Extremely efficient methanol oxidation reaction performance: A highly active catalyst derived from different Mn2-xOy phases-supported Ag@Ag2WO4

Abstract

Given the drawbacks of Pt-based catalysts, it is necessary to seek out a long-lasting and low-cost catalyst. In summary, we used a deposition-precipitation method to create novel catalysts composed of Ag@Ag2WO4 (20–95%)@Mn3O4 (AgW/Mn), which were thoroughly investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), surface texturing, and high resolution transmission electron microscope-selected area electron diffraction (HRTEM-SAED) techniques. We propose an efficient methanol oxidation reaction (MOR) electrocatalyst made up of 95% AgW/Mn that exhibits a current of 85 mA cm−2 (mass activity of 1685 mA g−1 at 1.5 V) and a long cycle life in 1.0 M KOH+1.0 M CH3OH. This is attributed to the presence of a large number of Mn3+/4+active sites (ratio of 2.5), increased conductivity, and a large number of Ag nanoparticles at the interface, in addition to the ease of charge transfer. According to the findings, the latter active sites boost catalyst stability, whilst AgW enhances reaction kinetics by alleviating CO adsorption for superior oxidation. The performance of the catalysts in view of the porosity, morphology, and structure correlated with the catalysts' MOR activities was thoroughly examined.