Novel nanocomposite proton exchange membranes based on Nafion® and AMPS-modified montmorillonite for fuel cell applications

A series of novel proton exchange membranes based on Nafion® and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) modified montmorillonite (MMT) were prepared and investigated for high performance fuel cell applications. X-ray diffraction patterns revealed an exfoliated microstructure for the modified clay in the Nafion® matrices. Proton conductivity and methanol permeability results indicated that the incorporation of AMPS-modified MMT into Nafion® matrices results in considerably reduced methanol crossover while maintaining conductivity properties. Direct methanol–air single fuel cell tests revealed a cell efficiency of 20% for Nafion®/AMPS-MMT-3 wt.% compared to 13.72% for Nafion®117 at 5 M methanol feed, and also a higher power density of 88 mW cm−2 compared to 39 mW cm−2 for Nafion®117. Owing to such favorable features, fabricated Nafion®/AMPS-MMT membranes could be considered as promising polymeric electrolytes for high performance fuel cell applications.

Research highlights▶ Montmorillonite modified with 2-acrylamido-2-methylpropanesulfonic acid (AMPS-MMT). ▶ Nanocomposite proton exchange membranes prepared using AMPS-MMT and Nafion®. ▶ Membranes showed high selectivity as well as low methanol crossover. ▶ Membranes enhanced the electrochemical performance of direct methanol fuel cell.