Using a good mixed oxide ion and electrical conductor makes it possible to reduce CO2 to CO even by the unelectrical methods. The La(Sr)CrO3-based perovskite oxide was chosen as the mixed conductor because these oxides are stable under a reduced condition. In order to increase the oxide ion conductivity, Ga was doped for Cr site synthesizing La1-xSrxCr1-y(Ga1-zMgz)yO3-δ La1-xSrxCr1-y(Ga1-zMgz)yO3-δexhibit high electronic and oxide ionic conductivity, thermal stability and stability in the wide oxygen partial pressure. Oxygen permeation rate was increased with temperature and increasing Ga rate.
