Ce基低温NH3-SCR催化剂的研究进展

Research process of ceria-based low-temperature catalysts for selective catalytic reduction of NO with NH_3

NH_3选择催化还原(NH_3-SCR)是一种优异的NOx脱除技术,当前该技术中使用最广泛的商业催化剂为V_2O_5-WO_3(WO_3)/TiO_2。由于这种催化剂中含有毒的V﹑且具有强的SO_2氧化能力以及高的操作温度窗口(350～400℃)等原因,并不适用于低温条件下使用。因此,发展一种在低温下具有较高活性以及对环境友好的催化剂受到了研究者们的广泛关注。近些年,人们发现Ce基氧化物催化剂具有独特的氧储存和释放以及氧化还原性能,在NH_3-SCR反应中表现出优异的低温催化活性,被认为是SCR反应催化剂的候选者。在此本文详细地阐述了Ce基氧化物催化剂用于低温NH_3-SCR反应过程中的研究进展(活性以及抗硫性能)和存在的缺点,为未来高效Ce基氧化物催化剂的研发提供指导。

Selective catalytic reduction by NH3(NH3-SCR) is a kind of excellent technology for NOxremoval. Currently,V2O5-WO3(WO3)/Ti O2 is widely used as the commercial catalyst. But it is not suitable for low temperature environment because of the poisonousness of vanadium of the catalyst,strong ability of SO2 oxidation and high operating temperature window(350 ~ 400 ℃). Based on the above reasons,researchers focus more attention on developing an environmental-friendly catalyst with high activity at low-temperature. In recent years,investigators found that Ceria-based oxides catalyst showed preferable catalytic performance in the NH3-SCR reaction due to the unique oxygen storage and release as well as redox ability. Therefore,it is considered as the catalyst candidate for the NH3-SCR reaction. In this review,the research progress( activity and sulfur resistance) and existing disadvantage of the Ceria-based catalysts for low-temperature selective catalytic reduction of NO with NH3 are particularly discussed in order to provide guidance for the future development of Ceria-based oxides catalyst.