Abstract
Over HMOR zeolites, hydrogen inhibits n-butane isomerization which occurs through a bimolecular pathway and has practically no effect on n-hexane isomerization, of which the reaction mechanism is intramolecular. The large inhibiting effect found with butane isomerization is certainly related to the demanding character of the bimolecular process: two sec-butyl carbenium ions are necessary for the alkylation step. Hydrogen could react with carbenium ions limiting their concentration. Over sulfated zirconia hydrogen has also an inhibiting effect on n-butane isomerization, this effect being particularly pronounced at low temperature, and has no effect on n-hexane isomerization. It is suggested that the differences in the butane isomerization mechanisms proposed in the literature in the case of sulfated zirconia are mainly due to the ``diluent'' gas used (nitrogen and hydrogen) and for a small part to the reaction temperature.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
D.M. Brouwer, in: Chemistry and Chemical Engineering of Catalytic Processes, NATO Advanced Study Institutes Series E, No. 39, eds. R. Prins and G.C.A. Schuit (Sijthoff & Noordhoff, Alphen aan den Rijn, 1980) p. 137.
F. Chevalier, M. Guisnet and R. Maurel, Proc. 6th Int. Congr. on Catalysis, Vol. 1, eds. G.C. Bond, P.B. Wells and F.C. Tompkins (The Chemical Society, London, 1977) p. 478.
C. Bearez, F. Avendano, F. Chevalier and M. Guisnet, Bull. Soc. Chim. Fr. 3 (1985) 346.
N.N. Krupkina, A.L. Proskurin and A.Z. Dorogochinski, React. Kinet. Catal. Lett. 32 (1983) 135.
R.A. Asuquo, G. Eder-Mirth and J.A. Lercher, J. Catal. 155 (1995) 376.
K. Arata, Adv. Catal. 37 (1990) 165.
M.A. Coelho, D.E. Resasco, E.C. Sikabwe and R.L. White, Catal. Lett. 32 (1995) 253.
M. Hino and K. Arata, Catal. Lett. 34 (1996) 125.
C.Y. Hsu, C.R. Heimbuch, C.T. Armes and B.C. Gates, J. Chem. Soc. Chem. Commun. (1992) 1645.
F. Garin, L. Seyfried, P. Girard, G. Maire, A. Abdulsamad and J. Sommer, J. Catal. 151 (1995) 26.
V. Adeeva, G.D. Lei and W.M.H. Sachtler, Catal. Lett. 33 (1995) 135.
P. Nascimento, C. Akratopoulou, M. Oszagyan, G. Coudurier, C. Travers, J.F. Joly and J.C. Vedrine, New Frontiers in Catalysis, Proc. 10th Int. Congr. on Catalysis, eds. L. Guczi et al. (Elsevier, Amsterdam, 1993) p. 1185.
M. Daage and F. Fajula, J. Catal. 81 (1983) 405.
D.M. Brouwer and J.M. Oelderick, Rec. Trav. Chim. Pays Bas 87 (1968) 721.
H. Hattori, O. Takahashi, M. Takagi and K. Tanabe, J. Catal. 68 (1981) 132.
M. Guisnet and N.S. Gnep, Appl. Catal. A 146 (1996) 33.
N.S. Gnep and M.Guisnet, Appl. Catal. 1 (1981) 329.
M. Guisnet, J. Catal. 88 (1984) 251.
Rights and permissions
About this article
Cite this article
Tran, MT., Gnep, N., Guisnet, M. et al. Influence of hydrogen and of reaction temperature on the mechanism of n-butane isomerization over sulfated zirconia. Catalysis Letters 47, 57–61 (1997). https://doi.org/10.1023/A:1019051425839
Issue Date:
DOI: https://doi.org/10.1023/A:1019051425839