EXHAUST EMISSIONS FROM OTTO ENGINES WITH 3-WAY CATALYSTS - MEASUREMENT REGARDING THE SECONDARY-EMISSION OF NITROUS-OXIDE

With three-way catalyst systems in cars pollutant reduction rates of m ore than go % can be achieved. Besides the reduction of exhaust emissi ons the formation of new components is observed. These secondary emiss ions are hydrogen sulphide and nitrous oxide N2O. Considerable amounts of N2O are developed at the catalyst surface. N2O is a trace gas that contributes to the greenhouse-effect as well as it is involved in cat alytically destroying the ozone layer. Measurements of the exhaust and N2O-emissions were carried put on chassis dynamometers. The influence s of the age of the catalytic converter, car velocity and air/fuel-rat io on the exhaust and N2O-emissions were investigated with cars with d ifferent mileages.