Have a closer view of GRWA "three-way catalytic converter" production line The catalytic converter is a device used in automobiles to purify automobile exhaust. The reason why it is called catalytic converter is that it contains three precious metals: platinum (Pt), rhodium (Rh), and palladium (Pd), so it is called "catalytic converter ". Its role in automobiles is mainly to oxidize and reduce the main pollutants in automobile exhaust: carbon monoxide, hydrocarbons and nitrogen oxides to generate harmless carbon dioxide, nitrogen and water to achieve purification results.