Is the Three-Way Catalyst Useful?

[MacRachel]

Automotive three-way catalytic converters are useful. The automotive three-way catalytic converter is the most important external purification device installed in the vehicle's exhaust system. It converts harmful gases such as CO, HC, and NOx emitted from vehicle exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. The working principle of the three-way catalytic converter is as follows: when high-temperature vehicle exhaust passes through the purification device, the catalyst in the three-way catalytic converter enhances the activity of the three gases—CO, HC, and NOx—promoting certain oxidation-reduction chemical reactions. Among these, CO oxidizes at high temperatures into colorless, non-toxic carbon dioxide gas; HC compounds oxidize at high temperatures into water (H2O) and carbon dioxide; and NOx is reduced into nitrogen and oxygen. These three harmful gases are transformed into harmless gases, thereby purifying the vehicle's exhaust. Because this catalytic converter can simultaneously convert the three main harmful substances in exhaust gases into harmless substances, it is called a three-way catalytic converter.