Concave Pt–Cu nanocuboctahedrons with high-index facets and improved electrocatalytic performance†
In this study, concave cuboctahedral Pt–Cu nanoalloys were successfully prepared via an overgrowth process. The retarded reduction rate of Pt and the selective surface-binding of oleylamine and oleic acid were both crucial for the formation of the concave cuboctahedral nanostructures. High-resolution electron microscopy (HRTEM) characterization in combination with the 3D modeling results indicated that the concave nanostructures were enclosed by high-index facets (HIFs). The concave Pt–Cu cuboctahedrons showed significantly enhanced electrochemical activity and improved long-term stability towards methanol oxidation reaction (MOR) compared to the spherical Pt–Cu nanoparticles and pure Pt nanoparticles. The excellent catalytic performance could be primarily attributed to the high density of active sites on the surface, the efficiently modulated electronic structure and the inert chemical nature of Cu.