Ion exchange of alkali metals and control of acidic/basic properties of MCM-22 and MCM-36

摘要

MCM-22 (Si/Al = 12) and MCM-36 pillared with SiO2 (Si/Al = 29) were modified by ionrnexchange of alkali cations. A critical point was the pH of the ion exchange solution, which should bernadjusted to about 9 and 4, respectively. The degree of exchange decreased from Na+ to Cs+ (exceptrnthe lowest value for Li+). The basic character in both series of materials increased from Li+ to Cs+ ionrnexchanged samples as concluded from i.r. spectra of pyridine adsorption and TPD of ammonia.