What is a Three-Way Catalytic Converter in Automobiles?
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An automobile's three-way catalytic converter is a device that transforms harmful gases such as CO, HC, and NOx emitted from vehicle exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction reactions. Below is an introduction to the three-way catalytic converter: 1. Three-Way Catalytic Converter: The core component of a three-way catalytic converter is a porous ceramic material, installed in a specially designed exhaust pipe. It is called a substrate because it does not participate in the catalytic reaction itself but is coated with precious metals such as platinum, rhodium, and palladium. It is the most important external purification device installed in a vehicle's exhaust system. 2. Three-Way Catalytic Converter at High Temperatures: When high-temperature exhaust gases pass through the purification device, the catalyst in the three-way catalytic converter enhances the activity of CO, HC, and NOx, promoting specific oxidation-reduction chemical reactions. CO is oxidized into colorless, non-toxic carbon dioxide gas at high temperatures; HC compounds are oxidized into water (H2O) 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. 3. Cleaning the Three-Way Catalytic Converter: The three-way catalytic converter generally does not require cleaning. If it becomes severely oxidized, it should be replaced directly because the operating temperature of the converter is around 350 degrees Celsius, leaving no liquid water residue, making cleaning ineffective.
