Tungsten Carbide Nanofiber Prepared by Electrospinning for Methanol Oxidation Reaction

Tungsten carbide nanofibers for the anode catalyst of direct methanol fuel cells (DMFCs) were prepared from the precursor nanofibers with the diameter around 250 nm using an electrospinning technique. The electrospun nanofibers from the mixture of ammonium metatungstate and polyvinylpyrrolidone were dried and calcined in air at 700 °C to form tungsten oxide nanofibers, and reduced in 20 vol.% CH4/H2 atmosphere at 700 °C for 2 h. Surface morphology and crystalline structure of the prepared nanofibers were investigated using FE-SEM and XRD. The methanol oxidation reaction (MOR) activity of the prepared samples was evaluated by cyclic voltammetry (CV). The FE-SEM and XRD analyses showed that beaded nanofibers of tungsten carbide were successfully obtained. The WC nanofiber electrocatalyst exhibited a MOR activity suggesting it can be a candidate of the catalyst for DMFC. The presence of impurities, carbon and tungsten oxide, which may affect the activity, were detected at the surface.