Synthetic potassium zeolites - with improved thermal stability by direct synthesis

摘要

Direct synthesis of K zeolites, with SiO2:Al2O3 molar ratio 2.5 and effective pore dia. preventing entry of benzene molecules comprises adding Al2O3 carrier in water-insoluble form to (partly) aqs. soln. of KOH, opt. containing K2SiO3 and keeping resultant reaction mixture, after thorough stirring, at >40 degrees C until crystals of zeolite concerned have formed. Suitable alumina carriers include synthetic Al (meta) silicate and SiO2 hydrogel or tempered xerogel containing Al(OH)3.