کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
69007 | 48528 | 2006 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Chromium nitrosyl complexes in Cr-ZSM-5: An FTIR spectroscopic study
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
کاتالیزور
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The species formed after adsorption of NO on a Cr-ZSM-5 sample pre-subjected to different red-ox treatments have been studied by FTIR spectroscopy. Only NO+, occupying cationic positions in the zeolite, is formed on a non-reduced sample. Adsorption of NO on samples reduced by hydrogen at temperatures between 473 and 773Â K leads mainly to formation of different mononitrosyl (1890 and 1815Â cmâ1) and dinitrosyl species (1910Â +Â 1780Â cmâ1). The latter are decomposed without producing a measurable fraction of the corresponding mononitrosyls. The dinitrosyl complexes are likely produced with the participation of Cr3+ cations. Some Cr2+ sites are created after reduction of the sample with hydrogen at 873Â K or with CO at 773Â K. These sites form another kind of dinitrosyl species (bands at 1902 and 1768Â cmâ1) which are converted during evacuation to mononitrosyls (band at 1782Â cmâ1). The assignments of the different bands are supported by 14NO-15NO co-adsorption experiments.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Catalysis A: Chemical - Volume 249, Issues 1â2, 18 April 2006, Pages 40-46
Journal: Journal of Molecular Catalysis A: Chemical - Volume 249, Issues 1â2, 18 April 2006, Pages 40-46
نویسندگان
Mihail Mihaylov, Anna Penkova, Konstantin Hadjiivanov, Marco Daturi,