Three-way catalytic

The carrier component of the three-way catalytic converter is a porous ceramic material, which is installed in a special exhaust pipe. It is called a carrier because it does not participate in the catalytic reaction itself, but is covered with a layer of precious metals such as platinum, rhodium, and palladium. When the engine exhausts through the exhaust pipe, the three gases of CO, HC, and NOx pass through the purifier in the three-way catalytic reactor to enhance the activity of the three gases and perform oxidation-reduction chemical reactions. Among them, CO is oxidized to a colorless, non-toxic carbon dioxide (CO2) gas at high temperatures. The HC compounds are oxidized to water and (H2O) and CO2 at high temperatures. NOx is reduced to ammonia (N2) and (O2). The three harmful gases become harmless gases, so that the exhaust gas can be purified.

All three-way catalytic converters and their catalysts with good performance are mostly made of rare metals such as platinum (Pt), palladium (Pd), ruthenium, (Rn) and are expensive.

In order to give full play to the efficiency of three-way catalytic converters to reduce pollution and prevent early damage and failure, the following aspects should be noted in the use of automobiles:

1. Automobiles equipped with three-way catalysts cannot use leaded gasoline, especially when refueling in the field, because the lead particles will cover the surface of the catalyst when exhausted through the three-way catalytic converter due to burning of lead oil. The reduction of the area of ​​catalyst action greatly reduces the catalytic converter's conversion efficiency. This is often referred to as the "three-way catalyst lead poisoning." Experience has shown that even if only one box of leaded gasoline is used, it will result in a three-way catalytic converter. Serious failure, so the majority of owners must pay more attention.

2. Unburned gas mixture should be avoided from entering the catalyst. The operating temperature of the three-way catalytic converter is around 200 degrees Celsius, and the optimal working temperature is between 400 degrees Celsius and 800 degrees Celsius. When the temperature exceeds 1000 degrees Celsius, the precious metal component used as a catalyst itself will also undergo chemical changes, which will make the catalyst effective. Reduced catalyst components reduce catalytic activity.

The catalytic converter reduces the two hazardous substances, hydrocarbons (HC) and carbon monoxide (CO), which are converted into water (H2O) and carbon dioxide (CO2) by combustion inside the catalytic converter. This reflection produces Heat, the engine works normally, the content of these two components is appropriate, the heat generated by the combustion will keep the catalyst near the optimal working temperature, and the content of these two components in the exhaust gas is far More than normal.

Therefore, it is highly likely that the heat generated by the combustion will cause the temperature of the catalyst to exceed the upper working limit, thereby damaging the catalyst and damaging the catalyst. Therefore, pay attention to the following situations during the use of the vehicle:

All of these phenomena will cause premature failure and failure of the three-way catalyst, and these phenomena should be eliminated as soon as possible.

3, driving should pay special attention not to "supporting the bottom", because most of the three-way catalytic converter is a catalyst carrier formed by honeycomb crockery, easy to break after the collision, so that the catalytic converter and exhaust system plug.