Chromatography Research Today is a free monthly online journal that collates and summarizes the latest research about Chromatography, including details on column chromatography, gas chromatography (gc), liquid chromatograpy, hplc.

Determination of the acid/base properties of MgY and NH4Y molecular sieves by inverse gas chromatography.

Bilgiç C, Tümsek F

Department of Chemical Engineering, Faculty of Engineering and Architecture, Eskişehir Osmangazi University, 26480 Eskişehir, Turkey. cbilgic@ogu.edu.tr

The surface characterization of MgY and NH(4)Y zeolites was performed using inverse gas chromatography (IGC). The adsorption thermodynamic parameters (the standard enthalpy (DeltaH degrees ), standard entropy change (DeltaS degrees ), and free energy change of adsorption (DeltaG degrees ), the dispersive component of the surface free energies (gamma(S)(d)), and the acid-base character of the surface of MgY and NH(4)Y zeolites were estimated using the retention time of different non-polar and polar probes at infinite dilution region. The specific free energy of adsorption (DeltaG(sp)), the specific enthalpy of adsorption (DeltaH(sp)), and the specific entropy of adsorption (DeltaS(sp)) of polar probes on MgY and NH(4)Y zeolites were determined. The values of the DeltaH(sp) were correlated with both the donor and acceptor numbers of the probes to quantify the acidic K(A) and the basic K(D) parameters of the zeolite surfaces. The values obtained for the K(A) and K(D) parameters indicated a basic character for the surface of MgY and NH(4)Y zeolites.

Published 6 August 2007 in J Chromatogr A, 1162(1): 83-9.
Full-text of this article is available online (may require subscription).

© 2005-2008 Chromatography Research Today. All Rights Reserved.