Monodisperse and self-assembled Pt-Cu nanoparticles as an efficient electrocatalyst for the methanol oxidation reaction

Abstract

Monodisperse alloyed PtCu nanoparticles (NPs) have been synthesized via a facile one-pot hydrothermal method. In addition, this is the first time to obtain self-assembled NPs as a hexagonal array with six-fold symmetry in the PtCu NP system. In our synthesis, oleylamine (OAM) is essential for the self-assembly of uniform PtCu NPs. These PtCu spheres have a diameter of 4.78 ± 0.28 nm with a Pt-rich skin and are evaluated as a catalyst for the methanol oxidation reaction. The activity of the PtCu nanoparticles is 34.81 mA cm⁻², while that of the PtCu/C catalysts is 24.6 mA cm⁻², which is about 6.216 times and 4.4 times higher than that of the Pt/C catalyst (5.6 mA cm⁻²). Our studies provide a simple approach to synthesize monodisperse PtCu NPs with Pt-rich skin, making it possible to develop highly active catalysts for methanol oxidation.