Modeling of change for NH₃ storage and reaction path of SCR by hydrothermal aging

Abstract

To understand decline of SCR activity by catalysts aging is important for expand of commercial vehicle lifetime. In this report, the deactivation of active sites caused by hydrothermal aging effect was modeled by NH₃ storage capacity decreasing with the rising of hydrothermal treatment temperature. Simulation results of developed hydrothermal aging SCR model showed good agreement with the experimental results of synthetic gas bench. Based on analysis of reaction path changing by developed aging model, activity at low temperature was decreasing and selectivity of NOx conversion at high temperature was changing for deactivation of active sites.