A novel phosphoric acid loaded quaternary 1,4-diazabicyclo-[2.2.2]-octane polysulfone membrane for intermediate temperature fuel cells

Phosphoric acid loaded quaternary 1,4-diazabicyclo-[2.2.2]-octane (DABCO) polysulfone was synthesised with different degrees of substitution (DS) and the membranes were characterized. The polymer structure was investigated using NMR and FT-IR spectra. The effect of DS on ionic conductivity and fuel cell performance are described. Conductivities of 0.12 and 0.064 S cm−1 were achieved for the high degree of substitution membrane (DS106) and low degree of substitution membrane (DS58), respectively. Fuel cell tests gave a high power output of 400 mW cm−2 using H2 and O2 at 150 °C and atmospheric pressure. Therefore, PA/QDPSU membrane has potential applications for intermediate temperature fuel cells (ITFCs).