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

Hierarchical Beta (BEA-H) with intra-crystalline mesoporosity was synthesized by employing a designed template of N(CH 3 ) 2 -C 6 H 12 -N + (CH 3 ) 2 -CH 2 -(p-C 6 H 4 )-CH 2 -N + (CH 3 ) 2 -C 6 H 12 -N(CH 3 ) 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.