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 (5cm2 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 35h potentiostatic operation at 1.8V, the sulfonated polysulfone MEA reached a current density of 1.35Acm−2. The results indicate promising performance of the sulfonated polysulfone polymer electrolyte membrane for application in a PEM electrolyzer. •A membrane based on a non-perfluorinated polymer was investigated in a PEM-WE.•The performance was compared to that of an electrolyzer based on a Nafion 115.•The results indicate promising performance of the SPSf membrane in a PEM electrolyzer.