Role of e-beam irradiation treatment on detemplation and structural hierarchy of ZSM-5 zeolite

In this work, detemplation of tetrapropylammonium ZSM-5 zeolites was performed by e-beam irradiation technique. It was found that exposure to high-energy e-beam irradiation induces the partial detemplation from the ZSM-5 zeolites at ambient condition and facilitates the supplementary detemplation. Direct radiolysis of water molecules coupling with indirect ionization and dissociation along the chain of extraframework-framework interactions have led to fragmentation of the organic compounds (dehydration and detemplation) and even the framework T-O-T bonds (amorphization). The completely detemplated zeolites with different Si/Al molar ratios and thus different hydrophilicity were found to have different hierarchical structures. A network of large-mouth funnel-shaped pores was formed in the Al-rich ZSM-5 zeolite with the Si/Al molar ratio of ca. 18, whereas channels with ink-bottle shaped pores were formed in the Si-rich ZSM-5 zeolite with the Si/Al molar ratio of ca. 30.