Abstract: An assembly, a method and a motor vehicle for cleaning ambient air in the vicinity of an internal combustion engine (102) having combustion air inlet means (103) and energy emitting means (104)are disclosed. The assembly (101) further includes adsorbent means (105) for adsorbing at least one pollutant when in a first mode of operation and for desorbing the pollutant when in a second mode of operation. The adsorbent means have an inlet (106) for polluted ambient air (107, 107′) and an outlet (108) for cleaned ambient air (109, 109′). Furthermore, the assembly (101) includes a pollutant conduit (110) through which the desorbed pollutant is transferred from the adsorbent means (105) to the combustion air inlet means (103) when in the second mode of operation, and the adsorbent means (105) are arranged for being brought into the second mode of operation by means of energy supplied from the energy emitting means (104).

Abstract: A catalyst composition has an upstream stage and a downstream stage, the upstream stage containing a catalytic material which is different from the catalytic material contained on the downstream stage and is characterized by having a low ignition temperature, e.g., 350.degree. C. to less than 400.degree. C. for the substantially simultaneous conversion of HC, CO and NO.sub.x pollutants contained in, e.g., the exhaust of an automobile engine operating at a substantially stoichiometric air-to-fuel weight ratio. The downstream catalytic material is characterized by having a higher conversion efficiency for substantially simultaneous conversion of HC, CO and NO.sub.x than the upstream catalytic material at elevated operation temperatures which may be, for example, from about 400.degree. to 800.degree. C. The method of the invention includes passing a gaseous exhaust stream containing HC, CO and NO.sub.x pollutants sequentially through first the upstream and then through the downstream catalytic materials.

Abstract: A catalyst composition has an upstream stage and a downstream stage, the upstream stage containing a catalytic material which is different from the catalytic material contained on the downstream stage and is characterized by having a low ignition temperature, e.g., 350.degree. C. to less than 400.degree. C., for the substantially simultaneous conversion of HC, CO and NO.sub.x pollutants contained in, e.g., the exhaust of an automobile engine operating at a substantially stoichiometric air-to-fuel weight ratio. The downstream catalytic material is characterized by having a higher conversion efficiency for substantially simultaneous conversion of HC, CO and NO.sub.x than the upstream catalytic material at elevated operation temperatures which may be, for example, from about 400.degree. to 800.degree. C. The method of the invention includes passing a gaseous exhaust stream containing HC, CO and NO.sub.x pollutants sequentially through first the upstream and then through the downstream catalytic materials.