Patent ID: 7674743
Filing Date: 2010-03-09
Classification: B01D,F01N,Y02C,Y02T

Abstract:
1. An NOx purifying catalyst for purifying NOx in exhaust gas discharged from an internal combustion engine with air-fuel ratios controlled to be lean and rich, comprising: a first catalytic layer that includes a zeolite having at least one element selected from the group consisting of iron and cerium elements; a second catalytic layer that includes a noble metal and cerium oxide-based material; wherein the second and the first catalytic layers are coated on a support in that order, so that the first catalytic layer is the uppermost layer, NOx passes through the first catalytic layer and is oxidized and adsorbed on the second catalytic layer in the lean condition, NOx adsorbed on the second catalytic layer is converted to NH the NH