Supported bimetallic PdAu nanoparticles with superior electrocatalytic activity towards methanol oxidation

Abstract

Monodispersed bimetallic PdAu nanoparticles with controlled composition are prepared by an emulsion-assisted synthetic strategy with ternary metal precursors in the surfactants of oleic acid and oleylamine. The PdAu nanoparticles are loaded on a carbon support, and their electrocatalytic activities are tested for methanol oxidation in alkaline media. The bimetallic PdAu nanoparticles show superior electrocatalytic activities for methanol oxidation compared with the pure Pd nanoparticles prepared by the same method. The most active Pd₃₀Au₇₀ nanoparticles, with significantly low Pd content, even show remarkably higher activities than the commercial Pt/C catalyst. Various characterization techniques such as TEM, XPS and UV-vis are applied to study the nature of the catalysts. It is concluded that the increased activity is dependant on the unique Pd-rich shell and Au-rich core structure of such bimetallic PdAu particles as well as the nature of the Pd species on the catalyst surface.