NOx purification catalyst

摘要

A NOx purification catalyst is provided capable of suppressing degradation of NOx purifying performance due to a sulfur component and efficiently purifying NOx even in cases where running is performed under low to medium temperatures. The NOx purification catalyst provided, which is used to purify NOx in exhaust gas emitted from an internal combustion engine in which lean/rich control is carried out, has a first catalyst layer that is supported on a carrier and includes a noble metal containing at least platinum as a main component, a cerium-containing material, and a lanthanum-containing material, in which NOx is oxidized and adsorbed to the first catalyst layer when made to a lean condition, and NOx oxidized and adsorbed to the first catalyst layer in a lean condition is converted into nitrogen and water when made to a rich condition by a reducing component present near the first catalyst layer.