Composition-Tunable PtCu Alloy Nanowires and Electrocatalytic Synergy for Methanol Oxidation Reaction

Abstract

The ability to impart Pt-based catalysts with high catalytic activity and low cost is essential for advancing fuel cell technologies. This report describes the synthesis of composition-tunable PtCu alloy nanowires (NWs) of ultrathin diameters (ca. 1 nm) to create synergistic catalytic sites along the nanowire surfaces. The bimetallic NWs exhibit composition-tunable fcc-type alloy phase. The electrocatalytic properties of the PtCu alloy NWs for methanol oxidation reaction were shown to display an intriguing composition-dependent catalytic synergy. The maximum mass activity for Pt32Cu68 NWs was about 2 times higher than that of Pt NWs. It also exhibited the highest stability and tolerance to CO poisoning. The enhanced activity and stability were attributed to a bifunctional synergy whereby the alloyed Cu atoms in the Pt lattice provides CO-maneuvering sites for reducing the poisoning effect of CO intermediate species on the active surface sites of the NWs.