کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1261812 971833 2015 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Low temperature selective catalytic reduction of NO by C3H6 over CeOx loaded on AC treated by HNO3
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Low temperature selective catalytic reduction of NO by C3H6 over CeOx loaded on AC treated by HNO3
چکیده انگلیسی

The activated carbons from coal were treated by HNO3 (named as NAC) and used as carriers to load 7% Ce (named as Ce(0.07)/NAC) by impregnation method. The physical and chemical properties were investigated by thermogravimetric-differential thermal analysis (TG-DTA), Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), scanning electron microscopy (SEM) and NH3-temperature programmed desorption (NH3-TPD) and NO-temperature programmed desorption techniques. The catalytic activities of Ce(0.07)/NAC were evaluated for the low temperature selective catalytic reduction (SCR) of NO with C3H6 using temperature-programmed reaction (TP-reaction) in NO, C3H6, O2 and N2 as a balance. The results showed that the specific surface area of Ce(0.07)/NAC was 850.8 m2/g and less than NAC, but Ce oxides could be dispersed highly on the activated carbons. Ce oxides could change acid sites and NO adsorption as well as oxygen-containing functional groups of activated carbons, and Ce4+ and Ce3+ coexisted in catalysts. The conversion of NO with C3H6 achieved 70% at 280 °C over Ce(0.07)/NAC, but with the increase of O2 concentration, heat accumulation and nonselective combustion were exacerbated, which could cause surface ashing and roughness, resulting in a sharp decrease of catalytic activities. The optimum O2 concentration used in the reaction system was 3% and achieved the high conversion of NO and the widest temperature window. The conversion of NO was closely related to the NO concentrations and [NO]/[C3H6] ratios, and the stoichiometric number was just close to 2:1, but the presence of H2O could affect the denitration efficiency of catalyst.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Rare Earths - Volume 33, Issue 4, April 2015, Pages 371–381
نویسندگان
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