کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1526938 | 1511850 | 2008 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A complementary spectroscopic study on the nickel-containing zeolite Y modified by solid-state dealumination A complementary spectroscopic study on the nickel-containing zeolite Y modified by solid-state dealumination](/preview/png/1526938.png)
The coordination of Ni2+ ions in the dehydrated and dealuminated zeolite Y samples were studied by solid-state UV–vis diffuse reflectance spectroscopy. A solid-state dealumination method was employed for preparation of two successively dealuminated zeolite Y using crystalline (NH4)2SiF6. Both solid-state and aqueous ion exchange methods were used to prepare nickel-containing zeolite samples. In the dehydrated zeolite samples, nickel cations are located in both regular and distorted tetrahedral symmetries. Their coordination may change from four to five upon adsorption of water molecules following the removal of sample cell from the helium purge system. The spectrum of the dehydrated nickel-containing sample which the zeolite Y was subjected to one step dealumination shows preference for five or six coordinated nickel cations. The spectrum of nickel-containing zeolite sample subjected to a further second step of dealumination is more broaden and does not give reliable data on the coordination of nickel.
Journal: Materials Chemistry and Physics - Volume 110, Issues 2–3, 15 August 2008, Pages 228–233