MEMBRANE-SUPPORTED NONVOLATILE ACIDIC ELECTROLYTES ALLOW HIGHER TEMPERATURE OPERATION OF PROTON-EXCHANGE MEMBRANE FUEL-CELLS

The feasibility of using nonvolatile molten and solid acidic electroly te impregnated ion-exchange membranes in higher temperature proton-exc hange membrane fuel cells (PEMFCs) to alleviate their water dependence is investigated. Higher temperature PEMFC operation reduces CO poison ing as well as passivation of the Pt electrocatalyst by other condensa ble species. Further, higher temperature operation could eventually al low direct use of low-temperature reformable fuels such as methanol in the PEMFC. The methodology proposed here involves supporting an appro priate acidic solid, melt, or solution of low volatility within the po res of Nafion(R) so as to enhance its protonic conductivity at higher temperatures and lower humidity levels. Preliminary experimental resul ts reported here for a PEM fuel cell operating at temperatures of 110 to 120 degrees C based on Nafion supported solutions of heteropolyacid indicate the feasibility of the technique.