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Ammonia Thermal Treatment toward Topological Defects in Porous Carbon for Enhanced Carbon Dioxide Electroreduction
Author(s) -
Dong Yan,
Zhang Qiuju,
Tian Ziqi,
Li Boran,
Yan Wensheng,
Wang Shuo,
Jiang Kemin,
Su Jianwei,
Oloman Colin W.,
Gyenge Elod L.,
Ge Ruixiang,
Lu Zhiyi,
Ji Xiulei,
Chen Liang
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202001300
Subject(s) - materials science , density functional theory , carbon fibers , electrochemical reduction of carbon dioxide , redistribution (election) , dopant , catalysis , topology (electrical circuits) , porosity , chemical engineering , chemical physics , faraday efficiency , thermal treatment , nanotechnology , electrochemistry , computational chemistry , chemistry , doping , organic chemistry , electrode , composite material , optoelectronics , carbon monoxide , law , composite number , political science , combinatorics , politics , engineering , mathematics
Topological defects, with an asymmetric local electronic redistribution, are expected to locally tune the intrinsic catalytic activity of carbon materials. However, it is still challenging to deliberately create high‐density homogeneous topological defects in carbon networks due to the high formation energy. Toward this end, an efficient NH 3 thermal‐treatment strategy is presented for thoroughly removing pyrrolic‐N and pyridinic‐N dopants from N‐enriched porous carbon particles, to create high‐density topological defects. The resultant topological defects are systematically investigated by near‐edge X‐ray absorption fine structure measurements and local density of states analysis, and the defect formation mechanism is revealed by reactive molecular dynamics simulations. Notably, the as‐prepared porous carbon materials possess an enhanced electrocatalytic CO 2 reduction performance, yielding a current density of 2.84 mA cm −2 with Faradaic efficiency of 95.2% for CO generation. Such a result is among the best performances reported for metal‐free CO 2 reduction electrocatalysts. Density functional theory calculations suggest that the edge pentagonal sites are the dominating active centers with the lowest free energy (Δ G ) for CO 2 reduction. This work not only presents deep insights for the defect engineering of carbon‐based materials but also improves the understanding of electrocatalytic CO 2 reduction on carbon defects.