NOVELTY - A electrode-membrane combination has at least one reactant diffusive electronically conducting electrode (1, 3) with a catalytically active metal(s) and an ionically conductive polymer(s); and an ionically conducting membrane(s) (2) contacting the electrode to form an electrode-membrane interfacial region (4, 5). T    USE - For use in a fuel cell. The invention is versatile and can be used in a variety of applications including (i) transportation vehicles, e.g. cars, trucks and buses which have requirements including high power density and low cost; (ii) stationary power applications, where high efficiency and long life are required; and (iii) portable power applications, e.g. portable televisions, fans and other consumer products.    ADVANTAGE - The invention improves power output with better catalyst utilization. It can be applied to different fuel cell reactants and the process scalability has been demonstrated. It is commercially realistic. In addition, multiple methods can be used to prepare the structures and can be tailored to different commercial applications. More precise design and control is now possible. The zone of catalyst metal does not upset the water balance of the fuel cell system.    DETAILED DESCRIPTION - The region has a vacuum deposited zone. INDEPENDENT CLAIMS are also included for (a) a membrane electrode assembly (MEA) comprising the combination as above; (b) a fuel cell stack, comprising electronically connected membrane electrode assemblies; (c) a transportation vehicle comprising the fuel cell stack; and (d) a method of improving the power output of a fuel cell membrane electrode assembly, comprising the combination of, providing assembly elements including as above, depositing into at least one of the assembly elements a zone of at least one second catalytically active metal having a zone thickness between 3-475 Angstrom; and optionally assembling the membrane electrode assembly from the assembly elements. The zone deposition is an (in)direct deposition into the assembly element. The deposited zone is first deposited into a substrate and then transferred from the substrate into the assembly element.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a MEA.    Conductive electrode (1, 3)    Conductive membrane (2)    Interfacial region (4, 5)