High performance of catalytic sheet filters of V₂O₅-WO₃/TiO₂ for NO_x reduction

Nitrogen oxide (NO_x) emissions in fuel from the stationary as well as from mobile sources primarily from power stations, industrial heaters, cogeneration plants, and diesel engines represent a major worldwide environmental problem. The selective catalytic reduction (SCR) of NO_x with NH₃ over catalyst based on V₂O₅-WO₃/TiO₂ (VWT) is the most effective benchmark technique to efficiently reduce NO_x emissions from stationary and mobile sources. Among the different transition metals (Mn, Nb, Co, Cr, Cu, Ce) used in current research work, the manganese could make up the loss of SCR activity caused by the decrease of V₂O₅ loading (50%) in prepared VWT powder catalyst. The optimal loading of Mn is 3 wt% in case of 3V9WT powder catalyst, which shows the best catalytic performance. 3Mn3V9WT powder catalyst exhibits enhanced NO conversion performance, i.e., ~ 95-98% with NH₃ leakage < 20 ppm, for the temperature window of 260-320 °C in comparison with all other metal-doped 3V9WT catalyst powder. Manganese is the best substitute (50%) to vanadium in VWT catalyst without compromising the NO conversion performance even in presence of SO₂ (1000 ppm), i.e., > 94% for the temperature of 300-320 °C. The recovery of SCR activity of the 3Mn3V9WT catalyst after SO₂ effect was good, i.e., ~ 94% at 320 °C for long interval of time, where NH₃ leakage was < 5 ppm.