On the rotational intergrowth of hierarchical FAU/EMT zeolites

A structural study of a hierarchical zeolite X, which is similar to the one first synthesized by Inayat et al.,12 was performed using transmission electron microscopy imaging and diffraction. Evidence is provided, by comparison to simulations, that this material is an intergrowth of FAU and EMT and a conceptual model is presented for the growth of the FAU material with a small fraction of EMT in an atypical morphology of assembled sheets with well-defined intersection angles. Atypical morphology: Hierarchical faujasite is identified as an intergrowth of FAU and EMT. It is proposed that, under the appropriate growth conditions of faceting and branching, this intergrowth with a very small fraction of EMT, not detectable by XRD, leads to the repetitively branched morphology of faujasite.