不同分子筛负载锰铈催化剂的低温NH_3-SCR脱硝性能  

Performance of Mn-Ce catalysts supported on different zeolites in the NH_3-SCR of NO_x

作　　者：黄增斌[1] 李翠清[1] 王振[1] 徐胜美[1] 冯凌波 王虹[1] 宋永吉[1] 张伟[1] 

机构地区：[1]北京石油化工学院绿色化学与催化材料研究所,北京102617

出　　处：《燃料化学学报》2016年第11期1388-1393,共6页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21343009)资助~~

摘　　要：分别以β、ZSM-5和USY分子筛为载体,采用浸渍法制备了锰铈催化剂,对其低温NH_3-SCR反应性能进行了评价,并采用XRD、BET、NH_3-TPD、H_2-TPR以及XPS对催化剂进行了表征。结果表明,三种分子筛负载的锰铈催化剂均具有较好的低温NH_3-SCR反应活性,其中,Mn-Ce/USY的催化性能最好,在107℃时NOx转化率可达到90%。负载锰铈后催化剂的比表面积和孔体积均有所下降;活性组分MnOx主要以无定型态分布于催化剂表面,且在ZSM-5上检测到聚集的CeO_2。催化剂表面弱酸对低温NH3-SCR反应起主要作用,催化剂表面上活性组分的表面浓度和氧化态明显不同,较高的Mn^(4+)/Mn^(3+)原子比和吸附氧表面浓度对提高催化剂的低温NH3-SCR反应活性有利。With various zeolites such as β,ZSM-5 and USY as the support,a series of Mn-Ce catalysts were prepared by impregnation method and characterized by XRD,BET,NH_3-TPD,H_2-TPR and XPS; their catalytic performance in the NH_3-SCR of NOx at low temperature was investigated. The results show that all these catalysts are highly active in the NH_3-SCR reaction at low temperature; especially,over the Mn-Ce/USY catalyst,the conversion of NOx reaches 90% at 107 ℃. After loaded of manganese and cerium,the specific surface area and pore volume of supported catalysts are decreased. Amorphous MnOx as the active component and crystalline CeO_2 are detected on the surface of ZSM-5 zeolite. The weak acid sites on the catalyst surface probably play an important role in the NH_3-SCR at low temperature. Meanwhile,a high atomic ratio of Mn^(4+)/Mn^(3+) and concentration of adsorbed oxygen may also promote the NH_3-SCR reaction at low temperature.

关 键 词：NH3-SCR 锰 铈 分子筛 NO 

分 类 号：O643[理学—物理化学]