The PtAu/C alloy catalyst is firstly synthesized by the co-reduction of both metal precursors under microwave conditions and then heat-treated to enable the migration of Au atoms to the exterior surface of the obtained PtAu/C catalyst. The bulk crystallite structures and the surface Au contents of PtAu/C catalysts are characterized by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The electrocatalytic activity and durability measurements exhibit the superior catalytic performance of PtAu/C catalysts over that of Pt/C catalyst on formic acid electrooxidation. Moreover, the initial and final activity after 3600 s reaction of the heat-treated PtAu/C alloy catalyst is two and five times as high as that of the untreated PtAu/C catalyst. The performance enhancement of the PtAu/C catalysts is discussed in terms of the electronic effect and ensemble effect. (C) 2011 Elsevier Ltd. All rights reserved.