A predictive numerical model was developed to determine the
impact of phosphorus exposure on the performance of flow through
aftertreatment components such as Diesel Oxidation Catalysts (DOC)
or Selective Catalytic Reduction (SCR) catalysts. The model is able
to successfully determine the distribution of the phosphorus over
the catalyst as a function of the aging history (temperature, flow
rates, oil consumption rate, phosphorus content of the oil) as well
as the component properties (diameter, length, cell density, wall
thickness).
The model then incorporates this information regarding the
distribution of phosphorus over the catalyst surface to determine
the impact of the phosphorus exposure on the overall catalytic
activity. The model results were successfully validated using
accelerated bench aging tests for the oxidation of hydrocarbons
over DOC's and NH₃ oxidation and NOx reduction over SCR
catalysts.
The modeling approach and methodology should, however, be
readily extendable to wall flow aftertreatment components such as
Diesel Particulate Filters (DPF) as well as other flow through
components such as Lean NOx Traps (LNT's) that were not
included in this study.