Re-evaluation of Ba0.5Sr0.5Co0.8Fe0.2O3−δ perovskite as oxygen semi-permeable membrane

Zeng, Pingying; Chen, Zhihao; Zhou, Wei; Gu, Hongxia; Liu, Shaomin

doi:10.1016/j.memsci.2007.01.003

Cited by 235 publications

(105 citation statements)

References 40 publications

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“…The excess oxygen ions of x = 0.4 sample increase the repulsion between oxygen anions so that the distance between the oxygen anions in the lattice of x = 0.4 sample increase and the cations radius on A site became larger [16] ) distance on x = 0.4 sample.…”

Section: Methodsmentioning

confidence: 99%

“…The x = 0.2 sample has both the smallest oxygen stoichiometry and the highest Fe 4+ content ( Table 1). The oxygen losses lead the decrease in the coordination number of A site metal ions so that the radii of A site metal ions in La1-xSrxCo0.8Fe0.2O3±δ are also decreased [16]. The small radius of metal ion in A site and the shortened Fe Fig.…”

Section: Thermal Expansion Coefficient (Tec)mentioning

confidence: 99%

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Thermal Expansion, Microhardness and Oxygen Permeation of La1-xSrxCo0.8Fe0.2O3+δ Membranes

Aliyatulmuna¹,

Utomo²,

Burhan³

et al. 2017

Asian J. Chem.

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Dense ceramic membranes acting as oxygen and electron ion-conductors can be used as the catalysts for syngas production. The La1-xSrxCo0.8Fe0.2O3+δ (LSCF) systems were known to have a high ionic and electronic conductivity. In the application, the La1-xSrxCo0.8Fe0.2O3+δ membranes required low thermal expansion, microhardness and high oxygen permeation flux. The changes in the expansion, hardness, and oxygen flux of the La1-xSrxCo0.8Fe0.2O3+δ perovskite membranes with various strontium substitutions were studied. The magnitude of both the thermal expansion and the oxygen content of the La1-xSrxCo0.8Fe0.2O3+δ membranes decreased with up to 20 % strontium substitution and then increased with 30 and 40 % strontium ion substitution. Meanwhile, the hardness and shrinkage improved by various strontium ion substitutions, except with 20 % strontium. The highest oxygen flux over La1-xSrxCo0.8Fe0.2O3+δ (0.0 ≤ x ≤ 0.4) membranes in the surface exchange-controlled processes was found of the membrane with 30 % strontium substitution.

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Section: Methodsmentioning

confidence: 99%

Section: Thermal Expansion Coefficient (Tec)mentioning

confidence: 99%

Thermal Expansion, Microhardness and Oxygen Permeation of La1-xSrxCo0.8Fe0.2O3+δ Membranes

Aliyatulmuna¹,

Utomo²,

Burhan³

et al. 2017

Asian J. Chem.

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“…BSCF powder was synthesized by microwave assisted combustion synthesis. Stoichiometric amounts of metal nitrates corresponding to BSCF phase (Ba(NO 3 ) 2 , Sr(NO 3 ) 2 , Co(NO 3 ) 2 .6H 2 O, Fe(NO 3 ) 3 .9H 2 O) and the fuel urea ((CO(NH 2 ) 2 ) were dissolved in deionized water into a silica crucible at temperature of 80 °C. After that, the crucible was placed in a domestic microwave oven (2.45 GHz, 900W) for 8 min.…”

Section: Methodsmentioning

confidence: 99%

“…In this application, an oxygen partial pressure gradient between the membrane sides acts as the driving force for the oxygen transport across the membrane. The oxygen permeation process through these membranes involves oxygen exchange on the membrane surfaces and migration of oxygen anions through the crystal lattice via oxygen vacancies until to reach the opposite side and the exchange reverse process occurs [1][2][3][4][5] . In particular, the BSCF perovskite is known by its high oxygen diffusivity and extremely low surface resistance to oxygen reduction, and incorporation into crystal lattice 1,2,[6][7][8] .…”

Section: Introductionmentioning

confidence: 99%

Microwave Assisted Synthesis and Sintering of Ba0.5Sr0.5Co0.8Fe0.2O3-δ Perovskite

Nuernberg

Morelli

2015

Mat. Res.

