Effect of thermal and acid treatment on the structure of NHNa-Y zeolite by IR data.

Autor: Kosheleva, L.
Zdroj: Russian Chemical Bulletin; 1995, Vol. 44 Issue 2, p228-232, 5p
Abstrakt: The structural transformations of ammonium-exchanged forms of Na-Y zeolite during thermal evacuation and acid treatment were studied using IR spectroscopy. The formation of the zeolite H-forms by shallow-bed evacuation of NHN-Y at 570 K is accompanied by a high-frequency shift of the bands in the IR lattice vibration spectra. In the formation of the H-forms resulting from the decationization of zeolite by treatment with an aqueous HCl solution, no shifts of the bands are observed. During deep-bed calcination in air the H-form, is transformed into the H-form completed by the formation of a highly-crystalline stabilized zeolite at 623 K. A rapid increase in the shallow-bed calcination temperature results in a collapse of the structure of the H- and H-forms followed by the formation of amorphous SiO. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz: