Combined alkali dissolution and re-assembly approach toward ZSM-5 mesostructures with extended lifetime in cumene cracking.

The basis and contribution of mesopores created in ZSM-5 structures at different treatment conditions are systematically investigated. The results reveal that the mesopores originated from the alkali dissolution of pristine ZSM-5 are mainly intracrystalline and they contribute to excessive Brønsted acid sites, while the mesopores originated from the re-assembly of alkali dissolved aluminosilicate species possess Lewis acid sites. These ZSM-5 mesostructures showed an extended lifespan during the cracking of cumene (88.0%) in comparison to the pristine ZSM-5 (27.0%) after 460 min. The zeolite mesostructures obtained in this study could be used as a base for further design of new porous materials with desired acidic properties.