Electro-oxidation of methanol on co-deposited Pt-MoOx prepared by cyclic voltammetry with different scanning potential ranges

Pt-MoOx supported on glassy carbon was co-deposited by cyclic voltammetry ( CV). The lower limit of potential was fixed at - 0.25 V ( vs. SCE), whereas the upper limit was adjusted to be 0.0, 0.10, 0.40, 0.60 and 1.0 V. The as-prepared catalysts were characterized by X-ray photoelectron microscopy, scanning electron microscopy and transmission electron microscopy. The results show that Pt-MoOx particles are uniformly dispersed on the substrate and the agglomerated microparticles are composed of numerous nanoparticles with a size of several nanometers. The catalytic capabilities of Pt-MoOx for methanol oxidation were examined by CV and chronoamperometry. Electrochemical measurements demonstrate that the catalytic activities and stabilities of Pt-MoOx prepared in the potential ranges from - 0.25 to both 0.60 and 1.0 V were higher than the others, which may due to the higher active surface area, more appropriate Pt/Mo ratio and more preferred Pt crystallographic orientation.