Rôles of catalytic oxidation in control of vehicle exhaust emissions

摘要: Abstract Catalytic oxidation was initially associated with the early development of catalysis and it subsequently became a part many industrial processes, so is not surprising used to remove hydrocarbons CO when necessary control these emissions from cars. Later NOx reduced in process involving reduction over Pt/Rh catalyst followed by air injection front Pt-based catalyst. If over-reduction NO NH 3 took place, or if H 2 S produced, important undesirable species were converted SOx catalytic stage. When exhaust gas composition could be kept stoichiometric hydrocarbons, simultaneously single three-way (TWC). With modern TWCs car tailpipe can exceptionally low. catalytically dissociated O N presence , only . Its lean-burn gasoline engines involves thence nitrate that stored periodically enrichment. This method being modified for diesel engines. These produce soot, filtration introduced it. The temperature heavy-duty diesels sufficient (250–400 °C) oxidised an upstream platinum smoothly oxidises soot filter. passenger too low this take place all time, trapped burnt above 550 °C. higher than normal amounts hydrocarbon give combustion place.