Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Oxygen Permeation Properties of La0.7Sr0.3Co0.3Fe0.7O3-δ Membrane

La0.7Sr0.3Co0.3Fe0.7O3-δ 분리막의 산소투과특성

  • Received : 2009.04.23
  • Accepted : 2009.05.11
  • Published : 2009.06.30
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Abstract

Perovskite-type ceramic powder, $La_{0.7}Sr_{0.3}Co_{0.3}Fe_{0.7}O_{3-{\delta}}$, have been synthesized successfully by the citrate method. As a result of TGA for precursor, metal-citrate complex in precursor was decomposed in the temperature range of $150{\sim}650^{\circ}C$. XRD analysis showed the single perovskite structure was observed over $1,000^{\circ}C$ without impurities. Typical dense membrane with 1.6 mm thickness has been prepared using as-prepared powder by pressing unilaterally and sintering at $1,300^{\circ}C$. The electrical conductivity of $La_{0.7}Sr_{0.3}Co_{0.3}Fe_{0.7}O_{3-{\delta}}$ membrane increased with increasing temperature at atmosphere of air and then decreased over $600^{\circ}C$ due to oxygen loss from the crystal lattice. The oxygen flux of $La_{0.7}Sr_{0.3}Co_{0.3}Fe_{0.7}O_{3-{\delta}}$ membrane in the range of 700 to $950^{\circ}C$ increased with the increasing temperature from 0.045 to $0.415ml/cm^2{\cdot}min$. The activation energy for oxygen permeation was calculated to be 89.17 kJ/mol.

$La_{0.7}Sr_{0.3}Co_{0.3}Fe_{0.7}O_{3-{\delta}}$ 조성의 페롭스카이트 산화물을 구연산 법으로 합성하였다. 전구물질의 TGA 열분해 분석 결과 $150{\sim}650^{\circ}C$에서 구연산 복합체가 분해되고, XRD 분석결과 $1,000^{\circ}C$ 이후에 순수한 페롭스카이트 구조가 나타났다. 분말을 일축가압 성형 후 $1,300^{\circ}C$로 소결하여 두께 1.6 mm의 치밀한 구조의 분리막을 제작하였다. $La_{0.7}Sr_{0.3}Co_{0.3}Fe_{0.7}O_{3-{\delta}}$의 전기 전도도는 공기분위기에서 $600^{\circ}C$까지는 온도가 증가함에 따라 증가하고, 그 이상의 온도에선 결정 격자로부터의 산소결함 증가에 따라 점차 감소하였다. $700{\sim}950^{\circ}C$ 범위에서 수행된 산소투과실험에서, 투과량은 온도증가에 따라 0.045에서 $0.415ml/cm^2{\cdot}min$로 증가하였으며, 산소투과의 활성화에너지는 89.17 kJ/mol이었다.

Keywords

Acknowledgement

Supported by : 교육과학기술부

References

  1. Rubin, E., MeYer, L. and Coninck, H. D., IPCC Special Report on Carbon dioxide Capture and Storage, CAMBRIDGE UNIVERSITY PRESS, New York(2005)
  2. Park, J. H., Kim, J.-P. and Baek, I. H., 'Preparation and Oxygen Permeation Properties of $La_{0.7}Sr_{0.3}Co_{0.2}Fe_{0.8}O_{3-\delta}$ Membrane, ' J. Korean Ind. Eng. Chem., 19(5), 477-483(2008)
  3. Sunarso, J., Baumann, S., Serra, J. M., Meulenberg, W. A., Liu, S., Lin, Y. S. and Diniz da Costa, J. C., "Mixed Ionic-electronic Conducting(MIEC) Ceramic-based Membranes for Oxygen Separation," J. Membr. Sci., 320(1-2), 13-41(2008) https://doi.org/10.1016/j.memsci.2008.03.074
  4. Iguchi, F., Sata, N., Yugami, H. and Takamura, H., "Oxygen Permeation Properties and the Stability of $La_{0.6}Sr_{0.4}Fe_{0.8}Co_{0.2}O_3$ Studied by Raman Spectroscopy," Solid State Ionics, 177(26-32), 2281-2284(2006) https://doi.org/10.1016/j.ssi.2006.07.025
  5. Ge, L., Zhou, W., Ran, R., Liu, S., Shao, Z., Jin, W. and Xu, N., "Properties and Performance of A-site Deficient $(Ba_{0.5}Sr_{0.5})_{1-x}Co_{0.8}Fe_{0.2}O_{3-\delta}$ for Oxygen Permeating Membrane," J. Membr. Sci., 306(1-2), 318-328(2007) https://doi.org/10.1016/j.memsci.2007.09.004
  6. Kim, S., Yang, Y. L., Christoffersen, R. and Jacobson, A. J., "Oxygen Permeation, Electrical Conductivity and Stability of the Perovskite Oxide $La_{0.2}Sr_{0.8}Cu_{0.4}Co_{0.6}O_{3-x}$," Solid State Ionics, 104 (1-2), 57-65(1997) https://doi.org/10.1016/S0167-2738(97)00427-X