Tungsten carbide on directly grown multiwalled carbon nanotube as a co-catalyst for methanol oxidation
Multiwalled carbon nanotubes (MWCNT) were grown directly on the surface of graphite rod by using CVD process and then modified with tungsten carbide by carbothermal hydrogen carbonization technique. Then, platinum nanoparticles were deposited on the MWCNTs by means of electrodeposition technique. Catalyst materials were characterized by electron microscopy, X-ray photoelectron spectroscopy and three electrode electrochemical measurements. Catalysts supported on the directly grown MWCNTs exhibit notably better electrocatalytic performance towards methanol oxidation compared to the commercial Pt/C catalyst. Modification of MWCNTs with tungsten carbide was shown to further increase the catalyst performance. It is believed that the superior performance of catalysts prepared on the MWCNTs as catalyst support results mostly from the superior electrical contact and unique spatial configuration of the directly grown MWCNTs, while the positive effect of the tungsten carbide co-catalyst is mostly attributed to its improved resistance towards poisoning with the reaction intermediates produced during the methanol oxidation.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Tungsten carbide was synthesized on directly grown MWCNTs as co-catalyst. ► Electrocatalytic performance of the catalysts was studied for methanol oxidation. ► Unique spatial configuration of directly grown MWCNTs was substantially effective. ► Modification of MWCNTs with tungsten carbide enhances the catalyst performance.
Journal: Applied Catalysis B: Environmental - Volume 127, 30 October 2012, Pages 265–272