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Journal of Materials Science

, Volume 30, Issue 7, pp 1794–1800 | Cite as

Thermal stability of aluminas by hydrothermal treatment of an alkoxide-derived gel

  • T. Fukui
  • M. Hori
Papers

Abstract

Alumina precursors were prepared by hydrothermal treatment of alkoxide-derived alcogels. The crystalline structure of precursor beohmites and their microstructural change during heat treatment were examined and the specific surface area of the alumina precursors after heating was measured. The alumina prepared by hydrothermal treatment at 270 °C retained high specific surface areas at high temperatures; e.g. 35.0, 8.3 and 5.4 m2g−1 at 1200, 1400 and 1500 °C, respectively. The thermal stability of the aluminas depended on the hydrothermal temperatures. For excellent thermal stability, the following factors are necessary: (1) grain growth of beohmite as an alumina precursor, and a grain size of more than 20 nm for the (1 2 0) plane; (2) a crystallite size for the (2 0 0) plane exceeding that for the (0 0 2) plane; (3) anisotropic growth of the beohmite crystal. In the transition alumina region (≤ 1200 °C), the thermal stability of the alumina is caused by raising the α transformation temperature, resulting from decreasing the number of grain boundaries by beohmite growth. In the α-alumina region (> 1200 °C), inhibiting the three-dimensional grain growth achieves thermal stability, resulting from preservation of the anisotropic structure introduced into the beohmite.

Keywords

Alumina Grain Size Heat Treatment Thermal Stability Crystallite Size 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    R. Prasad, L. A. Kennedy and E. Ruckenstein, Catal. Rev. Sci. Eng. 26 (1984) 1.CrossRefGoogle Scholar
  2. 2.
    H. Yamashita, A. Kato, N. Watanabe and S. Matsuda, Nippon-Kagaku-Kaishi (1986) 1169.Google Scholar
  3. 3.
    S. Mastuda and H. Yamashita, Syokubai 29 (1987) 293.Google Scholar
  4. 4.
    M. Machida, K. Eguchi and H. Arai, J. Catal. 103 (1987) 385.CrossRefGoogle Scholar
  5. 5.
    B. Beguin, E. Garbowski and M. Primet, ibid. 127 (1991) 595.CrossRefGoogle Scholar
  6. 6.
    T. Mori, T. Horiuchi, T. Ida and Y. Murase, J. Mater. Chem. 2 (1992) 577.CrossRefGoogle Scholar
  7. 7.
    M. Inoue, H. Otsu, H. Kominami and T. Inui, J. Mater. Sci. Lett. 11 (1992) 269.CrossRefGoogle Scholar
  8. 8.
    K. Maeda, F. Mizukami, M. Watanabe, N. Arai, S. Niwa, M. Toba and K. Shimizu, ibid. 9 (1990) 522.CrossRefGoogle Scholar
  9. 9.
    Y. Mizushima and M. Hori, “Eurogel '91”, edited by S. Vilmint, R. Nass and H. Schmidt (Elsevier Science, Amsterdam, 1992) p. 195.CrossRefGoogle Scholar
  10. 10.
    N. Tsustumi, K. Sakata and T. Kunitake, Chem. Lett. 1992 (1992) 1465.Google Scholar
  11. 11.
    T. Fukui and M. Hori, J. Mater. Sci. Lett. 13 (1994) 413.CrossRefGoogle Scholar
  12. 12.
    B. E. Yoldas, Am. Ceram. Soc. Bull. 54 (1975) 289.Google Scholar
  13. 13.
    M. Inoue, H. Kominami and T. Inui, J. Am. Ceram. Soc. 73 (1990) 1100.CrossRefGoogle Scholar
  14. 14.
    T. Adschiri, K. Kanazawa and K. Arai, ibid. 75 (1992) 2615.CrossRefGoogle Scholar
  15. 15.
    M. Inoue, Y. Kondo and T. Imui, Inorg. Chem. 27 (1988) 215.CrossRefGoogle Scholar
  16. 16.
    H. Schaper, E. B. M. Doesburg, P. H. M. de Körte and L. L. Van Reijen, Solid State Ionics 16 (1985) 261.CrossRefGoogle Scholar
  17. 17.
    T. Ishikawa, R. Ohashi, H. Nokabayashi, N. Kakuta, A. Ueno and A. Furuta, J. Catal. 134 (1992) 87.CrossRefGoogle Scholar

Copyright information

© Chapman & Hall 1995

Authors and Affiliations

  • T. Fukui
    • 1
  • M. Hori
    • 1
  1. 1.Technical Research CenterKrosaki CorporationKitakyushuJapan

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