Deactivation of a co-precipitated $Co/Al_2O_3$ catalyst

The effects of reaction temperature, feed ratio, space time, and CO percentage in feed on the deactivation conditions of a co-precipitated 36 wt% Co/Al2O3 catalyst in CO hydrogenation were investigated. Environmental-SEM-EDX and temperature-programmed reduction (TPR) studies were performed on used catalysts to investigate the effect of reaction conditions on catalyst deactivation. Intensive coke deposition on the catalyst was observed at a reaction temperature of about 573 K. Increasing the H2/CO ratioal soi ncreased the catalyst activity. Methane formed as the main product at high H2/CO ratios. Although catalyst activity did not change significantly during the 9-h reaction period at all conditions, a maximum of 6.8% C deposition was observed with increasing H2/CO, and this caused a 2% decrease in the total surface area of the used catalyst. Space time and CO percentage in the feed had less influence on catalyst decomposition.

PDF

___

1. P.M. Maitlis, J. Org. Chem. 689, 4366-4374 (2004).
2. A.N. Akin and Z.İ. Önsan, React. Kinet. Catal. Lett. 70, 275-280 (2000).
3. B. Jongsomjit, T. Wongsalee and P. Praserthdam, Catal Commun. 6, 705-710 (2005).
4. A. Loaiza-Gil, B. Fontal, F. Rueda, J. Mendialdua and R. Casanova, Appl. Catal. A-Gen. 177, 193-203 (1999).
5. K. Sapag, S. Rojas, M.L. Granados, J.L.G. Fierro and S. Mendioroz, J. Mol. Catal. A-Chem. 167, 81-89 (2001).
6. G. Jacobs, P.M. Patterson, Y. Zhang, T. Das, J. Li and B.H. Davis, Appl. Catal. A- Gen. 233, 215-226 (2002).
7. S. Storsaeter, Oφ Borg, E.A. Blekkan, B. Toφdal and A. Holmen, Catal. Today, 100, 343-347 (2005).
8. S.A. Hosseini, A. Taeb, F. Feyzi and F. Yaripour, Catal. Commun. 5, 137-143 (2004).
9. F.M.T. Mendes, C.A.C. Perez, F.B. Noronha and M. Schmal, Catal. Today, 101, 45-50 (2005).
10. R. Bechara, D. Balloy and D. Vanhove, Appl. Catal. A-Gen. 207, 343-353 (2001).
11. A.N. Akin, A.E. Aksoylu and Z.İ. Önsan, React. Kinet. Catal. Lett. 66, 393-399 (1999).
12. A.N. Akin and Z.İ. Önsan, J. Chem. Tech. Biotech. 69, 337-344 (1997).
13. A.N. Akin and Z.İ. Önsan, J. Chem. Tech. Biotech. 70, 304-304 (1997).