The Pt-Cu alloy/C (AC-PtCu-4/C) with uniform nanoparticles and high density of surface defects was synthesized by the microwave-polyol technique following acid-treatment. The AC-PtCu-4/C contained much higher density of surface defects than did the commercial Pt/C. Electrochemical characterization demonstrated that the AC-PtCu-41C exhibited mass activity and surface activity 4.8 and 3.9 times higher than those of Pt/C for ethanol oxidation. Moreover, the AC-PtCu-4/C can enhance the C-C bond cleavage of ethanol to generate CO2 2.47 times more than that of Pt/C under the same conditions, as evidenced by in situ FTIR reflection spectroscopy. (C) 2014 Elsevier Ltd. All rights reserved.