Catalytic Converter: Description and Operation

DESCRIPTION AND OPERATION
The engine exhaust consists mainly of nitrogen (N2); however, it also contains carbon monoxide (CO), carbon dioxide (CO2), water vapor (H2O), oxygen (02), nitrogen oxides (NOx), and hydrogen (H2) as well as various, unburned hydrocarbons (HC). Three of these exhaust components CO, NOx, and HC are major air pollutants, so their emission to the atmosphere must be controlled.

The three-way catalytic (TWC) converter, mounted in the engine exhaust system, works as a gas reactor to convert and reduce the pollutant levels to within legally prescribed limits.

The catalyst metals are thinly coated onto and supported by a honeycomb-shaped high temperature ceramic, mounted inside the converter shell. The result is a highly effective converter design having minimum restriction to exhaust gas flow and good durability.