کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9609892 | 46540 | 2005 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Quantification of the in situ DRIFT spectra of Pt/K/γ-A12O3 NOx adsorber catalysts
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
کاتالیزور
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Quantification of the in situ DRIFT spectra of Pt/K/γ-A12O3 NOx adsorber catalysts Quantification of the in situ DRIFT spectra of Pt/K/γ-A12O3 NOx adsorber catalysts](/preview/png/9609892.png)
چکیده انگلیسی
A method to quantify DRIFT spectral features associated with the in situ adsorption of gases on a NOx adsorber catalyst, Pt/K/Al2O3, is described. To implement this method, the multicomponent catalyst is analysed with DRIFT and chemisorption to determine that under operating conditions the surface comprised a Pt phase, a pure γ-Al2O3 phase with associated hydroxyl groups at the surface, and an alkalized-Al2O3 phase where the surface -OH groups are replaced by -OK groups. Both DRIFTS and chemisorption experiments show that 93-97% of the potassium exists in this form. The phases have a fractional surface area of 1.1% for the 1.7 nm-sized Pt, 34% for pure Al2O3 and 65% for the alkalized-Al2O3. NO2 and CO2 chemisorption at 250 °C is implemented to determine the saturation uptake value, which is observed with DRIFTS at 250 °C. Pt/Al2O3 adsorbs 0.087 μmol CO2/m2and 2.0 μmol NO2/m2, and Pt/K/Al2O3 adsorbs 2.0 μmol CO2/m2and 6.4 μmol NO2/m2. This method can be implemented to quantitatively monitor the formation of carboxylates and nitrates on Pt/K/Al2O3 during both lean and rich periods of the NOx adsorber catalyst cycle.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Catalysis B: Environmental - Volume 58, Issues 3â4, 28 June 2005, Pages 245-254
Journal: Applied Catalysis B: Environmental - Volume 58, Issues 3â4, 28 June 2005, Pages 245-254
نویسندگان
Todd J. Toops, D. Barton Smith, William P. Partridge,