Lattice characteristics, structure stability and oxygen permeability of BaFe₁₋ₓYₓO₃₋δ ceramic membranes

• Published in: Journal of membrane science 2011-11, Vol.383 (1-2), p.235-240
• Main Authors: Liu, Xiaotong, Zhao, Hailei, Yang, Jianying, Li, Yuan, Chen, Ting, Lu, Xionggang, Ding, Weizhong, Li, Fushen
• Format: Article
• Language: English
• Subjects: artificial membranes; ceramics; Chemistry; cobalt; Colloidal state and disperse state; crystal structure; electrical conductivity; energy; Exact sciences and technology; General and physical chemistry; ions; iron; Membranes; oxidation; oxygen; permeability; yttrium
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2011.08.059

BaFe₁₋ₓYₓO₃₋δ (x=0–0.2) materials were synthesized by conventional solid-state reaction process for oxygen separation application. The effects of Y-doping on the crystal structure development, electrical conductivity and oxygen permeability were evaluated. Yttrium introduction effectively stabilize the cubic structure of BaFe₁₋ₓYₓO₃₋δ. With Y-doping, the oxidation state of Fe ions reduces, resulting in the increase in oxygen vacancy concentration as charge compensation and the decreases in electrical conductivity. Y-doping enhances the structural stability of BaFe₁₋ₓYₓO₃₋δ in reducing atmosphere but decreases the oxygen permeability. Both of them are attributed to the strong binding energy of Y–O bond. The cobalt free membrane BaFe₀.₉₅Y₀.₀₅O₃₋δ shows good structural stability under reducing atmosphere and acceptable oxygen permeation flux of 0.798ml (STP) min⁻¹cm⁻² at 900°C for 1.1mm thick membrane, making it a promising candidate for future practical applications.