Pt-zirconium phosphate-Nafion composite membrane was fabricated for self-humidifying polymer electrolyte membrane fuel cells (PEMFC), and the effects of the size, distribution and amount of Pt impregnated in the Nation membrane were investigated. Water was produced by the crossover of hydrogen and oxygen on Pt particles embedded in the membrane and the generated water hydrated the membrane. Zirconium phosphate particles into self-humidifying membrane enhance the cell performance at elevated temperatures due to the Zirconium phosphate characteristics of water retention and electrochemical properties. Pt-membrane was prepared by equilibrium impregnated reduction, in 0.1 M NaBH4 solution after soaked in 0.5 mM Pt(NH3)(4)Cl2 solution. The amount and distribution of Pt particles in the membrane was the key to the performance of self-humidifying PEMFC. Pt-zirconium phosphate-Nafion composite membrane was prepared by adding ZrP in situ to Pt-membrane with 1 M H3PO4 solution after soaked in 0.5 M ZrOCl2 solution. The amount of Zirconium phosphate was controlled by the concentration of ZrOCl2. The result of FT-IR and NMR showed that zirconium phosphate was synthesized in the membrane. (C) 2004 Elsevier Ltd. All rights reserved.