- Title
- Effects of scandium doping concentration on the properties of strontium cobalt oxide membranes
- Creator
- Zeng, Pingying; Ran, Ran; Shao, Zongping; Yu, Hai; Liu, Shaomin
- Relation
- Brazilian Journal of Chemical Engineering Vol. 26, Issue 3, p. 563-574
- Publisher Link
- http://dx.doi.org/10.1590/S0104-66322009000300012
- Publisher
- Associacao Brasileira de Engenharia Quimica (ABEQ)
- Resource Type
- journal article
- Date
- 2009
- Description
- Perovskite-type mixed conducting oxides of SrCo₁₋yScyO₃₋δ (y=0.02-0.7) were synthesized by a combined EDTA-citrate complexing method. Different scandium doping concentrations in SrCo₁₋yScyO₃₋δ have significant effects on the phase structure, electrical conductivity, surface properties and oxygen permeation behaviour of the resultant membranes. SrCoO₃₋δ without scandium incorporation displayed a 2H BaNiO₃-type structure with almost zero oxygen flux at high temperatures. Small amounts of Sc₂O₃ doping (y<0.1) efficiently stabilized the oxide in a cubic perovskite structure, leading to a sharp increase in the permeation flux, with a maximum value of 3.1ml.cm⁻².min⁻¹ achieved at 900ºC for SrCo₀․₉₅Sc₀․₀₅O₃₋δ and SrCo₀․₉Sc₀․₁O₃₋δ membranes. The permeation process could be rate-limited by either the oxygen bulk diffusion, oxygen surface exchange, or a combination of both depending on the scandium doping level. Further increases of the Sc³⁺ doping concentration (y>0.1) were found to lower the membrane oxygen fluxes, with y³≥0.4 doped SrCo₁₋yScyO₃₋δ ceramics no longer showing any oxygen permeation.
- Subject
- perovskite; mixed conduction; oxygen separation membrane; rate limiting
- Identifier
- http://hdl.handle.net/1959.13/917089
- Identifier
- uon:8204
- Identifier
- ISSN:0104-6632
- Language
- eng
- Full Text
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