IM-20 is a novel microporous germanosilicate with an interesting zeolitic structure. It has been prepared via the fluoride route with 3-butyl-1-methyl-3H-imidazol-1-ium as the organic structure-directing agent and its structure solved from synchrotron powder X-ray diffraction data. The chemical formula per unit cell is Si(42.2)Ge(17.8)O(120) under its calcined form. IM-20 possesses a new framework topology, the 3D channel system being formed by straight intersecting 12- and 10-membered rings. Two types of d4r composite building units are present in IM-20, their average Si/Ge molar ratio being about 8.52 or 0.56. Surprisingly, the pure silica or silica-rich units are fluoride-free in the as-synthesized material.

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Despite having been used in hydrocracking processes for decades, zeolite Y is still nowadays the subject of intense research aiming at improving its physicochemical properties. Here, and for the first time, the synthesis of zeolite Y nanocrystals prepared in organic template-free medium, featuring both extremely reduced dimensions (mean diameter below 30 nm) and a high silicon to aluminum ratio (Si/Al ≈ 2.2), is reported. The singularity of the protocol lies in the progressive adding of a silica source during synthesis combined with the use of prolonged aging times. These high-silica ultra-nanosized zeolite Y crystals display excellent textural properties (V micropore = 0.33 cm3/g and S BET = 830 m2/g), comparable to their microsized counterparts. In this work, the extensive study of the influence of various parameters (i.e., gel composition, aging time, and crystallization conditions) intended for the optimization of the synthesis protocol is also presented.