Development and Implementation of a Method to Track Hydrothermal Age of a Cu Zeolite SCR Catalyst

Josh  Ratts, Caterpillar Inc.

Catalyst hydrothermal aging is a key element to consider when designing aftertreatment systems to meet end-of-life requirements.  Core samples were aged at various temperatures and durations to understand the hydrothermal aging behavior of a small pore Cu zeolite urea SCR catalyst.  Changes to performance of various functionalities of the catalyst were quantified using a simulated exhaust flow bench.  The results were then used to develop a simple method to track catalyst hydrothermal age based on the changes measured to the NH3 oxidation reaction (in the absence of NOx).  The implementation of this method will be briefly discussed.