Facile preparation of trace-iron doped manganese oxide/N-doped ketjenblack carbon composite for efficient ORR electrocatalyst

摘要

Low-cost and highly efficient catalysts toward oxygen reduction reaction (ORR) are extremely required for the rapid development of Al-air batteries. Herein, novel trace-iron doped manganese oxide/N-doped ketjenblack carbon composites (Fe-MnOx/N-KB) were prepared by a facie and scalable route using cheap, more abundant, and commercially available raw materials (i.e. manganese sulfate, ferrous nitrate, melamine and KB). The proposed route only consisted of one-pot hydrothermal treatment and subsequent a mild calcination process. The high spefic area and synergistic effect from Fe-N-C active sites and Mn3+ greatly boosted the ORR activity. As a result, Fe-MnOx/N-KB showed superior ORR activity in terms of positive half-wave potential (0.78 V) and high limiting current density (5.8 mA/cm(2)), comparable to those of commercial Pt/C (0.82 V, 5.3 mA/cm(2)). Moreover, Fe-MnOx/N-KB exhibited excellent catalytic stability. When used as cathode catalyst in home-made Al-air battery, Fe-MnOx /N-KB showed higher discharge voltage (1.51 V) at constant current density of 50 mA/cm(2) than that of commercial Pt/C (1.46 V). Considering its low cost, high efficiency and scalable preparation, Fe-MnOx/N-KB has great potential to substitute commercial Pt/C for ORR. (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.