Abstract: A series of MnOx–CeO2 and MnOx–TiO2 catalysts were prepared by a homo白知geneous precipitation method and thei畫長r catalytic activities for t你影he NO oxidation in t但刀he absence or presence of SO2 were evaluated. Results show暗校 that the optimal mola樂玩r ratio of Mn/Ce and 鐵音Mn/Ti are 0.7 and 0.5算子, respectively. The MnO遠房x–CeO2 catalyst exhibits higher cata腦開lytic activity and better resist睡報ance to SO2 poisoning than the MnOx–TiO2 catalyst. On the basis of可司 Brunauer–Emmett–Teller (BET), X-ray di要數ffraction (XRD), and黃女 scanning transmission electron 水少microscope with mapping (STEM-mapping暗媽) analyses, it is seen that the M到書nOx–CeO2 catalyst possesses higher BE爸志T surface area and better dispersion間現 of MnOx over the catalyst than MnOx–TiO2 catalyst. X-ray photoelectron spect黃黃roscopy (XPS) measuremen城男ts reveal that MnOx–CeO2 catalyst provides the a舞海bundance of Mn3+ and more surface adsorbed oxygen, and S老討O2 might be preferentia話學lly adsorbed to the surfac村司e of CeO2 to form sulfate species,視做 which provides a protectio書聽n of MnOx active sites from being poisoned. In co機如ntrast, MnOx active sites over the MnOx–TiO2 catalyst are easily and quickly sul雜是fated, leading to rapid deactivatio內民n of the catalyst for NO o女能xidation. Furthermore, temperat月慢ure programmed desorption w鐵開ith NO and O2 (NO + O2-TPD) and in situ diffuse reflectanc光到e infrared transform spectros銀老copy (in situ DRIFTS大到) characterizations result通我s show that the MnOx–CeO2 catalyst displays much s司志tronger ability to adsorb NOx than the MnOx–TiO2 catalyst, especially a他可fter SO2 poisoning.
