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Simultaneous oxidation of Hg and NH-SCR of NO by catalyst is one of the key methods for co-purification of coal-fired flue gas. Till now, the interaction between the oxidation of Hg and NH-SCR of NO and its mechanism have not clarified. In this study, a series of nanophase Ce Zr Mn O was prepared for the simultaneous oxidation of Hg and NH-SCR of NO at low temperature. The catalysts were characterized using surface area analysis, X-ray diffraction, temperature-programmed techniques, and several types of microscopy and spectroscopy. The experimental results indicated that the CeZrMnO exhibited superior Hg removal efficiency (> 99%) and NO conversion efficiency (> 90%) even at 150 °C, and it also exhibited a good durability in the presence of SO and HO. The excellent performance of CeZrMnO on co-purifying Hg and NO was due to the stronger synergistic effects of Ce-Zr-Mn in CeZrMnO than that of the others, which was illustrated by the characterization results of XPS, XRD, and FT-IR. Moreover, it was found that the NO conversion of CeZrMnO could be slightly influenced by Hg and was decreased about 4% to the max, while that of Hg could rarely be affected by the selected catalytic reduction process of NO. It might be due to the co-purification mechanism of NO and Hg. The mechanism of the simultaneous oxidation of Hg and NH-SCR of NO was mainly due to the synergetic effect on the mobility of surface oxygen and the activation of lattice oxygen of CeZrMnO. The effect of the oxidation of Hg on the NH-SCR of NO was mainly due to the absorbed Hg/Hg on the surface of CeZrMnO, which attenuated the formation of NH, -NH, and NH on its acid sites. Similarly, the NH-SCR of NO process could hardly influence the oxidation of Hg when NO and Hg were co-purified.

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