کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
76565 | 49142 | 2007 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Dehydration and rehydration of mesolite: An in situ FTIR study Dehydration and rehydration of mesolite: An in situ FTIR study](/preview/png/76565.png)
The dehydration and rehydration processes of mesolite belonging to NAT group of zeolites were investigated using in situ Fourier Transform Infrared spectroscopy (FTIR). The thermal induced variations of the water molecule bending (ν2), the stretching (ν3 and ν1) modes and the corresponding second order modes in the wavenumber region 4000–8000 cm−1 were followed as indicative of the dehydration process. Observed spectral variations were well correlated with thermogravimetric studies and indicate that the mesolite dehydrates in three stages (470; 510 and 650 K). Anomalous spectral variations of 4600 cm−1 at first stage indicate that the dehydration is triggered by the expulsion of water coordinating AlO4 tetrahedron. Partial rehydration (up to 85%) at second stage indicates disordering of natrolite and scolecite layers. During the third stage mesolite completely dehydrates, causing the destruction of framework.
Journal: Microporous and Mesoporous Materials - Volume 100, Issues 1–3, 23 March 2007, Pages 287–294