Cu(Mn)MgAl mixed oxides with enhanced performance for simultaneous removal of NOx and toluene: Insight into the better collaboration of CuO and MnOx via layered double hydroxides (LDHs) precursor template

In this study, Cu(Mn)MgAl oxide catalysts prepared by layered double hydroxides (LDHs) precursor template method for simultaneous removal of NOx and toluene. Firstly, we prepared CuMgAl layered double oxides (LDO) derived from LDHs by co-precipitation method. Subsequently, Mn active species were introduced to partially replace Cu species by one-step in situ and mechanical mixing method to obtain Cu2.5Mn0.5MgAl-LDO and MnOx + Cu2.5MgAl-LDO, respectively. XRD, BET, SEM, TEM, XPS, NH3-TPD, H2-TPR and in situ DRIFTs were applied to characterize the as-prepared catalysts. The catalytic results show that the activity of Mn-doped catalysts is significantly higher than that of Cu3MgAl-LDO, and the Cu2.5Mn0.5MgAl-LDO exhibits the best catalytic activity for both NH3-SCR and toluene oxidation. The obtained Cu2.5Mn0.5MgAl-LDO shows superior redox ability and highest concentration of surface Mn4+ and Cu2+ species, which may be responsible for its excellent catalytic performance. In addition, Cu2.5Mn0.5MgAl-LDO also possesses superior reusability and good tolerance to H2O/SO2.