TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The catalyst layers on the front and back sides of conductive membrane have different or the same surface dimensions. The conductive membrane on the front side has a surface that is not supported by a gas distributor substrate. The edge of gas distributor substrate and the free surface (6) of conductive membrane are surrounded by a sealing material. The sealing material additionally impregnates an edge region of the gas distributor substrates to a depth of greater than or equal to1 mm. It may be integrally combined with another peripheral plastic frame. The sealing material is cured by elevated pressure and temperature or by contact with air and/or elevated temperature. Preferred Dimensions: The conductive membrane has a thickness of 10-200 microns.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Materials: The catalyst layers comprise catalyst containing noble metals and optionally ionically conductive materials. The conductive membrane may be made of ionically conductive ceramic material.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Materials: The catalyst layers comprise catalyst containing noble metals and optionally ionically conductive materials. The conductive membrane may be made of ionically conductive ceramic material.    TECHNOLOGY FOCUS - POLYMERS - Preferred Materials: The conductive membrane is made of organic polymer (e.g. proton-conducting perfluorinated polymeric sulfonic acid compound), doped polybenzimidazole, polyether ketone, or polysulfone. The sealing material contains thermoplastic polymer, e.g. polyethylene, polypropylene, PTFE, polyvinylidene fluoride, ethylene-propylene-diene-monomer, polyester, polyamide, polyamide elastomer, polyimide, polyurethane, silicone, and/or silicon elastomer; and/or thermosetting polymer of epoxide and/or cyanoacrylate.    TECHNOLOGY FOCUS - TEXTILES AND PAPER - Preferred Materials: The gas distributor substrate comprises porous electrically conductive materials containing carbon fiber paper, carbon fiber nonwoven cloth, carbon fiber cloth, metal mesh, and/or metallized fiber cloth.