One-Pot Synthesis of Aluminosilicate AFI Zeolite Nanocrystals

Optimizing syntheses of known zeolite structures and exploring novel applications for them are enduring priorities in zeolite chemistry. A representative example is the AFI zeolite framework, which features one-dimensional 12-membered-ring channels but remains difficult to synthesize directly in its aluminosilicate form because of the lack of suitable organic templates. Herein, with the assistance of theoretical simulations for the design of novel organic templates, we have been successful in the one-pot synthesis of aluminosilicate AFI structure designated as ZJM-12, giving the nanocrystals with a size of approximately 20 nm. Characterization results revealed that the ZJM-12 zeolite exhibited high crystallinity, nanoscale crystal dimension, large specific surface area, fully 4-coordinated Al species, abundant acid sites, and good hydrothermal stability. In the catalytic tests for the conversion of lactic acid (LA) to lactide (LT) and the intramolecular cyclization of 5-(o-tolyl)-2-pentene (OTP) to 1,5-dimethyltetralin (1,5-DMT), the ZJM-12 zeolite displayed excellent catalytic performance compared with conventional catalysts used for these reactions, thus highlighting its considerable potential as a high-performance catalyst for the above conversion processes.