TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Parameter: The porous layer has pore diameters between 2 and 500 nm. Preferred Components: The porous layer has a perovskite structure having the formula of ABxy(B')1-yO3-delta.A=a combination of the elements Ca, Sr, and Ba;Bx=a combination of the elements Ti, Zr, Hf, and Ce;B'=a combination of lanthanide elements, Y, Sc, and Ga; andy=less than or equal to 0 but less than or equal to 1.The porous layer has the formula Ay(A')1-yOx.A=a combination of the elements Si, Ti, Zr, Nb, Hf, Ce, or Ta;A'=a combination of alkaline earths, lanthanides, Y, Sc, or Ga; andy=less than or equal to 0 but less than or equal to 1.The porous layer is an alkaline earth metal titanate, such as strontium titanate. It is metal carbide such as tantalum carbide, titanium carbide, titanium aluminum carbide or titanium silicium carbide. The porous layer is a metal nitride such titanium-aluminum nitride. It is a doped pyrochlore having the formula A2Bx2O7.A=a lanthanide, Y, or alkaline earth; andBx=a transition metal.The aqueous electrolyte is an aqueous solution of MOH, M2CO3, MHCO3, M2SO4, MX2PO4, M2XPO4, MXO4, MXO3, and MX.M=H, Li, Na, K, Rb or Cs; andX=Cl, Br or I, or its mixture.At least one of at least two gas diffusion electrodes comprises nickel or nickel alloys such as Inconel 600, 625, 690 or Ni-Co such as NiCo2O4 or Co-spinels. At least one of at least two gas diffusion electrodes comprises doped perovskites such as niobium (Nb)-doped strontium titanate. At least one of at least two gas diffusion electrodes comprises ceramic materials. At least one of at least two gas diffusion electrodes comprises perovskites with the formula ABxO3.A=a combination of alkali metal, alkaline earth, lanthanide or Y; andBx=a combination of transition metal, lanthanide, Ga or Mg.At least one of at least two gas diffusion electrodes comprises spinels with the formula A3O4.A=a combination of transition metals, Mg, Ga or Al.At least one of at least two gas diffusion electrodes comprises materials with the formula AOx.A=a combination of transition metal or Zr, Hf, Ce, Y, Sc or alkaline earth or lanthanide or Si, Ga, or Al.At least one of at least two gas diffusion electrodes is loaded with a catalyst. The electrochemical cell is an electrolysis cell for producing hydrogen and oxygen from water. It is a co-electrolysis cell for producing synthetic fuels from carbon dioxide and water. At least one of at least two porous gas diffusion electrodes comprises metal foam. At least two sheets of metal foam are nickel based foam sheets and at least one metal foil is a dense Ni-foil. At least two sheets of metal foam are loaded with a densely sintered perovskite structure. At least two metal foam sheets comprise hydrophobic materials. At least two sheets of metal foam comprise fluoropolymers such as polytetrafluoroethylene (PTFE) or perfluoroalkoxy (PFA). EXAMPLE - No example given.