Synthesis and Characterization of Three-Dimensionally Ordered Macroporous (3DOM) Tungsten Carbide: Application to Direct Methanol Fuel Cells

Three-dimensionally ordered macroporous tungsten carbide (3DOM WC) with varying pore size was synthesized using the "inverse-opal" method. Poly{methyl methacrylate} (PMMA) colloidal crystal template with sphere diameters ranging from 180 to 490 nm was used. Two synthesis procedures were performed, the first requiring calcination of tungsten impregnated PMMA colloidal template in air followed by carburization in H-2/CH4/N-2 atmosphere. The second procedure involved direct carburization Of the tungsten impregnated template without prior calcination. The effect of Pt-modification of the template prior to carburization on the resulting material composition was also investigated. The material properties were evaluated using Surface and bulk characterization techniques. Finally, cyclic voltammetry was used to investigate the methanol electro-oxidation activity of the 3DOM WC and Pt-modified 3DOM WC in acidic electrochemical environment.