Electrochemical characterization of a PEM water electrolyzer based on a sulfonated polysulfone membrane

A polymer electrolyte membrane (PEM) based on a non-perfluorinated polymer as an alternative to Nafion was investigated for application in a water electrolyzer. The sulfonated polysulfone (SPSf) was synthesized using trimethyl silyl chlorosulfonate as the sulfonating agent. The SPSf polymer was used for the preparation of a proton conducting membrane. A single cell (5 cm2 geometrical area) PEM electrolyzer based on SPSf membrane, IrO2 anode and Pt/C cathode electrocatalysts was investigated by polarization, impedance spectroscopy, chrono-amperometry and gas crossover measurements. The performance was compared to that of an electrolyzer based on a standard Nafion 115 membrane. The electrolyzer based on SPSf showed polarization and hydrogen permeation characteristics similar to those of Nafion. After 35 h potentiostatic operation at 1.8 V, the sulfonated polysulfone MEA reached a current density of 1.35 A cm−2. The results indicate promising performance of the sulfonated polysulfone polymer electrolyte membrane for application in a PEM electrolyzer.