Novel W-modified SnMnCeOx catalyst for the selective catalytic reduction of NOx with NH3.

A series of W-modified SnMnCeOx catalysts was prepared by a co-precipitation method and investigated for the selective catalytic reduction (SCR) of NOx with NH3. It was found that W-modified SnMnCeOx catalyst enhanced not only the N2-selectivity but also the SO2 and H2O resistance of SnMnCeOx. Based on the H2-TPR and XPS results obtained, the decline of redox ability for W-modified SnMnCeOx catalysts might account for its excellent N2-selectivity. The results of NH3-TPD and in situ DRIFTS revealed that addition of W into the SnMnCeOx catalyst significantly increased its surface acidity.