Silylation with trimethylchlorosilane and subsequent analyses of the products by 29Si CP MAS NMR is an appropriate method for the characterization of terminal groups in ZSM-5. It can be shown that the terminal groups are clustered and belong to gaps of missing T-atoms (Si or Al). These gaps are part of regularly 4-membered and larger rings in the lattice of ZSM-5. During prolonged heat treatment of ZSM-5 the amount of internal terminal groups decreases. We propose a T-jump mechanism of the gaps resulting in a migration of the terminal groups towards the external surface of the zeolite particles.
|Title of host publication||Innovation in zeolite materials science : proceedings of an international symposium, Nieuwpoort (Belgium), September 13-17, 1987|
|Editors||P.J. Grobet, W.J. Mortier, E.F. Vansant, G. Schulz-Ekloff|
|Place of Publication||Amsterdam|
|Publication status||Published - 1988|
|Name||Studies in Surface Science and Catalysis|
Kraushaar, B., Ven, van de, L. J. M., Haan, de, J. W., & Hooff, van, J. H. C. (1988). Clusters of terminal groups in ZSM-5 : a study performed by silylation and 29Si CP MAS NMR. In P. J. Grobet, W. J. Mortier, E. F. Vansant, & G. Schulz-Ekloff (Eds.), Innovation in zeolite materials science : proceedings of an international symposium, Nieuwpoort (Belgium), September 13-17, 1987 (pp. 167-174). (Studies in Surface Science and Catalysis; Vol. 37). Amsterdam: Elsevier. https://doi.org/10.1016/S0167-2991(09)60593-0, https://doi.org/10.1016/0039-6028(73)90315-4