کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10244831 | 47706 | 2005 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Mechanistic study of the influence of surface acidity on lean NO2 reduction by propane in HZSM-5
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
کاتالیزور
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
This study focuses on the mechanism of lean NOx reduction by propane, over acidic zeolites (HZSM-5), and the influence of surface acidity. In situ FTIR measurements of ammonia adsorption indicate a higher number of Brønsted acid sites for a sample with a low SiO2/Al2O3 ratio. The activity for NOx reduction and the selectivity for N2 formation correlate well with the Brønsted acidity. Step-response experiments with NO2 and propane show the formation of surface-bound NO+, isocyanate, unsaturated hydrocarbons, and amine species. Formation of the latter two seems to be closely related to the Brønsted acidity. In the NO2 reaction with propane, the NO+ species seem to play a vital role, probably reacting with carbenium ions (from propane cracking) to form isocyanates, which may be hydrolysed to amine species. Step-response experiments with isopropylamine and NO2 indicate a fast reaction, where the amine and NO+ species react over Brønsted acid sites. Hence, amine species are possible reaction intermediates in the lean reduction of NO2 by saturated hydrocarbons, such as propane, over HZSM-5.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Catalysis - Volume 232, Issue 1, 15 May 2005, Pages 68-79
Journal: Journal of Catalysis - Volume 232, Issue 1, 15 May 2005, Pages 68-79
نویسندگان
Hanna Härelind Ingelsten, Dongmei Zhao, Anders Palmqvist, Magnus Skoglundh,