Abstract
HF-21G quantum-chemical analysis of the protolytic attack of acid protons in zeolites at the C-H bonds in methane and ethane indicated that the resulting transition states depend on the sign of the bond polarization. If a hydride ion is split off from the paraffin, then the transition state resembles the adsorbed carbonium ion and the reaction results in molecular hydrogen and in formation of the surface alkoxy group. The case, when a proton tends to split off from the paraffin, corresponds to the hetero-isotope exchange of paraffins with surface OH groups. This is a concerted acid-base reaction with a transition state different from adsorbed carbonium ion.
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V.B. Kazansky, I.N. Senchenya, M.V. Frash and R.A. van Santen, Catal. Lett. 27 (1994) 345.
W.O. Haag and R.M. Dessau, in:Proc. 8th Int. Congr. on Catalysis, Vol. 2, Berlin 1984, p. 305.
J. Engelhardt and W.K. Hall, J. Catal. 119 (1992) 108.
C. Stefanidis, B.C. Gates and W.O. Haag, J. Mol. Catal. 67 (1991) 363.
H. Krannila, W.O. Haag and B.C. Gates, J. Catal. 135 (1992) 115.
J.A. Lercher, R.A. van Santen and H. Vinek, Catal. Lett. 27 (1994) 91.
H. Vinek and J.A. Lercher, J. Catal. (1993), submitted.
G.J. Kramer, R.A. van Santen, C.A. Emeis and A.K. Novak, Nature (1993) 363.
D.K. Bohme, in:Interaction between Ions and Molecules, ed. P. Ausloos (Plenum Press, New York, 1975).
W.J. Heghde, L. Radom, P. von R. Schleyer and J.A. Pople,Ab Initio Molecular Orbital Theory (Wiley, New York, 1985).
K. Raghavarchari, R.A. Whiteside, J.A. Pople and P. von R. Schleyer, J. Am. Chem. Soc. 103 (1981) 5649.
K. Hiraoka and P. Kebarle, J. Am. Chem. Soc. 98 (1976) 6119.
E.M. Evleth, E. Kassab and L.R. Sierra, J. Phys. Chem. 98 (1994) 1421.
C.J.A. Mota and R.L. Martins, J. Chem. Soc. Chem. Commun. (1991) 171.
C.J.A. Mota, L. Nogueira and V.B. Cover, J. Am. Chem. Soc. 114 (1992) 5884.
C.J.A. Mota, L. Nogueira, S.C. Menezses, V. Alekstich, L.C.R. Pereira and W.B. Cover,Preprint 10th Int. Congr. on Catalysis, Budapest 1992, p. 571.
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Kazansky, V.B., Frash, M.V. & van Santen, R.A. A quantum-chemical study of adsorbed nonclassical carbonium ions as active intermediates in catalytic transformations of paraffins. II. Protolytic dehydrogenation and hydrogen-deuterium hetero-isotope exchange of paraffins on high-silica zeolites. Catal Lett 28, 211–222 (1994). https://doi.org/10.1007/BF00806050
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DOI: https://doi.org/10.1007/BF00806050