Titanium-pillared clays （Ti-PILCs） were obtained by different ways from TiCl4, Ti（OC3H7）4 and TiOSO4, respectively. Mn-CeOx/Ti- PILCs were then prepared and their activities of selective catalytic reduction （SCR...Titanium-pillared clays （Ti-PILCs） were obtained by different ways from TiCl4, Ti（OC3H7）4 and TiOSO4, respectively. Mn-CeOx/Ti- PILCs were then prepared and their activities of selective catalytic reduction （SCR） of NO with NH3 at low-temperature were evaluated. Mn-CeOx/Ti-PILCs were characterized by X-ray diffraction, N2 adsorption, Fourier transform infrared spectroscopy, thermal analysis, temperature-programmed desorption of ammonia and H2-temperature-programmed reduction. It was found that Ti-pillar tend to be helpful for the enlargement of surface area, pore volume, acidity and the enhancement of thermal stability for Mn-CeOx/Ti-PILCs. Mn- CeOx/Ti-PILCs catalysts were active for the SCR of NO. Among three resultant Mn-CeOx/Ti-PILCs, the catalyst from TiOSO4 showed the highest activity with 98% NO conversion at 220°C, it also exhibited good resistance to H2O and SO2 in flue gas. The catalyst from TiCl4 exhibited the lowest activity due to the unsuccessful pillaring process.展开更多
MnO_(x)-CeO_(x)/ACFN were prepared by the impregnation method and used as catalyst for selective catalytic reduction of NO with NH_(3) at 80℃-150℃.The catalyst was characterized by N_(2)-BET,scanning electron micros...MnO_(x)-CeO_(x)/ACFN were prepared by the impregnation method and used as catalyst for selective catalytic reduction of NO with NH_(3) at 80℃-150℃.The catalyst was characterized by N_(2)-BET,scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FT-IR).The fraction of the mesopore and the oxygen functional groups on the surface of activated carbon fiber(ACF)increased after the treatment with nitric acid,which was favorable to improve the catalytic activities of MnO_(x)-CeO_(x)/ACFN.The experimental results show that the conversion of NO is nearly 100%in the range 100℃-150℃under the optimal preparation conditions of MnO_(x)-CeO_(x)/ACFN.In addition,the effects of a series of performance parameters,including initial NH3 concentration,NO concentration and O_(2) concentration,on the conversion of NO were studied.展开更多
Mn-CeOff-l＇i-pillared clay （PILC） is an attrac- tive catalyst for selective catalytic reduction of NOx at low temperature because of its low cost. The poisoning of K and Ca on the catalyst of Mn-CeOx/Ti-PILC is an ...Mn-CeOff-l＇i-pillared clay （PILC） is an attrac- tive catalyst for selective catalytic reduction of NOx at low temperature because of its low cost. The poisoning of K and Ca on the catalyst of Mn-CeOx/Ti-PILC is an important problem because K and Ca are always in presence in flue gas. To investigate the effect of K and Ca on the physicochemical characters of the catalysts, the techniques of NH3-temperature programmed desorption （TPD）, H2-temperature programmed reduction （TPR）, and X-ray photoelectron spectroscopy （XPS） were used to analyze the fresh and deactivated catalysts of Mn-CeOJTi- PILC. （Ca）Mn-CeOx/Ti-PILC and （K）Mn-CeOx/Ti-PILC are denoted for the dopes of the catalyst of Mn-CeOJTi- PILC with Ca and K, respectively. The activities of Mn- CeOx/Ti-PILC, （Ca）Mn-CeOx/Ti-PILC and （K）Mn-CeOx/ Ti-PILC for NH3-selective catalytic reduction （SCR） reaction at low temperature were investigated. The results showed that with the dopes of K and Ca on the catalysts, the SCR activities of the catalysts decreased greatly, and K exhibited more poisoning effect than Ca. With the dopes of K and Ca, the acidity, the redox property and chemisorbed oxygen on the surfaces of the catalysts were decreased, which resulted in a decreasing in SCR activity.展开更多
基金supported by the National Natural Science Foundation of China (No. 50976050, 51176077)the Research Fund for International Young Scientists (NO.51150110155)
文摘Titanium-pillared clays （Ti-PILCs） were obtained by different ways from TiCl4, Ti（OC3H7）4 and TiOSO4, respectively. Mn-CeOx/Ti- PILCs were then prepared and their activities of selective catalytic reduction （SCR） of NO with NH3 at low-temperature were evaluated. Mn-CeOx/Ti-PILCs were characterized by X-ray diffraction, N2 adsorption, Fourier transform infrared spectroscopy, thermal analysis, temperature-programmed desorption of ammonia and H2-temperature-programmed reduction. It was found that Ti-pillar tend to be helpful for the enlargement of surface area, pore volume, acidity and the enhancement of thermal stability for Mn-CeOx/Ti-PILCs. Mn- CeOx/Ti-PILCs catalysts were active for the SCR of NO. Among three resultant Mn-CeOx/Ti-PILCs, the catalyst from TiOSO4 showed the highest activity with 98% NO conversion at 220°C, it also exhibited good resistance to H2O and SO2 in flue gas. The catalyst from TiCl4 exhibited the lowest activity due to the unsuccessful pillaring process.
基金supported by the National Natural Science Foundation of China(Grant No.90610018)Tianjin Provincial Natural Science Foundation(Grant No.06YFJMJC-06200)“100 projects”of Creative Research for the Undergraduates of Nankai University.
文摘MnO_(x)-CeO_(x)/ACFN were prepared by the impregnation method and used as catalyst for selective catalytic reduction of NO with NH_(3) at 80℃-150℃.The catalyst was characterized by N_(2)-BET,scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FT-IR).The fraction of the mesopore and the oxygen functional groups on the surface of activated carbon fiber(ACF)increased after the treatment with nitric acid,which was favorable to improve the catalytic activities of MnO_(x)-CeO_(x)/ACFN.The experimental results show that the conversion of NO is nearly 100%in the range 100℃-150℃under the optimal preparation conditions of MnO_(x)-CeO_(x)/ACFN.In addition,the effects of a series of performance parameters,including initial NH3 concentration,NO concentration and O_(2) concentration,on the conversion of NO were studied.
文摘Mn-CeOff-l＇i-pillared clay （PILC） is an attrac- tive catalyst for selective catalytic reduction of NOx at low temperature because of its low cost. The poisoning of K and Ca on the catalyst of Mn-CeOx/Ti-PILC is an important problem because K and Ca are always in presence in flue gas. To investigate the effect of K and Ca on the physicochemical characters of the catalysts, the techniques of NH3-temperature programmed desorption （TPD）, H2-temperature programmed reduction （TPR）, and X-ray photoelectron spectroscopy （XPS） were used to analyze the fresh and deactivated catalysts of Mn-CeOJTi- PILC. （Ca）Mn-CeOx/Ti-PILC and （K）Mn-CeOx/Ti-PILC are denoted for the dopes of the catalyst of Mn-CeOJTi- PILC with Ca and K, respectively. The activities of Mn- CeOx/Ti-PILC, （Ca）Mn-CeOx/Ti-PILC and （K）Mn-CeOx/ Ti-PILC for NH3-selective catalytic reduction （SCR） reaction at low temperature were investigated. The results showed that with the dopes of K and Ca on the catalysts, the SCR activities of the catalysts decreased greatly, and K exhibited more poisoning effect than Ca. With the dopes of K and Ca, the acidity, the redox property and chemisorbed oxygen on the surfaces of the catalysts were decreased, which resulted in a decreasing in SCR activity.
