Proton exchange membranes based on aryl epoxy resin for fuel cells operated at elevated temperatures

This paper reports the characterization of a new type of low-cost proton exchange membrane (PEM) based on photo-patternable nano porous aryl epoxy resin (npAER) sulfonated by sulfanilic acid. The npAER PEM fabrication process involves solvent-casting nanoporous structure formation combined with standard photolithography steps for microstructure fabrication. The PEM was placed in the cathode of a half-fuel cell for testing in 0.5M H₂SO₄ at different temperatures with constant oxygen flow. When compared to commercial PEM Nafion^®, this npAER PEM exhibits increased current density by about 170% as temperature increased from 60°C to 90°C, while the current density of Nafion^® dropped by about 70%. The new npAER PEM demonstrates decent thermal stability, mechanical strength and proton transport ability at a higher temperature (90°C).