Journal of thermal analysis

, Volume 49, Issue 1, pp 535–540 | Cite as

Thermoanalytical characterization of molybdenum-based catalytic materials

  • J. L. Brito
Adsorption, Catalysis

Abstract

Thermoanalytical techniques, especially temperature-programmed reduction (TPR), were employed for the characterization of oxidic precursors of molybdenum-based catalysts, sulfides derived from them, and three thiomolybdate compounds, employed as models or precursors of hydrodesulfurization atalysts. Correlations were found between TPR data and the presence of single and mixed oxides of Mo and Ni, Co or Fe, as demonstrated by XRD. The same phases and the thiomolybdates were shown to be present in supported catalytic precursors. Differences between the reducibilities of the mixed oxides of Ni-Mo, Co-Mo and Fe-Mo are easily appreciated from TPR, including those of the α- and Β- polymorphic modifications of NiMoO4.

Keywords

Co-Mo Fe-Mo Mo-based catalysts Ni-Mo thiomolybdates TPR-XRD 

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References

  1. 1.
    S. Bhatia, J. Beltramini and D. D. Do, Catal. Today, 7 (1990) 309.CrossRefGoogle Scholar
  2. 2.
    J. V. Sanders and K. C. Pratt, J. Catal., 67 (1981) 331.CrossRefGoogle Scholar
  3. 3.
    J. L. Brito, A. L. Barbosa, A. Albornoz, F. Severino and J. Laine, Catal. Lett., 26 (1994) 329.CrossRefGoogle Scholar
  4. 4.
    J. Laine, J. L. Brito and F. Severino, J. Catal. 131 (1991) 385.CrossRefGoogle Scholar
  5. 5.
    J. L. Brito and J. Laine, J. Catal., 139 (1993) 540.CrossRefGoogle Scholar
  6. 6.
    J. L. Brito, M. Ilija and P. Hernández, Thermochim. Acta, 256 (1995) 325.CrossRefGoogle Scholar
  7. 7.
    J. L. Brito, J. Laine and K. C. Pratt, J. Mater. Sci., 24 (1989) 425.CrossRefGoogle Scholar
  8. 8.
    J. Haber and J. Janas, in Proc. 25th Int. Meet. Soc. Chim. Phys., Reaction Kinetics in Heterogeneous Chemical Systems (P. Barret, ed.). Elsevier, Amsterdam, 1975. pp. 737–744.Google Scholar
  9. 9.
    H. Zhang, J. Shen and X. Ge, J. Solid State Chem., 117 (1995) 127.CrossRefGoogle Scholar
  10. 10.
    S. R. Seyedmonir, S. Abdo and R. F. Howe, J. Phys. Chem., 86 (1982) 1233.CrossRefGoogle Scholar
  11. 11.
    H. Jeziorowsky and H. Knözinger, J. Phys. Chem., 83 (1979) 1166.CrossRefGoogle Scholar
  12. 12.
    J. L. Brito, M. Ilija and P. Hernández, Thermochim. Acta, 256 (1995) 325.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó 1997

Authors and Affiliations

  • J. L. Brito
    • 1
  1. 1.Laboratorio de Fisicoquímica de Superficies, Centro de QuímicaInstituto Venezolano de Investigaciones Cientifícas, I.V.I.C.CaracasVenezuela

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