A three-way catalytic converter is a crucial on-board emission purification device installed in a car's exhaust system. It converts harmful gases like CO, HC, and NOx emitted from the vehicle's exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. As the high-temperature exhaust gases pass through the purification unit, the catalyst in the three-way catalytic converter enhances the reactivity of the CO, HC, and NOx gases, prompting them to undergo certain oxidation-reduction chemical reactions. CO is oxidized into colorless, non-toxic carbon dioxide gas under high temperatures; HC compounds are oxidized into water (H2O) and carbon dioxide; and NOx is reduced to nitrogen and oxygen. The three harmful gases are transformed into harmless gases, thereby purifying the vehicle's exhaust.

Three-way catalytic converter, an essential after-treatment device installed in the car exhaust system, converts harmful gases like CO (carbon monoxide), HC (hydrocarbons), and NOx (nitrogen oxides) emitted from the tailpipe into harmless CO2 (carbon dioxide), water, and nitrogen through oxidation and reduction reactions. As this catalytic converter simultaneously converts the three main harmful substances in the exhaust into harmless substances, it is named "three-way."