PVDF supported silica immobilized phosphotungstic acid membrane for DMFC application

Abstract

Silica immobilized phosphotungstic acid (Si-PWA) based inorganic–organic hybrid ion exchange membrane was used in direct methanol fuel cell (DMFC). Chemical composition of the ion exchanging phase of membrane was determined using energy dispersive spectroscopy (EDS). TGA analysis showed that the thermal stability of synthesized membrane was better than Nafion-117 and it also possessed excellent water holding capacity even at elevated temperature. The proton conductivity of the membrane increased upon increasing the PWA concentration in silica. Room temperature (25 °C) proton conductivity of the membrane was 4.3 m Scm− 1 and it increased to 10.1 m Scm− 1 upon increasing temperature to 60 °C. At 25 °C and 60% relative humidity, the peak power density of DMFC with synthesized membrane (21.6 m Wcm− 2) was much better than that of DMFC with Nafion-117 membrane (11 m Wcm− 2).