Significant Promotion Effect of Mo Additive on a Novel Ce-Zr Mixed Oxide Catalyst for the Selective Catalytic Reduction of NOx with NH3

A novel Mo-promoted Ce-Zr mixed oxide catalyst prepared by a homogeneous precipitation method was used for the selective catalytic reduction (SCR) of NOx with NH3. The optimal catalyst showed high NH3-SCR activity, SO2/H2O durability, and thermal stability under test conditions. The addition of Mo inhibited growth of the CeO2 particle size, improved the redox ability, and increased the amount of surface acidity, especially the Lewis acidity, all of which were favorable for the excellent NH3-SCR performance. It is believed that the catalyst is promising for the removal of NOx from diesel engine exhaust.