New Insights into Sulfur Poisoning on a Vscr Catalyst Under Simulated Diesel Engine Operating Conditions

This work illustrates that during the low temperature events, simulating engine start-up and shut-down, SO₂ and NH₃ can combine and further be oxidized to ammonium sulfate species. The ammonium sulfate species formed during LTE make the VSCR catalyst susceptible to further degradation by SO₂ under SCR conditions at 473 K.