With an aim to study the possibility of operating the proton exchange membrane fuel cells (PEMFC) with dry H-2 and O-2 reactants, a thin double-layer composite membrane consisting of one layer of Pt/C catalyst dispersed recast Nafion and another layer of plain recast Nafion has been investigated in PEMFC. The Pt/C particles dispersed Nation layer and the plain Nafion layer were, respectively, on the anode and cathode sides of the membrane-electrode assembly (MEA). The Pt/C catalyst particles present in the membrane provide the sites for the catalytic recombination of H-2 and O-2 permeating through the membrane from the anode and cathode to produce water. The water generated directly humidifies the membrane and allows the operation of PEMFC with dry reactants. The electrochemical performances of the composite membranes with dry and humidified reactants are compared with those of the native Nation membrane to identify the optimum operating conditions with self-humidifying membranes. (C) 2004 Elsevier B.V. All rights reserved.