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 catalytic 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.