▎ 摘　　要

Ultrafine and uniformly dispersed bimetallic Pt-Ni nanoparticles (NPs) have been immobilized on novel 3-dimensional N-doped graphene networks (NGNs) by a facile wet chemical reduction method. NGNs were obtained by 3-dimensional assembly of graphene layers with simultaneous nitrogen doping via crosslinking of graphene oxide (GO) with melamine formaldehyde resin (MFR) under hydrothermal conditions followed by carbonization. Surprisingly, NGN-supported Pt0.5Ni0.5 NPs exhibit extremely high catalytic activity for the dehydrogenation of hydrazine hydrate, achieving 100% H-2 selectivity with the highest turnover frequency (TOF) of 943 h(-1) at 303 K reported thus far. The small size and synergistic effects are responsible for the superior catalytic activity.