Synthesis characterization and performance evaluation of ionic liquid immobilized SBA-15 /quaternised polysulfone composite membrane for alkaline fuel cell

Abstract

1-Methyl-3-(3-trimethoxysilylpropyl) imidazolium chloride, an imidazolium based ionic liquid, was synthesized and chemically grafted onto the synthesized mesoporous silica (SBA-15), resulting in a mesoporous solid (IL-SBA-15) with ion-exchange properties. The prepared IL- SBA-15 was characterized by FT-IR, solid state CP/MAS 13C NMR, solid state CP/MAS 29Si NMR, BET, XRD and TEM. Composite membranes with high ion exchange capacity (IEC) were then prepared by incorporating IL-SBA-15 into the quaternary polysulfone (QPSU) in different weight percentages (1–4%). The morphology and crystalline nature of the membranes were analyzed by SEM and XRD respectively. The membrane properties such as water uptake, IEC and hydroxyl conductivity were studied for its suitability in Anion Exchange Membrane Fuel Cell(AEMFC). The prepared membranes were tested in an in-house built AEMFC of 25 cm2 electrode area with platinum anode and silver cathode. 3 wt% IL-SBA-15 containing composite membrane showed a maximum power density of 278 mW/cm2 at 60 °C. The results suggest that these composite membranes have the potential to be used as an electrolyte in AEMFC.