ISSN:
1572-879X
Keywords:
Zeolite Y
;
ZSM-5
;
mordenite
;
acid-catalysed ethene oligomerisation
;
carbeniumion chemistry
;
alkoxides
;
reaction intermediates
;
13C CP-MAS NMR
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Solid-state13C NMR analysis of the oligomerisation of ethene over H-ZSM-5, H-Y and H-mordenite, indicates that the degree of branching of the final products increases with increasing pore dimensions of the zeolite. In order to monitor the formation of intermediate reaction products, we investigated the oligomerisation of ethene in zeolite H-ZSM-5 at lower temperature. Ethene sorbed in ZSM-5 is stable below 0 °C, but at higher temperatures it is oligomerised to higher, branched reaction products. The use of sealed capsules enabled us to identify several (apparently highly reactive) higher olefins as intermediates. Although the observation of intermediate olefinic oligomers is in line with the classical reaction mechanism of acid-catalysed oligomerisation via carbenium ions, no such charged species could be detected. Alkoxide species, on the other hand, were observed, and these may very well be involved in the reactions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00764317
Permalink