采用流变相法制备了无载体Nano—MnOx催化剂,在低温条件下(50-150℃)以NH为还原剂系统考察了氮氧化物的选择催化还原特性.结果表明,流变相法制备的Nano-MnOx催化剂具有良好的低温催化活性.实验条件下,80℃即可获得98.25%的NO转化率,100-150℃内NO几乎完全转化;SO2和H2O会与NO和NH3在催化剂表面产生竞争吸附,导致催化活性下降,但该影响是可逆的.经分析,较大的比表面积和较低的晶化度是Nano-MnOx具有良好低温活性的2个主要原因.
Nanometer particles composed of manganese oxides (Nano-MnOx), which prepared by theological phase reaction method, show superior low-tcmporature SCR activity for NO with NH3 in the presence of excess O2 . In experiments, the NO conversion is 98.25% at 80℃, and nearly 100% NO could bc converted in 100 - 150℃ . Due to the reason of competing adsorption, H2O has a slight impact on the activity and the dcactivation of SO2 is reversible. The experiments implied that the superior low-temperature catalytic activity of Nano-MnOx was mainly due to its high BET specific areas and poor crystallinity.