▎ 摘　　要

The oxygen reduction reaction (ORR) has been studied on graphene-supported electrocatalysts in alkaline media. Uniformly dispersed Pd nanoparticles with a mean diameter of ca. 1.8 nm can be successfully obtained on graphene sheets (GNSs) through chemical synthesis, even at a high metal loading of 60 wt.%. The ORR activity of these catalysts was investigated in a 0.1 M NaOH solution, and the kinetic parameters were determined by the rotating disk electrode (RDE) technique. The GNS-supported Pd catalyst (Pd/GNS) shows significantly high catalytic activity for the ORR. For comparison, the GNS-supported Pt catalyst (Pt/GNS) was also synthesized and investigated under the same experimental conditions. (C) 2010 Elsevier B.V. All rights reserved.