Hollow tungsten carbide/carbon sphere promoted Pt electrocatalyst for efficient methanol oxidation

摘要

The surface carbon thickness and particle size of tungsten carbide (WC) are critical to its synergistic effect on noble metal based electrocatalysts. We report the synthesis of hollow tungsten carbide/carbon sphere composites (HWCSs) with a thinner surface carbon layer and smaller particle size. The polystyrene sphere (PS) as a template and P123 as a surfactant favor the dispersion of carbon and WC precursors, leading to HWCSs with a smaller-sized WC and thinner surface carbon. The above factors in turn favor a stable loading of smaller Pt particles on HWCSs, resulting in excellent electrocatalytic activity (due to the synergistic effect) and stability (due to stronger interaction force between WC and Pt) of Pt/HWCS in electrocatalyzing methanol oxidation in acidic media. The present method is imagined to easily prepare other small-sized carbide particles with a thinner surface carbon layer.