Challenges and opportunities for manganese oxides in low-temperature selective catalytic reduction of NOx with NH3: H2O resistance ability

Manganese oxides (MnOx) have attracted increasing attention in selective catalytic reduction of NOx with NH3 (NH3-SCR) due to their excellent low-temperature catalytic activities. However, MnOx still suffer from poor resistance to SO2 and H2O in NH3-SCR. In particular, the irreversible poisoning of SO2 limits their practical applications in NH3-SCR. With the new regulations concerning the emission of SO2 gas, MnOx may be used for control over NOx (i.e. NO and NO2) emission in NH3-SCR. This mini-review was devoted to challenges and opportunities of MnOx catalysts in NH3-SCR, which may be helpful for its practical application in NH3-SCR system.