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 NO_x 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.