Silica modified sulphonated Poly(ether ether ketone) proton exchange membranes for DMFC application

Herein, we report sol-gel modified sulfonated poly(ether ether ketone) (SPEEK) organosilane based composite proton exchange membranes for their suitability in direct methanol fuel cells (DMFCs). Different concentrations (0.2-1.5 wt%) of aminopropyl trimethoxysilane (APTES) are incorporated in SPEEK matrix by in-situ sol-gel method. Physico and electrochemical performances of composite membranes are enhanced by induced Hbonding interactions between free -NH2 and -SO3H groups. With increase in APTES concentration to 0.8 wt%, the ionic conductivity illustrates improvement by similar to 80% while IEC and Proton conductivity (Pc) enhances by similar to 21% and similar to 70%, respectively than SPEEK. To further explore the feasibility of the membranes in DMFC. Methanol crossover resistance is calculated to as low as 5.30 x 10(-7) cm(2) s(-1) and offers highest selectivity of 4.43 S s cm(-3) in contrast to 12.55 x 10(-7) cm(2) s(-1) and 0.31 S s cm(-3) for SPEEK, respectively. This study reveals that the Si-SPEEK membrane is a potential alternate for DMFC. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.