SO_2对Co/MOR催化剂上CH_4选择催化还原NO反应性能的影响  

Effect of SO_2 on the performance of Co/MOR catalyst for the selective catalytic reduction of NO by CH_4

作　　者：闫晓亮[1] 陈树伟[1] 于峰[1] 李瑞丰[1] 

机构地区：[1]太原理工大学化学化工学院,山西太原030024

出　　处：《燃料化学学报》2011年第6期455-459,共5页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(20876102);高等学校博士学科点专项科研基金(200801120006);山西省自然科学基金(2008011022)

摘　　要：考察了富氧条件下SO2存在对丝光沸石负载的钴催化剂(Co/MOR)上甲烷选择催化还原NO的反应性能的影响,并采用NO程序升温脱附(NO-TPD)、X射线衍射(XRD)、H2程序升温还原(H2-TPR)和紫外可见漫反射光谱(UV-v is DRS)等技术对反应前后催化剂的NO吸附性能和结构特征进行了表征。结果表明,受SO2气氛的影响,Co/MOR催化剂上NO转化率在低于550℃时下降较大,但在高于600℃时SO2的影响不明显,而且这种影响是可逆的。SO2的存在抑制了NO在催化剂活性位上的吸附,同时在反应过程中促进了CoO物种的生成,导致催化剂活性中心数减少、催化剂活性下降。The selective catalytic reduction（SCR） of NO by CH4 in the presence of SO2 was investigated over the catalyst cobalt supported on Mordenite（Co/MOR）;both the fresh and spent catalysts were characterized by temperature-programmed desorption of NO（NO-TPD）,X-ray diffraction（XRD）,H2 temperature-programmed reduction（H2-TPR）,and UV-vis diffuse reflectance spectroscopy（UV-vis DRS）.The results indicated that the presence of SO2 in the feed leads to a decrease of NO conversion at a temperature below 550℃;however,this influence is not evident at a temperature above 600℃.Moreover,the negative effect of SO2 on the NO conversion is reversible over the Co/MOR catalyst.SO2 may inhibit the adsorption of NO on the active sites and promote the formation of CoO during the reaction,which leads to a decrease of the active sites and the activity of Co/MOR for the SCR of NO.

关 键 词：二氧化硫 一氧化氮 甲烷 选择催化还原 钴 丝光沸石 

分 类 号：O643[理学—物理化学]