Solid-state nuclear magnetic resonance studies of the transformation of the zeolite Y catalyst in the course of hydrochlorination of 1-methylcyclohexen

✍ Scribed by Waclaw Kolodziejski; Lionel Delaude; Pierre Laszlo; Marie-Thérèse Montaufier; Jacek Klinowski

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 411 KB
• Volume: 98
• Category: Article
• ISSN: 0926-860X
• DOI: 10.1016/0926-860x(93)85026-l

✦ Synopsis

1-Methylcyclohexene was hydrdchlorinated with SOClz to 1-chloro-1-methylcyclohexane at room temperature in CH& as the solvent and in presence of the faujasitic seolite ZF520 catalyst. I-Coordinated framework aluminium in the parent sample coexisting with a small amount of immobile extraframework aluminium at ca. -1 ppm is completely removed after just one reaction run and transformed into two distinct 6-coordinated species resonating at 0.2 and -3.1 ppm. The former line is assigned to Al(&O):+ cations, the latter is likely to come from a species with mixed solvation shells, probably Al(Cl-)(H,O)g' andAl(OH-)(H,O)g+. Crystallinity of the catalyst is seriously affected by the reaction. The spectra confirm that before reaction the zeolite contains Si(3Si,lOH) and Si(2Si,20H) groups. During the reaction most hydroxyl groups created by dealumination are removed, although some Si (BSi,lOH ) remain. MAS NMR spectra are fully consistent with the proposed reaction mechanism.