One-pot synthesis of efficient reduced graphene oxide supported binary Pt-Pd alloy nanoparticles as superior electro-catalyst and its electro-catalytic performance toward methanol electro-oxidation reaction in direct methanol fuel cell

Abstract

The development of the clean synthesis of efficient bimetallic Pt-Pd alloy nanoparticles supported reduced graphene oxide (RGO) catalyst (RGO/Pt-Pd) through a facile, rapid, surfactant–free and novel one-pot process of chemical reduction-assisted hydrothermal reaction using formic acid as reducing agent have been introduced. The structural, elemental composition analysis and surface morphology of the as-prepared catalysts were extensively characterized by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, energy dispersive x-ray spectroscopy (EDX), high resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM), respectively. The electrochemical properties, catalytic activity and long-term stability performance of the RGO/Pt-Pd nanocomposite catalyst were employed by cyclic voltammogram and chronoamperometry. Furthermore, owing to the synergetic effects of Pt and Pd nanoparticles, the unique structure of Pt-Pd alloy nanoparticles and enhanced electron transfer by RGO, the as-synthesized RGO/Pt-Pd nanocomposite catalyst has demonstrated the enlarged electrochemical surface area (ECSA) (ECSA = 0.91 cm2), remarkably higher electro-catalytic activity (If = 59.6 mA/cm2) and enhanced stability as compared to RGO/Pt (If = 23.32 mA/cm2, ECSA = 0.18 cm2) and RGO/Pd (If = 8.65 mA/cm2, ECSA = 0.11 cm2) nanocomposite catalysts toward methanol oxidation reaction (MOR). This superior catalytic activity of the as-prepared RGO/Pt-Pd nanocomposite catalyst with facile and simple preparation approach is promising a great opportunity for the development of direct methanol fuel cell.