Monodispersed sub-5.0 nm PtCu nanoalloys as enhanced bifunctional electrocatalysts for oxygen reduction reaction and ethanol oxidation reaction

The development of effective electrocatalysts with enhanced activity and stability for both the anode and the cathode reaction in fuel cells still remains a challenge. Here, we report a one-pot route to prepare monodispersed, uniform sub-5.0 nm PtCu alloy polyhedra with a narrow size distribution. These PtCu alloy polyhedra exhibit enhanced electrocatalytic activity for both cathode and anode reactions as compared to the commercial Pt/C catalyst under alkaline conditions. The specific activity and mass activity on Pt68Cu32 nanoalloys are 15 and 2.8 times that on Pt/C catalyst toward oxygen reduction reaction (ORR), respectively. And the peak current density and mass activity on Pt68Cu32 nanoalloys are 11.8 and 2.12 times that on Pt/C catalyst toward ethanol oxidation reaction (EOR), respectively. Furthermore, the as-synthesized Pt68Cu32 nanoalloys have much higher stability than commercial Pt/C black for both ORR and EOR. These experimental results show an effective approach to the development of monodispersed, sub-5.0 nm PtCu nanoalloys as bifunctional electrocatalysts for both the cathode and the anode reaction in fuel cells.