Surfactant-Directed Zeolite Nanosheets: A High-Performance Catalyst for Gas-Phase Beckmann Rearrangement

Silica nanosheets with an MFI zeolite topology having a thickness of 2 nm were synthesized following a synthetic route using [C16H33−N+(CH3)2−C6H12−N+(CH3)2−C6H13](OH−)2 as a zeolite structure-directing agent. The surfactant-directed zeolite nanosheets exhibited a remarkably long catalytic lifetime and high selectivity for the production of ε-caprolactam via gas-phase Beckmann rearrangement of cyclohexanone oxime, as compared with amorphous silica and bulk silica zeolite. The distinct catalytic performance of the nanosheets is attributable to silanol groups located on the surfactant-terminated crystal surfaces.