Abstract
Various dealuminated Y zeolites (4.5 ≤ Si/Al ≤ 46) have been studied with the aim to determine their structural evolution after acid or basic treatment at 80°C, in order to simulate the pH media in cation exchange reactions. The stability of the samples is followed by X-ray diffraction and MAS-n.m.r. spectroscopy ( 29Si and 27Al). It is shown that in acidic media the low dealuminated samples are unstable, while in basic solution they do not undergo drastic modification. By contrast samples with a high dealumination degree (Si/Al >18) are quite stable in acidic media but lose easily their crystalline structure in basic solution. Abstract The influence of dealumination conditions—hydrothermal or SiCl 4 gas phase reaction—on the amount of structural defects and on the stability is shown.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
