ISSN:
1572-879X
Keywords:
in situ MAS NMR flow probe
;
on-line gas chromatography
;
synthesis of MTBE
;
zeolite HBeta
;
Brønsted acid sites
;
methanol adsorption
;
alkoxy species
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract A new technique is introduced allowing simultaneous in situ MAS NMR investigations of hydrocarbon conversions on solids under flow conditions and on-line gas chromatography. For adsorption of methanol on zeolite HBeta, equal amounts of adsorbed molecules were determined by both analytical methods. Studying the synthesis of methyl tertiary-butyl ether (MTBE) on zeolite HBeta using an MAS NMR rotor reactor, a constant yield of MTBE of Ymtbe= 27% was obtained up to a weight hourly space velocity of 1.4 h-1. The variation of the reaction temperature led to a simultaneous change of the 13C MAS NMR signals of isobutoxy species and of the yield of MTBE determined by on-line gas chromatography which indicates that isobutoxy species act as chemically active compounds. In this first application, the new in situ technique has demonstrated its advantage for a simultaneous investigation of compounds with a long residence time on the catalyst surface and of compounds rapidly leaving the catalyst surface.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1019064003201
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