| abstract |
A diesel exhaust gas purification catalyst contains a substrate, and a catalyst layer formed on the substrate. The catalyst layer contains a carrier, a noble metal and/or an oxide thereof supported by the carrier, and a composite oxide of cerium and one or more Group III and/or Group IV elements. The diesel exhaust gas purification catalyst when in use is disposed on an upstream side of an exhaust gas stream with respect to a denitration catalyst. |