Low temperature selective catalytic reduction of NO by C3H6 over Ce Ox loaded on AC treated by HNO3
来源期刊：JOURNAL OF RARE EARTHS2015年第4期
论文作者：楚英豪 张腾腾 郭家秀 刘超 尹华强 朱晓帆 刘勇军
文章页码：371 - 381
摘 要：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 H2 O could affect the denitration efficiency of catalyst.
楚英豪1,2，张腾腾1，郭家秀1,2,3，刘超1,2，尹华强1,2,3，朱晓帆2，刘勇军1,2
1. College of Architecture and Environment, Sichuan University2. National Engineering Technology Research Center for Flue Gas Desulfurization, Sichuan University3. Sichuan Provincial Environmental Protection & Environmental Catalytic Materials Engineering Technology Center, Sichuan University
摘 要：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 H2 O could affect the denitration efficiency of catalyst.
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