Insights into catalytic converters
Modern catalytic converters for the treatment of exhaust gases in vehicles with a combustion engine have largely contributed to reducing of pollutant emissions. By oxidation or reduction, i.e. the donation or acceptance of electrons, the catalysts convert combustion pollutants, such as carbon monoxide, nitrogen oxides and hydrocarbons, into carbon dioxide, water, and nitrogen. Increasingly strict emission regulations call for a further reduction of fuel consumption and for an efficient use of the exhaust gas aftertreatment system. When adding the reduction agent ammonia formed by e.g. decomposition of urea, nitrogen oxides are converted into harmless nitrogen and water vapor over the catalytic converter. For this purpose, typically an urea solution (AdBlue) is injected into the exhaust gas section upstream of the catalytic converter.