Hybrid Polyelectrolyte Materials for Fuel Cell Applications: Design, Synthesis, and Evaluation of Proton-Conducting Bridged Polysilsesquioxanes

Abstract

A method for the synthesis of chemically and thermally robust sulfonic-acid-containing hybrid membrane materials has been established. These polyelectrolyte membranes are prepared by oxidation of the corresponding disulfide-bridged polysilsesquioxanes. This strategy allows for high acid-group loading. Their microstructure is determined by nitrogen adsorption porosimetry, solid-state NMR spectroscopy, and atomic force microscopy. Application of these hybrid materials as proton-exchange membranes for fuel cells is investigated by measuring their proton conductivity, which increases linearly with increasing sulfonic acid content to 6.2 mS/cm.