Importance of the surface exchange kinetics as rate limiting step in oxygen permeation through mixed-conducting oxides

Attention is drawn to the possible involvement of the surface exchange kinetics in limiting the rate of oxygen permeation through mixed-conducting oxide ceramics. A theoretical approach is provided with which it is possible to distinguish between surface exchange- and bulk diffusion controlled kinetics of oxygen permeation. New results on the oxygen permeability of perovskites La0.8Sr0.2CoO3−σ and SrCo0.8Fe0.2O3−σ are presented. The importance of the exchange reaction re to diffusion in limiting overall oxygen transport through (La,Sr)(Co,Fe)O3−σ perovskite-type oxides is emphasized.

[1]  V. Cherepanov,et al.  Oxygen nonstoichiometry of La1−xSrxCoO3−δ (0 < x ≤ 0.6) , 1990 .

[2]  B. Steele.  Oxygen ion conductors and their technological applications , 1992 .

[3]  B. Boukamp,et al.  Mixed conductivity in terbia-stabilized bismuth oxide , 1992 .

[4]  J. Mizusaki,et al.  Diffusion of oxide ions in LaFeO3 single crystal , 1984 .

[5]  J. Mizusaki,et al.  Tracer diffusion coefficient of oxide ions in LaCoO3 single crystal , 1984 .

[6]  R. Grasselli,et al.  Oxidative dehydrodimerization of propylene over a Bi2O3La2O2 oxide ion-conductive catalyst , 1986 .

[7]  H. Tagawa,et al.  Nonstoichiometry of the perovskite-type oxides La1−xSrxCoO3−δ , 1989 .

[8]  B. Steele,et al.  Mixed electronic/ionic conductivity of the solid solution La(1 − x)SrxCo(1 − y)NiyO3 − δ (x: 0·4, 0·5, 0·6 and y: 0·2, 0·4, 0·6) , 1993 .

[9]  W. L. Worell,et al.  Electrical properties of mixed-conducting oxides having high oxygen-ion conductivity , 1992 .

[10]  E. Kurumchin,et al.  An isotope exchange study of the behaviour of electrochemical systems , 1990 .

[11]  Harumi Yokokawa,et al.  Oxygen permeation modelling of perovskites , 1993 .

[12]  J. Nowotny,et al.  Influence of the surface on the equilibration kinetics of nonstoichiometric oxides , 1981 .

[13]  P. Pacey,et al.  Mechanism of Oxygen Permeation Through Lime‐Stabilized Zirconia , 1985 .

[14]  Norio Miura,et al.  Influence of constituent metal cations in substituted LaCoO3 on mixed conductivity and oxygen permeability , 1991 .

[15]  K. Kishio,et al.  Diffusion of oxide ion vacancies in perovskite-type oxides , 1988 .

[16]  J. Mizusaki,et al.  Nonstoichiometry and defect structure of the perovskite-type oxides La1−xSrxFeO3−° , 1985 .