One-step synthesis of reduced graphene oxide-supported PtCo nanoalloys with enhanced electrocatalytic activity for methanol oxidation

Direct methanol fuel cells (DMFCs) have recently become the research hotspot, due to their high energy-conversion efficiency, low operating temperature, and low exhaust emission. In this study, PtCo nanoalloys supported on reduced graphene oxide (RGO) were successfully synthesized via a one-step reduction method, carried out by coreduction of PtCl6 (2-), Co2+ and graphene oxide (GO) in ethylene glycol. Fourier-transform infrared spectra, X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy techniques were used to study microstructure, composition, particle size, and morphology, respectively. The results show that highly dispersed PtCo nanoalloys with average sizes of ca. 2.4 nm are dispersed on the surfaces of RGO sheets. The catalytic performances of the PtCo/RGO, Pt/RGO, and Pt/C catalysts toward methanol oxidation were studied, which indicates that PtCo/RGO nanoalloys show higher catalytic performance and stability than Pt/RGO and Pt/C catalysts. Furthermore, the PtCo/RGO catalyst exhibits improved CO-tolerance ability due to the addition of Co.