Synthesis and Structure of a 22 x 12 x 12 Extra-Large Pore Zeolite ITQ-56 Determined by 3D Electron Diffraction

[EN] A multidimensional extra-large pore germanosilicate, denoted ITQ-56, has been synthesized by using modified memantine as an organic structure-directing agent. ITQ-56 crystallizes as plate-like nanocrystals. Its structure was determined by 3D electron diffraction/MicroED. The structure of ITQ-56 contains extra-large 22-ring channels intersecting with straight 12-ring channels. ITQ-56 is the first zeolite with 22-ring pores, which is a result of ordered vacancies of double 4-ring (d4r) units in a fully connected zeolite framework. The framework density is as low as 12.4 T atoms/1000 angstrom(3). The discovery of the ITQ-56 structure not only fills the missing member of extra-large pore zeolite with 22-ring channels but also creates a new approach of making extra-large pore zeolites by introducing ordered vacancies in zeolite frameworks.This work has been supported by the European Union through ERC-AdG-2014-671093 (SynCatMatch), by the Spanish Government-MINECO through "Severo Ochoa" (SEV-2016-0683), the Swedish Research Council (VR, 2017-04321, 201905465), and the Knut & Alice Wallenberg Foundation through the project grant 3DEM-NATUR (KAW, 2012-0112). The EM facility was supported by the Knut and Alice Wallenberg Foundation. J.J. thanks the National Natural Science Foundation 21971259.Kapaca, E.; Jiang, J.; Cho, J.; Jorda Moret, JL.; Díaz Cabañas, MJ.; Zou, X.; Corma Canós, A.... (2021). Synthesis and Structure of a 22 x 12 x 12 Extra-Large Pore Zeolite ITQ-56 Determined by 3D Electron Diffraction. Journal of the American Chemical Society. 143(23):8713-8719. https://doi.org/10.1021/jacs.1c02654871387191432