کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
76775 49149 2007 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Periodic density functional and FTIR spectroscopic studies on CO adsorption on the zeolite Na-FER
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Periodic density functional and FTIR spectroscopic studies on CO adsorption on the zeolite Na-FER
چکیده انگلیسی

Carbon monoxide adsorption on Na-FER was studied by a combination of variable-temperature IR spectroscopy and computational methods involving, mainly, periodic density functional theory and ωCO/rCO correlation. Both, C–O stretching frequency and interaction energy of adsorption complexes were investigated. Interplay between calculated and experimental results led to identification of the following adsorbed species: (i) C-down monocarbonyls formed on single Na+ sites, characterized by an infrared absorption band at 2175 cm−1; (ii) O-down isocarbonyls showing a characteristic IR absorption band at 2113 cm−1; and (iii) bridged Na+⋯CO⋯Na+ complexes formed on dual cation sites constituted by a pair of nearby Na+ ions, and characterized by an IR absorption band at 2158 cm−1. The bridged carbonyl complex was found to be about 4 kJ mol−1 more stable than the C-down monocarbonyl, despite its smaller C–O stretching frequency. The least stable adsorption complex is the O-down (isocarbonyl) species formed on single Na+ sites. Besides carrying out a detailed characterization of the CO/Na-FER system, investigation of the bridged CO complex on dual cation sites was one of the main aims pursued; such a novel type of CO adsorption complex was described very recently, for the first time, for the case of CO adsorbed on K-FER [J. Phys. Chem. B 110 (2006) 22542].

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Microporous and Mesoporous Materials - Volume 106, Issues 1–3, 1 November 2007, Pages 162–173
نویسندگان
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