Synthesis of highly active and stable Au–PtCu core–shell nanoparticles for oxygen reduction reaction

Abstract

Au–PtCu core–shell nanoparticles were successfully synthesized via galvanic replacement of Cu by Pt on hollow Au nano-spheres. Characterizations of the nanoparticles were conducted by X-ray diffraction (XRD), transmission electron microscopy (TEM), and electrochemical measurements. Results indicate 2–2.5 times higher specific activity and mass activity of the Au–PtCu catalysts than commercial Pt black and Pt/C in oxygen reduction reaction (ORR), measured in a rotating disk electrode system. Besides, thinner PtCu coating (25 nm thick, deposition time of 20 min) on the hollow Au nano-spheres demonstrated a pronounced CO oxidation peak shift (by 0.13 V) and long-term durability probably due to the unique core–shell structure and strong electronic coupling between the Au core and the PtCu shell.