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“…6,8,9 Lattice changes attributed by the oxygen vacancy with elevated temperature can affect the conduction path for oxygen vacancies as a geometrical factor. 10 The difference in the ionic radii induced by the valence change of transition metals in the B-site is also another factor contributing to BO 6 distortion. We hypothesize that the difference in the ionic radius between cobalt ions and Mn ion in SCMCo has an effect on the octahedral change of BO 6 because cobalt ion has a stronger self-reduction property from Co 3+ to Co 2+ relative to other transition metal ions at elevating temperature.…”

mentioning

confidence: 99%

Lattice Relaxation and Electrochemical Performances of Cobalt-Doped Sr_0.9Ce_0.1MnO_3-δComposite Cathodes for Intermediate-Temperature Solid Oxide Fuel Cells

Ryu

Noh²,

Kim

et al. 2016

J. Electrochem. Soc.

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The relaxation mechanism of the octahedral distortion in Sr 0.9 Ce 0.1 Mn 1-x Co x O 3-δ (SCMCo) as a function of the cobalt content and temperature, and the electrochemical properties of the SCMCo-SDC composite cathodes were investigated. Substituted cobalt ions and manganese ions were in a mixed valence state consisting of Co 3+ /Co 2+ and Mn 4+ /Mn 3+ , respectively. The Co K-edges were shifted toward low energy by an increase in the Co content, which indicates that Co 3+ (0.55 Å) is reduced to Co 2+ (0.65 Å). The decrease in the difference in ionic radii between B-site elements relieved the octahedral distortion as confirmed by a decrease in the peak intensity in the Fourier transformed EXAFS of the Co K-edge. The lattice volume increased up to 1.4 and 1.9 vol.% with Co content and temperature, respectively. The Co-O bond angle was closer to 180 • C with an increase in Co content thereby leading to an increase in the oxygen ion conductivity. Therefore, the relaxation of the distortion by substitution of cobalt ions should affect the improvement in the oxygen mobility. The polarization resistances of the SCMCo-SDC composite cathodes at 650 • C were decreased up to four times with an increase in the cobalt content, and the power densities of the single cells (Ni-SDC/SDC/SCMCo-SDC) were also enhanced up to 177% with increasing cobalt content. However, the polarization resistance (R p ) can be increased through doping of cerium ions for structural stability and enhancement of the electrical conductivity. 4 The increase in R p is associated with a decrease in oxygen vacancy concentration and mobility, due to the strong hybridization between the Ce 4f/5d and oxygen 2p orbitals and an increase in the MnO 6 structural distortion, respectively. 5,6 We have investigated Sr 0.9 Ce 0.1 Mn 1-x Co x O 3-δ (SCMCo) to enhance the oxygen vacancy concentration and have identified the lower R p because of the increase in oxygen vacancy, which is a result of the mixed valence state of cobalt ions. 7 It is reported that BO 6 octahedral distortion can occur in most perovskite oxides (expressed as ABO 3 ) because of formation of oxygen vacancy and difference in ionic radii, which is occurred by temperature and mixed valence state changes of the transition metals. 6,8,9 Lattice changes attributed by the oxygen vacancy with elevated temperature can affect the conduction path for oxygen vacancies as a geometrical factor. 10 The difference in the ionic radii induced by the valence change of transition metals in the B-site is also another factor contributing to BO 6 distortion. We hypothesize that the difference in the ionic radius between cobalt ions and Mn ion in SCMCo has an effect on the octahedral change of BO 6 because cobalt ion has a stronger self-reduction property from Co 3+ to Co 2+ relative to other transition metal ions at elevating temperature. Therefore, the conduction properties of oxygen vacancies are a result of Co doping, in terms of the carrier mobility, based on the investigation of the effects of temperature and t...

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Re-evaluation of Ba0.5Sr0.5Co0.8Fe0.2O3−δ perovskite as oxygen semi-permeable membrane

Cited by 235 publications

References 40 publications

Thermal Expansion, Microhardness and Oxygen Permeation of La1-xSrxCo0.8Fe0.2O3+δ Membranes

Thermal Expansion, Microhardness and Oxygen Permeation of La1-xSrxCo0.8Fe0.2O3+δ Membranes

Microwave Assisted Synthesis and Sintering of Ba0.5Sr0.5Co0.8Fe0.2O3-δ Perovskite

Lattice Relaxation and Electrochemical Performances of Cobalt-Doped Sr_0.9Ce_0.1MnO_3-δComposite Cathodes for Intermediate-Temperature Solid Oxide Fuel Cells

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Re-evaluation of Ba0.5Sr0.5Co0.8Fe0.2O3−δ perovskite as oxygen semi-permeable membrane

Cited by 235 publications

References 40 publications

Thermal Expansion, Microhardness and Oxygen Permeation of La1-xSrxCo0.8Fe0.2O3+δ Membranes

Thermal Expansion, Microhardness and Oxygen Permeation of La1-xSrxCo0.8Fe0.2O3+δ Membranes

Microwave Assisted Synthesis and Sintering of Ba0.5Sr0.5Co0.8Fe0.2O3-δ Perovskite

Lattice Relaxation and Electrochemical Performances of Cobalt-Doped Sr0.9Ce0.1MnO3-δComposite Cathodes for Intermediate-Temperature Solid Oxide Fuel Cells

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Lattice Relaxation and Electrochemical Performances of Cobalt-Doped Sr_0.9Ce_0.1MnO_3-δComposite Cathodes for Intermediate-Temperature Solid Oxide Fuel Cells