✦ LIBER ✦
Enhanced resolution in the 1H NMR spectra of zeolite H-ZSM-5 by heteronuclear dipolar-dephasing spin-echo MAS
✍ Scribed by Dieter Freude
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 513 KB
- Volume
- 235
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
Dipolar-dephasing with high power 2~M irradiation yields 1H MAS NMR echo spectra of 'aluminium-unconnected' hydroxyl groups in dehydrated zeolites. The aluminium-connected SiOHAI and AIOH hydroxyls can be observed as the difference spectra. The technique increases the number of OH lines in the 1H NMR spectra of dehydrated zeolite H-ZSM-5. Two kinds of Brcnsted sites can be distinguished and interpreted in terms of their mobility in the vicinity of framework aluminium atoms.