1. High temperature

 The reason for high temperature inactivation of three-way catalyst is very simple. Long-term exposure to high temperature will cause engine misfire, so that the incompletely combusted mixture will continue to burn inside the catalyst, resulting in a severe oxidation and heat release reaction. It may also be due to sudden braking, slowing down or continuous high-speed driving.

 Because the range of engine exhaust temperature is very large, it is generally 300 °C to 400 °C at idle speed, 400 °C to 600 °C at medium and low speed, and 900 °C at high speed. If the three-way catalyst is in a high temperature environment above 800 °C for a long time, it will rapidly reduce the oxygen absorption capacity of the catalyst and greatly reduce the activity of the catalyst.

2. Chemical poisoning

 The reason for chemical poisoning is that sulfur and phosphorus in fuel and lubricating oil and lead and manganese in anti-knock agent will produce carbon monoxide, causing the failure of three-way catalyst poisoning. It will be adsorbed on the active surface of the catalyst and form a chemical adsorption complex. In this case, it is often irreversible, especially after lead poisoning, which can only be replaced.

3. Surface area carbon Don't miss translation: the inactivation caused by carbon blockage, because the carbon covered on the surface of the three-way catalyst and coating, will cause the failure of the three-way catalyst, the three-way catalyst because of the carbon blockage and the engine is not working properly, is a common problem that the automobile engine will encounter.

 The three-way catalyst carbon blockage is gradually formed, the common form is ethanol gasoline produces colloidal carbon which leads to sintering blockage, sulfur and phosphorus chemical complex sintering blockage, lead and manganese metal deposits sintering blockage, engine misfire caused by ceramic carrier burning blockage, engine misfire caused by the ceramic carrier and metal shell between the seal layer part of high temperature aging, become a powder after the blockage of the ceramic carrier.

4. exhaust deterioration

 The exhaust deterioration, the catalytic converter to pollutants conversion capacity has certain limitations.Therefore, the original exhaust must be reduced to the lowest through the internal purification technology.If the concentration and total amount of exhaust pollutants are too large, such as the mixture is too thick, it will affect the catalytic conversion capacity of the catalyst and reduce its conversion efficiency.