Laboratory sulfation of an ammonia slip catalyst with a real-world SO <sub>2</sub> concentration

WCX SAE World Congress Experience
Authors Abstract
Upcoming, stricter diesel exhaust emissions standards will likely require aftertreatment architectures with multiple diesel exhaust fluid (DEF) introduction locations. Managing NH3 slip with technologies such as an ammonia slip catalyst (ASC) will continue to be critical in these future aftertreatment systems. In this study, we evaluate the impact of SO2 exposure on a state-of-the-art commercially available ASC. SO2 is co-fed at 0.5 or 3 ppmv to either approximate or accelerate a real-world exhaust SO2 impact. ASC performance during sulfur co-feeding is measured under a wide variety of simulated real-world conditions. Results indicate that the loss of NO conversion during SCR is dependent on the cumulative SO2 exposure, regardless of the inlet SO2 concentration. Meanwhile, N2O formation under SCR conditions is nonlinearly affected by SO2 exposure, with formation increasing during 0.5 ppmv SO2 exposure but decreasing in the presence of 3 ppmv SO2. TPO experiments reveal the formation of ammonium sulfate species, but only after prolonged SO2 exposure at 0.5ppmv or accelerated SO2 exposure at 3 ppmv. Reactivation at 550°C is sufficient to recover ASC reactivity following multiple SO2 exposure tests in all cases. These findings are especially relevant for the development of diesel exhaust aftertreatment accelerated aging protocols.
Meta TagsDetails
Ottinger, N., Xi, Y., Kiani, D., and Liu, Z., "Laboratory sulfation of an ammonia slip catalyst with a real-world SO 2 concentration," Advances and Current Practices in Mobility 6(2):736-742, 2024,
Additional Details
Apr 11, 2023
Product Code
Content Type
Journal Article