화학공학소재연구정보센터
International Journal of Hydrogen Energy, Vol.43, No.33, 16230-16239, 2018
Metallic iron doped vitamin B12/C as efficient nonprecious metal catalysts for oxygen reduction reaction
The development of efficient nonprecious metal catalysts for oxygen reduction reaction (ORR) is crucial but challenging. Herein, one simple and effective strategy is developed to synthesize bimetallic nitrogen-doped carbon catalysts by pyrolyzing Fe-doped Vitamin B12 (VB12) supported carbon black (Fe-VB12/C). A typical Fe-20-VB12/C catalyst with a nominal iron content of 20 wt% pyrolyzed at 700 degrees C exhibits remarkably ORR activity in alkaline medium (half-wave potential of 0.88 V, 10 mV positive than that of commercial Pt/C), high selectivity (electron transfer number > 3.93), excellent stability (only 6 mV negative shift of half-wave potential after 5000 potential cycles) and good methanol-tolerance. The superior ORR activity of the composite is mainly attributed to the improved mesoporous structure and co-existence of abundant Fe-N-x and Co-N-x active sites. Meanwhile, the metallic Fe are necessary for the improved ORR activity by means of the interaction of metallic Fe with neighboring active sites. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.