A catalyst in vehicles, commonly referred to as a catalytic converter, is a critical component of the exhaust system that helps reduce harmful emissions produced by the engine. Its primary function is to convert toxic gases and pollutants in exhaust gas into less harmful substances before they are released into the atmosphere.
The catalytic converter operates on the principles of oxidation and reduction (redox) reactions to reduce harmful emissions. Here’s how it works:
Exhaust gases from the engine enter the catalytic converter. These gases contain pollutants such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).
The first section of the catalytic converter contains rhodium and sometimes platinum, which help reduce NOx emissions.
Reaction: NOx gases are reduced by removing oxygen atoms, breaking them down into nitrogen (N2) and oxygen (O2).
Equation: 2NOx → xO2 + N2
The second section contains platinum and palladium, which help oxidize CO and HC.
Carbon Monoxide Oxidation: CO reacts with O2 to form carbon dioxide (CO2).
Equation: 2CO + O2 → 2CO2
Hydrocarbons Oxidation: HC reacts with O2 to form CO2 and water (H2O).
Equation: CxHy + O2 → CO2 + H2O
The converted, less harmful gases (primarily CO2, N2, and H2O) exit the catalytic converter and are released through the vehicle’s exhaust system.
