کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9617583 | 49169 | 2005 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Photochemistry of benzophenone adsorbed on MCM-41 surface
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
کاتالیزور
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چکیده انگلیسی
The photochemistry of benzophenone adsorbed on a channel-type solid support MCM-41 was studied by the use of diffuse reflectance and chromatographic techniques. For comparison purposes parallel studies were also conducted on silicalite and H-ZSM-5. The observed ground state absorption, luminescence and transient absorption spectra and photoproduct distribution strongly depend on the substrate under study. Triplet state luminescence was observed in all solids, hydrogen-bonded excited benzophenone emission was detected on MCM-41 while protonated excited benzophenone luminescence was observed only on H-ZSM-5. Transient absorption showed the triplet state in all solids and formation of the OH benzophenone adduct on MCM-41 and H-ZSM-5. Ketyl radical formation occurs after 355 nm irradiation but is a minor degradation pathway. The formation of transients resulting from the reaction of benzophenone with molecular oxygen was also detected on MCM-41, in air-equilibrated conditions and benzoic acid is the main degradation product. 2-Hydroxybenzophenone is one of the major photodegradation products on MCM-41 and H-ZSM-5. Products resulting from the α-cleavage were also detected under 266 nm irradiation. Benzophenone was found to be very stable in silicalite under all used conditions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Microporous and Mesoporous Materials - Volume 84, Issues 1â3, 15 September 2005, Pages 1-10
Journal: Microporous and Mesoporous Materials - Volume 84, Issues 1â3, 15 September 2005, Pages 1-10
نویسندگان
J.P. Da Silva, I. Ferreira Machado, J.P. Lourenço, L.F. Vieira Ferreira,