کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5416256 | 1506883 | 2010 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Density functional theory study of relevant properties of lanthanum species and 1-butene activation over lanthanum modified zeolite
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The structure and acidity of lanthanum species of modified zeolites have been investigated by using the density functional theory. The mechanism of 1-butene activation has also been studied with the effect of the channel wall in the zeolites. Lanthanum sites are computed to be less acidic than the Brønsted (Al-OH-Si) ones. The lanthanum species are very stable in modified zeolites even at the temperature of 650 K. The average frequency of the O-H stretching in lanthanum species is 3758 cmâ1, while the frequency of the O-H stretching in H-ZSM-5 is 3646 cmâ1. The reaction path of more stable carbenium formation is considered. The activation barrier is 42.93 kcal/mol. There is no Ï-complex presented in the adsorption states and the reaction mechanism is different from the catalytic cracking reactions on H-ZSM-5 zeolites.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure: THEOCHEM - Volume 962, Issues 1â3, 30 December 2010, Pages 1-6
Journal: Journal of Molecular Structure: THEOCHEM - Volume 962, Issues 1â3, 30 December 2010, Pages 1-6
نویسندگان
Shujun Jiang, Shiping Huang, Lijia Qin, Weixia Tu, Jiqin Zhu, Huiping Tian, Peng Wang,