Stirring effect on zeolites synthesis with different Si/Al molar ratios Using 1-Butyl-3-methylimidazolium chloride as structure-direct agent

Resumo

Different types of zeolites could be synthesized changing the variables in the synthesis process. This paper studies the stirring effect on zeolites synthesis at different Si/Al molar ratios (1, 8, 20, 50 and 120) using the ionic liquid 1-butyl-3-methylimidazolium chloride (BMI.Cl) as structure-direct agent. The results suggest that the ionic liquid BMI.Cl would be a highly effective directing agent for the crystallization of zeolites type A, ZSM-5, Beta and ZSM-35. The stirring effect on compositional and morphological parameters seems to be significant. Therefore, ternary composition diagrams were plotted for the static and stirring conditions,  showing the influence of stirring on the composition and morphology of the generated materials. It was possible to verify, in the ternary diagrams, the conditions for obtaining the pure ZSM-5 and ZSM-35 zeolites, as well as the different morphologies found for the same regions, when the zeolites were synthesized under static and stirring conditions. It is also observed that the zeolites ZSM-35 and Beta show a greater amount of Al2O3 (4 mol% and 1.6 mol%) only when the reaction is carried out under stirring conditions.