CHANGES IN PHYSICOCHEMICAL AND CATALYTIC PROPERTIES OF SYNTHETIC ERIONITE AFTER VARIOUS TREATMENT

Influence of decationization by ammonium ions and dealumination by HCl as well as calcination under self-steaming conditions at 1 053 K with following treatment by ammonium ions or by HCl solution on the extent of alkali metals extraction was studied together with surface, sorption, acidic and catalytic properties of synthetic erionite. Samples were also characterized by X-ray diffraction spectra and IR skeletal vibration spectra. Results showed increasing catalytic activity and acidity after thermal treatment, followed by ion exchange with HCl or ammonium ions, which can be connected with deeper substitution of potassium cations of erionite. At the same time by the treatment under self-steaming conditions, as a result of framework dealumination, the zeolite obtained a secondary pore system, which resulted in increasing sorption capacity for aromatics, suppression of coking during o-xylene conversion and also increased diffusion of Hammet indicators into the zeolite.