Controlled synthesis of hierarchical beta zeolite through design template to enhance gas-phase beckmann rearrangement performance

Abstract

Hierarchical Beta (BEA-H) with intra-crystalline mesoporosity was synthesized by employing a designed template of N(CH3)2-C6H12-N+(CH3)2-CH2-(p-C6H4)-CH2-N+(CH3)2-C6H12-N(CH3)2 [Cl-]2. Characterization results indicate that BEA-H was crystallized from the outer surface of quasi-spherical particle to the inner part. When it was used as a catalyst for the gas-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam, BEA-H exhibited a 2.3-fold longer lifetime in comparison to conventional Beta zeolite (BEA-C). The superior catalytic performance of BEA-H is attributed to its hierarchical pore structure and suitable acidity.