What is the car three-way catalytic converter?

The automobile three-way catalytic converter is the most important external purification device installed in the automobile exhaust system. Its main function is to convert the harmful gases such as CO, HC and NOx in the automobile exhaust into harmless carbon dioxide, water and nitrogen ‌. ‌

The working principle of the three-way catalytic converter is to enhance the activity of these gases and promote their oxidation-reduction chemical reactions. Specifically, CO is oxidized to a colorless, non-toxic carbon dioxide gas at high temperatures; HC compounds are oxidized to water and carbon dioxide at high temperatures; NOx is reduced to nitrogen and oxygen. This catalytic converter can handle three main harmful substances at the same time, so it is called "three-way".

The structure of the ternary catalyst consists of a carrier of porous ceramic material or metal carrier, which does not itself participate in the catalytic reaction, but is covered with a layer of precious metals such as platinum, rhodium, palladium and rare earth coating. These precious metals enhance the activity of the gas under high temperature, thus achieving catalytic effect.

The three-way catalytic converter is of great significance for environmental protection, because it can effectively reduce the pollution of automobile exhaust to the environment. However, due to the rarity and high value of these precious metal materials, three-way catalysts have also become the target of theft. In order to protect the three-way catalytic converter, regular addition of cleaning agent for maintenance is a common and effective method, which can not only extend its service life, but also maintain its catalytic effect.