A New Environmental Friendly Zirconium-Titanic-Ceria-Tungsten Mixed Oxides for Durable NH_3-SCR deNO_x Catalysts

摘要

With increasing stringent automobile exhaust emission regulations for diesel vehicles advanced emission control systems may require SCR catalysts with substantially improved thermal durability. Zirconia-Titania-Ceria-Tungsten (ZrTiCeW) mixed oxides were evaluated in the selective catalytic reduction of nitrogen oxides (NO_x) by ammonia (NH_3-SCR). The hydrothermal aging and sulfur aging were performed under severe conditions. They were compared with a commercial V/W/Ti SCR catalyst treated in the same manner. ZrTiCeW exhibits the superior NO_x conversion performance and higher selectivity. The influence of space velocity, NO_x/NH_3 and NO/NO_2 on the NO_x conversion were investigated. The presence of NO_2 in the feed (NO_2/NO = 50/450) boosts the NO conversion in the low temperature range.