کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9608131 | 46074 | 2005 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Low temperature water-gas shift reaction on cerium containing mordenites prepared by different methods
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
کاتالیزور
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Cerium containing mordenites catalysts were prepared by impregnation (CeMimp), solid-state ion exchange (CeMss) and in situ incorporation during synthesis (CeMin). The structure of the samples has been investigated by X-ray diffraction, FT-IR, N2 adsorption, thermal analyses (TG and DTA) and pyridine-FT-IR. Water-gas shift reaction (WGSR) was carried out over various catalysts and the catalytic reaction was monitored using in situ FT-IR. The results obtained showed the presence of cerium silicate phase in case of CeMin sample as evidenced by XRD and FT-IR spectroscopy. In case of CeMimp and CeMss, a separate CeO2 phase was observed in a highly dispersed state in the former than in the latter, which measured the highest specific surface area. FT-IR results of pyridine adsorption indicate the presence of acid-base site pairs on the surface of CeMimp and CeMss samples where only Lewis acidity was found on CeMin, reflecting the presence of Ce3+ with Si4+ cations at tetrahedral lattice sites in mordenite. CeMimp showed the highest catalytic activity followed by CeMss. It has been shown that reduction by H2 carried out at 500 °C was responsible for activating different carbonyls attached to Ce3+; such as Ce3+-CO and Ce3+-(CO)2 which decomposed into CO2 ads. The role of basicity, Ce dispersion and surface texture of reduced Ce-mordenites on their catalytic activity in CO oxidation by H2O was evaluated and discussed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Catalysis A: General - Volume 279, Issues 1â2, 28 January 2005, Pages 23-33
Journal: Applied Catalysis A: General - Volume 279, Issues 1â2, 28 January 2005, Pages 23-33
نویسندگان
M.M. Mohamed, T.M. Salama, A.I. Othman, G.A. El-Shobaky,