WO_3/CeO_2-ZrO_2, a promising catalyst for selective catalytic reduction (SCR) of NO_X with NH_3 in diesel exhaust

摘要

A WO_3/CeO_2-ZrO_2 catalyst system was discovered for selective catalytic reduction of NO_x with NH_3; the catalyst (10 wt% WO_3 loading) showed nearly 100% NO_x conversion in a temperature range of 200-500℃, at a space velocity of 90000 h~(-1) in a simulated diesel exhaust containing 550 ppm NO_x (NO : NO_2 feed ratio at 1.0), 10 vol% H_2O and 10 vol% CO_2; the catalyst also exhibited high temperature stability. In light of the impending emission standards, interest in reducing NO_x emissions of diesel powered vehicles has increased significantly in recent years.