ISSN:
1572-879X
Schlagwort(e):
selective hydrogenation
;
zeolite catalysis
;
forcefield simulations
;
biased diffusion method
;
ZSM-5 and zeolite-Y catalysts
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract Dehydrogenation of the natural terpene α-limonene to the industrially important p-cymene was studied over two zeolite-supported Pd catalysts, ZSM-5 and zeolite-Y. Reactor tests indicate that transalkylation of the p-cymene product can be avoided by employing the shape-selective properties of a medium-pore ZSM-5 catalyst. The diffusion properties of the three isomers of cymene were then calculated in the two zeolites using molecular mechanics. In case of ZSM-5, p-cymene was found to have the lowest barrier of the three isomers for diffusion through the straight, spherical channel of the zeolite. For zeolite-Y, differences in diffusivity for the three isomers were very small. Theory and experiments showed, in excellent agreement, that only ZSM-5 selectively produces p-cymene. This work shows that molecular mechanics is a powerful and reliable method for the screening of zeolites for performing shape-selective catalysis.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1019075521122
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