LAUSR

Throughout this study, the SiO2, Na2O and H2O contents in the starting gel were modified in order to understand their influence on obtaining pure Y faujasite small crystals. Results were assembled in a ternary phase diagram (SiO2–H2O–Na2O). Furthermore, thorough characterization using multiple structural and physicochemical methods is reported for all the pure faujasite samples, in order to emphasize the effect of H2O, SiO2 and Na2O amounts on their structural (the crystallization rate and the Si/Al molar ratio of the framework) and textural properties (the micropore volume and the crystal size). Good yields in Y faujasite small crystals were obtained when optimizing the starting gel composition compared to the one provided in the literature (typically below 10 wt% of the engaged Si). The results show that the gel domains that are able to give pure Y zeolites are very restricted, making predictions very complicated.