Due to the high temperature of the use environment, automotive exhaust treatment usually uses ceramic honeycomb or metal honeycomb as the substrate, plus catalyst, i.e. accelerant, in order to control automotive exhaust pollution and reduce the emission of carbon monoxide, black smoke and other toxic gases. When the exhaust gases pass through the honeycomb carrier, the nitrogen oxide is first decomposed into nitrogen and oxygen. As the exhaust gases pass further through the oxidizing honeycomb ceramic, carbon monoxide and hydrocarbons are further oxidized to carbon dioxide and water.