Facile synthesis of PVP-assisted PtRu/RGO nanocomposites with high electrocatalytic performance for methanol oxidation

Abstract

In this paper, we report a facile approach for the synthesis of polyvinylpyrrolidone (PVP)-stabilized PtRu/RGO nanocomposites (PtRu/RGO/PVP) by the one-pot method. The structure, morphology and composition of the as-prepared catalysts were characterized by Raman, transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX), respectively. It was found that PVP plays an important role in controlling the size of PtRu nanoparticles (NPs) as well as their dispersion stability. TEM images show that as-prepared PtRu NPs with a mean particle size of about 3.09 nm are uniformly dispersed on the RGO surface in the presence of PVP. The electrocatalytic properties of the as-prepared catalysts were evaluated by cyclic voltammetry (CV) and chronoamperometry (CA). Compared to PtRu/RGO and PtRu/PVP catalysts, our PtRu/RGO/PVP hybrids exhibited enhanced electrocatalytic activity and stability for the methanol oxidation reaction. Moreover, our multicomposites also showed higher electrocatalytic performance than the commercial PtRu/C catalysts. The PtRu/RGO/PVP nanostructures with an optimized molar ratio of Pt/Ru (1 : 1) displayed 1.96 times greater stability than the commercial PtRu/C nanospecies. These findings indicated that PtRu/RGO catalysts show a promising future of potential applications in direct methanol fuel cells with the assistance of PVP stabilized.