Abstract
Acidic zirconia materials have been tested as catalysts for the Selective Catalytic Reduction of nitrogen oxides (NOx) by ammonia (NH 3 -SCR). This paper focuses on the promotion of acidic zirconia by ceria. The introduction of ceria increases the NOx conversion, the selectivity to N 2 and the durability and makes acidic zirconia materials attractive for Diesel after treatment systems.