High efficiency conversion of nitrogen oxides in an exhaust aftertreatment device at low temperature

摘要

A system and method for providing operating conditions that provide higher efficiency NOx reduction in a lean NOx catalyst coupled to a lean-burning internal combustion engine. A catalyst containing reductant is caused to attain a temperature greater than 300° C. After a duration of about 10 seconds at the elevated temperature, the NOx conversion efficiency of the catalyst is increased in the 140-250° C. temperature range.