不同Mn/(Mn+Ce)质量比对整体式MnO_x-CeO_2/WO_3-ZrO_2催化剂NH_3-SCR性能的影响(英文)  

Influence of Mn/(Mn+Ce) Ratio of MnO_x-CeO_2/WO_3-ZrO_2 Monolith Catalyst on Selective Catalytic Reduction of NO_x with Ammonia

作　　者：徐海迪[1] 房志涛[1] 曹毅[1] 孔爽[1] 林涛[1] 龚茂初[1] 陈耀强[1] 

机构地区：[1]四川大学化学学院,教育部绿色化学与技术重点实验室,四川成都610064

出　　处：《催化学报》2012年第12期1927-1937,共11页

基　　金：supported by the National Natural Science Foundation of China (20773090 and 20803049)~~

摘　　要：制备了一系列不同Mn/（Mn＋Ce）质量比的MnOx-CeO2/WO3-ZrO2整体式催化剂用于富氧条件下的NH3选择性催化还原NOx（NH3-SCR）,并采用N2吸脱附、储氧量、X射线衍射、X光电子能谱、NH3/NO程序升温脱附以及H2程序升温还原等手段对催化剂进行表征.结果表明,当Mn/（Mn＋Ce）质量比为0.5时,整体式催化剂具有较好的NH3-SCR性能,在空速10000h-1和173~355oC条件反应下,NOx转化率达90%以上.这是由于该MnOx-CeO2/WO3-ZrO2催化剂具有更高的NO氧化活性、更高的表面Ce和Mn原子浓度以及Ce3＋/Ce值较低的NH3和NO脱附温度以及优异的氧化还原性能所致.A series of monolith MnOx-CeO2/WO3-ZrO2 catalysts with different mass ratios of Mn/（Mn＋Ce） were prepared and used for the selective catalytic reduction （SCR） of NOx with NH3 in the presence of excess O2. The catalysts were characterized by N2 adsorption, oxygen storage capacity, X-ray diffraction, X-ray photoelectron spectroscopy, NH3/NO temperature-programmed desorption, and H2 temperature-programmed reduction. The best catalyst had the mass ratio of Mn/（Mn＋Ce）=0.5. It gave 90% NOx conversion in the range of 173？355 oC at the gas hourly space velocity of 10000 h？1, and characterization results showed that a higher oxidation activity of NO to NO2, more surface Ce and Mn with a larger Ce3＋/Ce4＋ ratio, lower NH3 and NO desorption temperatures, and excellent redox ability were together responsible for its best NH3-SCR performance.

关 键 词：锰 铈 氨选择性催化还原 氮氧化物 质量比 

分 类 号：O643.32[理学—物理化学]