Process for the catalytic purification of automobile exhaust gases with improved cold start behaviour

摘要

A significant reduction of the hydrocarbon emissions during the cold start of internal combustion engines is achieved if a hydrocarbon adsorber is introduced into the exhaust gas pipe upstream of the actual exhaust gas catalyst, the heat capacity of which hydrocarbon adsorber is made greater than the heat capacity of the downstream catalyst by suitable material selection and design of the adsorber.