Patent ID: 10159958

Abstract:
A lean NOx trap (LNT) catalyst includes a plurality of carriers connected to each other in series, wherein each of the carriers is embedded with at least one of a first wash coat containing magnesium (Mg)-substituted alumina, ceria (CeO2), barium (Ba), and a precious metal, a second wash coat containing magnesium (Mg)-substituted alumina, ceria (CeO2), barium (Ba), a third wash coat containing magnesium (Mg)-substituted alumina, ceria (CeO2), and a fourth wash coat containing magnesium (Mg)-substituted alumina, ceria (CeO2), and a higher content of a precious metal than the first wash coat, a ratio of the magnesium-substituted alumina to ceria (CeO2) being lower than that of the third wash coat, wherein the third and first wash coats are disposed in a foremost carrier through which exhaust gas passes sequentially from a front portion of the foremost carrier.