View PDF Version
 
DOI: 10.1039/A809200A (Paper) Reference Section for: J. Mater. Chem., 1999, 9, 1155-1159

Sol-gel processed fluorite-structured PrOy-ZrO2 mixed oxides deposited on alumina

(Note: The full text of this document is currently only available in the PDF Version )

C. K. Narula, L. F. Allard and G. W. Graham

Abstract

Preparation of PrOy (Pr6O11) or single-phase fluorite-structured PrOy-ZrO2 mixed oxide, supported on high-surface-area γ-alumina, was achieved for the first time by impregnation of γ-alumina powder with Pr(OiC3H7)3 or a mixture of Pr(OiC3H7)3 and Zr(OiC3H7)4·iC3H7OH and calcination at 600[thin space (1/6-em)]°C. Subsequent calcination at 900[thin space (1/6-em)]°C caused partial transformation of Pr6O11 to PrAlO3 but only improved the crystallinity of the mixed oxide. Further calcination at 1200[thin space (1/6-em)]°C led to complete transformation of Pr6O11 but only partial disproportionation of PrOy-ZrO2 to PrAlO3 and ZrO2; transformation of γ- to α-alumina was also inhibited in the case of the mixed oxide. In contrast, there was no evidence of any crystalline phase containing praseodymium upon calcination of γ-alumina powder impregnated with a mixture of praseodymium nitrate and zirconium chloride in a 1:0 or 1:1 molar ratio. These results show that praseodymium oxide can be supported on alumina and stabilized against reaction with the alumina by the incorporation of zirconium in the form of the mixed oxide, PrOy-ZrO2, provided it is deposited using alkoxide precursors. This stabilization should allow praseodymia to undergo redox processes and thus provide oxygen storage capacity when supported on alumina in a catalyst washcoat.

References

  1. C. K. Narula, J. E. Allison, D. R. Bauer and H. S. Gandhi, Chem. Mater., 1996, 8, 984 CrossRef CAS.
  2. A. D. Logan and M. Shelef, J. Mater. Res., 1994, 9, 468 CAS.
  3. B. G. Baker and M. Jasieniak, in Surface Science: Principles and Current Applications, ed. R. J. MacDonald, E. C. Tagauer and K. R. Wandelt, Springer, Berlin, 1996, pp. 348–362 Search PubMed.
  4. M. Yu. Sinev, G. W. Graham, L. P. Haack and M. Shelef, J. Mater. Res., 1996, 11, 1960 CrossRef CAS.
  5. M. D. Krasil'nikov, I. V. Vinokurov and S. D. Nikitina, Fiz. Khim. Electrokhim. Rasplavl. Tverd. Electrolitov, Tezisy Dokl. Vses. Konf. Fiz. Khim. Ionnykh Rasplanov Tverd. Electrolitov 7th, 1979, 3, 123 Search PubMed.
  6. C. K. Narula, K. L. Taylor, L. P. Haack, L. F. Allard, A. Datye, M. Yu. Sinev, M. Shelef, R. W. McCabe, W. Chun and G. W. Graham, in Recent Advances in Catalytic Materials, ed. N. M. Rodriguez, S. L. Soled and J. Hrbek(1997 MRS Fall Meeting Proc., vol. 497), Materials Research Society, 1998, p. 15 Search PubMed; C. K. Narula, L. P. Haack, W. Chun, H.-W. Jen and G. W. Graham, J. Phys. Chem., submitted Search PubMed.
  7. D. C. Bradley, R. C. Mehrotra and D. P. Gaur, Metal Alkoxides, Academic Press, London, 1978 Search PubMed.
  8. Y. Xie, M. Qian and Y. Tang, Sci. Sin. Ser. B, 1984, 6, 27 Search PubMed; Y. Xie, M. Qian and Y. Tang, Sci. Sin. Ser. B, 1984, 6, 549 Search PubMed.
  9. Y. Xie and Y. Tang, Advances in Catalysis, ed. D. D. Eley, H. Pines and P. B. Weisz, Academic Press, Inc., New York, 1990, vol. 37, p. 1 Search PubMed.
  10. M. Bettman, R. E. Chase, K. Otto and W. H. Weber, J. Catal., 1989, 117, 447 CrossRef CAS.
  11. N. Ya. Turova, N. I. Kozlova and A. V. Novoselova, Russ. J. Inorg. Chem., 1980, 25, 1788.
Click here to see how this site uses Cookies. View our privacy policy here.