Spatial construction of ultrasmall Pt-decorated 3D spinel oxide-modified N-doped graphene nanoarchitectures as high-efficiency methanol oxidation electrocatalysts

Direct methanol fuel cell technology recently becomes the focus of both academic and engineering circles, which stimulates the exploitation and utilization of advanced electrode catalysts with high activity and long lifespan. Herein, we demonstrate a robust bottom-up approach to the spatial construction of three-dimensional (3D) spinel manganese-cobalt oxide-modified N-doped graphene nanoarchitectures decorated with ultrasmall Pt nanoparticles (Pt/MnCo2O4-NG) via a controllable self-assembly process. The incorporation of MnCo2O4 nanocrystals provides abundant hydroxyl sources to promote the oxidative removal of CO-like byproducts on Pt sites, while the existence of 3D porous N-doped graphene networks facilitates the transportation of both ions and electrons in the hybrid system, thus giving rise to remarkable synergetic coupling effects during the methanol oxidation process. Consequently, the optimized Pt/MnCo2O4-NG nanoarchitecture expresses exceptional electrocatalytic properties with a large electrochemically active surface area of 99.5 m(2)g(-1), a high mass activity of 1508.3 mAmg(-1), strong toxicity resistance and reliable long-term durability, which have obvious competitive advantages over those of conventional Pt/carbon black, Pt/carbon nanotube, Pt/graphene, and Pt/N-doped graphene catalysts with the same Pt usage.