Impact of Chemical Contaminants on Stoichiometric Natural Gas Engine Three-Way Catalysts with high mileage history
2022-01-0655
03/29/2022
- Event
- Content
- Stoichiometric natural gas engines with Three-way catalysts (TWCs) more efficiently reduce NOx and CH4 emissions compared to lean burn natural gas engines. Even though TWCs are well known, there is a need for deeper understanding beyond hydrothermal aging (HTA) to explain the real-world performance and aging behaviors. In this investigation, we characterized the real-world TWC to specifically identify the contribution of chemical aging to overall performance. The sulfur (S) species was evenly distributed throughout the whole catalyst volume, whereas phosphorous (P) contamination was mainly observed at the inlet section of the TWC and its concentration sharply declined along the axial length. Sulfur amount on the catalyst surface is quantified by TPD and ICP. Performance is measured pre and post sulfur removal on TWC to isolate the contribution of degradation due to HTA+P and that due to S. By applying the above method to the cores taken at different axial locations, we were able to attribute the dominant aging mechanisms operating at different axial locations in a given TWC aftertreatment system. We will also show the comparison of field aged and bench aged catalysts to show potential gaps in the aging contributions.
- Citation
- Kim, M., Gong, J., Kamasamudram, K., Cunningham, M. et al., "Impact of Chemical Contaminants on Stoichiometric Natural Gas Engine Three-Way Catalysts with high mileage history ," SAE Technical Paper 2022-01-0655, 2022, .