Oxygen conducting membranes, preparation method thereof, and reactor and method using same

An oxygen conducting membrane, comprising:

• a mixed conducting dense membrane of multimetal oxide, one surface of which is covered with dispersed particles containing magnesium oxide or noble metals,
• wherein the mixed conducting dense membrane is a layer comprising a multimetal oxide compound having a formula:
• BaxSr1-xCo1-yFeyO3-z
• where 0≦x≦1,
• 0≦y≦1, and
• z is a number which renders a charge of the compound neutral and which defines oxygen deficiency, and
• the particles based on magnesium oxide or noble metals represent from 0.01 to 0.1% by weight of the dense membrane.