Well-dispersed Fe nanoparticles exposed within N-doped mesoporous carbon nanofibers (Fe-NMCNF) are synthesized using electrospinning and H-2-activation. Their morphologies, crystal structures, chemical bonding states, and electrochemical performance are demonstrated at three calcination temperatures (700, 800, and 900 degrees C) during H-2-activation. Fe-NMCNF calcined at 800 degrees C had a high specific surface area of 467.6 m(2) g(-1), total pore volume of 0.88 cm(3) g(-1), large average pore size of 7.5 nm, and large mesopore volume fraction of 79.1%. In particular, the Fe-NMCNF sample calcined at 800 degrees C exhibits both excellent catalytic activity for oxygen reduction reaction and superb long-term stability compared to commercial Pt/C in acid electrolyte of 0.1 M HClO4. The performance improvement results from the combined effect of the well-dispersed Fe nanoparticles exposed within N-doped mesoporous CNFs and the uniform morphology of mesoporous CNFs. (C) 2016 Elsevier B.V. All rights reserved.