Abstract: A series of MnO生樂x–CeO2 and MnOx–TiO2 catalysts were prepare音了d by a homogeneous pre工厭cipitation method and their cata短鐘lytic activities for the NO 科刀oxidation in the abse我身nce or presence of SO2 were evaluated. Resu著呢lts show that the optima河為l molar ratio of Mn/Ce and Mn/Ti a山子re 0.7 and 0.5, respectively. The MnO厭土x–CeO2 catalyst exhibits higher catalytic acti聽會vity and better resistance to S照和O2 poisoning than the MnOx–TiO2 catalyst. On the basis of Brunau身他er–Emmett–Teller (BET), X-爸好ray diffraction (XRD), and scanning tra林算nsmission electron micro劇生scope with mapping (STEM-mapping) ana的化lyses, it is seen that the MnOx–CeO2 catalyst possesses higher B近雨ET surface area and better dispersion 工路of MnOx over the catalyst than MnO爸說x–TiO2 catalyst. X-ray photoelectr員子on spectroscopy (XPS) measurements路雪 reveal that MnOx–CeO2 catalyst provides the abundance of姐水 Mn3+ and more surface ads玩內orbed oxygen, and SO2 might be preferentially adsorb物們ed to the surface of CeO2 to form sulfate species, which prov相銀ides a protection of MnOx active sites from being poisoned. In co兵爸ntrast, MnOx active sites over the MnOx–TiO2 catalyst are easily and q制好uickly sulfated, leading to 得下rapid deactivation of 習著the catalyst for NO oxidatio鐵湖n. Furthermore, temperature programm那老ed desorption with NO and要離 O2 (NO + O2-TPD) and in situ diffuse re北金flectance infrared trans國件form spectroscopy (in situ DRIFTS) 問山characterizations results 線關show that the MnOx–CeO2 catalyst displays much stronger 鄉如ability to adsorb NOx than the MnOx–TiO2 catalyst, especially after SO森問2 poisoning.
