LAUSR

Abstract The design of active and durable cathodic electrocatalysts with low Pt loading is critical for efficient oxygen reduction reaction. Herein, a general method is reported to prepare monodispersed Pt nanoparticle encapsulated in N-doped hollow carbon sphere with cage-bell structure (Pt@NHCS) by hard-template method. The materials with ultralow Pt content (2.8 wt%) possess typical a thin N-doped carbon layer (∼12 nm) as a shell and monodispersed Pt nanoparticle (∼20 nm) as a core. Due to unique structure and potential synergistic effect from interaction between Pt and nitrogen species, the cage-bell Pt@NHCS shows excellent catalytic activity and methanol-tolerant durability for oxygen reduction reaction. This method is of significant importance for the design of cost-efficiency electrocatalysts with cage-bell structure for excellent oxygen reduction reaction and beyond.