What is the function of a car's three-way catalytic converter?

[AlejandroFitz]

The function of a car's three-way catalytic converter is to purify exhaust gases. Here are the relevant details: 1. Function: It promotes specific oxidation-reduction chemical reactions, where CO is oxidized into colorless, non-toxic carbon dioxide gas at high temperatures; HC compounds are oxidized into water and carbon dioxide; and NOx is reduced into nitrogen and oxygen. These three harmful gases are converted into harmless gases, thereby purifying the vehicle's exhaust. 2. Features: The three-way catalytic converter has stable performance, reliable quality, and a long lifespan, making it widely applicable. The core component of the three-way catalytic converter is a porous ceramic material installed in a specially designed exhaust pipe. It is called a 'carrier' because it does not participate in the catalytic reaction itself but is coated with precious metals such as platinum, rhodium, and palladium.

[RuthAnn]

Last time I saw a clogged catalytic converter in the workshop, the car owner was puzzled why the fuel consumption suddenly soared. This thing is essentially an 'exhaust gas purifier' that sits in the middle of the exhaust pipe. Inside it, there are three precious metals—platinum, palladium, and rhodium—acting as catalysts, which convert three harmful substances in the exhaust—carbon monoxide, hydrocarbons, and nitrogen oxides—into harmless carbon dioxide, water, and nitrogen. If it stops working, not only will the exhaust smell pungent, but it will definitely fail the annual inspection, and the dashboard might light up with a warning light. Usually, you should avoid using low-quality gasoline, as it can easily poison and deactivate the catalytic converter. Replacing a new one can cost several thousand yuan!

[MacGraham]

Back when I first started driving twenty years ago, you could still smell gasoline on the road. Nowadays, we rarely catch a whiff, and we have the three-way catalytic converter to thank for that. It's like a chemical magician, using precious metals attached to a honeycomb ceramic substrate to perform a high-temperature transformation on toxic gases: turning carbon monoxide into carbon dioxide, unburned gasoline into water vapor, and breaking down the most troublesome nitrogen oxides directly into nitrogen and oxygen molecules. Here's a cool fact: the converter needs to reach 300°C to work properly, so its purification efficiency is lower when you first start your car in winter. Remember not to idle for too long, as carbon buildup can easily clog those tiny, intricate channels.

[Douglas]

A friend who works in vehicle emission testing complained to me that 90% of cars failing tailpipe tests have faulty catalytic converters. This device is ingeniously designed: exhaust gases flow through densely packed honeycomb channels, undergoing redox reactions when contacting the platinum-rhodium-palladium coating. In layman's terms, it's like a detox system for exhaust pipes. However, it's quite delicate - hitting the undercarriage can crack the ceramic substrate, and cars burning oil can contaminate the metal coating. Last time, my neighbor's car had weak acceleration, and inspection revealed the converter was completely clogged with carbon deposits. Soaking it overnight in oxalic acid only restored about 70-80% of its functionality.

[DeNathan]

A few days ago, my female colleague mentioned her car failed the annual inspection due to the emissions test - it turned out the catalytic converter had aged and failed. This device is embedded in the middle section of the exhaust pipe, resembling a metal box externally with a honeycomb-structured ceramic block inside. When high-temperature exhaust gases pass through, the precious metal coating triggers molecular recombination of harmful gases: carbon monoxide combines with oxygen to form carbon dioxide, hydrocarbons get oxidized into water, and nitrogen oxides decompose into nitrogen and oxygen. Special reminder for modification enthusiasts: while straight-pipe headers may boost performance, removing the catalytic converter is illegal and environmentally harmful.