Ultrafiltration (UF)-based proton-conductive membranes, which comprised nanosize SiO2, polyethersulfone and aqueous acid absorbed, as an alternative to traditional ion exchange membranes, were first proposed and successfully prepared for H-2/Cl-2 fuel cell. Various membranes were prepared with different weight fractions of SiO2 nanoparticles. The effect of silicon content on the performance of membranes was characterized. The ionic conductivity of a membrane doped with 3 M hydrochloric acid increased with the silicon content and reached 0.150 S cm(-1) at 15 wt.% SiO2. A non-optimized H-2/Cl-2 fuel cell assembled with the modified UF membrane (115 pm thick) exhibited better performance than that with Nafion 115 membrane. It demonstrated that 12.67% and 55.03% improved at 10 wt.% and 15 wt.% SiO2, respectively. The study provides an effective way to fabricate high performance porous membranes for H-2/Cl-2 fuel cell application. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.