Collect. Czech. Chem. Commun. 1992, 57, 788-793

Zeolite Syntheses from Superalkaline Reaction Mixtures

Falk Fischer, Marianne Hadan and Günter Fiedrich

Institute of Chemical Technology, Rudower Chaussee 5, D(O)-1199 Berlin-Adlershof, Germany


The synthesis of faujasite-type zeolite from superalkaline reaction mixtures are described. The contribution shows the influence of component K2O added in the system Na2O-Al2O3-SiO2-H2O with H2O/(K2O + Na2O) = 13-15. The reaction course was investigated in the range K2O/(K2O + Na2O) from about 0.07 to 0.5. Under used conditions it is quite possible to isolate faujasite-type zeolite as a single crystalline phase. By means of IR spectroscopy, low SiO2/Al2O3 ratios from 2.0 to 2.1 in the faujasite framework have been indicated. The low SiO2/Al2O3 ratios are interpreted by a higher stability of the Si-O-Al- than the Si-O-Si- bond with increasing hydroxyl ion concentration.