Electrochemical alcohol oxidation: a comparative study of the behavior of methanol, ethanol, propanol, and butanol on carbon-supported PtSn, PtCu, and Pt nanoparticles

Carbon-supported PtCu and PtSn (both with an atomic ratio of 3:1) nanoparticles were prepared by reducing Pt, Sn, and Cu precursors via refluxing in ethanol. They were characterized using energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM). X-ray diffraction indicated that the lattice parameter of Pt increases with the addition of Sn and decreases with the addition of Cu, indicating that both PtCu and PtSn are solid solutions. EDX analysis revealed that the compositions of these materials are close to their nominal compositions, while TEM showed that both materials presented a homogeneous particle distribution on the carbon support and low particle agglomeration. Electrochemical experiments indicated that all of the materials are electrochemically active with respect to methanol, ethanol, propanol, and butanol oxidation in H2SO4 solution. The electrochemical measurements also showed that PtSn is more active in ethanol oxidation, whereas PtCu is more active in methanol oxidation. Both materials showed similar electrooxidative activities towards propanol and butanol, and they presented higher electrochemical acidities than pure platinum for alcohol oxidation.