TECHNOLOGY FOCUS - POLYMERS - Preferred Process: The step of combining the catalyzed support with an ion-conducting polymer is performed in a liquid medium that is aqueous-based and is essentially free from organic solvents. The catalyzed support in particle form is applied as a binder to form a fiber network to which the ion-conducting polymer is subsequently applied to produce the membrane. The catalyzed support is in particle form and is applied as a binder to form a fiber network to which the ion conducting polymer is subsequently applied to produce the membrane.Preferred Composition: The ion-conducting polymer composition is an essentially aqueous solution of a perfluorinated co-polymer with ion-exchange groups.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The catalyst comprises a precious metal(s) or combination and/or other transition group metals, preferably platinum. The catalyst is deposited into the support material at a loading of 0.01-50, preferably 1-10 wt.% of the total catalyzed support. The amount of catalyzed support incorporated into the membrane is such that the metal loading is lower than 0.1, preferably 0.03 mg/cm2. The high surface area support material is in the form of a fiber made up of silica, titania, alumina, zirconium oxides, zirconium silicates, tungsten oxides, tin oxides or zeolites.Preferred Property: The support material is in the form of a particles with a mean particle size of 0.001-10, preferably 0.01-5 mum. EXAMPLE - Mixed amorphous silica substrate was first cast with aqueous Nafion solution (5wt.%), prepared to produce, after drying, a substrate with a Nafion layer applied and embedded within a face of the substrate. Aqueous Nafion solution (10.3wt.%) was heated to 80degreesC and the 5.6wt.% platinum (Pt) on silica catalyst (0.28g) was added. The mixture was sprayed into the second face of the substrate to produce a thin layer of Pt catalyst and dried in the oven at 80degreesC. This step was repeated and then drying was performed at 150degreesC to produce a membrane. An identical membrane was prepared and the two membranes were laminated with the Pt catalyst face of each membrane facing each other at 177degreesC and at 296 psi for 6 min. This produced a composite membrane of higher thickness of 58 microns with a central region that contained the Pt on silica catalyst at a Pt loading of 0.05 mg/cm2 and with an overall Nafion loading of 13.2 mg/cm2 compared to the pair of membranes prepared without the addition of the Pt on silica catalyst.