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Synthesis and Characterization of Aerogel-derived Cation-substituted Hexaaluminates

Published online by Cambridge University Press:  10 February 2011

Lin-chiuan Yan  and
Levi T. Thompson
Lin-chiuan Yan
Affiliation:
Department of Chemical Engineering, The University of Michigan, Ann Arbor, MI 48109–2136, USA
Levi T. Thompson
Affiliation:
Department of Chemical Engineering, The University of Michigan, Ann Arbor, MI 48109–2136, USA
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Abstract

New methods have been developed for the synthesis of high surface area cation-substituted hexaaluminates. These materials were prepared by calcining high temperature (ethanol extraction) or low temperature (CO2 extraction) aerogels at temperatures up to 1600°C. Cation-substituted hexaaluminates have emerged as promising catalysts for use in high temperature catalytic combustion. In comparing unsubstituted and cation-substituted hexaaluminates, we found that the phase transformations were much cleaner for the cation-substituted materials. BaCO3 and BaAl2O4 were intermediates during transformation of the unsubstituted materials, while the cation-substituted materials transformed directly from an amorphous phase to crystalline hexaaluminate. Moreover, the presence of substitution cations caused the transformation to occur at lower temperatures. Mn seems to be a better substitution cation than Co since the Mn-substituted materials exhibited higher surface areas and better heat resistances than the Co-substituted materials. The low temperature aerogel-derived materials possessed quite different characteristics from the high temperature aerogel-derived materials. For example, phase transformation pathways were different.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 457: Symposium V – Nanophase and Nanocomposite Materials II , 1996 , 481
Copyright
Copyright © Materials Research Society 1997

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References

REFERENCE

1. Trimm, D.L., Appl. Catal., 7, 249–282 (1983).Google Scholar
2. Zwinkels, M.F.M., Jaras, S.G., and Menon, P.G., Catal. Rev. Sci. Eng., 35(3), 319–358 (1993).Google Scholar
3. Arai, M. and Machida, M., Catal. Today, 10, 82–94 (1991).Google Scholar
4. Arai, M. and Machida, M., J. Catal., 103, 385–393 (1987)Google Scholar
5. Machida, M., Eguchi, K and Arai, H., J. Catal., 120, 377–386 (1989).Google Scholar
6. Busca, G., Catalysis Letter, 31, 65–74 (1995).Google Scholar
7. Mizushima, Y. and Hori, M., J. Mater. Res., 9(9), 2272–76 (1994).Google Scholar
8. Groppi, G., Bellotto, M., Cristiani, C., Forzatti, P. and Villa, P.L., Appl. Catal. A, 104, 101–108(1993)Google Scholar
9. Machida, M., Eguchi, K and Arai, H., J. Am. Ceram. Soc., 71(12), 1142–47 (1988).Google Scholar