Functionalized carbon support with sulfonated polymer for direct methanol fuel cells

Recently electrodes for direct methanol fuel cell (DMFC) have been developed for getting high fuel cell performances by controlling composition of catalysts and sulfonated polymers, developing catalyst particles, modifying carbon supports, etc. The electrodes in DMFCs are porous layers, which are composed of catalyst, which is black or carbon supported, and sulfonated polymers in a blended form. In the present study, carbon support for catalysts was functionalized to play dual roles of a mass transport and a catalyst support. The functionalized carbon support was characterized and compared with pristine one by thermal and spectroscopic analysis, and loading of platinum (Pt) catalysts on modified support was performed by gas reduction. The electrodes with Pt on functionalized carbon support were fabricated, though the conventional electrodes were prepared with sulfonated polymer and Pt catalysts. Membrane electrode assembly with Pt catalyst on functionalized support showed a higher DMFC performance of 30 mW cm⁻² at 50 °C without using additional sulfonated polymer. Integration of electrode components in one body has another advantage of easier and simpler process in preparing electrodes for DMFCs. Improved DMFC performance of the electrode containing functionalized carbon was be attributed to a better mass transport which maximize the catalytic activities.