▎ 摘　　要

It is of great interest to explore non-precious metal electrocatalysts with high catalytic activity, complete tolerance, and long durability for oxygen reduction reaction (ORR) and then to move the alkaline fuel cell technology closer to commercialization. Here, we fabricated reduced graphene oxide (RGO) supported CoO/MnO2 nanocomposites from Co, Mn-containing layered double hydroxides (Co3Mn-CO3-LDH) by calcination at 550 degrees C under nitrogen atmosphere. Also, we systemically investigated the electrocatalytic performance of CoO/MnO2/RGO composite for ORR in 0.1 M KOH. Because of synergistic effect between CoO and MnO2, the CoO/MnO2/RGO nanocomposite exhibits excellent ORR catalytic activity with a 4-electron transfer pathway, an onset potential of 0.95 V vs. RHE, a half-wave potential of 0.76 V vs. RHE, and cathodic current density of 4.2 mA cm(-2) at 0.5 V vs. RHE at a rotating speed of 1600 rpm, which are comparable with the commercial Pt/C catalyst. Furthermore, the catalyst has complete tolerance to methanol and longer durability compared to the Pt/C catalyst under the investigated conditions. The CoO/MnO2/RGO nanocomposite is one of promising non-precious metal electrocatalysts for alkaline membrane/membraneless fuel cells. (C)2015 Elsevier Ltd. All rights reserved.