Besides the further reduction of the harmful gaseous emissions
(HC, CO and NOx) to reach upcoming emission limits, the discussion
on lowering the CO₂ emissions is omnipresent. From engine
development point of view further optimization of the
stoichiometric-operated gasoline engine as well as the introduction
of lean-operated engines are the main development trend.
The emission control system can support the engine development
by dedicated catalyst technologies as presented in this paper.
A new family of TWC technologies offers to tune the catalyst
system to the engine performance and the back pressure requirement
- which helps to reduce CO₂ emissions. In addition these
technologies show improved performance in HC, CO, NOx light-off,
and in CO and NOx conversions under dynamic conditions - this again
can positively impact the CO₂ emissions as less harsh heating
strategies for cold start is required.
By further optimization of the aftertreatment system with regard
to system integration (catalyst volume, precious metal
distribution, calibration) a considerable reduction in precious
metal is realized with improved overall performance when compared
to the current series applications.