Catalytic control of diesel exhaust pollutants

V.G.MILT; M.A.ULLA; E.E.MIRÓ

Recent Research Developments in Environmental Technology,

Transworld Research Network

Lugar: Kerala, India; Año: 2008; p. 57 - 79

Particulate matter (soot) and NOx are the main pollutants in diesel engine emissions. The combination of a filter with oxidation catalysts has been the most studied process as after-treatment technique to eliminate soot particles. Useful catalysts have to operate efficiently at low temperatures (200- 400°C) and be thermally stable. The reaction mechanism and therefore a rational catalyst design for this system has been considered only recently. Studies with a large number of formulations have been reported during the last few years, and the soot-catalyst contact appears to be one of the most important problems to be overcome. For NOx abatement, NOx adsorbers (traps) and NOx SCR with ammonia or hydrocarbons constitute developing technologies both for partial lean-burn gasoline engines and for diesel engines. Both the fundamentals of these processes and the technological approaches are described and critically discussed in this chapter.