doped Fe-NC catalyst has emerged as one of the most promising candidates to replace noble metal-based catalysts for highly efficient oxygen reduction reaction (ORR). However, delicate controls over their structure parameters to optimize the catalytic efficiency and molecular-level understandings of the catalytic mechanism are still challenging. Herein, a novel pyrrole-thiophene copolymer pyrolysis strategy to synthesize Fe-isolated single atoms on sulfur and nitrogen-codoped carbon (Fe-ISA/SNC) with controllable S, N doping is rationally designed. The catalytic efficiency of Fe-ISA/SNC shows a volcano-type curve with the increase of sulfur doping. The optimized Fe-ISA/SNC exhibits a half-wave potential of 0.896 V (vs reversible hydrogen electrode (RHE)), which is more positive than those of Fe-isolated single atoms on nitrogen codoped carbon (Fe-ISA/NC, 0.839 V), commercial Pt/C (0.841 V), and most reported nonprecious metal catalysts. Fe-ISA/SNC is methanol tolerable and shows negligible activity decay in alkaline condition during 15 000 voltage cycles. X-ray absorption fine structure analysis and density functional theory calculations reveal that the incorporated sulfur engineers the charges on N atoms surrounding the Fe reactive center. The enriched charge facilitates the rate-limiting reductive release of OH* and therefore improved the overall ORR efficiency.
['Li|Qiheng|Q|', 'Chen|Wenxing|W|', 'Xiao|Hai|H|', 'Gong|Yue|Y|', 'Li|Zhi|Z|', 'Zheng|Lirong|L|', 'Zheng|Xusheng|X|', 'Yan|Wensheng|W|', 'Cheong|Weng-Chon|WC|', 'Shen|Rongan|R|', 'Fu|Ninghua|N|', 'Gu|Lin|L|', 'Zhuang|Zhongbin|Z|', 'Chen|Chen|C|', 'Wang|Dingsheng|D|', 'Peng|Qing|Q|', 'Li|Jun|J|', 'Li|Yadong|Y|http://orcid.org/0000-0003-1544-1127']
copolymer pyrolysis oxygen reduction reaction Fe-isolated single atoms sulfur-nitrogen codoped carbon