FTIR spectroscopic investigation of inorganic fillers for composite DMFC membranes

An infrared spectroscopic investigation of inorganic fillers employed in composite perfluorosulfonic membranes has been carried out. The surface acidity of the fillers appears to influence the bending and stretching vibrational frequencies of the water physically adsorbed on the filler surface. The conductivity of composite membranes and maximum power density of direct methanol fuel cells (DMFCs) at 145 °C appear to be related to the characteristics of the water adsorbed on the filler particles. Inorganic fillers characterised by acidic properties undergo a strong interaction with water and enhance the DMFC performance at high temperature.