Abstract
Supported chromium oxide catalysts containing 0.5 and 4.0 wt% Cr, respectively, on a 7 wt% La2O3/ZrO2 carrier were studied by in situ EPR equipped with on-line GC during the catalyst pretreatment in flowing H2 and the aromatization of n-octane in the range 293<T<823 K. Active catalysts contain almost exclusively Cr3+ in the form of Cr2O3 clusters and isolated, coordinatively unsaturated Cr3+ species on the surface. The latter appear to be less sensitive to poisoning by coke deposition and govern residual catalytic activity.
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References
J.P. Hogan, Applied Industrial Catalysis, Vol. 1 (Academic Press, New York, 1983).
V. Indovina, Catal. Today 41 (1998) 95.
S. De Rossi, G. Ferraris, S. Fremiotti, A. Cimino and V. Indovina, Appl. Catal. A 81 (1992) 113.
D.S. Kim and I.E. Wachs, J. Catal. 142 (1993) 166.
A. Cimino, D. Cordischi, S. Febbraro, D. Gazzoli, V. Indovina, M. Occhiuzzi and M. Valigi, J. Mol. Catal. 55 (1989) 23.
S. De Rossi, G. Ferraris, S. Fremiotti, V. Indovina and A. Cimino, Appl. Catal. A 106 (1993) 125.
D.L. Meyers and J.H. Lunsford, J. Catal. 92 (1985) 260.
K. Arata, M. Hino and H. Matsuhashi, Appl. Catal. A 100 (1993) 19.
J.R. Sohn and S.G. Ryu, Langmuir 9 (1993) 126.
H. Lieske and D.L. Hoang, German Patent DE 196 12 000 A1 (18 March 1996).
A. Cimino, D. Cordischi, S. De Rossi, G. Ferraris, D. Gazzoli, V. Indovina, M. Occhiuzzi and M. Valigi, J. Catal. 127 (1991).
A. Brückner, B. Kubias, B. Lücke and R. Stößer, Colloids Surf. 115 (1996) 179; (b) H.G. Karge, J.P. Lange, A. Gutze and M. Laniecki, J. Catal. 114 (1988) 144.
G.P. Lozos, B.M. Hofman and C.G. Franz, Quantum Chemistry Programs Exchange No. 265 (1973).
B.M. Weckhuysen, R.A. Schoonheydt, F.E. Mabbs and D. Collison, J. Chem. Soc. Faraday Trans. 92 (1996) 2431.
D.L. Hoang and H. Lieske, in preparation.
R. Merryfield, M. McDaniel and G. Parks, J. Catal. 77 (1982) 348.
W. Grünert, E.S. Shpiro, R. Feldhaus, K. Anders, G.V. Antoshin and Kh.M. Minachev, J. Catal. 100 (1986) 138.
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Brückner, A., Radnik, J., Hoang, DL. et al. In situ investigation of active sites in zirconia-supported chromium oxide catalysts during the aromatization of n-octane. Catalysis Letters 60, 183–189 (1999). https://doi.org/10.1023/A:1019067309929
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DOI: https://doi.org/10.1023/A:1019067309929