DRIFT study of manganese/titania-based catalysts for low-temperature selective catalytic reduction of NO with NH3
DRIFT study of manganese/titania-based catalysts for low-temperature selective catalytic reduction of NO with NH3
复制标题
锰/二氧化钛基催化剂用于NH3低温选择性催化还原NO的DRIFT研究
DOI：
10.1021/es0700350
复制
发表时间：
2007-08-15
影响因子：
11.4
通讯作者：
Jin, Ruiben
中科院分区：
文献类型：
--
作者：
Wu, Zhongbiao;Jiang, Boqiong;Jin, Ruiben
采用溶胶-凝胶法制备了负载在TiO2上的锰氧化物和铁锰氧化物，并将其用于NH3低温选择性催化还原NO。在前期研究的基础上，选择Mn(0.4)/TiO2和Fe(0.1)-Mn(0.4)/TiO2进行原位漫反射红外变换光谱（DRIFT）研究，揭示反应机理。吸附NH3的漂移谱分析表明，两种催化剂上都存在配位的NH3和NH4+。当NO加入时，催化剂表面的配位NH3被快速消耗，表明这些物质能与NO有效反应。当NH3被引入到预吸附了NO + O-2的样品中时，Mn(0.4)/TiO2不会发生SCR反应。然而，对于Fe(0.1)-Mn(O。NH3在Fe2O3上的配位形成了条带。同时，将双齿态硝酸盐转化为单齿态硝酸盐，并检测NH4+。催化剂上NO氧化产生的NO2可与NH4+反应，使NO还原。因此，我们认为Fe(0.1)-Mn(0.4)/TiO2上的SCR反应也可能以不同于其他研究者提出的Mn(0.4)/TiO2上的反应方式进行。并提出了两种催化剂的SCR反应步骤。
Manganese oxides and iron-manganese oxides supported on TiO2 were prepared by the sol-gel method and used for low-temperature selective catalytic reduction (SCR) of NO with NH3. Base on the previous study, Mn(0.4)/ TiO2 and Fe(0.1)-Mn(0.4)/TiO2 were then selected to carry out the in situ diffuse reflectance infrared transform spectroscopy (DRIFT) investigation for revealing the reaction mechanism. The DRIFT spectroscopy for the adsorption of NH3 indicated the presence of coordinated NH3 and NH4+ on both of the two catalysts. When NO was introduced, the coordinated NH3 on the catalyst surface was consumed rapidly, indicating these species could react with NO effectively. When NH3 was introduced into the sample preadsorbed with NO + O-2, SCR reaction would not proceed on Mn(0.4)/TiO2. However, for Fe(0.1)-Mn(O.4)/ TiO2 the bands due to coordinated NH3 on Fe2O3 were formed. Simultaneously, the bidentate nitrates were transformed to monodentate nitrates and NH4+ was detected. And NO2 from the oxidation of NO on catalyst could react with NH4+ leading to the reduction of NO. Therefore, it was suggested that the SCR reaction on Fe(0.1)-Mn(0.4)/TiO2 could also take place in a different way from the reactions on Mn(0.4)/TiO2 proposed by other researchers. Furthermore, the SCR reaction steps for these two kinds of catalysts were proposed.