Highly proton-conducting non-perfluorinated hybrid electrolyte/non-platinum catalyst for H2/O2fuel cells

Abstract

A class of hybrid proton-conducting membranes consisting of a polymer blend with heteropolyacids, poly(vinyl alcohol) (PVA), poly(vinylpyrrolidone) (PVP), silicotungstic acid (SiWA) and orthoethoxysilicate, was prepared. A maximum conductivity value of 0.4 S cm⁻¹ was obtained at 100 °C with excellent thermal and mechanical stabilities. This is the cutting edge that such a high proton conductivity value was achieved for a PVA/PVP/SiWA hybrid composite membrane. A maximum current density of 1200 mA cm⁻² for the membrane electrode assembly, consisting of a carbon black based catalyst and the hybrid membrane, was obtained at 80 °C and 100% relative humidity. To the best of our knowledge, no reports have been published using the same non-Pt catalyst and hybrid membrane electrolyte providing high current density at low temperatures. In this communication, we highlight two systems that present large proton conductivity and current density at relatively low temperatures by the combination of a new class of polymer blend hybrid membranes and a non-Pt catalyst.