Sulfosuccinic acid-sulfonated polyether ether ketone/organo functionalized microporous zeolite-13X membrane electrolyte for direct methanol fuel cells

Impact of modified hydrophilic microporous zeolite namely 13X by introducing organo-sulfonic acid groups through silane condensation; and its dispersion in sulfosuccinic acid-sulfonated polyether ether ketone (SSA-sPEEK) to form a mixed matrix membrane for its application in direct methanol fuel cells is explored. Organo-sulfonic acid groups present in modified zeolite-13X serves for dual purpose by restricting methanol cross-over and also providing additional ion conducting groups for overall improvement of the performance. Crosslinking of sPEEK with SSA proves to be beneficial in providing stability to the matrix and also helps in enhancing the ionic conductivity. Characteristic properties like ion exchange capacity, water sorption, water-methanol mixture sorption and proton conductivity for these mixed matrix membranes have been investigated. DMFC comprising SSA-sPEEK-HSO3-zeolite-13X (80:20 ratio) mixed matrix membrane delivers peak power density of 130 mW/cm(2), whereas peak power density of 73 mW/cm(2) was obtained for DMFC comprising pristine sPEEK membrane at 70 degrees C. These indicate that SSA-sPEEK-HSO3-zeolite-13X mixed matrix membrane exhibit higher DMFC performance and lower methanol permeability in comparison with pristine sPEEK membrane. (C) 2016 Elsevier Inc. All rights reserved.