High deNOx performance of Mn/TiO2 catalyst by NH3

The deNOx performance of the s-Mn/TiO2 catalyst prepared by sol–gel method has been significantly enhanced, particularly in the low temperature region. Mn is basically incorporated into the matrix of Ti and becomes a structural component of s-MnO2/TiO2 mixed oxide, whereas by impregnation method it simply exists on the surface of i-Mn/TiO2. The well-dispersed Mn over s-Mn/TiO2 catalyst is the primary cause for the high deNOx performance compared to that over i-Mn/TiO2. The addition of Fe onto the Mn/TiO2 catalyst improves the NOx removal activity by NH3 in a wide operating temperature window, including the low temperature region less than 250 °C, regardless of the catalyst preparation methods. Including NO2 (NO2/NO = 1) in the feed gas stream further enhances the low temperature deNOx activity of Mn/Fe/TiO2 catalyst.