Improving Pt utilization is of fundamental importance for many significant processes in energy conversion, which is strongly dependent on the surface structure of used catalysts. Based on the traditional Pt-on-Au system which has been proved to be an ideal nanostructure for improving the catalytic activity and stability of Pt, and the recent follow-up studies on this system, we introduce here a new strategy for fabricating Pt surface with high-index facets over the Pt-on-Au system. To achieve this goal, we elaborately designed and fabricated a unique zigzag PtAu alloy nanosurface on Au nano-pentagrams (PtAu/Au NPs) through epitaxial growth of Pt along the high-index facets on the presynthesized Au nano-pentagrams. Owing to the surface electronic interaction between Au and Pt and the exposed high-index facets from the unique morphology of zigzag PtAu alloy nanosurface, the asprepared PtAu/Au NPs exhibited excellent electrocatalytic performance toward ethanol oxidation reaction (EOR) in alkaline condition. The specific activity (8.3 mA cm(-2)) and mass activity (4.4 A mg(-1)) obtained from PtAu/Au NPs are about 5.2 and 5.5 times, respectively, higher than those from commercial Pt/C for EOR. (C) 2017 Elsevier Ltd. All rights reserved.