The Three-Way Catalyst (TWC) is indeed a critical component in automotive emission control systems. It combines two catalytic converters into a single unit housed in a single shell. Its primary function is to reduce the emissions of three harmful pollutants from internal combustion engines:
- Nitrogen Oxides (NOx): TWC reduces NOx emissions by converting them into nitrogen and oxygen through a reduction reaction.
- Hydrocarbons (HC): It oxidizes unburned hydrocarbons to carbon dioxide (CO2) and water (H2O) through an oxidation reaction.
- Carbon Monoxide (CO): TWC converts carbon monoxide into carbon dioxide (CO2) by oxidation.
These reactions occur inside the catalytic converter, which contains a honeycomb-like structure coated with precious metals such as platinum, palladium, and rhodium. These metals act as catalysts to facilitate the chemical reactions that convert harmful pollutants into less harmful or inert substances.
The term “Three-Way” refers to the catalyst’s ability to simultaneously reduce all three pollutants mentioned above. It is a critical component in modern gasoline-powered vehicles to meet emissions regulations and improve air quality.
See Related Term:
- WU TWC