Influence of process parameters on the reaction kinetics of the chromium-catalyzed trimerization of ethylene.
Chemistry
; 16(26): 7833-42, 2010 Jul 12.
Article
em En
| MEDLINE
| ID: mdl-20512824
ABSTRACT
In this paper we report the results of an extensive experimental kinetic study carried out on the novel ethylene trimerization catalyst system, comprising the chromium source [CrCl(3)(thf)(3)] (thf=tetrahydrofuran), a Ph(2)P-N(iPr)-P(Ph)-N(iPr)H (PNPNH) ligand (Ph=phenyl, iPr=isopropyl), and triethylaluminum (AlEt(3)) as activator. It could be shown that the initial activity shows a first-order dependency on the ethylene concentration. Also, a first-order dependency was found for the catalyst concentration. The initial activity follows a typical Arrhenius behavior with an experimentally determined activation energy of 52.6 kJ mol(-1). At elevated temperatures (ca. 80 degrees C), a significant deactivation was observed, which can be tentatively traced back to a ligand rearrangement in the presence of AlEt(3). After a fast initial phase, a pronounced 'kink' in the ethylene-uptake curve is observed, followed by a slow, almost linear, further increase of the total ethylene consumption. The catalyst composition, in particular the ligand/chromium and the cocatalyst/chromium molar ratio, has a strong impact on the catalytic performance of the trimerization of ethylene.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Chemistry
Assunto da revista:
QUIMICA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Alemanha