What is Automotive Exhaust Catalytic Reduction Technology?
2 Answers
SCR stands for "Selective Catalytic Reduction" technology, which is a method for treating diesel engine exhaust. Technical Approach: The technical approach involves first addressing the particulate emissions from diesel engines through in-engine purification technologies such as optimizing in-cylinder combustion and reducing oil consumption, and then using an SCR after-treatment device to reduce NOx emissions from the engine. International Standards: Currently, the catalysts used internationally mainly include V2O5/WO3(MoO3)/TiO2 and other vanadium-containing and metal-based zeolite catalysts. Zeolite catalysts are known for their excellent low-temperature characteristics and high conversion efficiency at high space velocities. Vanadium-based catalysts, due to their internationally recognized high conversion activity and certain resistance to SO2 poisoning, have become the commonly used catalysts.
The automotive exhaust catalytic reduction technology is a specialized system for treating vehicle emissions, and I often encounter its operational details during maintenance. This technology primarily relies on the three-way catalytic converter, which transforms harmful gases in the exhaust into harmless substances. For example, nitrogen oxides are reduced to nitrogen, while carbon monoxide and hydrocarbons are oxidized into carbon dioxide and water vapor. The catalysts used are metals such as platinum, palladium, and rhodium, which require high temperatures to react efficiently, leading to higher pollution levels during cold starts. The catalytic converter is installed at the front end of the exhaust pipe. If it fails, the vehicle may emit excessive pollutants, trigger the check engine light, and even affect fuel efficiency. Modern vehicles heavily rely on this system to meet environmental standards, so it's crucial to avoid using leaded gasoline to prevent catalyst poisoning. Regular inspections of the catalytic converter can extend its lifespan and reduce maintenance costs.
