ISSN:
1572-879X
Keywords:
Dimethylether amination
;
methylamines
;
zeolite T
;
acidic properties
;
TPDA
;
IR spectroscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Freshly prepared and used H/Na, K-T-zeolite catalysts for the conversion of dimethyl ether and ammonia to the three methylamines have been characterized by temperature-programmed desorption of ammonia and IR spectroscopy. Activity and selectivity depend on the nature and number of the acid sites. With time on-stream, deep alterations in the catalyst behaviour have been observed. The activity of the catalyst is decreased by blocking of active sites ≈ 5–10 h: furthermore, during an initial period hydrocarbons were formed almost exclusively on strong-acid sites. A second period is characterized by an increased “shape selectivity” observed in the distribution of the methylamines. The amination will proceed probably on left weak-acid sites and on the outer surface in a third period, however, without “shape selectivity” due to the progressive blocking of the inner catalyst surface.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00769674
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