title: High-Performance Microchanneled Asymmetric Gd(0.1)Ce(0.9)O(1.95-δ)-La(0.6)Sr(0.4)FeO(3-δ)-Based Membranes for Oxygen Separation.
abstract: A microchanneled asymmetric dual phase composite membrane of 70 vol % Gd(0.1)Ce(0.9)O(1.95-δ)-30 vol % La(0.6)Sr(0.4)FeO(3-δ) (CGO-LSF) was fabricated by a "one step" phase-inversion tape casting. The sample consists of a thin dense membrane (100 μm) and a porous substrate including "finger-like" microchannels. The oxygen permeation flux through the membrane with and without catalytic surface layers was investigated under a variety of oxygen partial pressure gradients. At 900 °C, the oxygen permeation flux of the bare membrane was 1.6 (STP) ml cm(-2) min(-1) for the air/He-case and 10.10 (STP) ml cm(-2) min(-1) for the air/CO-case. Oxygen flux measurements as well as electrical conductivity relaxation show that the oxygen flux through the bare membrane without catalyst is limited by the oxygen surface exchange. The surface exchange can be enhanced by introduction of catalyst on the membrane surface. An increase of the oxygen flux of ∼1.49 (STP) mL cm(-2) min(-1) at 900 °C was observed when catalyst is added for the air/He-case. Mass transfer polarization through the finger-like support was confirmed to be negligible, which benefits the overall performance. A stable flux of 7.00 (STP) ml cm(-2) min(-1) was observed between air/CO/CO2 over 200 h at 850 °C. Partial surface decomposition was observed on the permeate side exposed to CO, in line with predictions from thermodynamic calculations. In a mixture of CO, CO2, H2, and H2O at similar oxygen activity the material will according to the calculation not decompose. The microchanneled asymmetric CGO-LSF membranes show high oxygen permeability and chemical stability under a range of technologically relevant oxygen potential gradients.
authors.affiliation: Department of Energy Conversion and Storage, Technical University of Denmark , Risø campus, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
authors.forename: Shiyang
authors.initials: S
authors.lastname: Cheng
authors.affiliation: CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China , Hefei 230026, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Energy Conversion and Storage, Technical University of Denmark , Risø campus, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
authors.forename: Simona
authors.initials: S
authors.lastname: Ovtar
authors.affiliation: Department of Energy Conversion and Storage, Technical University of Denmark , Risø campus, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
authors.forename: Søren B
authors.initials: SB
authors.lastname: Simonsen
authors.affiliation: Department of Energy Conversion and Storage, Technical University of Denmark , Risø campus, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Key Laboratory of Mobile Materials MOE, Jilin University , 130012 Changchun, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Energy Conversion and Storage, Technical University of Denmark , Risø campus, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Søgaard
authors.affiliation: Department of Energy Conversion and Storage, Technical University of Denmark , Risø campus, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kaiser
authors.affiliation: Department of Energy Conversion and Storage, Technical University of Denmark , Risø campus, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
authors.forename: Peter Vang
authors.initials: PV
authors.lastname: Hendriksen
authors.affiliation: CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China , Hefei 230026, China.
authors.forename: Chusheng
authors.initials: C
authors.lastname: Chen
keywords: dual-phase composite membranes; electrical conductivity relaxation; mass transfer polarization; phase inversion; surface exchange; thermodynamic calculation