Synthesis and characterization of purely sulphonated and composite membranes for high temperature fuel cells

Abstract

Fuel cell technologies have developed high interest due to their ability to provide energy in an environmentally friendly method. Proton exchange membrane fuel cells (PEM-FCs) require a PEM for use, where the most accepted PEM used today is Nafion. Nafion is ideal due to its chemical durability and high proton conductivity however it is highly expensive and limited to 80˚C during operation. To target these issues two methods have been developed. One was to synthesize a new membrane material to replace Nafion based upon sulphonated polysiloxanes and the other was to improve Nafion by synthesizing a composite. Both of these methods involved the sulphonated silane 2-4-chlorosulphonylphenethyltrimethoxysilane. Methods to characterize membranes to observe their properties compared to Nafion were thermogravimetric analysis (TGA), Fourier transmission infrared spectroscopy (FT-IR), electrochemical impedance spectroscopy (used to determine proton conductivity) and fuel cell performance.