Promotion effect and mechanism of MnOx doped CeO2 nano-catalyst for NH3-SCR

MnOx-CeO2 (denoted as Mn-Ce) nanorod and MnOx-CeO2 nanooctahedra catalysts were synthesized by the hydrothermal method and were used for selective catalytic reduction of NO with NH3. The catalytic performance tests showed that the NO removal efficiency of CeO2 catalysts was obviously improved after loading MnOx. The structure and properties of catalysts had been characterized by SEM, TEM, XRD, BET, XPS, H-2-TPR, NH3-TPD and in situ DRIFTS. It was found that Mn-Ce catalyst were of uniform core-shell structure, higher concentrations of Mn4+ and Ce3+, better reducibility, the increase of weak acid sites. The results of in situ DRIFTS indicated that the NH3-SCR reaction should obey the E-R mechanism. Moreover, the promotion effect and mechanism of MnOx doped CeO2 was demonstrated, which improved the catalytic activity of Mn-Ce catalysts.