title: Mesoporous N-doped carbons prepared with thermally removable nanoparticle templates: an efficient electrocatalyst for oxygen reduction reaction.
abstract: 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 m(2)/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 m(2)/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.
authors: †New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
authors: Wenhan
authors: W
authors: Niu
authors: †New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
authors: Ligui
authors: L
authors: Li
authors: †New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
authors: Xiaojun
authors: X
authors: Liu
authors: †New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
authors: Nan
authors: N
authors: Wang
authors: †New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
authors: Ji
authors: J
authors: Liu
authors: †New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
authors: Weijia
authors: W
authors: Zhou
authors: †New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
authors: Zhenghua
authors: Z
authors: Tang
authors: †New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.|‡Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States.
authors: Shaowei
authors: S
authors: Chen