Electrocatalytic methanol oxidation by Au nanoparticles decorated nickel tungstate/oxide nanocomplexes

Abstract

The methanol oxidation reaction (MOR) serves as a critical determinant of the energy conversion efficiency within direct methanol fuel cells (DMFC). Consequently, the development of cost-effective and efficient electrocatalysts is paramount for enhancing energy conversion efficiency associated with MOR. The nanomaterials with diverse metal atomic molar ratio of (Ni:W) were synthesized via hydrothermal method for the immobilization of Au nanoparticles (Au NPs) onto the sample surface. The crystal structure of nanocomposites was confirmed through X-ray diffraction (XRD), and transmission electron microscopy (TEM) images depicted a specific surface topography. The catalytic performance of the synthesized catalysts in the MOR was assessed through electrochemical analysis. Notably, catalyst with the Ni:W atomic ratio of 2:1, displayed superior electrocatalytic performance when compared to catalysts possessing other different metal ratios. Moreover, chronoamperometry tests conducted over 7200 s and Tafel slope analysis demonstrated the enduring activity and strong resistance to toxicity of the synthesized catalysts. These results highlight the potential of nickel-tungstate bimetallic oxide as an exceptionally efficient catalyst in the field of electrocatalysis.