Large-scale Synthesis of Porous Pt Nanospheres/Three-dimensional Graphene Hybrid Materials as a Highly Active and Stable Electrocatalyst for Oxygen Reduction Reaction

In order to facilitate widespread commercialization of proton-exchange membrane fuel cells (PEMFCs), the synthesis of advanced catalysts toward oxygen reduction reaction with high activity and stability is essential. Here, we report the synthesis of strongly coupled porous Pt nanospheres /three-dimensional graphene (P-Pt @3DG) hybrid materials through a facile strategy. The P-Pt @3DG displays an excellent oxygen reduction reaction (ORR) performance with the mass activity of 0.542 A/mg(Pt) and specific activity of 0.976 mA/cm(2) at 0.9 V vs. RHE, respectively, which are 4.0- and 3.7- times higher than those of commercial Pt/C catalysts. More importantly, high stability with only 5.35 % loss after 10,000 cycles is achieved. The superior performance of P-Pt @3DG is mainly attributed to the open structure of porous Pt spheres, which exposes the internal Pt atoms with an ultrahigh Pt utilization. Moreover, the 3D graphenes possess an open and interconnected porous structure and allow efficient charge and mass transfer. Besides, this synthetic method is suitable for large scale production, which is highly applicable to the commercialization of PEMFCs.