Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

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.