Kinetics of methanol dehydration on dealuminated H-mordenite: Model with acid and basic active centres

Abstract

The kinetics of methanol dehydration catalysed by dealuminated H-mordenite were studied using a packed bed flow reactor at atmospheric pressure in the 473–573 K temperature range. The data were interpreted in terms of Langmuir-Hinshelwood rate equations and they suggested that two different sites are operative during the dehydration, probably an acid site and its adjacent basic site on which methanol forms respectively [CH 3·OH 2] + and [CH 3O] - species which, upon condensation, give dimethyl ether and water. Dimethyl ether and/or water compete with the methanol adsorption particularly at lower reaction temperatures and the surface coverages by activated complexes are always large, so that one observes a kinetic order with respect to methanol of less than one.