TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method further comprises disposing a catalyst layer onto the inorganic oxide layer so that the inorganic oxide layer is situated between the catalyst layer and the proton-exchange membrane. The curing temperature in step (e) is 50-150 degrees C. Preferred Components: The proton-exchange membrane is completely covered by the inorganic oxide layer. The proton-conducting metal oxide is vanadium oxide, tungsten oxide, ruthenium oxide, manganese oxide, tin oxide, zirconium oxide, titanium oxide, tantalum oxide, hafnium oxide, niobium oxide, molybdenum oxide or their hydrates. The inorganic oxide layer: comprises tungsten oxide and a proton-conducting metal acid; is capable of conducting protons in unhydrated form and electrically conductive; has a thickness of 10 nm to 250 mu m, preferably 0.1-100 mu m; and is substantially uniform with respect to thickness. The wetting agent is an anionic or non-ionic surfactant. The surfactant contains hydrophilic polyethylene oxide or 4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol. The wetting agent comprises a fluorosurfactant. The fluorosurfactant is poly(oxy-1,2-ethanediyl), alpha -hydro- omega -hydroxy-ether with alpha -fluoro- omega -(2-hydroxyethyl)poly(difluoromethylene). The neutralized solution contains at least 0.05 wt.% hydrogen peroxide. EXAMPLE - Nafion (RTM: Sulfonated tetrafluoroethylene based fluoropolymer-copolymer) was received, cut and boiled in deionized water for one hour and in 0.1 M hydrochloric acid for one hour. Then Nafion (RTM: Sulfonated tetrafluoroethylene based fluoropolymer-copolymer) squares were removed, washed with deionized water, and stored in a deionized water bath. Tungsten oxide sol was prepared by making a solution of 24 g hydrogen peroxide and 28 g deionized water. The solution was stirred rapidly and 8 g tungsten was added over 2 hours. The reaction between hydrogen peroxide and tungsten is very exothermic. When the solution begins to boil, it was placed in a room-temperature water bath while being stirred. The hydrogen peroxide in the tungsten oxide sol was neutralized by placing a platinum mesh in the solution and putting the solution in an 80 degrees C oven for 25 minutes. Then platinum mesh was removed and the solution was cooled. A wetting agent was placed in the tungsten oxide sol. The solution was weighed and 1 wt.% Triton X-100 (RTM: Polyethylene glycol p-(1,1,3,3-tetramethylbutyl) was added. The solution was stirred resulting in a yellow solution. The sol is transferred to Petri dish. The Nafion (RTM: Sulfonated tetrafluoroethylene based fluoropolymer-copolymer) square was floated on the tungsten oxide sol in the Petri dish and pulled out of the solution to create a dip coat of tungsten oxide sol on one side of the material. The coated Nafion (RTM: Sulfonated tetrafluoroethylene based fluoropolymer-copolymer) sheet was transferred to 80 degrees C oven and cured for one hour. The coated Nafion (RTM: Sulfonated tetrafluoroethylene based fluoropolymer-copolymer) sheet was removed, washed with deionized water, and floated on the tungsten oxide sol with the coated side in the solution. The Nafion (RTM: Sulfonated tetrafluoroethylene based fluoropolymer-copolymer) was pulled out of the solution to create an additional dip coat of tungsten oxide sol. The resulting sheet was transferred to 80 degrees C oven and cured for one hour.