An Oxidation Catalyst works similar to the way that the catalytic converter on a car functions. As exhaust gas passes over the catalyst material, a chemical exchange occurs and the emissions constituents (HC, CO, PM ) are oxidized to CO2 and water.

An oxidation catalyst is often referred to as a passive technology because it requires no external supplemental energy to be added. It needs only the natural temperatures within the diesel exhaust to catalytically convert through chemical reactions.