▎ 摘　　要

Platinum nanoparticles anchored N-doped graphene (Pt/NG) catalysts are synthesized using a thermal annealing-potentiodynamic electrodeposition approach with melamine, graphene oxide, and PtCl62- as precursors. SEM, TEM, XRD, and XPS measurements indicate the relatively uniform and good dispersal of Pt nanoparticles on NG nanosheets. Compared to control catalysts of Pt nanoparticles loaded onto glassy carbon, undoped graphene and g-C3N4, the Pt/NG(1-1) catalyst (with a nominal mass ratio of melamine/graphene oxide of 1:1) shows the highest electrocatalytic activity towards the oxidation of ammonia among a series of Pt/NG catalysts. The mass activity of Pt/NG(1-1) catalyst is nearly 5.1times as high as that of Pt/glassy carbon. The excellent electrochemical performance of Pt/NG catalysts is attributed mainly to the considerable extent of pyridinic N and graphitic N-doping in the graphene network, which improves the dispersion state of Pt nanoparticles on the NG support, resulting in an apparent enhancement in mass activity.