Preparation of Pt/mesoporous carbon (MC) electrode catalyst and its reactivity toward oxygen reduction

Highly structurally controllable mesoporous carbon (MC) support was synthesized through the self-organization of surfactants and carbon precursors, followed by carbonization. Then, Pt catalysts were successfully deposited on MC, in order to create a model of an ideal triple phase boundary in such a nano-space. The resulting Pt/MC catalysts showed better oxygen reduction reactivity with the existence of Nafion® than without that. Handling of ionomers is a key to develop an ideal triple phase boundary within the pores of MC. Depending on the solvent where Nafion® was diluted, the reactivity toward oxygen reduction was different. Due to its hydrophobic pores of MC, Nafion® diluted by more hydrophobic solvent was able to access to the pores easily. As a result, Pt inside the mesopores was efficiently used. Furthermore, by changing a Pt precursor, oxygen reduction current started to increase at more positive potential, indicating the enhanced activity.