Patent ID: 8894944

Claim:
A membrane comprising, in order, a first catalyst layer, an electronically and ionically conducting layer having a nanosized microstructure, and a second catalyst layer, wherein the electronically and ionically conducting layer is formed from an electrolyte material, a grain growth inhibitor and/or a grain boundary modifier, wherein the electronically and ionically conducting layer comprises Ce 1-x M x O 2- δ (where M is selected from the group consisting of Ca, Sm, Gd, Sc, Ga and Y, and 0 ≦x≦1); wherein the grain growth inhibitor comprises an oxide selected from the group consisting of Sc 2 O 3 , VO x , TaO x , MnO x , NbO x , SrO, CaO, MgO, Bi 2 O 3 , LnO x , MgCr 2 O 4 , MgTiO 3 , CaAl 2 O 4 , LaAlO 3 , YbCrO 3 , ErCrO 4 , NiTiO 3 , NiCr 2 O 4 , metal carbides, metal nitrides, and mixtures thereof; and wherein the grain boundary modifier comprises an oxide selected from the group consisting of MnO x , VO x , MgCr 2 O 4 , CaCr x V y O 4 , SrCr x V y O 4 , YbCrO 3 , ErCrO 4 , NiTiO 3 , NiCr 2 O 4 , and mixtures thereof.