Oxidation catalyst for a compression ignition engine

• Main Authors: DAVID BERGEAL, PAUL RICHARD PHILLIPS, DANIEL HATCHER, ANDREW FRANCIS CHIFFEY, JAMES LEELAND, FRANCOIS MOREAU
• Format: Patent
• Language: English
• Published: 19.11.2014
• Subjects: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; THEIR RELEVANT APPARATUS; TRANSPORTING

An oxidation catalyst for treating an exhaust gas from a compression ignition engine comprises: a first washcoat region comprising platinum and a first support material, wherein the first washcoat region is substantially free of a hydrocarbon adsorbent; a second washcoat region comprising platinum, palladium and a second support material, wherein the second washcoat region has a ratio by mass of platinum to palladium of 4:1 to 1:1; a hydrocarbon at sorbent; and a substrate; wherein the first washcoat region is arranged to contact inlet exhaust gases before the hydrocarbon adsorbent, and the first washcoat region is arranged to contact inlets gases before the second washcoat region. The first washcoat region may further comprise palladium, wherein the first washcoat region has a ratio by mass of platinum to palladium of >4:1. The hydrocarbon adsorbent may be a zeolite. The first support material may be a refractory metal oxide selected from the group consisting of alumina, silica, titania, zirconia, ceria and mixed or composite oxide of two or more thereof.