A superior Fe-V-Ti catalyst with high activity and SO2 resistance for the selective catalytic reduction of NOx with NH3.

A series of Fe-V-Ti oxide catalysts were prepared by a co-precipitation method, among which the Fe0.1V0.1TiOx catalyst showed the optimal NH3-SCR performance and excellent SO2 resistance. Fe0.1V0.1TiOx achieved > 90% NOx conversion at 225-450 °C under a GHSV of 200,000 h-1. When introducing SO2 and H2O to the SCR reaction for 24 h, the NOx conversion maintained a level above 93% at 250 °C. The Raman and Mössbauer spectra showed that FeVO4 and Fe2O3 coexisted on the surface of TiO2. In Fe-V-Ti catalysts, the charge interaction between Fe2O3 and FeVO4 as well as the electronic inductive effect between Fe and V species resulted in the improvement of SCR activity and N2 selectivity at high temperatures. The NH3-SCR process on the Fe0.1V0.1TiOx catalyst mainly followed the Eley-Rideal (E-R) reaction mechanism with gaseous NO reacting with adsorbed NH3 adsorbed species.