Abstract
This research was focused at getting deeper insight into the circumstances of “cobalt aluminate” formation in alumina-supported cobalt catalysts. It was desired to determine which state(s) of cobalt (i.e. reduced or oxidized) and what reaction conditions play a significant role in the aluminate formation at the relatively mild conditions used for reduction or Fischer–Tropsch synthesis. Reduction and hydrothermal pretreatments were applied to influence the formation of nonreducible Co-support compounds. Temperature-programmed reduction (TPR) was used to measure the amount of reducible cobalt compounds formed in 20 wt% Co/Al2O3 catalyst. The results reveal that the presence of partially reduced cobalt in a well-dispersed form is required for the formation of cobalt aluminate. The presence of water vapor promotes cobalt aluminate formation probably by hydrating the alumina and possibly by partially reoxidizing highly dispersed cobalt.
Similar content being viewed by others
References
H. P. Withchers Jr., K. F. Eliezer and J. W. Mitchell, Ind. Eng. Chem. Res. 29 (1990) 1807.
E. Iglesia, Appl. Catal. A161 (1997) 59.
R. C. Brady and R. J. Pettit, J. Am. Chem. Soc. 103 (1981) 1287.
A. Kogelbauer, J. C. Weber and J. G. Goodwin Jr., Catal. Lett. 34 (1995) 259.
D. Schanke, A. M. Hilmen, E. Bergene, K. Kinnari, E. Rytter, E. Adnanes and A. Holmen, Catal. Lett. 34 (1995) 269.
Y. Zhang, D. Wei, S. Hammache and J. G. Goodwin Jr., J. Catal. 188 (1999) 281.
A. M. Hilmen, D. Schanke, K. F. Hanssen and A. Holmen, Appl. Catal. A: Gen. 186 (1999) 169.
B. Jongsomjit, J. Panpranot and J. G. Goodwin Jr., J. Catal. 204 (2001) 98.
P. J. van Berge, J. van de Loosdrecht, S. Barradas and A. M. van der Kraan, Catal. Today 58 (2000) 321.
P. Arnoldy and J. A. Moulijn, J. Catal. 93 (1985) 38.
A. M. Hilmen, D. Schanke and A. Holmen, Catal. Lett. 38 (1996) 143.
A. R. Belambe, R. Oukaci and J. G. Goodwin Jr., J. Catal. 166 (1997) 8.
D. Schanke, S. Vada, E. A. Blekkan, A. M. Hilmen, A. Hoff and A. Holmen, J. Catal. 156 (1995) 85.
A. Lapidus, A. Krylova, V. Kazanskii, V. Borovkov, A. Zaitsev, J. Rathousky, A. Zukal and M. Jancalkova, Appl. Catal. 73 (1991) 65.
G. P. Huffmann, N. Shah, J. Zhao, F. E. Huggins, T. E. Hoost, S. Halvorsen and J. G. Goodwin Jr., J. Catal. 151 (1995) 17.
G. J. Haddad and J.G Goodwin Jr., J. Catal. 157 (1995) 25.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Sirijaruphan, A., Horváth, A., Goodwin, J.G. et al. Cobalt Aluminate Formation in Alumina-Supported Cobalt Catalysts: Effects of Cobalt Reduction State and Water Vapor. Catalysis Letters 91, 89–94 (2003). https://doi.org/10.1023/B:CATL.0000006322.80235.8f
Issue Date:
DOI: https://doi.org/10.1023/B:CATL.0000006322.80235.8f