Browse Publications Technical Papers 2010-01-0302
2010-04-12

Advanced Catalysts for Combined (NAC + SCR) Emission Control Systems 2010-01-0302

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 NH₃ 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.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
JOURNAL ARTICLE

The Effects of Sulfur Poisoning and Desulfation Temperature on the NOx Conversion of LNT+SCR Systems for Diesel Applications

2010-01-0300

View Details

JOURNAL ARTICLE

Laboratory and Vehicle Demonstration of “2nd-Generation” LNT + in-situ SCR Diesel NOx Emission Control Systems

2010-01-0305

View Details

TECHNICAL PAPER

Engine Performance of Cu- and Fe-Based SCR Emission Control Systems for Heavy Duty Diesel Applications

2011-01-1329

View Details

X