Aluminium alkoxide sulphate catalysts have been used to promote ethoxylatio
n of fatty alcohols with a narrow distribution of the molecular weights. Ba
sed on experimental observations, a reaction mechanism and a related kineti
c model able to simulate all the performed kinetic runs have been proposed
in a previous work by M. Di Serio et al. [M. Di Serio, P. Iengo, R. Gobetto
, S. Bruni, E. Santacesaria, J. Mol. Catal. A: Chem. 112(1996)235]. In the
present work the plausibility of the mechanism suggested and the role playe
d by the sulphate groups in the reaction have been evaluate by a computatio
nal study. The promoting effect on the reaction rate of sulphate groups is
similar to that observed in the heterogeneous catalysis for different oxide
s treated with sulphuric acid, so the results obtained in this work will al
so be applied to explain the catalytic behaviour of sulphated alumina. (C)
1999 Elsevier Science B.V. All rights reserved.