Hydrocarbon adsorbing body

In an exhaust treating body for adsorbing hydrocarbon from an internal combustion engine exhaust gas, the improvement wherein a monolith carrier is coated with a first coating layer of a zeolite powder, which in turn is overcoated with a coating layer of HZSM-5 zeolite powder ion-exchanged with palladium, with the proviso that the inner layer is other than the material of the outer layer.

In a process for making an exhaust treating body for adsorbing hydrocarbons from an internal combustion engine exhaust gas wherein a monolith carrier is coated with a first layer of HZSM-5 zeolite powder ion-exchanged with palladium, which in turn is overcoated with a coating layer of a zeolite powder other than that of the first layer, the improvement comprising forming the first coating layer by firing a powder comprising HZSM-5 zeolite ion-exchanged with palladium at a temperature not less than 600.degree. C. in air for not less than two hours.

In a process for making an exhaust creating body for adsorbing hydrocarbons from an internal combustion engine exhaust gas wherein a monolith carrier is coated with a first layer of a zeolite powder, which in turn is overcoated with a layer of HZSM-5 zeolite powder ion-exchanged with palladium, with the proviso that the inner layer is other than the material of the outerlayer, the improvement comprising forming the outerlayer by firing a powder comprising HZSM-5 zeolite ion-exchanged with a palladium at a temperature of not less than 600.degree. C. in air for not less than two hours.