Single Phase PtAg Bimetallic Alloy Nanoparticles Highly Dispersed on Reduced Graphene Oxide for Electrocatalytic Application of Methanol Oxidation Reaction

As renewable materials having high specific energy and environmentally safe characteristics, direct methanol fuel cells (DMFCs) have attracted huge interest to develop promising power devices with different strategies. Herein, single phase PtAg bimetallic alloy highly dispersed electrocatalyst on reduced graphene oxide (rGO) by a facile wet chemical co-reduction method. Different kinds of catalysts have been prepared with varying atomic ratios of Pt and Ag. Structural and morphological characterizations of as-synthesized catalysts are performed by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) and X-ray photoelectron diffraction (XPS) analysis. It is found that single phase PtAg bimetallic nanoparticles are successfully synthesized that are uniformly dispersed and attached on rGO sheets. High-angle annular dark-field scaning TEM (HAADF-STEM) and energy dispersive X-ray spectroscopic (EDX) analysis have also been performed, which confirm the single phase synthesis of uniformly dispersed PtAg bimetallic catalyst. MOR activity and durability has significantly increased by mutual coordination of both the metals in bimetallic nanocatalyst in comparison with the monometallic commercial Pt/C catalyst. The results can be attributed to the collective effects of the PtAg nanoparticles and the enhanced electron transfer characteristics of rGO sheets. (C) 2016 Elsevier Ltd. All rights reserved.