High Temperature Ultra Stable Close-Coupled Catalysts

Close-coupled catalysts are being actively pursued by automotive engineers in order to meet stringent LEV/ULEV emission standards. However, future applications of close coupled catalyst will be exposed to 50 to 100°C higher operating temperatures with elimination of fuel enrichment to cool the catalyst. A successful close coupled catalyst technology must then be resistant to even higher temperature deactivation and yet continue to function at low temperature during the vehicle cold start. A close coupled catalyst technology is formulated through advanced catalyst design to meet LEV and ULEV emission standards after high temperature aging at 1050°C. This paper will show the inherent stability of the close coupled catalyst for both light-off temperature and steady state performance for aging temperatures up to 1100°C. In vehicle evaluation, experimental results on the effect of close coupled catalyst volume, precious metal loading and aging temperature on HC emissions during cold start and FTP will be presented. Results show that this close coupled catalyst technology achieves LEV/ULEV HC emissions after high temperature aging.