Nafion/mordenite hybrid membrane for high-temperature operation of polymer electrolyte membrane fuel cell

Nafion/mordenite hybrid membranes for the operation of polymer electrolyte membrane fuel cells (PEMFCs) above 100 degreesC were prepared by mixing of H+-form mordenite powder and perfluorosulfonylfluoride copolymer resin. PEMFC operation above 100 degreesC reduces CO poisoning as well as passivation of the Pt anode electrocatalyst by other condensable species. The physico-chemical properties of hybrid membranes were investigated by tensile strength and proton conductivity measurements. As the mordenite content increases at the high temperature region, the proton conductivity of hybrid membranes increased due to the late dehydration rate of existent water in the mordenite. Also, from the results of current-voltage relationship for single cells under 130 degreesC of operation condition, the hybrid membrane cell with 10 wt.% mordenite showed better performance than that of the others over the entire current density range. This result indicated that the existent water in the hybrid membrane containing 10 wt.% mordenite was higher than that with the others, thereby maintaining its conductivity. The Nafion/mordenite hybrid membrane prepared by this present method is thought to be a satisfactory polymer electrolyte membrane for PEMFC operation above 100 degreesC. (C) 2003 Elsevier B.V. All rights reserved.