Exhaust gas purifying catalyzer for use in exhaust pipe of diesel engine of vehicle for reductively cleaning nitrogen oxide in exhaust gas, has catalyzer layers, where average particle sizes of catalyzer particles in layers lie in range

摘要

The catalyzer (11) has a catalyzer layer provided on a carrier, and containing precious metal containing platinum, aluminum oxide, cerium oxide, zirconium oxide, and complex oxide containing cerium and zirconium. Another catalyzer layer is provided on the former catalyzer layer, and contains precious metal containing rhodium, cerium oxide, zirconium oxide, and complex oxide containing cerium and zirconium. A third catalyzer layer is provided on the latter layer, and contains zeolite. Average particle sizes of catalyzer particles in the three layers lie in a range from 4 to 9 micrometers.