TY - JOUR
T1 - Advanced catalysts for combined (NAC + SCR) emission control systems
AU - Chen, Hai Ying
AU - Weigert, Erich
AU - Fedeyko, Joseph
AU - Cox, Julian
AU - Andersen, Paul
PY - 2010
Y1 - 2010
N2 - Emission control systems combining NOx Adsorber catalysts with Selective Catalytic Reduction catalysts (NAC + SCR) offer potential performance advantages for NOx control under lean conditions compared to systems consisting of only one of these technologies. The combined systems, however, also present new catalyst design challenges. In contrast to NAC only systems, formation of NH3 over the NAC component under NOx regeneration conditions is a desirable feature in the combined (NAC + SCR) system. The SCR component in the combined system needs to be as thermally durable as the stand-alone SCR technology and also has to withstand repeated high-temperature lean/rich transients encountered during periodic desulfation of the upstream NAC component. In this study, advanced NAC and SCR components were developed specifically for the combination system. The advanced NAC component exhibited a wider operating temperature window and higher NH 3 generation activity at reduced PGM loading. The advanced SCR component had excellent NOx reduction efficiency at low temperature and was extremely durable even after repeated high-temperature lean/rich cycling. Significant performance improvements were observed on systems with the advanced NAC and SCR catalysts. The advantages of the newly developed catalysts were also demonstrated on a vehicle.
AB - Emission control systems combining NOx Adsorber catalysts with Selective Catalytic Reduction catalysts (NAC + SCR) offer potential performance advantages for NOx control under lean conditions compared to systems consisting of only one of these technologies. The combined systems, however, also present new catalyst design challenges. In contrast to NAC only systems, formation of NH3 over the NAC component under NOx regeneration conditions is a desirable feature in the combined (NAC + SCR) system. The SCR component in the combined system needs to be as thermally durable as the stand-alone SCR technology and also has to withstand repeated high-temperature lean/rich transients encountered during periodic desulfation of the upstream NAC component. In this study, advanced NAC and SCR components were developed specifically for the combination system. The advanced NAC component exhibited a wider operating temperature window and higher NH 3 generation activity at reduced PGM loading. The advanced SCR component had excellent NOx reduction efficiency at low temperature and was extremely durable even after repeated high-temperature lean/rich cycling. Significant performance improvements were observed on systems with the advanced NAC and SCR catalysts. The advantages of the newly developed catalysts were also demonstrated on a vehicle.
UR - https://www.scopus.com/pages/publications/85072358828
U2 - 10.4271/2010-01-0302
DO - 10.4271/2010-01-0302
M3 - Conference article
AN - SCOPUS:85072358828
SN - 0148-7191
JO - SAE Technical Papers
JF - SAE Technical Papers
T2 - SAE 2010 World Congress and Exhibition
Y2 - 13 April 2010 through 13 April 2010
ER -