HYDROCARBON TRAP/CATALYST COMPOSITION

摘要

A hydrocarbon trap/catalyst composition comprising a hydrocarbon-adsorbing material and an active metal from potassium rubidium, caesium, beryllium, magnesium, calcium, barium or strontium or a mixture of any two or more thereof, preferably caesium characterised in that the active metal is impregnated on the material. The composition can be used for adsorbing hydrocarbons from an automotive internal combustion engine exhaust gas stream when the exhaust gas is at a first relatively cool temperature, and later desorbing and oxidising the hydrocarbons when the exhaust gas stream is at a second relatively warmer temperature.