Patent ID: 6841511
Filing Date: 2005-01-11
Classification: B01D,B01J

Abstract:
1. A lean NOx elimination catalyst used in an internal combustion engine wherein a lean-burn operation is able to shift to fuel-excess operation or stoichiometric air/fuel ratio operation, wherein the catalyst comprises a porous carrier and an active component supported on the porous carrier, the active components comprising: (a) at least one member selected from the group consisting of Rh, Pt and Pd; (b) at least one member selected from the group consisting of an alkali metal and an alkaline earth metal; and (c) Mn, amounts of supported active metals being 0.0003 to 0.01 part by mole of Rh if present, 0.002 to 0.05 parts by mole of Pt if present, 0.001 to 0.2 part by mole of Pd if present, 0.05 to 3 parts by mole of the alkali metal if present, 0.05 to 3 parts by mole of alkaline earth metal if present and 0.05 to 2 parts by mole of Mn based on 1.5 parts by mole of the porous carrier.