Warmup and underfloor catalysts
Results of a warmup/underfloor converter parametric study indicate that improvements in HC emissions can be achieved using Pd-containing catalysts and that a warmup converter can impact tailpipe emissions depending on engine calibration and/or exhaust system configuration. Emission engineers have been investigating numerous strategies to lower cold-start HC emissions, with technologies such as electrically heated catalysts, hydrocarbon absorbers, gas burner heated catalysts, exhaust gas ignition, and close-coupled catalysts demonstrating significant reductions. Close-coupled catalysts are mounted near an exhaust manifold, but in some cases, because of vehicle packaging constraints, only a portion of the catalyst`s volume can be located close to the exhaust manifold. These converters--often called preconverters, lightoff converters, or warmup converters--must be designed to survive this severe environment. For these units, suppliers are developing thermally stable, Pd-containing catalysts with improved HC and NOx performance.
- OSTI ID:
- 419466
- Journal Information:
- Automotive Engineering, Journal Name: Automotive Engineering Journal Issue: 11 Vol. 104; ISSN 0098-2571; ISSN AUEGBB
- Country of Publication:
- United States
- Language:
- English
Similar Records
Emission performance of ceramic preconverters evaluated by FTP and Euro Stage III emission test cycle
Impact of revised FTP on emissions and new modifications required for catalysts