▎ 摘　　要

1,5-diaminonaphthalene and ultrasmall palladium nanoparticles (PdNPs) embedded electrochemically reduced graphene oxide (denoted as ERGO-DAN-Pd) was successfully synthesized and employed as a cathode catalyst for enhanced oxygen reduction reaction (ORR) in direct alkaline fuel cells (DAFCs). The physical properties of ERGO-DAN-Pd were investigated using several instrumental methods. The morphological characterizations demonstrate that the ultrasmall PdNPs were homogeneously dispersed on the ERGO-DAN film. X-ray analysis confirmed the successful covalent functionalization of graphene sheets with DAN. The electrocatalytic activity of ERGO-DAN-Pd towards ORR was excellent compared to other electrodes in 0.1 M KOH electrolyte. Particularly, it showed 1.8 and 2.7 magnitude higher mass activity with large specific activity compared to 20 wt.% Pt/C and nonfunctionalized ERGO/Pd, respectively. Moreover, the reaction kinetic parameters confirmed that the ORR at ERGO-DAN-Pd catalyst was followed by a 4e(-) process with faster electron transfer rate per O-2 with better stability and fuel selectivity than state-of-the-are Pt/C for DAFCs application. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.