✦ LIBER ✦

Structural evolution of dealuminated Y zeolites during various chemical treatments

✍ Scribed by L. Aouali; J. Teanjean; A. Dereigne; P. Tougne; D. Delafosse

Publisher: Elsevier Science
Year: 1988
Tongue: English
Weight: 494 KB
Volume: 8
Category: Article
ISSN: 0144-2449
DOI: 10.1016/s0144-2449(88)80229-x

No coin nor oath required. For personal study only.

✦ Synopsis

Various dealuminated

Y zeolites (4.5 I SVAI 546) have been studied with the aim to determine their structural evolution after acid or basic treatment at 8O"C, in order to simulate the pH media in cation exchange reactions. The stability of the samples is followed by X-ray diffraction and MA.5n.m.r. spectroscopy (*%i and 27AI) 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.

The influence of dealumination conditions-hydrothermal or SiC14 gas phase reaction-on the amount of structural defects and on the stability is shown.

📜 SIMILAR VOLUMES

Chemical reactions during alkaline treat

Chemical reactions during alkaline treatment of dealuminated Y zeolites — impossibility of aluminium reinsertion into the framework

✍ Dr. rer. nat. W. Lutz; Dr. sc. nat. U. Lohse; Dr. rer. nat. B. Fahlke 📂 Article 📅 1988 🏛 John Wiley and Sons 🌐 English ⚖ 551 KB

Structural changes of Y zeolites during

Structural changes of Y zeolites during ion exchange treatment: effects of Si/Al ratio of the starting NaY

✍ Koichi Sato; Yoichi Nishimura; Nobuyuki Matsubayashi; Motoyasu Imamura; Hiromich 📂 Article 📅 2003 🏛 Elsevier Science 🌐 English ⚖ 750 KB

The effects of Si/Al ratio of starting NaY zeolites on structural changes during ion exchange treatments were studied. Three zeolites of different Si/Al ratio were subjected to three cycles of ion exchange treatment using (NH 4 ) 2 SO 4 and subsequent calcinations, and analyzed after each cycle. In

Response to Howard Sherry’s Critique of

Response to Howard Sherry’s Critique of “Structural changes of Y zeolites during ion exchange treatment: effects of Si/Al ratio of the starting NaY” by Koichi Sato, Yoichi Nishimura, Nobuyuki Matsubayashi, Motoyasu Imamura, Hiromichi Shimada [Micropor. Mesopor. Mater. 59 (2003) 133–146]

✍ Koichi Sato 📂 Article 📅 2004 🏛 Elsevier Science 🌐 English ⚖ 201 KB