Effect of lean/rich high temperature aging on NO oxidation and NOx storage/release of a fully formulated lean NOx trap

▶ Thermal aging of commercial-intent lean NOx traps combined with extensive materials characterization. ▶ NO oxidation to NO2 shown to increase with increasing precious metal sintering; although overall NOx conversion decreases. ▶ Ba phase shown to lose crystallinity either forming an amorphous phase or dispersing over the alumina support when aging above 900 °C. ▶ Nitrate stability shown to increase with aging; impacts product selectivity and N2 to NH3 ratios.