The effect of ferric ions on cell performance of proton exchange membrane water electrolyzer (PEM WE) was studied by injecting Fe-2 (SO4)(3) solution into DI water to prepare different Fe3+ concentrations contamination (1, 10, 100 parts per million (ppm, molar ratio)). Results showed that there was clear cell performance decay with increasing Fe3+ concentrations, and the cell stopped running at 100 ppm Feat concentration in feed water. With increasing temperature, the cell performance increased for a short period. With low Fe3+ concentrations, cell performance decreased with increasing current density, but with 10 ppm Fe3+ concentration and higher current density of 2 A/cm(2), cell performance was enhanced. Therefore, both temperature and current density can make positive contributions to improve cell performance under the condition of contaminated feed water. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.