摘要
以MnOx-CeO2为活性组分,以三聚氰胺为还原剂,制备了球形活性炭（SAC）担载MnOx-CeO2和三聚氰胺的复合催化剂,并考察了该催化剂在低温下（120-180℃）对NO的选择性催化还原（SCR）反应行为。实验还利用扫描电子显微镜–能谱仪（SEM-EDS）、X射线衍射（XRD）和低温N2吸附法等技术对催化剂进行了表征。结果表明,当反应温度为180℃、空速为6000 h-1、NO和O_2浓度分别为0.1%和8%时,担载8%Mn（摩尔比Mn：Ce固定为1：1）和10%三聚氰胺的催化剂可在8.8 h内实现99%的NOx转化率。煅烧温度高于400℃将促使MnOx-CeO2形成更大的晶体颗粒和更加规整的晶型结构,从而降低其melamine-SCR活性。三聚氰胺担载量高于15%将造成催化剂比表面积和孔容的急剧减小,最终导致其稳态NOx转化率的下降。而金属氧化物担载量的增加和反应温度的升高都有利于Melamine-SCR反应,且在较宽的NO和O2浓度范围内,催化剂的稳态NOx转化率都能维持在99%左右。
A spherical activated carbon （SAC） loaded with MnOx-CeO2 and melamine was prepared as the cata-lyst for selective catalytic reduction （SCR） of NO at low temperature （120-180℃）. Physical and chemical prop-erties of the catalysts were characterized by scanning electron microscopy-energy disperslve spectrometer （SEM-EDS）, X-ray diffraction （XRD）, and N2 adsorption-desorption technologies, resPectivelY. The results show that about 99% NOx conversion for 8.8 h at 180℃ is achieved over the catalyst with 10% melamine and 8% Mn loading （the mole ratio of Mn：Ce was fixed at 1：1） under the condition of 0.1% NO, 8% O2 and a space velocity of 6000 h-1. When the calcination temperature is higher than 400℃, the melamine-SCR activity is decreased ob-viously due to the crystallinity of the metal oxides increasing. When melamine loading is more than 15%, the specific surface area and pore volume of the catalysts decrease significantly, leading to a decline in the station-ary-state NOx conversion. However, the increase of metal oxides loading and reaction temperature is found to be beneficial to melamine-SCR reactivity, and the stationary-state NOx conversion is always maintained at about 99% over a wide concentration range of NO and O2.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2016年第11期1205-1211,共7页
Journal of Inorganic Materials
基金
国家自然科学基金(51302083
51172071
51272077
21506061)~~
