(475c) Tuning Zeolite L (LTL) Crystals Using Diols As Co-Solvents

Zeolite L (LTL) has been widely applied as a catalyst in the aromatization reaction of converting n-alkane to aromatic compounds. The catalytic activity of LTL crystals depends strongly on the crystal size due to the unique feature of one-dimensional pore structure in LTL framework. Conventional approaches of tuning the size of LTL crystals essentially rely on varying the mineralizing agent content, the synthesis temperature, and the synthesis duration. However, the approach of altering the mineralizing agent content usually defers the zeolite crystallization rate and encourages the formation of impurity phase(s). In this work, a co-solvent synthesis route to form LTL crystals will be adopted to tune the morphology of zeolite crystals.  This study systematically investigates effects of synthesis temperature, synthesis duration, co-solvent identity, and co-solvent content. This work demonstrates that the co-solvent approach to synthesize LTL crystals can lead to: (i) uniformity of zeolite crystal morphology; (ii) lower synthesis temperature; (iii) desired phase with high purity. This work will present a potential crystallization mechanism of the co-solvent approach.