Search Results

A 5.9 liter medium-heavy-duty diesel engine, equipped with a diesel exhaust aftertreatment system consisting of catalyzed diesel particulate filters and NOx adsorber catalysts arranged in a dual-path configuration was evaluated with the goal of studying the thermal aging characteristics of a number of NOx adsorber formulations and documenting adsorber formulation improvements over time. The performance of 2005 vintage NOx adsorber formulations was compared with the performance of older formulations. The testing was performed in three steps. The first was to run with zero sulfur fuel at a high temperature engine operating mode to characterize performance losses due to exposure to the highest temperatures experienced under normal operation. This was followed by aging without sulfur but with desulfation events to characterize the impact of the higher desulfation temperatures on catalyst deactivation.