Insight on MWW siliceous zeolites: From 2D precursors toward 3D structure

• Published in: Microporous and mesoporous materials Vol. 366; p. 112924
• Main Authors: Rosso, Francesca, Airi, Alessia, Signorile, Matteo, Dib, Eddy, Bordiga, Silvia, Crocellà, Valentina, Mintova, Svetlana, Bonino, Francesca
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15-02-2024; Elsevier
• Subjects: Chemical Sciences; ITQ-1; Material chemistry; MWW; Siliceous zeolite; Spectroscopic characterization; Structure directing agent; Spectroscopic characterization; MWW; Siliceous zeolite; ITQ-1; Structure directing agent
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2023.112924

ITQ-1 layered zeolites, with MWW framework, were prepared using different synthesis and calcination procedures and fully characterized by means of X-ray diffraction, scanning electron microscopy, N2 sorption and vibrational and nuclear magnetic resonance spectroscopies. Exploring different compositions of the precursor gel, the role of the Organic Structure Directing Agent (OSDA) was definitely disclosed. We proved that the concentration of OSDA in the synthesis gel affects the short-range crystalline order of zeolite crystals. In particular, diluted precursor gels led to the formation of low-density materials in the form of hollow spheres, with partially disordered layers, thinner crystals and high defectivity. In general, all ITQ-1 samples had the same crystalline structure but different morphology, either rose-like or hollow spheres. Moreover, the calcination procedure had an impact on the structural defects of the ITQ-1 zeolite: the higher the removal rate of the OSDA, the higher the defectivity degree of the zeolite.
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•Study of layered zeolite ITQ-1 (MWW) with different long and short range order.•Effect of the composition of the synthesis gel on the defectivity of ITQ-1 (MWW).•Multitechnique approach to the characterization of ITQ-1 (MWW) zeolite.•Monitoring the Organic Structure Directing Agent degradation (calcination).