Silica and Sulfonated Silica Functionalized Nexar Nanocomposite Membranes for Application in Proton Exchange Membrane Fuel Cell

Present work demonstrates development and characterization of Nexar-based nanocomposite membranes to evaluate their potential as an alternative to Nafion. Nanocomposite membranes are characterized through XRD, FTIR, SEM, and TGA for crystallinity, surface morphology, functionalities, and thermal stability. Membrane thickness, and protonic resistivity are determined. Modification of Nexar with doped silica and sulfonated silica nanoparticles is checked for water uptake (UR), swelling ratio (SR), ion exchange capacity, proton conductivity at different temperatures, humidity, and activation energies. Incorporating silica and functionalized silica into Nexar drastically changed WU and SR. Proton conductivity improved by 58.8% for sulfonated silica membrane, comparing pristine Nexar. At low humidity, composite membranes showed better proton conductivity than pristine Nexar. Low activation energies supported mainly Grotthus mechanism for proton transport. Thus, present work suggests Nexar-based functionalized nanocomposite membranes owing to higher IEC and less swelling ratio may help higher proton conductivity necessary for PEM fuel cell operation.