Monodisperse Cu@PtCu nanocrystals and their conversion into hollow-PtCu nanostructures for methanol oxidation

Abstract

In this study, we report a facile one-pot strategy towards highly monodisperse and hexagonal shaped bimetallic Pt–Cu nanocrystals with a pure Cu-core coated with a PtCu alloy shell (designated as Cu@PtCu nanocrystals). The Cu@PtCu nanocrystals can be deposited on commercial carbon black evenly and the Cu core in the Cu@PtCu nanocrystal can be selectively etched. The resulting hollow-PtCu/C is a high-performance electro-catalyst for methanol oxidation. It has been demonstrated that the hollow-PtCu/C had a methanol oxidation specific activity of 1.77 mA cm⁻² and a mass activity of 0.889 A mg_Pt⁻¹, which are far better than those of solid-PtCu/C and commercial Pt/C catalysts. The hollow-PtCu/C also exhibited better tolerance to poisoning species and is more stable under electro-oxidation conditions. The results reported herein suggest that superior catalysts can be developed by engineering the structure/composition of the nanocrystals.