화학공학소재연구정보센터
홈 로그인 로그아웃 연락처 사이트맵
Journal of the Korean Industrial and Engineering Chemistry, Vol.19, No.5, 477-483, October, 2008
Export Citation
La0.7Sr0.3Co0.2Fe0.8O3-δ 분리막의 제조 및 산소투과 특성
Preparation and Oxygen Permeation Properties of La0.7Sr0.3Co0.2Fe0.8O3.δ Membrane
박정훈†, 김종표, 백일현
  • 한국에너지기술연구원 온실가스연구센터, 대전 305-343
Jung Hoon Park†, Jong Pyo Kim, and Il Hyun Baek
  • Green House Gas Research Center, Korea Institute of Energy Research, Daejeon 305-343, Korea
E-mail:
초록
구연산법을 이용하여 La0.7Sr0.3Co0.2Fe0.8O3-δ 산화물을 합성하였으며, 합성된 분말은 압축 성형 후 1300 ℃에서 소결하여 치밀한 페롭스카이트 분리막을 제조하였다. 구연산법으로 제조한 La0.7Sr0.3Co0.2Fe0.8O3-δ의 전구물질은 TGA와 XRD로 분석하였다. 260∼410 ℃ 온도 영역에서 전구물질의 금속.구연산 복합체가 분해되며 페롭스카이트 산화물이 얻어지나 XRD 분석결과 900 ℃ 이하에서는 SrCO3가 불순물로 존재하였다. 분리막의 전기전도도는 온도가 증가함에 따라 증가하다. 결정격자의 산소 손실로 인해 공기분위기에서는 700 ℃ (Po2 = 0.2 atm)부터, 헬륨분위기에서는 600 ℃ (Po2 = 0.01 atm) 부터 각각 감소하였다. 산소투과량은 온도가 증가할수록 증가하였고, 두께 1.6 mm의 La0.7Sr0.3Co0.2Fe0.8O3.δ 분리막은 950 ℃에서 0.31 cm 3 /cm2 .min의 최대 투과도를 보였다. 산소투과에 대한 활성화 에너지는 750∼950 ℃ 온도 영역에 서 88.4 kJ/mol이었다. 40 h의 투과실험 후에 분리막의 페롭스카이트 결정 구조는 변하지 않았으며 0.3 mol Sr doping 시 2차상이 생성되지 않고 안정하였다.
La0.7Sr0.3Co0.2Fe0.8O3-δ oxide was synthesized by a citrate method and a typical dense membrane of perovskite oxide has been prepared using as-prepared powder by pressing and sintering at 1300 ℃. Precursor of La0.7Sr0.3Co0.2Fe0.8O3-δ prepared by citrate method was investigated by TGA and XRD. Metal-citrate complex in precursor was decomposed into perovskite oxide in the temperature range of 260∼410 ℃ but XRD results showed SrCO3 existed as impurity at less than 900 ℃. Electrical conductivity of membrane increased with increasing temperature but then decreased over 700 ℃ in air atmosphere (Po2 = 0.2 atm) and 600 ℃ in He atmosphere (Po2 = 0.01 atm) respectively due to oxygen loss from the crystal lattice. The oxygen permeation flux increased with increasing temperature and maximum oxygen permeation flux of La0.7Sr0.3Co0.2Fe0.8O3-δ membrane with 1.6 mm thickness was about 0.31 cm 3 /cm 2 .min at 950 ℃. The activation energy for oxygen permeation was 88.4 kJ/mol in the temperature range of 750∼950 ℃. Perovskite structure of membrane was not changed after permeation test of 40 h and the membrane was stable without secondary phase change with 0.3 mol Sr addition.
Keywords:La0.7Sr0.3Co0.2Fe0.8O3-δ membrane;electrical conductivity;oxygen permeation;stability
  1. Thambimuthu K, Soltanieh M, Abanades JC, IPCC Special Report on Carbon dioxide Capture and Storage, ed. O. Davidson, B. Metz, 1, 6, Cambridge University Press London (2005)
  2. Burggraaf AJ, H J, Bouwmeester M, Fundamentals of Inorganic Membrane Science and Technology, ed. A. J. Burggraaf and L. Cot, 4, 435, Elsevier, Amsterdam (1996)
  3. Park JH, Park SD, Korean J. Chem. Eng., 24(5), 897 (2007)
  4. Kao CF, Yang WD, Appl. Organomet. Chem., 13, 383 (1999)
  5. Kim S, Yang YL, Christoffersen R, Jacobson AJ, Solid State Ion., 104(1-2), 57 (1997)
  6. Park JH, Kim JP, Kwon HT, Soo KJ, Desalination, 233, 73 (2008)
  7. K. R. Patent 10-2007-0130276 (2007)
  8. Li SG, Jin WQ, Huang P, Xu NP, Shi J, Lin YS, Hu MZC, Payzant EA, Ind. Eng. Chem. Res., 38(8), 2963 (1999)
  9. Teraoka Y, Nobunaga T, Yamazoe N, Chem. Lett., 503 (1988)
  10. Tsai CY, Dixon AG, Ma YH, Moser WR, Pascucci MR, J. Am. Ceram. Soc., 81, 1437 (1998)
  11. Stevenson JW, Armstrong TR, Carneim RD, Pederson LR, Weber WJ, J. Electrochem. Soc., 143(9), 2722 (1996)
  12. Qi XW, Lin YS, Swartz SL, Ind. Eng. Chem. Res., 39(3), 646 (2000)