Browse Publications Technical Papers 1999-01-1279

Development of NOx Storage-Reduction Three-way Catalyst for D-4 Engines 1999-01-1279

It is an essential task for automobiles to reduce their fuel consumption. A direct injection gasoline engine (D-4 engine) is effective in reducing fuel consumption, but the reduction of NOx in the lean combustion region is impossible with a conventional three-way catalyst. The NOx storage-reduction three-way catalyst was put into practical use in 1994 for vehicles with lean-burn engines. This catalyst, however, is poisoned by SO2 caused by fuel sulfur, thus its activity is reduced. The conversion efficiency of this sulfur poisoned catalyst was not sufficient for reducing NOx in the exhaust gas of D-4 engine. We have, therefore, studied the mechanism of sulfur poisoning, and succeeded in improving the catalytic performance with the newly developed monolithic substrate and the newly developed additives.


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


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.