In this paper, ZSM-5@MnOx catalyst was firstly prepared by in situ growth for the selective oxidation of benzyl alcohol to benzaldehyde. The coating effects of MnOx on ZSM-5 and OV formation mechanism at the ZSM-5-MnOx interface were investigated. Results showed that the sodium ions of ZSM-5 are found to be conducive to the better coating for MnOx. Hydrogen protons of zeolite can dehydrate with the OH groups on MnOx to generate the OVs where the oxidation of benzyl alcohol occurs. Besides, the deep dehydration at the ZSM-5-MnOx interface via increasing post-treatment temperature can further enrich the OV concentrations. The ~100% benzyl alcohol conversion and ~100% benzaldehyde selectivity over the ZSM-5@MnOx catalyst can be obtained within 3 h at 383 K. The findings of the structure-activity relationship of zeolite’s surface properties and OVs over MnOx can provide important guiding principles for the rational design of oxidation catalysts.

Hierarchical (micro/mesopore) ZSM-5 zeolites were hydrothermally synthesized with enhancing micromixing of the high viscosity reaction system in a rotating packed bed (RPB). Herein, the effects of four operating processes with different micromixing intensity on nucleation/crystal growth process as well as properties of ZSM-5 zeolites were investigated. Results indicated that enhancing micromixing by RPB in the zeolite synthesis could facilitate the formation of Al sites and shorten the nucleation and crystallization period. ZSM-5 samples prepared by the RPB premix process exhibit hierarchical structure, smaller average particle size, more uniform particle size distributions, larger specific surface areas, higher catalytic stability as well as more Brønsted and Lewis acid sites. While adopting the prepared ZSM-5 zeolites with RPB premix for catalyzing C4-olefin cracking reaction, the conversion of C4-olefin and yield of propylene were higher than that obtained by traditional stirring tank reactor premix.