The viscosities of as received 5.1wt.% Nafion solutions (EW = 1100, Du Pont Co) blended with various concentrations of ZrOCl2 were studied. We show the solution viscosity decreases as the wt. ratio of [ZrOCl2]/[Nafion] is increased from 0.0 to 0.03, then the viscosity does not change significantly as the wt. ratio of [ZrOCl2]/[Nafion] is increased from 0.03 to 0.16, and then the viscosity increases dramatically as the wt. ratio of [ZrCCl2]/[Nafion] is increased above 0.16. Four Nafion solutions consisting of 5.1 wt.% Nafion and ZrOCl2 with [ZrOCl2]/[Nafion] wt. ratios of 0.019-0.24 were used with porous poly(tetrafluoroethylene) (PTFE) film to prepare zirconium hydrogenphosphate (ZrP) hybridized Nafion/PTFE (NF-ZrP) composite membranes by direct impregnating porous PTFE in Nafion/ZrOCl2 solutions. The influence of [ZrOCl2]/[Nafion] wt. ratio of Nahon/ZrOCl2 solution on the membrane morphology of NF-ZrP and polyelectrolyte membrane fuel cell (PEMFC) performance at temperatures of 110-130 degrees C with relative humidity of 51.7-28.8% RH was investigated. (C) 2008 Elsevier B.V. All rights reserved.