Sorption properties of Mo(CO)6 on thin Y-zeolite layers

Bernd R. Müller and Gion Calzaferri
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland

Abstract

The loading of activated thin NaY zeolite layers on ZnSe with gaseous Mo(CO)6 at room temperature under static vacuum is reported. The encapsulation process was investigated by in situ transmission FTIR spectroscopy. The loading of zeolite Y with metal carbonyl takes place within 80 minutes under mild conditions. The uptake curve indicates a complex sorption kinetics which differs from the conventional Fickian law of diffusion. At low coverages, Mo(CO)6 initially diffuses very slowly into the zeolite (D » 10-16 cm2s-1). After this induction period, it enters with a much higher velocity (D » 10-13 cm2s-1), leading to a coverage as high as 1.80 molecules per supercage. The kinetics of the encapsulation is described by two different sorption steps, based on the gas translation and the solid vibration model.

published in: Microporous and Mesoporous Materials 1998, 21, 59.

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