Efficient Epoxidation of Cyclohexene Catalyzed by W-Substituted Self-Pillared Pentasil Zeolite Nanosheets

Heteroatom zeolites that contain Lewis acid sites (LASs) are of immense interest in heterogeneous catalysis processes. Herein, we report a one-pot facile synthesis of tungsten-substituted self-pillared pentasil (W-SPP) zeolite nanosheets. The obtained W-SPP reveals the high crystallinity and house-of-card arrangement of the nanosheets. The framework-introduced W species not only act as LASs but also effectively enhance the hydrophobicity of the SPP substrate through neutralizing structure silanols. After using as a catalyst for cyclohexene epoxidation with H2O2, W-SPP exhibits improved catalytic performance with a superior TOF of 2192 h–1 and cyclohexene oxide selectivity of 92.6% in comparison with Ti-SPP (148 h–1 and 28.5%) and TS-1 (125 h–1 and 65.1%). A combination of experiments with theoretical calculations clearly demonstrates that the superior catalytic performance of W-SPP is ascribed to the isolated W sites of high activity, modified hydrophobicity to prevent the hydrolytic side reaction, and enhanced accessibility by the SPP configuration.