Diesel oxidation catalyst having a capture region for exhaust gas impurities

An oxidation catalyst for treating an exhaust gas produced by a diesel engine, wherein the oxidation catalyst comprises:

• a substrate;
• a capture region comprising a capture material for capturing at least one phosphorus containing impurity or at least one sulfur containing impurity in the exhaust gas produced by the diesel engine, wherein the capture material comprises a molecular sieve having a silica to alumina molar ratio of 10 to 200, and wherein the molecular sieve comprises a base metal selected from the group consisting of iron (Fe), copper (Cu), nickel (Ni) and a combination of two or more thereof;
• and
• a catalytic region disposed on the substrate;
• wherein the catalytic region comprises a catalytic material comprising a platinum group metal (PGM) supported on a support material comprising a refractory oxide, wherein the platinum group metal (PGM) is selected from the group consisting of platinum (Pt), palladium (Pd) and a combination of platinum (Pt) and palladium (Pd);
• and
• wherein the capture region is arranged to contact the exhaust gas before the exhaust gas has contacted or passed through the catalytic region.