Advertisement

Catalysis Letters

, Volume 134, Issue 1–2, pp 37–44 | Cite as

Studies on KIT-6 Supported Cobalt Catalyst for Fischer–Tropsch Synthesis

  • Muthu Kumaran Gnanamani
  • Gary Jacobs
  • Uschi M. Graham
  • Wenping Ma
  • Venkat Ramana Rao Pendyala
  • Mauro Ribeiro
  • Burtron H. Davis
Article

Abstract

KIT-6 molecular sieve was used as a support to prepare cobalt catalyst for Fischer–Tropsch synthesis (FTS) using an incipient wetness impregnation method to produce cobalt loadings of 15 and 25 wt%. The catalysts were characterized by BET surface area, X-ray diffraction, scanning transmission election microscopy (STEM), extended X-ray absorption fine spectroscopy and X-ray absorption near edge spectroscopy. The catalytic properties for FTS were evaluated using a 1L CSTR reactor. XRD, pore size distribution, and STEM analysis indicate that the KIT-6 mesostructure remains stable during and after cobalt impregnation and tends to form smaller cobalt particles, probably located inside the mesopores. The mesoporous KIT-6 exhibited a slightly higher cobalt dispersion compared to amorphous SiO2 supported catalyst. With the higher Co loading (25 wt%) on KIT-6, partial structural collapse was observed after the FTS reaction. Compared to an amorphous SiO2 supported cobalt catalyst, KIT-6 supported cobalt catalyst displayed higher methane selectivity at a similar Co loading, likely due to diffusion effects.

Graphical Abstract

KIT-6 molecular sieve was used as a support to prepare cobalt catalyst for Fischer–Tropsch synthesis (FTS) using an incipient wetness impregnation method to produce cobalt loadings of 15 and 25 wt%. The catalysts were characterized by BET surface area, X-ray diffraction (XRD), scanning transmission election microscopy (STEM), extended X-ray absorption fine spectroscopy (EXAFS) and X-ray absorption near edge spectroscopy (XANES). The catalytic properties for FTS were evaluated using a 1L CSTR reactor. The mesoporous KIT-6 exhibited a slightly higher cobalt dispersion compared to amorphous SiO2 supported catalyst. With the higher Co loading (25 wt%) on KIT-6, partial structural collapse was observed after the FTS reaction. XRD, pore size distribution, and STEM analysis indicate that the KIT-6 mesostructure remains stable during and after cobalt impregnation and tends to form smaller cobalt particles, probably located inside the mesopores. Compared to an amorphous SiO2 supported cobalt catalyst, KIT-6 supported cobalt catalyst displayed higher methane selectivity at a similar Co loading, likely due to diffusion effects.

Keywords

Fischer–Tropsch synthesis KIT-6 Cobalt Mesoporous silica Catalyst 

Notes

Acknowledgments

This research was carried out, in part, at the National Synchrotron Light Source, Brookhaven National Laboratory, which is supported by the U.S. DOE, Divisions of Materials Science and Chemical Sciences, as well as at the Nanotechnology Center at the University of Louisville. Special thanks to Drs. Syed Khalid and Nebojsa Marinkovic (Beamline X18b, NSLS, Brookhaven) for help with XAFS studies and Joel Young (University of Oklahoma, Dept. of Physics) for XAFS cell construction.

