writer：Wenhan Niu, Ligui Li*, Xiaojun Liu, Nan Wang, Ji Liu, Weijia Zhou, Zhenghua Tang, Shaowei Chen*
keywords：nitrogen doped-mesoporous carbon, oxygen reduction reaction, fuel cell, catalyst
source：期刊
specific source：J. Am. Chem. Soc., 2015, 137, 5555.
Issue time：2015年
Thermally removable nanoparticle templates were used for the
fabrication of self-supported N-doped mesoporous carbons with a trace amount of
Fe (Fe-N/C). Experimentally Fe-N/C was prepared by pyrolysis of poly(2-
fluoroaniline) (P2FANI) containing a number of FeO(OH) nanorods that were
prepared by a one-pot hydrothermal synthesis and homogeneously distributed within
the polymer matrix. The FeO(OH) nanocrystals acted as rigid templates to prevent
the collapse of P2FANI during the carbonization process, where a mesoporous
skeleton was formed with a medium surface area of about 400 m2/g. Subsequent
thermal treatments at elevated temperatures led to the decomposition and evaporation
of the FeO(OH) nanocrystals and the formation of mesoporous carbons with the
surface area markedly enhanced to 934.8 m2/g. Electrochemical measurements
revealed that the resulting mesoporous carbons exhibited apparent electrocatalytic
activity for oxygen reduction reactions (ORR), and the one prepared at 800 °C (Fe-
N/C-800) was the best among the series, with a more positive onset potential (+0.98 V vs RHE), higher diffusion-limited
current, higher selectivity (number of electron transfer n > 3.95 at +0.75 V vs RHE), much higher stability, and stronger tolerance
against methanol crossover than commercial Pt/C catalysts in a 0.1 M KOH solution. The remarkable ORR performance was
attributed to the high surface area and sufficient exposure of electrocatalytically active sites that arose primarily from N-doped
carbons with minor contributions from Fe-containing species.