Impact of Cu-Pt nanotubes with a high degree of alloying on electro-catalytic activity toward oxygen reduction reaction

摘要

Well-defined copper-platinum (Cu-Pt) nanotubes with a high degree of alloying were synthesized through a galvanic replacement reaction; this reaction utilized aqueous solutions containing H2PtCl6 and copper nanowires, which acted as the sacrificial templates, without other surfactants or organic solvents at room temperature. The size, morphology and alloy composition of the well-alloyed Cu-Pt nanotubes were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD) and inductively coupled plasma (ICP) mass spectrometry. The electrochemical replacement reaction generated a hollow one-dimensional (1D) structure and the high degree of alloying in the as-synthesized products. Compared to a commercial Pt/C catalyst (40 wt.%, E-TEK), the as-synthesized Cu-Pt alloy nanotubes exhibited superior electro-catalytic activity and stability during oxygen reduction reaction in acidic solutions due to their unique hollow 1D structure and the high alloying degree. In addition, the kinetic parameters of the oxygen reduction over the Cu-Pt alloy nanotubes were calculated based on ring-disk electrode, Tafel plot, and electrochemical impedance spectra (EIS) measurements. (C) 2014 Elsevier Ltd. All rights reserved.