Lean NOx catalysis for gasoline fueled European cars
There is increasing interest in operating gasoline fueled passenger cars lean of the stoichiometric air/fuel (A/F) ratio to improve fuel economy. These types of engines will operate at lean A/F ratios while cruising at partial load, and return to stoichiometric or even rich conditions when more power is required. The challenge for the engine and catalyst manufacturer is to develop a system which will combine the high activity rates of a state-of-the-art three-way catalyst (TWC) with the ability to reduce nitrogen oxides (NOx) in the presence of excess oxygen. The objective is to achieve the future legislative limits (EURO III/IV) in the European Union. Recent developments in automotive pollution control catalysis show that the use of NOx adsorption materials is a suitable way to reduce NOx emissions of gasoline-fueled lean-burn engines. However, the primary task for the implementation of this technology in the European market will be to improve the catalyst`s high-temperature stability and to decrease its susceptibility to sulfur poisoning. Outlined here are results of a recent R and D program to achieve NOx reduction under lean-burn gasoline engine conditions. Model gas test results as well as engine bench data are used for discussion of the parameters which control NOx adsorption efficiency under various conditions.
- OSTI ID:
- 479416
- Journal Information:
- Automotive Engineering, Vol. 105, Issue 2; Other Information: PBD: Feb 1997
- Country of Publication:
- United States
- Language:
- English
Similar Records
Ammonia Generation and Utilization in a Passive SCR (TWC+SCR) System on Lean Gasoline Engine
Ammonia Generation and Utilization in a Passive SCR (TWC+SCR) System on Lean Gasoline Engine