Adsorption properties of natural and Cu(II), Zn(II), Ag(I) exchanged Cuban mordenites

• Published in: Microporous and mesoporous materials 2008-02, Vol.108 (1), p.325-332
• Main Authors: Autié Castro, G., Guerra Echegarrúa, M., Autié Pérez, M., Moreno-Tost, R., Rodríguez-Castellón, E., Jiménez-López, A.
• Format: Article
• Language: English
• Subjects: Adsorption; Carbon dioxide; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Ion-exchange; Mordenite; Nitrogen; Porosity; Porous materials; Surface physical chemistry; Water; Zeolites: preparations and properties
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2007.05.012

The micro and mesoporosity of natural and ion-exchanged (Cu(II), Zn(II) and Ag(I)) mordenites from Palmarito ore (Cuba) have been studied by adsorption of N 2 at 77 K, H 2O at 300 K and CO 2 at 273 K, and compared with other natural and synthetic mordenites with the main objective of explaining the previously reported excellent performance of the Cu(II)-exchanged mordenite in the selective catalytic reduction of NO. Palmarito ore possesses a high concentration of mordenite and a more open porosity than other naturally found mordenites, as determined from the adsorption of the probe molecules studied. The ion-exchange processes modify the micro and mesoporosity of the zeolite, resulting in more accessibility to N 2 adsorption. In the case of the Cu(II) exchanged sample, the presence of CuO microcrystals on the surface causes an increase in the secondary porosity, with a subsequent enhancement of the capillary condensation at low relative pressures. These are some of the factors which explain the good catalytic performance of this sample.