Multinuclear solid-state NMR study of cadmium- and lead-exchanged LTA zeolites

✍ Scribed by Abdussallam Eldewik; James M. Hook; Nagindar K. Singh; Russell F. Howe

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 107 KB
• Volume: 37
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/(sici)1097-458x(199912)37:13<s63::aid-mrc563>3.0.co;2-n

✦ Synopsis

This paper describes 29 Si, 27 Al, 207 Pb and 113 Cd NMR studies of Pb-and Cd-exchanged LTA zeolites. The 113 Cd NMR spectra identify for the first time two different coordination states for Cd 2C in hydrated CdLTA, consistent with x-ray single crystal diffraction data for this zeolite. The effects of Cd 2C exchange on the 29 Si NMR spectra of LTA are also consistent with the structural data. Cd 2C exchange perturbs the 27 Al NMR spectrum of the zeolite, as does Pb 2C exchange. Changes in the 29 Si NMR spectra on Pb 2C exchange are explained in terms of structural distortion of the framework. 207 Pb NMR spectra of Pb 2C exchanged LTA show a single broad signal indicating that Pb 2C cations are rigidly located in the zeolite at relatively long Pb-O distances in the hydrated zeolites.