References

  1. 1.
    Khodakov AY, Chu W, Fongarland P (2007) Chem Rev 175(5):1692CrossRefGoogle Scholar
  2. 2.
    Reuel RC, Bartholomew CH (1984) J Catal 85:78CrossRefGoogle Scholar
  3. 3.
    Martens JHA, van’t Blik HFJ, Prins R (1986) J Catal 97:200CrossRefGoogle Scholar
  4. 4.
    Bessell S (1995) Appl Catal A 126:235CrossRefGoogle Scholar
  5. 5.
    Ohtsuka Y, Arai T, Takasaki S, Tsubouchi N (2003) Energy Fuels 17:804CrossRefGoogle Scholar
  6. 6.
    Jacobs G, Das TK, Zhang Y, Li J, Racoillet G, Davis BH (2002) Appl Catal A: Gen 233:263CrossRefGoogle Scholar
  7. 7.
    Iglesia E, Soled SL, Fiato RA (1992) J Catal 137:212CrossRefGoogle Scholar
  8. 8.
    Iglesia E, Soled SL, Fiato RA (1993) J Catal 143:345CrossRefGoogle Scholar
  9. 9.
    Kresge CT, Leonowicz ME, Roth WJ, Vartuli JC, Beck JS (1992) Nature 359:230CrossRefGoogle Scholar
  10. 10.
    Inagaki S, Fukushima Y, KurodaK (1993). J Chem Soc Chem Commun, 680Google Scholar
  11. 11.
    Zhao E, Feng J, Huo Q, Melosh N, Gredrickson GH, Chmelka BF, Stucky GD (1998) Science 279:548CrossRefGoogle Scholar
  12. 12.
    Panpranot J, Goodwin JG Jr, Sayari A (2002) Catal Today 77:269CrossRefGoogle Scholar
  13. 13.
    Ohtsuka Y, Takahashi Y, Noguchi M, Arai T, Takasaki S, Tsubouchi N, Wang Y (2004) Catal Today 89:419CrossRefGoogle Scholar
  14. 14.
    Martinez A, Lopez C, Marquez F, Diaz I (2003) J Catal 220:486CrossRefGoogle Scholar
  15. 15.
    Kleitz F, Choi SH, Ryoo R (2003) Chem Commun 2136Google Scholar
  16. 16.
    Ressler T (1997) WinXAS 97, version 1.0Google Scholar
  17. 17.
    Ravel B (2001) EXAFS analysis using FEFF and FEFFIT workshop, June 27Google Scholar
  18. 18.
    Newville M, Ravel B, Haskel D, Stern EA, Yacoby Y (1995) Analysis of multiple-scattering XAFS data using theoretical standards. Physica B 154:208–209Google Scholar
  19. 19.
    Wang Y, Noguchi M, Takahashi Y, Ohtsuka Y (2001) Catal Today 68:3CrossRefGoogle Scholar
  20. 20.
    Jacobs G, Ji Y, Davis BH, Cronauer D, Jeremy Kropf A, Marshall CL (2007) Appl Catal A: Gen 333(2):177CrossRefGoogle Scholar
  21. 21.
    Englisch M, Lercher JA, Haller GL (1996) In: Iwasawa Y (ed) X-ray absorption fine structure for catalysts and surfaces. World Scientific Publishing, LondonGoogle Scholar
  22. 22.
    Bart J (1986) Adv Catal 34:203CrossRefGoogle Scholar
  23. 23.
    Barbier A, Tuel A, Arcon I, Kodre A, Martin GA (2001) J Catal 200:106CrossRefGoogle Scholar
  24. 24.
    Arcon I, Tuel A, Kodre A, Martin G, Barbier A (2001) J Synchrotron Radiat 8:106Google Scholar
  25. 25.
    Khodakov AY, Constant AG, Bechara R, Zholobenko VL (2002) J Catal 206:230CrossRefGoogle Scholar
  26. 26.
    Kim DJ, Dunn BC, Cole P, Turpin G, Ernst RD, Pugmire RJ, Kang M, Kim JM, Eyring EM (2005). Chem Commun, 1462Google Scholar
  27. 27.
    Yin D, Li W, Yang W, Xiang H, Sun Y, Zhong B, Peng S (2001) Microporous Mesoporous Mater 47:15CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Muthu Kumaran Gnanamani
    • 1
  • Gary Jacobs
    • 1
  • Uschi M. Graham
    • 1
  • Wenping Ma
    • 1
  • Venkat Ramana Rao Pendyala
    • 1
  • Mauro Ribeiro
    • 1
  • Burtron H. Davis
    • 1
  1. 1.Center for Applied Energy ResearchUniversity of KentuckyLexingtonUSA

Personalised recommendations