کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7832435 | 1503295 | 2006 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Base-induced Brönsted Acid Sites on Dealuminated HY Zeolite: A Solid-state NMR Spectroscopy Study
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
Using trimethylphosphine (TMP) and d5-pyridine(deuterated pyridine) as the basic probe molecules, the concentrations of Brönsted acid sites on both HY zeolite and dealuminated HY zeolite have been quantitatively determined using solid-state 1H and 31P magic-angle spinning (MAS) NMR. After adsorption of the probe molecules, the concentration of Brönsted acid sites on the dealuminated HY zeolite increases by about 25%, whereas that in the parent HY sample remains almost unchanged. The increase in the concentration of Brönsted acid sites is due to the appearance of base-induced Brönsted acid sites in the dealuminated HY zeolite. The terminal SiOH in the vicinity of the aluminum atom is “induced” to form a bridging hydroxyl group (SiOHAl) in the presence of the basic probe molecules. The mechanism of formation of the induced Brönsted acid sites has also been discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Physico-Chimica Sinica - Volume 22, Issue 10, October 2006, Pages 1233-1237
Journal: Acta Physico-Chimica Sinica - Volume 22, Issue 10, October 2006, Pages 1233-1237
نویسندگان
Wei Hu, Qing Luo, Shenhui Li, Wanling Shen, Yong Yue, Feng Deng,