Synthesis of Truncated-Octahedral Pt-Pd Nanocrystals Supported on Carbon Black as a Highly Efficient Catalyst for Methanol Oxidation

A novel PtPd/C nanocrystals catalyst with truncated-octahedral structure has been successfully prepared by ethylene glycol reduction to induce anisotropic growth in an isotropic medium by adding a small amount of Fe3+ species. Its structure, composition, and morphology are characterized by X-ray diffraction, transmission electron microscopy, and scanning transmission electron microscopy-energy dispersive spectroscopy elemental maps, respectively. The electrochemical measurements demonstrate that the highly dispersed and uniform PtPd/C nanocrystals have excellent poisoning tolerance, significantly higher electrocatalytic activity and durability for the methanol oxidation, as compared to solid solution PtPd/C and Pt/C catalysts. This may be ascribed to the stepped atoms and dangling bonds, which served as active sites for breaking chemical bonds during oxidation-reduction reaction; the high density of preferred crystal planes of (111) facets greatly enhanced the oxidation of poisonous residues during reaction.