Abstract: A series of MnOx–CeO2 and MnOx–TiO2 catalysts were prepared by a homogen近大eous precipitation method a道議nd their catalytic activities購影 for the NO oxidation 湖窗in the absence or pres海作ence of SO2 were evaluated. Results 兒多show that the optimal molar ratio 能線of Mn/Ce and Mn/Ti are 0.舊來7 and 0.5, respectively. The MnOx–CeO2 catalyst exhibits higher catalytic acti議務vity and better resista話的nce to SO2 poisoning than the MnOx–TiO2 catalyst. On the basis of Brunau高黃er–Emmett–Teller (BET), X-ra就火y diffraction (XRD), an鐘這d scanning transmission electr湖唱on microscope with mapping樹錢 (STEM-mapping) analyses, it is 還跳seen that the MnOx–CeO2 catalyst possesses high老火er BET surface area and better dispers知醫ion of MnOx over the catalyst than MnOx–TiO2 catalyst. X-ray photoelectron spectr去理oscopy (XPS) measuremen兵問ts reveal that MnOx–CeO2 catalyst provides the abunda跳短nce of Mn3+ and more surface adsorbed oxygen, 房腦and SO2 might be preferentially ads得科orbed to the surface o還黃f CeO2 to form sulfate species, which 通長provides a protection件醫 of MnOx active sites from bei麗水ng poisoned. In contrast, MnOx active sites over the MnOx–TiO2 catalyst are easily and quic員技kly sulfated, leading to rapid de紅廠activation of the catalyst for NO oxida火這tion. Furthermore, temperature progr吃服ammed desorption with NO and 器微O2 (NO + O2-TPD) and in situ diffuse r市開eflectance infrared transform spec懂器troscopy (in situ DRIFTS) charact文煙erizations results s到高how that the MnOx–CeO2 catalyst displays much stronger 草視ability to adsorb NOx than the MnOx–TiO2 catalyst, especially after SO2 poisoning.
