▎ 摘　　要

Downsizing noble metal nanoparticles, such as Pt, is an essential goal for many catalytic reactions. A non-noble metal sacrificial approach was used to immobilize monodispersed Pt nanoparticles (NPs) with a mean size of 1.2 nm on reduced graphene oxide (RGO). ZnO co-precipitated with Pt NPs and subsequently sacrificed by acid etching impedes the diffusion of Pt atoms onto the primary Pt particles and also their aggregation during the reduction of precursors. The resulting ultrafine Pt nanoparticles exhibit high activity (a turnover frequency of 284 min(-1) at 298 K) in the hydrolytic dehydrogenation of ammonia borane. The non-noble metal sacrificial approach is demonstrated as a general approach to synthesize well-dispersed noble metal NPs for catalysis.