Through synthesizing a series of carbon supported ternary PtAuCu nanoparticle catalysts with the varied Cu content followed by subsequently electro-chemical activation treatment, highly active Pt-Au-rich nanoparticle catalysts have successfully been acquired in the present paper. The as-synthesized and activated catalysts were characterized using X-ray diffraction (XRD), transmission electron spectroscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and chronoamperometry (CA). The results show that the electrochemical activation process has a strongly interrelationship with the compositional ratio between Pt/Au and Cu. The higher the Cu content is in the precursor, the lower the residual buried-underneath Cu atoms retain after the activation. Among the catalysts, the activated Pt10Au10Cu80/C exhibits the best catalytic performance for the electro-oxidation of commonly-targeted small organic molecule fuels including formic acid, methanol and ethanol in acid circumstance. The catalytic activity enhancement mechanism based upon the electrochemical activation process as well as induced possible synergistic effect from elemental interactions was also discussed. (C) 2015 Elsevier Ltd. All rights reserved.