Three-way catalysis mainly uses some rare and precious metals to purify and reduce exhaust gases. For example, platinum, rhodium, and palladium are used as catalysts to oxidize and reduce carbon monoxide, hydrocarbons, and nitrogen oxides in the exhaust. Carbon dioxide, nitrogen and water are thus produced and discharged.
Its structure is composed of shell, catalyst coating, shock absorbing pad, heat insulation layer and carrier.
There are two types of carriers, metal and rare earth ceramics, which are shaped like honeycombs. Currently, family cars mainly use 400-mesh carriers.