In situ characterization of carbonaceous residues from zeolite-catalysed reactions using high resolution solid state 13C-n.m.r. spectroscopy

✍ Scribed by Eric G. Derouane; Jean-Pierre Gilson; Janos B. Nagy

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 471 KB
• Volume: 2
• Category: Article
• ISSN: 0144-2449
• DOI: 10.1016/s0144-2449(82)80039-0

✦ Synopsis

High resolution 13C-n.m.r. spectroscopy can be performed in the solid state by taking advantage of 1H-13C cross-polarization (CP) and magic angle spinning (MAS). This technique is presently applied to identify in situ carbonaceous residues from zeolite-catalysed reactions.

H-ZSM 5 and H-Mordenite catalysts used in the conversion of methanol and ethylene were investigated. Depending on the zeolite and the reactant, differences occur in the nature of the carbonaceous residues. In addition, this technique allows a distinction between hydrocarbon molecules which are trapped inside the intracrystalline volume of the zeolite as a result of pore plugging and strongly chemisorbed or surface alkoxide species. Finally, it can be applied to investigate the successive chemical modifications of carbonaceous deposits following selected pretreatments.