NH3-SCR performance improvement over Mo modified Mo(x)-MnOx nanorods at low temperatures

A series of novel Mo modified Mo(x)-MnOx catalysts were prepared by co-precipitation and used for NH3-SCR removal of NOx at low temperatures, which were characterized by XRD, BET, TEM, H-2-TPR, NH3-TPD, XPS and in situ DRIFT. It can be found that the addition of Mo species could induce the granular crystals transformed to the oblong-shaped nanorods, then BET surface area was obviously increased. Among the tested catalysts with different doping ratio, Mo(2)-MnOx exhibited nearly 100% NOx conversion from 150 degrees C to 350 degrees C with a gas hourly space velocity of 50000 h(-1), meanwhile, better H2O resistance performance could also be found on Mo (2)-MnOx catalyst. These were due to its higher Mn4+ content, abundant surface adsorbed oxygen (O-alpha) and more acid sites based on H-2-TPR, NH3-TPD, XPS and in situ DRIFT. Moreover, these preferable features could be correlated with the addition of Mo species by contrast with pure MnOx.