Crystallization of phase-pure zeolite NaP from MCM-22-type gel compositions under microwave radiation

• Published in: Microporous and mesoporous materials Vol. 109; no. 1; pp. 542 - 548
• Main Authors: Zubowa, Heide-Lore, Kosslick, Hendrik, Müller, Dirk, Richter, Manfred, Wilde, Lutz, Fricke, Rolf
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.03.2008; Elsevier
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; Gel alkalinity; General and physical chemistry; Ion-exchange; Microwave-assisted synthesis; Morphology; NaP; Phase-purity; Porous materials; Surface physical chemistry; Zeolites: preparations and properties; Gel alkalinity; Phase-purity; NaP; Morphology; Microwave-assisted synthesis; Composition; Crystallization; Microwave; Purity; Zeolite; Molecular sieve; Synthesis; Microwave irradiation; Alkalinity
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2007.06.002

Applying microwave heating, crystallization of NaP without by-products could be achieved from synthesis gel compositions typically resulting in MCM-22 formation under thermal heating. Adjusting the alkalinity of Na/SiO 2 to 1.17, and the synthesis time to 5 h, zeolite NaP (Na 4.5Al 4.5Si 11.5O 32 · 9.9H 2O) was the main product (91%) with analcime (9%) as by-phase. Phase-pure zeolite NaP was obtained from a gel composed of 60 Na 2O: Al 2O 3:103SiO 2:4500H 2O with and without hexamethylenediimine (HMI) template under microwave heating at 140 °C for 3 h. Formation of crystalline MCM-22 was not observed. Characterization methods comprised chemical analysis (ICP-OES), XRD, thermal analysis (TG/DTA), 27Al as well as 29Si MAS NMR spectroscopy, and electron microscopy (SEM).