Facile synthesis of tungsten carbide-carbon composites for oxygen reduction reaction

Tungsten carbide-carbon composite (XWC-C, where X=10 or 30 represents the tungsten content) supports were prepared by pyrolyzing tungsten-adsorbed poly(4-vinylpyridine)-functionalized carbon. The supports were used to prepare Pt catalysts (Pt/XWC-C) for oxygen reduction reactions (ORR) in alkaline solution. Prepared XWC-C revealed highly dispersed tungsten carbide species composed of WC and W₂C phases. The tungsten carbide species proved to have a positive effect on the dispersion of Pt particles. Compared to the Pt catalyst supported on carbon (Pt/ C), Pt/XWC-C showed higher ORR performance. In addition, the catalytic performance of Pt/XWC-C was enhanced with increasing tungsten carbide content. The highest ORR activity was achieved for the Pt/30WC-C catalyst, which had a 2.9-fold enhanced performance (at 0.8V vs. RHE) compared to that of Pt/C. It is believed that the unique interaction between Pt and the tungsten carbide species was responsible for the enhanced ORR performance of the Pt/XWC-C catalysts.