TY - JOUR
T1 - A comparative structure and performance study of La1-xSr xCoO3-d and La1-xSrxCo0.9 Nb0.1O3-d (x=0.5, 0.7, 0.9, and 1.0) oxygen permeable mixed conductors
AU - Zhao, Jing
AU - Sunarso, Jaka
AU - Zhou, Wei
AU - Shao, Zongping
AU - Ran, Ran
AU - Liu, Shaomin
PY - 2011
Y1 - 2011
N2 - In this work, we investigate and contrast the perovskite structure of La1-x Srx Co O3-δ and La1-x Srx Co0.9 Nb0.1O3-δ (both for x=0.5, 0.7, 0.9, and 1.0) as well as their oxygen nonstoichiometry, oxygen bulk-diffusion, and surface exchange coefficients to describe their distinct performance as ceramic oxygen ionic transport membranes. Le Bail refinements of x-ray diffraction data demonstrate that except for SrCo O3-δ, the structure for all title compounds at room temperature can be fitted adequately using rhombohedrally distorted perovskite structure. The presence of lanthanum is found to reduce the solubility of niobium in perovskite lattice. Aside from Sr Co0.9 Nb0.1 O3-δ, structure deterioration or transformation occurs for all title compounds upon subjected to modest reducing atmosphere of nitrogen. Oxygen permeation testing reveals that Sr0.9 Co0.9 Nb0.1 O3-δ membrane exhibits the largest fluxes among all the title compounds, followed by La0.1 Sr0.9 Co0.9 Nb0.1 O 3-δ and La0.1 Sr0.9 Co0.9 Nb0.1 O3-δ and La0.1 Sr0.9 Co O3-δ. The oxygen permeation values exhibit exact the same trend as a function of composition with the bulk-diffusion and surface exchange coefficients values indicating both bulk-diffusion and surface exchange limits the oxygen transport through title compounds. In addition, 300-hour permeation testing on the best doped compounds, La0.1 Sr0.9 Co 0.9 Nb0.1 O3-δ and La0.1 Sr0.9 Co O3-δ demonstrates that La0.1 Sr0.9 Co O3-δ has better performance stability, e.g. lower degradation percentage with time relative to its non niobium doped counterpart.
AB - In this work, we investigate and contrast the perovskite structure of La1-x Srx Co O3-δ and La1-x Srx Co0.9 Nb0.1O3-δ (both for x=0.5, 0.7, 0.9, and 1.0) as well as their oxygen nonstoichiometry, oxygen bulk-diffusion, and surface exchange coefficients to describe their distinct performance as ceramic oxygen ionic transport membranes. Le Bail refinements of x-ray diffraction data demonstrate that except for SrCo O3-δ, the structure for all title compounds at room temperature can be fitted adequately using rhombohedrally distorted perovskite structure. The presence of lanthanum is found to reduce the solubility of niobium in perovskite lattice. Aside from Sr Co0.9 Nb0.1 O3-δ, structure deterioration or transformation occurs for all title compounds upon subjected to modest reducing atmosphere of nitrogen. Oxygen permeation testing reveals that Sr0.9 Co0.9 Nb0.1 O3-δ membrane exhibits the largest fluxes among all the title compounds, followed by La0.1 Sr0.9 Co0.9 Nb0.1 O 3-δ and La0.1 Sr0.9 Co0.9 Nb0.1 O3-δ and La0.1 Sr0.9 Co O3-δ. The oxygen permeation values exhibit exact the same trend as a function of composition with the bulk-diffusion and surface exchange coefficients values indicating both bulk-diffusion and surface exchange limits the oxygen transport through title compounds. In addition, 300-hour permeation testing on the best doped compounds, La0.1 Sr0.9 Co 0.9 Nb0.1 O3-δ and La0.1 Sr0.9 Co O3-δ demonstrates that La0.1 Sr0.9 Co O3-δ has better performance stability, e.g. lower degradation percentage with time relative to its non niobium doped counterpart.
UR - http://www.scopus.com/inward/record.url?scp=79551613319&partnerID=8YFLogxK
U2 - 10.1149/1.3533904
DO - 10.1149/1.3533904
M3 - 文章
AN - SCOPUS:79551613319
SN - 0013-4651
VL - 158
SP - H299-H304
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 3
ER -
