Surface Design of Hierarchical Zeolites for Mass Transport Enhancement

The exceptional performance of hierarchical zeolites is closely related to the diffusion process for applications in oil refining and chemical synthesis. However, the knowledge of structure-diffusion-reactivity relationships, and particularly the dynamically evolving data of guest molecules in catalysis, for hierarchical zeolites is still incomplete. Herein, a dual structure-directing agents’ strategy is used to synthesize hierarchical ZSM-5 with fish scale-like micro-nano structures (F-ZSM-5) in fluoride medium. The structure-diffusion-reactivity relationships of F-ZSM-5 and conventional ZSM-5 crystals while catalyzing the oligomerization of furfuryl alcohol are elucidated by using an in situ microimaging technique. Additionally, distinct differences of catalytic performance are observed in individual zeolite crystals due to their different nano-architectures, suggesting the high correlation between diffusion and reaction rate and crystal morphologies. Observations made in this investigation deepen the understanding of molecular transport in zeolites and provide guidance for the rational design of desired nanostructures that lead to optimal catalytic properties.