Microexplosion under Microwave Irradiation: A Facile Approach to Create Mesopores in Zeolites

Abstract

A facile microexplosion approach has been successfully developed to produce an interwoven mesopore network in zeolite crystals via the rushing-out of gases generated by decomposition of H2O2 under microwave irradiation. This “gas imprint” method creates the mesopores from the interior crystal toward the exterior, in line with the direction of the pristine microporous channels, and is different from the previous methods in which the reagent starts an attack from the crystal surface and perforates inward. The created mesopores extend throughout the whole crystal and highly blend into the intrinsic micropores around. The acidity of zeolite is also well preserved due to this unique mechanism of pore creation. The continuous high quality hierarchical architecture with intact acidity leads to a notable increase both in the conversion of 2-methoxynaphthalene acylation and in the selectivity to the target molecule of 2-acetyl-6-methoxynapthalene. This microexplosion approach offers an efficient synthesis protocol of zeolitic hierarchy integrating intersected mesoporosity and zeolitic microporosity and opens the way to the rational organization of meso- and microporosity for maximal advantage in applications.