Improvement of cathode materials for polymer electrolyte fuel cell

摘要

An exergy analysis was applied to a methanol reforming polymer electrolyte fuel cell system in order to provide guidelines for improving the efficiency of the system. The increase of the cell voltage is the only way to get higher efficiency. A cell voltage over 0.82V was necessary in order to obtain an exergy efficiency of more than 0.5. The cathode overvoltage causes the most large exergy loss, so that it should be reduced to raise the cell voltage. In this study, the improvements of the catalytic activity of cathode have been tried. The interactions between Pt and substrates (IrO2, WO3 and carbon) have been evaluated to improve the catalytic activity of oxygen reduction. The WC based material has been tested as the substitutive material of Pt. Ta added WC showed the improved stability and the catalytic activity. The thermal spray reaction method which was a new preparation method was tried for preparing the active electrocatalysts.