Composite mixed ionic-electronic conductors for oxygen separation and electrocatalysis

A mixed oxygen ion and electronic conducting gas impervious membrane having high ambipolar conductivity for oxygen ion transport having a non-homogeneous mixed microstructure comprising about 5 to about 95 volume percent oxygen ion conductor phase is selected from the group consisting of Bi.sub.2-x-y M'.sub.x M.sub.y O.sub.3-.delta., Ce.sub.2-x-y M'.sub.x M.sub.y O.sub.2-.delta., and Th.sub.2-x-y M'.sub.x M.sub.y O.sub.2-.delta. wherein M' is a stabilizer selected from the group consisting of Er, Y, Tm, Yb, Lu, Nd, Sm, Dy, Zr, Hf, Th, Ta, Nb, Pb, Sn, In, and mixtures thereof, M is a dopant selected from the group consisting of Cu, Ti, V, Cr, Mn, Fe, Co, Ni, and mixtures thereof, x is a positive number of about 0.10 to about 0.30, y is a number of 0 to about 0.30, and .delta. is a number to satisfy valence requirements and about 5 to about 95 volume percent of a substantially continuous electronic conducting phase selected from the group consisting of at least one metal selected from the group consisting of Ag, Ir, Pd, Pt and Au, an electronically conductive metal oxide of CrO.sub.2, IrO.sub.2, MnO.sub.2, MoO.sub.2, OsO.sub.2, ReO.sub.2, RhO.sub.2, RuO.sub.2, WO.sub.2, VO.sub.2, Bi.sub.2-y' M.sub.y' O.sub.3-.delta., wherein y' is a numeral of about 0.40 to 2.0 and M and .delta. have the meanings defined above, and mixtures thereof, and an electronically conductive perovskite material selected from La.sub.1-z Sr.sub.z CoO.sub.3-.delta., La.sub.1-z Sr.sub.z MnO.sub.3-.delta., La.sub.1-z Sr.sub.z Mn.sub.1-W Co.sub.W O.sub.3-.delta., La.sub.1-z Sr.sub.z Co.sub.1- W Fe.sub.W O.sub.3-.delta., SrFe.sub.1-z Co.sub.z O.sub.3-.delta., VTiO.sub.3, LaTiO.sub.3, SrFeO.sub.3, SrRuO.sub.3, LaNi.sub.1-z Co.sub.z O.sub.3-.delta., derivative forms and mixtures thereof wherein z is a positive numeral of about 0.01 to about 0.8, w is a positive numeral of about 0.01 to about 0.8, and .delta. is a number to satisfy valence requirements.

A mixed oxygen ion and electronic conducting gas impervious bismuth oxide based membrane having a thickness of about 1 to about 50 microns with high ambipolar conductivity comprising a non-homogeneous mixed microstructure material selected from the group consisting of:

• about 30 to about 99 mole percent of an oxygen ion conducting bismuth oxide based phase having the chemical formulation Bi.sub.2-x-y M'.sub.x M.sub.y O.sub.3-.delta. wherein M' is a stabilizer selected from the group consisting of Er, Y, Tm, Yb, Lu, Nd, Sm, Dy, Zr, Hf, Th, Ta, Nb, Pb, Sn, In, and mixtures thereof, M is a dopant selected from the group consisting of Cu, Ti, Vn, Cr, Mn, Fe, Co, Ni, and mixtures thereof, x is a positive number of about 0.10 to about 0.30, y is a number of 0 to about 0.30, and .delta. is a number to satisfy valence requirements and about 1 to about 70 mole percent of a substantially continuous electronic conducting phase percent selected from the group consisting of metal oxide of at least one metal, at least one perovskite material and mixtures thereof electronically conductive and chemically inert to said oxygen ion conducting bismuth oxide based phase;
• and about 50 to about 95 volume percent said oxygen ion conducting bismuth oxide phase and about 5 to about 50 volume percent of the electronic conductive phase of at least one metal selected from the group consisting of Ag, Ir, Pd, Pt and Au.

A process for oxygen separation from an oxygen containing gas comprising contacting a first side of a gas impermeable mixed oxygen ion and electronic conducting membrane with said oxygen containing gas at an elevated pressure concurrently with contacting a second opposite side of said membrane with gas at a lower pressure than said oxygen containing gas withdrawing oxygen ions from said second opposite side of said membrane, said mixed oxygen ion and electronic conducting membrane with high ambipolar conductivity for oxygen ion transport having a non-homogeneous mixed microstructure comprising about 5 to about 95 volume percent predominantly oxygen ion conductor phase is selected from the group consisting of Bi.sub.2-x-y M'.sub.x M.sub.y O.sub.3-.delta., Ce.sub.2-x-y M'.sub.x M.sub.y O.sub.2-.delta., and Th.sub.2-x-y M'.sub.x M.sub.y O.sub.2-.delta. wherein M' is a stabilizer selected from the group consisting of Er, Y, Tm, Yb, Lu, Nd, Sm, Dy, Zr, Hf, Th, Ta, Nb, Pb, Sn, In, and mixtures thereof, M is a dopant selected from the group consisting of Cu, Ti, V, Cr, Mn, Fe, Co, Ni, and mixtures thereof, x is a positive number of about 0.10 to about 0.30, y is a number of 0 to about 0.30, and .delta. is a number to satisfy valence requirements and about 5 to about 95 volume percent of a substantially continuous electronic conducting phase selected from the group consisting of at least one metal selected from the group consisting of Ag, Ir, Pd, Pt and Au, an electronically conductive metal oxide of CrO.sub.2, IrO.sub.2, MnO.sub.2, MoO.sub.2, OsO.sub.2, ReO.sub.2, RhO.sub.2, RuO.sub.2, WO.sub.2, VO.sub.2, Bi.sub.2-y' M.sub.y' O.sub.3-.delta., wherein y' is a numeral of about 0.40 to 2.0 and M and .delta. have the meanings defined above, and mixtures thereof, and an electronically conductive perovskite material selected from La.sub.1-z Sr.sub.z CoO.sub.3-.delta., La.sub.1-z Sr.sub.z MnO.sub.3-.delta., La.sub.1-z Sr.sub.z Mn.sub.1-W Co.sub.W O.sub.3-.delta., La.sub.1-z Sr.sub.z Co.sub.1-W Fe.sub.W O.sub.3-.delta., SrFe.sub.1-z Co.sub.z O.sub.3-.delta., VTiO.sub.3, LaTiO.sub.3, SrFeO.sub.3, SrRuO.sub.3, LaNi.sub.1-z Co.sub.z O.sub.3-.delta., derivative forms and mixtures thereof wherein z is a positive numeral of about 0.01 to about 0.8, w is a positive numeral of about 0.01 to about 0.8, and .delta. is a number to satisfy valence requirements.

