Synthesis and Ex-situ Characterization of Nafion/TiO2 Composite Membranes for Direct Ethanol Fuel Cell

Nafion/TiO2 composite membranes for different loadings of TiO2 were prepared by casting method for the possible application in direct ethanol fuel cell (DEFC). The properties of the composite membranes were investigated by scanning electron microscopy (SEM), x-ray diffraction (XRD), thermogravimetric analyser (TGA), ion exchange capacity, water and alcohol uptake, swelling ratio, proton conductivity, and ethanol crossover. The observed characteristics of the membranes were evaluated for DEFC and compared with the direct methanol fuel cell (DMFC) membrane. The analysis reveales a significant influence on the TiO2 surface characteristics, water and alcohol uptake, and swelling of the membrane. The TiO2 composite membranes exhibited a sharp decrease in methanol and ethanol crossover for 5% TiO2 and the proton conductivity was heighest for 1% TiO2 loading. The best compromise between proton conductivity and crossover has been found out with the help of the characteristic factor phi. The optimum loading of 5% TiO2 composite membrane has shown the maximum characteristic factor.