کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9567246 | 1503711 | 2005 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Periodic density functional investigation of Lewis acid sites in zeolites: relative strength order as revealed from NH3 adsorption
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Different types of cationic species acting as Lewis acid sites as well as Na-counter ion in dealuminated zeolites are investigated, for the first time, using periodic density functional method. The energy of ammonia adsorption is taken as a measure for the acidity. The results reveal that the relative strength of the investigated active sites increases in the order: Na+Â <Â Al(OH)2+Â <Â AlO+Â <Â Si+. Moreover, the interaction of NH3 with tri-coordinated aluminum dislodged in the framework is less favorable than that with the neighboring silicon ion.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 246, Issues 1â3, 15 June 2005, Pages 96-101
Journal: Applied Surface Science - Volume 246, Issues 1â3, 15 June 2005, Pages 96-101
نویسندگان
Mohamed Elanany, Michihisa Koyama, Momoji Kubo, Ewa Broclawik, Akira Miyamoto,