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
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.
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.
