Experimental and modeling study of a dual-layer (SCRÂ +Â PGM) NH3 slip monolith catalyst (ASC) for automotive SCR aftertreatment systems. Part 1. Kinetics for the PGM component and analysis of SCR/PGM interactions

► NH3/O2/NONO2 steady-state and transient kinetic runs over a PGM catalyst ► original PGM kinetic model accounts for T and NO2/NOx (0-1) effects on NH3 oxidation ► study of the interaction between SCR and PGM kinetics (double bed vs. mech. mixture) ► positive interaction between PGM and SCR chemistries favors N2 selectivity ► interaction is well predicted by superposition of individual SCR & PGM kinetics.