Methods for Controlling Automotive Exhaust Emissions
2 Answers
Methods for controlling automotive exhaust emissions: 1. The most fundamental and ultimate approach is to change the vehicle's power source. For example, developing electric vehicles and alternative fuel vehicles. This method ensures that vehicles produce little to no polluting gases. 2. Improve the vehicle's power system and fuel quality. Using well-designed engines, optimizing combustion chamber structures, adopting new materials, and enhancing fuel quality can all reduce exhaust emissions, although achieving "zero emissions" remains unattainable. 3. Utilize purification technologies. Advanced after-treatment technologies can purify exhaust gases to minimize pollution. Automotive exhaust purification catalysts are the most effective means to control emissions and reduce vehicle pollution. These primarily include noble metal catalysts and rare-earth automotive exhaust purification catalysts. Noble metal catalysts, typically using platinum and palladium, offer high activity, long lifespan, and excellent purification performance, making them highly practical but difficult to widely adopt. Rare-earth automotive exhaust purification catalysts are prepared using rare-earth elements, alkaline earth metals, and some alkali metals, sometimes with small amounts of noble metals. The rare-earth elements used in these catalysts mainly consist of a mixture of cerium oxide, praseodymium oxide, and lanthanum oxide, with cerium oxide being the key component. Due to cerium oxide's redox properties, it effectively regulates exhaust gas composition by supplying oxygen in reducing atmospheres or consuming oxygen in oxidizing atmospheres. Cerium dioxide also stabilizes noble metals, maintaining high catalytic activity.
To address vehicle exhaust emissions, I believe we should start with the maintenance of the car itself. Older vehicles are most prone to emission issues. I regularly check the engine condition—changing the engine oil and air filter is particularly important, as it ensures cleaner fuel combustion and reduces black smoke emissions. Additionally, if the catalytic converter is old, it should be replaced or cleaned promptly, as it converts harmful gases into harmless substances. Moreover, maintaining proper tire pressure reduces engine strain and results in cleaner exhaust. When driving, avoid sudden acceleration or idling, as these habits increase emissions. Keeping detailed maintenance records and scheduling regular inspections of the emission system at repair shops, especially for older cars, can significantly reduce pollution. In summary, paying attention to small details can help cut emissions effectively.