A process for oxygen separation from an oxygen containing gas comprising contacting a first side of a gas impermeable mixed oxygen ion and electronic conducting membrane with said oxygen containing gas at an elevated pressure concurrently with contacting a second Opposite side of said membrane with gas at a lower pressure than said oxygen containing gas withdrawing oxygen ions from said second opposite side of said membrane, said mixed oxygen ion and electronic conducting membrane is a bismuth oxide based membrane having a thickness of about 1 to about 50 microns with high ambipolar conductivity comprising a non-homogeneous mixed microstructure material selected from the group consisting of:

• about 30 to about 99 mole percent of an oxygen ion conducting bismuth oxide based phase having the chemical formulation Bi.sub.2-x-y M'.sub.x M.sub.y O.sub.3-.delta. wherein M' is a stabilizer selected from the group consisting of Er, Y, Tm, Yb, Lu, Nd, Sm, Dy, Zr, Hf, Th, Ta, Nb, Pb, Sn, In, and mixtures thereof, M is a dopant selected from the group consisting of Cu, Ti, V, Cr, Mn, Fe, Co, Ni, and mixtures thereof, x is a positive number of about 0.10 to about 0.30, y is a number of 0 to about 0.30, and .delta. is a number to satisfy valence requirements and about 1 to about 70 mole percent of a substantially continuous electronic conducting phase percent selected from the group consisting of metal oxide of at least one metal, at least one perovskite type material and mixtures thereof electronically conductive and chemically inert to said oxygen ion conducting bismuth oxide based phase;
• and about 50 to about 95 volume percent said oxygen ion conducting bismuth oxide phase and about 5 to about 50 volume percent of the electronic conductive phase of at least one metal selected from the group consisting of Ag, Ir, Pd, Pt and Au.

A composite mixed oxygen ion-electronic conductor having a non-homogeneous mixed microstructure comprising about 5 to about 95 volume percent oxygen ion conducting phase selected from the group consisting of Bi.sub.2-x-y M'.sub.x M.sub.y O.sub.3-.delta., Ce.sub.2-x-y M'.sub.x M.sub.y O.sub.2-.delta., and Th.sub.2-x-y M'.sub.x M.sub.y O.sub.2-.delta. wherein M' is a stabilizer selected from the group consisting of Zr, Hf, Th, Ta, Nb, Pb, Sn, In, and mixtures thereof, M is a dopant selected from the group consisting of Cu, Cr, Mn, Fe, Co, Ni, and mixtures thereof, x is a positive number of about 0.10 to about 0.30, y is a number of 0 to about 0.30, and .delta. is a number to satisfy valence requirements and about 5 to about 95 volume percent of a substantially continuous electronic conducting phase selected from the group consisting of at least one metal selected from the group consisting of Ag, Ir, Pd, Pt and Au, an electronically conductive metal oxide of CrO.sub.2, IrO.sub.2, MnO.sub.2, MoO.sub.2, OsO.sub.2, ReO.sub.2, RhO.sub.2, RuO.sub.2, WO.sub.2, VO.sub.2, Bi.sub.2-y' M.sub.y' O.sub.3-.delta. wherein y' is a numeral of about 0.40 to 2.0 and M and .delta. have the meanings defined above, and mixtures thereof, and an electronically conductive perovskite material selected from La.sub.1-z Sr.sub.z CoO.sub.3-.delta., La.sub.1-z Sr.sub.z MnO.sub.3-.delta., La.sub.1-z Sr.sub.z Mn.sub.1-W Co.sub.W O.sub.3-.delta., La.sub.1-z Sr.sub.z Co.sub.1-W Fe.sub.W O.sub.3-.delta., SrFe.sub.1-z Co.sub.z O.sub.3-.delta., VTiO.sub.3, LaTiO.sub.3, SrFeO.sub.3, SrRuO.sub.3, LaNi.sub.1-z Co.sub.z O.sub.3-.delta., derivative forms and mixtures thereof wherein z is a positive numeral of about 0.01 to about 0.8, w is a positive numeral of about 0.01 to about 0.8, and .delta. is a number to satisfy valence requirements.