Electrochimica Acta, Vol.212, 277-285, 2016
Dealloyed PtAuCu electrocatalyst to improve the activity and stability towards both oxygen reduction and methanol oxidation reactions
In the present work, we synthesize ternary PtAuCu nanoparticles supported on carbon by a sequent galvanic displacement method and study the relationship between the structure and properties. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) reveal that PtAuCu displays a compressive lattice, and X-ray photoelectron spectroscopy (XPS) also presents an altered electronic environment. After electrochemical dealloying, a rich PtAu skin is exposed on the surface of the PtAuCu. With the changes in the geometric, electronic and surface structure, the PtAuCu electrocatalyst shows an enhancement in ORR and MOR activity, as well as an improvement in their stability. The Pt10Au10Cu64/C catalyst exhibits a Pt mass activity of 0.376 Amg(Pt) (1) at 0.85V for the ORR, which is 2.22 times higher than that of Pt/C, and the current density at 0.8 V for the MOR is 4.43 times higher than that of Pt/C. Furthermore, Pt10Au3Cu44/C exhibits superior stability for the ORR, with a mass activity loss of only 7.25% after 3000 cycles, whereas Pt/C exhibits a 48.82% loss under the same conditions. (C) 2016 Elsevier Ltd. All rights reserved.