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SCR Deactivation Study for OBD Applications
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 16, 2012 by SAE International in United States
Annotation ability available
Selective catalytic reduction (SCR) catalysts will be used to reduce oxides of nitrogen (NOx) emissions from internal combustion engines in a number of applications. Southwest Research Institute® (SwRI)® performed an Internal Research & Development project to study SCR catalyst thermal deactivation. The study included a V/W/TiO₂ formulation, a Cu-zeolite formulation and an Fe-zeolite formulation. This work describes NOx timed response to ammonia (NH₃) transients as a function of thermal aging time and temperature. It has been proposed that the response time of NOx emissions to NH₃ transients, effected by changes in diesel emissions fluid (DEF) injection rate, could be used as an on-board diagnostic (OBD) metric. The objective of this study was to evaluate the feasibility and practicality of this OBD approach. While these experiments showed a noticeable trend with aging, there were also observations and considerations that suggest this approach may be reasonable as a catalyst-aging evaluation test method, but impractical for OBD purposes.
CitationBartley, G. and Kostek, T., "SCR Deactivation Study for OBD Applications," SAE Technical Paper 2012-01-1076, 2012, https://doi.org/10.4271/2012-01-1076.
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