Preparation of Highly Crystalline Graphitic Nanocarbon for the Electro-Oxidation of Methanol

Highly crystalline graphitic nanocarbons (GNC) have been prepared by the wet-air treatment of hydrothermally-derived graphitic porous carbon. The materials were characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and electrochemical methods. The experimental results revealed that the treatment temperature has a significant effect on the morphology and degree of graphitic crystallinity. When GNC was treated at 450 degrees C under a wet-air atmosphere, the product (GNC-450) consisted of aggregates of silkworm-shaped carbon nanoparticles with enhanced graphitic characteristics. GNC-450 was evaluated as a catalyst support in the electro-oxidation of methanol. The Pt/GNC-450 catalyst contained smaller Pt particles and had a higher electrochemically active surface area than a commercial carbon black-supported Pt catalyst. In the electro-oxidation of methanol, the Pt/GNC-450 catalyst showed the highest performance among the Pt catalysts examined in this study. The superior catalytic performance appears to be closely related to the enhanced graphitic characteristics with highly dispersed Pt nanoparticles on the graphitic layers, which have a positive effect on the electrochemical performance.