Abstract: A series of MnOx–CeO2 and MnOx–TiO2 catalysts were prepared 筆就by a homogeneous precipit兒紙ation method and their catalytic activ雨樂ities for the NO oxida房件tion in the absence or prese文報nce of SO2 were evaluated. Results show that t兒花he optimal molar ratio of Mn/Ce 舞到and Mn/Ti are 0.7 and 0.5, res熱現pectively. The MnOx–CeO2 catalyst exhibits higher catalyt購間ic activity and better resista呢站nce to SO2 poisoning than the MnOx–TiO2 catalyst. On the basis of Brun她做auer–Emmett–Teller (BET),醫議 X-ray diffraction (XR區見D), and scanning transmission站兵 electron microscope with m不站apping (STEM-mapping) 對可analyses, it is seen購紅 that the MnOx–CeO2 catalyst possesses higher BET surface工大 area and better dispersion of雜風 MnOx over the catalyst than 花老MnOx–TiO2 catalyst. X-ray phot場要oelectron spectroscopy 會畫(XPS) measurements reve秒愛al that MnOx–CeO2 catalyst provides the abundanc關海e of Mn3+ and more surface adsorbed外視 oxygen, and SO2 might be preferentially adsorbe姐可d to the surface of CeO2 to form sulfate species,腦樂 which provides a protection of M妹雪nOx active sites from being poisoned水事. In contrast, MnOx active sites over the MnO大歌x–TiO2 catalyst are easily and quickly sulfa少兵ted, leading to rapid deactivation 理地of the catalyst for NO oxidation. Fu門費rthermore, temperatur亮們e programmed desorpti厭唱on with NO and O2 (NO + O2-TPD) and in situ diffuse reflectanc訊高e infrared transform spectroscopy (in s議呢itu DRIFTS) characterizations r吧了esults show that the 司月MnOx–CeO2 catalyst displays much stronger abil通會ity to adsorb NOx than the MnOx–TiO2 catalyst, especially 費玩after SO2 poisoning.
