| 초록 |
PEMFC operating at high temperatures (＞ 90 oC) has advantages such as higher system efficiency, flexibility in fuel selection and simplification in water management. However, most commercialized membranes are based on sulfonic-acid moieties, which are not dissociable at anhydrous conditions. But phosphonic acids could be conductive at higher temperatures due to their self-dissociation nature. Therefore, we synthesized solid proton conductors by grafting alkyl phosphonic acids to zirconium phosphate. The synthesized zirconium diphosphophenyl phosphate (Zr3P) showed the very high conductivity over 10-2 S/cm at anhydrous conditions above 120 oC. When Zr3P was incorporated in the nanochannels of Nafion, the composite membrane also resulted in very high conductivity at high temperature (0.01 S/cm at 120 oC, ＜ 25% RH). The result may be resulted from the improved self-humidification inside the nano- channels of sulfonic-acid baesed Nafion. |
