Novel polysilsesquioxane hybrid membranes for proton exchange membrane fuel cell (PEMFC) applications

FUEL 18

Grace Jones Daba Kalaw, gdk042000@utdallas.edu, John Patrick Ferraris, ferraris@utdallas.edu, Inga H. Musselman, imusselm@utdallas.edu, Kenneth Balkus Jr., balkus@utdallas.edu, and Duck-Joo Yang. Department of Chemistry, University of Texas at Dallas, 2601 N. Floyd Rd, BE 26, Richardson, TX 75080
Various novel three-dimensionally cross-linked, sulfonic acid-functionalized polysilsesquioxane hybrid membranes are prepared via a sol-gel procedure. These sulfonic acid functionalized polysilsesquioxane hybrid membranes with the empirical formula R-Si-(O)1.5 consist of the highly cross-linked Si-O backbone and pendant organic side chain R, which is terminated in a sulfonic acid group. This design for proton exchange membranes takes advantage of the thermal and mechanical stability of the inorganic silicon backbone, flexibility of the incorporated organic chains and high proton conductivity of the pendant sulfonic acid groups. The membranes exhibited hydrolytic stability over long periods of time and high proton conductivities (10-2 S/cm) at low relative humidity and a wide range of temperatures which are comparable to NafionŽ membranes. Extent of methanol crossover and fuel cell performance studies are currently being investigated. These membranes are promising for proton exchange membrane fuel cell applications at a much lesser cost and facile membrane fabrication.