Sulfur-resistant mechanism of MnO_x@CeO₂@MgO core-shell catalyst in simultaneous removal of NO_x and chlorobenzene

Herein, Mn-Ce based catalysts with different structures were rationally designed to explore their sulfur-resistant mechanism for simultaneous removal of NO_x and chlorobenzene (CB) from waste incineration at low temperature. In the presence of SO₂, MnO_x@CeO₂@MgO exhibits the highest sulfur resistance among prepared catalysts. Both NO_x and CB conversion over MnO_x@CeO₂@MgO can reach up to 80 % at 300 °C. However, the significant deactivation is observed for MnCeMgO_x within all temperature ranges. For the selectivity of products, MnO_x@CeO₂@MgO displays the excellent N₂ selectivity (93 %) and good CO₂ selectivity (80 %) at 300 °C. Compared with NO reduction, SO₂ has a greater impact on CB destruction due to the consumption of reactive oxygen species during SO₂ oxidation. The reduction of active oxygen is proposed to be the reason for the significant inhibition of CB oxidation. The addition of MgO shell increases the proportion of lattice oxygen, which is beneficial to improving the sulfur resistance of MnO_x@CeO₂@MgO catalyst. In addition, SO₂ can react with MgO preferentially to protect the active sites and improve the sulfur resistance. This work indicates that MnO_x@CeO₂@MgO core-shell catalyst with good sulfur tolerance and stability is expected to be applied in the potential application.