Synthesis of ordered mesoporous carbon/tungsten carbides as a replacement of platinum-based electrocatalyst for methanol oxidation

摘要

The mesoporous material ordered mesoporous carbon/tungsten carbide (OMC/WC) was prepared and used as electrocatalyst for methanol electro-oxidation. WC embedded OMCs was synthesized through carbothermal reactions with a blow of argon and hydrogen by employing ammonium metatungstate as a precursor. In this method, because OMC acted both as the support and the carbon sources, not only the surface area of materials is enlarged, but also the generation of deposit carbon which covers the active sites can be effectively avoided. The characterization, which carried out by X-ray diffraction, Transmission electron microscopy and N_2 adsorption-desorption measurement showed a homogeneous distribution of WC throughout the surface of the mesoporous carbon and the surface area of OMC/WCs was up to 344 m~2/g. Electro-catalytic properties and mechanism of methanol oxidation on the OMC/WCs electrode has been investigated using cyclic voltammetry and in situ FTIR technique. The results showed that there was only one characteristic methanol oxidation peak during the whole potential scan on the OMC/WCs electrode surface, it also showed an improved CO tolerance of the WC surface. It proved that tungsten carbide had good electro-catalytic property close to that of the Pt-based materials for methanol oxidation and provided a new idea for developing electrode materials in the future.