Anhydrous proton-conducting properties of nafion-1,2,4-triazole and nafion-benzimidazole membranes for polymer electrolyte fuel cells

Recently, fuel cells have gathered a lot of interest due to their potential as future sources of clean energy. Polymer electrolyte fuel cells (PEFCs) require high operating temperatures (100-200°C) for high conversion efficiency. Anhydrous proton-conducting polymers employing Nafion-1,2,4- triazole- and Nafion-benzimidazole-blend membranes were studied for use in PEFCs above 100°C. The solvents 1,2,4-triazole and benzimidazole are thermally stable, organic reagents with low volatility and are used to replace water as the proton acceptor in the perfluorinated ionomer membrane. The Nafion-benzimidazole blend had high thermal stability above 200°C and proton conductivity of 8.64× 10-3 Scm at 200°C under nonhumidified conditions. Fuel cell tests using a single membrane electrode assembly cell with the Nafion-blend membranes were successfully performed.