TY - JOUR
T1 - The effects of SO2 exposure on three-way catalysts for passive SCR operation
AU - Thomas, Calvin
AU - Pihl, Josh
AU - Prikhodko, Vitaly
AU - Parks, James
AU - Lauterbach, Jochen
AU - Toops, Todd
N1 - Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/8/5
Y1 - 2022/8/5
N2 - Efficient lean-burn gasoline engines cannot employ traditional three-way catalysts (TWCs) to control NOX emissions due to excess oxygen. Passive selective catalytic reduction (pSCR) is a process designed to control NOx by generating NH3 over the TWC during fuel-rich operation, storing it on a downstream SCR, and then converting NOx during fuel-lean operation. This work is focused on studying sulfur effects on this promising strategy. Two hydrothermally-aged commercial catalysts were studied for their effectiveness in the presence of SO2: a Pd-based TWC and a TWC with NOX storage. The sulfated samples were evaluated in a flow reactor under pSCR conditions and with targeted reactions. SO2 inhibited the water gas shift and steam reforming reactions, decreasing (but not eliminating) NH3 production; however, initial activity is recoverable after a simple thermal treatment at 650 °C. This work will prove valuable in understanding, mitigating, and even reversing the effects of SO2 inhibition on real pSCR systems.
AB - Efficient lean-burn gasoline engines cannot employ traditional three-way catalysts (TWCs) to control NOX emissions due to excess oxygen. Passive selective catalytic reduction (pSCR) is a process designed to control NOx by generating NH3 over the TWC during fuel-rich operation, storing it on a downstream SCR, and then converting NOx during fuel-lean operation. This work is focused on studying sulfur effects on this promising strategy. Two hydrothermally-aged commercial catalysts were studied for their effectiveness in the presence of SO2: a Pd-based TWC and a TWC with NOX storage. The sulfated samples were evaluated in a flow reactor under pSCR conditions and with targeted reactions. SO2 inhibited the water gas shift and steam reforming reactions, decreasing (but not eliminating) NH3 production; however, initial activity is recoverable after a simple thermal treatment at 650 °C. This work will prove valuable in understanding, mitigating, and even reversing the effects of SO2 inhibition on real pSCR systems.
KW - Ammonia (NH)
KW - Generation
KW - Lean-burn gasoline emissions control
KW - Passive SCR
KW - Sulfur
KW - Three-way catalysts (TWC)
UR - http://www.scopus.com/inward/record.url?scp=85134624506&partnerID=8YFLogxK
U2 - 10.1016/j.apcata.2022.118771
DO - 10.1016/j.apcata.2022.118771
M3 - Article
AN - SCOPUS:85134624506
SN - 0926-860X
VL - 643
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
M1 - 118771
ER -