What is the function of the three-way catalytic converter in a car?

[DelVanessa]

The three-way catalytic converter is the most important external purification device installed in the automotive 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 substrate of the three-way catalytic converter is a porous ceramic material installed in a specially designed exhaust pipe. It does not participate in the catalytic reaction itself but is coated with precious metals such as platinum, rhodium, and palladium that facilitate the reaction. The three-way catalyst begins to react at a minimum temperature of 350°C. When the temperature is too low, the conversion efficiency drops sharply; excessively high temperatures can also accelerate catalyst aging. To check whether the catalytic converter is damaged or overheated during operation, observe its surface for dents, severe discoloration spots, or slight bluish and purple traces on the shell. Additionally, due to catalyst substrate breakage, peeling, or oil accumulation, the channels in the substrate can become blocked, increasing flow resistance. This can be checked by measuring the pressure loss.