INFLUENCE OF THE ALUMINUM CONTENT ON THE ADSORPTIVE PROPERTIES OF MCM-41

Experimentally determined adsorption isotherms of nitrogen, water and various aromatics and alcohols show that the sorption capacity of MCM- 41 is only slightly affected by the aluminum content in the structure. Capillary condensation in the intracrystalline volume occurs independ ent of the nature of the adsorbed species. The experimental equilibriu m data can be described well by a simplified model which distinguishes between the sorption in the inter- and the intraparticle voids. Furth ermore, it is shown that the affinity between the sorbed species and M CM-41 increases with the molar polarizability alpha.