Inter-zeolite transformation from *MRE to EUO: A new synthesis route for EUO zeolite

The morphology control of zeolite has attracted extensive attention because of its close relationship with cata-lytic performance. How to control the crystal morphology of EUO zeolite on premise of low silica to alumina ratio is a challenging task. This study provides a novel route for controlling the morphology of Al-rich EUO zeolite via inter-zeolite transformation from Si-rich *MRE zeolite within 24 h. The morphology change from nanocrystals to coffin-like single crystal exhibits the merits of inter-zeolite transformation strategy in morphology control. Characterization tracking reveals that the deposition of aluminum species on parent *MRE zeolite is not uniform and migration between different precursors happens during the crystallization. No obvious mass transfer is observed between the liquid and solids after 2 h indicating it may follow a solid phase crystallization mechanism. Compared with conventional EUO samples, the EUO zeolite obtained by inter-zeolite transformation exhibits higher p-xylene selectivity. This approach not only provides a novel morphology control strategy for Al-rich EUO zeolite, but also promotes the understanding of the zeolite crystallization through inter-zeolite transformation route.

Automated summary

This study successfully controlled the morphology of Al-rich EUO zeolite through inter-zeolite transformation and discovered a solid phase crystallization mechanism. The EUO zeolite obtained by this new strategy showed higher selectivity. This research provides new insights into zeolite morphology control and crystallization mechanisms through inter-zeolite transformation.