The three-way catalytic converter is an important external purification device installed in the vehicle exhaust system. It converts harmful gases like CO, HC, and NOx emitted from the car's tailpipe into harmless carbon dioxide, water, and nitrogen through oxidation and reduction processes. As the high-temperature exhaust passes through the purification device, the catalyst within the three-way converter enhances the reactivity of CO, HC, and NOx gases, prompting them to undergo specific oxidation-reduction chemical reactions. CO is oxidized into colorless, non-toxic carbon dioxide at 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, purifying the car's exhaust.

The three-way catalytic converter is a crucial external purification device installed in the car exhaust system. It converts harmful gases such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) emitted from car exhausts into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. Due to its ability to simultaneously convert three main harmful substances in exhaust gas into harmless substances, it is named "three-way."