In this study, the electrochemical activity of Pt(50)Au(50)/C toward oxygen reduction reaction has been promoted by the manipulation of their surface condition through CeO(2) addition and N(2) heat treatment synergistically. Pt(50)Au(50)/C with CeO(2) additions (PtAuCe) were prepared by the DP process and then further treated at 520-620 K under N(2). The surface segregation profile of the PtAuCe alloys and surface-activity correlation has been elucidated systematically by use of the surface analysis and electrochemical characterization. It is observed that the inherent surface segregation of Au of Pt-Au systems at high temperatures based on the thermodynamic models has been changed due to the CeO(2) modification, and accordingly in the PtAuCe catalysts, CeO(2)-induced Pt surface segregation and surface reconstruction takes place. As a result, the variations in surface compositions affect the ORR activity of the Pt-Au catalysts, and the enhancement of Pt or Au surface composition causes the promotion or deterioration in ORR activity for various heat-treated catalysts, respectively
