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Corresponding Author

Chun-an MA(science@zjut.edu.cn)

Abstract

At present, one of the major hurdles for commercialization of system with direct methanol fuel cell (DMFC) is still the requirement of a significant amount of platinum (Pt) catalyst to achieve an acceptable power density. Pt and Pt-based metals are expensive due to limited supplies. In order to find the catalyst alternative to the Pt metal, we selected tungsten carbide (WC) and its composites as the study object. We synthesized WC with carbon materials as the suitable support to modify the electronic structure and to increase the specific surface area of WC. In this study, tungsten carbide/carbon (WC/C) was prepared by block copolymer template synthesis method using resorcinol-formaldehyde resin (RF) as a carbon source. These novel, ordered, mesoporous WC/C nanocomposites showed high surface areas (414 m2·g-1) and appropriate pore-size (about 38 nm). The experimental conditions including the stirring time of phenol formaldehyde polymer and carburization temperature were systematically studied. The results indicated that the composites had optimized crystal phases and ordered arrangement of pores structures. The characteristics of WC/C composites were determined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Brunauer-Emmet-Teller gas adsorption. The Pt nanoparticles were uniformly distributed on WC/C and a new electrocatalyst of Pt-WC/C was prepared by microwave-assisted (MW) polyol method. The electro-catalytic performances of the as-prepared Pt-WC/C and commercial carbon-supported Pt (Pt/C) toward methanol oxidation were compared by cyclic voltammetry and chronoamperometry. It was found that the Pt-WC/C exhibited higher catalytic activity for methanol oxidation than commercial Pt/C catalyst. Especially, the Pt-WC/C achieved the long-term stability which was attributed to the high dispersion of WC with smaller sizes on the surface of carbon.

Graphical Abstract

Keywords

tungsten carbide, block copolymer, methanol oxidation, electrocatalyst, template method

Publication Date

2015-08-28

Online Available Date

2015-08-28

Revised Date

2015-05-25

Received Date

2015-04-15

References

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