Characterization of offretite during hydrothermal treatment by high-resolution solid-state 29Si magic angle spinning NMR and 27Al triple-quantum magic angle spinning NMR spectroscopy

✍ Scribed by P. Lentz; A. P. Carvalho; L. Delevoye; C. Fernandez; J.-P. Amoureux; J. B. Nagy

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 116 KB
• Volume: 37
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/(sici)1097-458x(199912)37:13<s55::aid-mrc564>3.0.co;2-f

✦ Synopsis

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Si magic angle spinning (MAS) NMR, 27 Al MAS NMR and 27 Al triple-quantum MAS NMR were used to study the dealumination of offretite occurring during hydrothermal treatment. Deformed tetrahedral ( Si-O-) 3 Al-OH species and two octahedral extra-framework species are formed during the course of the process. Specific dealumination takes place under mild conditions since the aluminium distribution changes to the detriment of the T 2 sites. The connection between 27 Al and 29 Si NMR results suggests that while aluminium is extracted, silanol groups partly recombine to form new Si-O-Si bonds.