What is the function of CatCon in an exhaust system?

The primary function of a catalytic converter (CatCon) in an exhaust system is to reduce the emission of harmful pollutants from an internal combustion engine. Here are the key aspects of its function:

Conversion of Pollutants

• The catalytic converter converts toxic gases and pollutants in the exhaust gas into less-toxic substances. Specifically, it targets carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx)135.

Catalytic Process

• The converter uses a chemical catalyst, typically a combination of precious metals such as platinum, palladium, and rhodium, to facilitate the conversion process. These catalysts are coated on a honeycomb-shaped ceramic or metallic substrate235.

Stages of Conversion

• In a three-way catalytic converter, there are two main stages:
  • The reduction catalyst stage, where nitrogen oxides (NOx) are converted into nitrogen (N2) and oxygen (O2) using platinum and rhodium.
  • The oxidation catalyst stage, where carbon monoxide (CO) and hydrocarbons (HC) are oxidized into carbon dioxide (CO2) and water (H2O) using platinum and palladium35.

Integration with Engine Control

• The catalytic converter works in conjunction with the vehicle's engine control unit (ECU) and oxygen sensors. These sensors monitor the oxygen levels in the exhaust stream before and after the converter, allowing the ECU to adjust the fuel injection to maintain optimal conditions for the catalytic reactions135.

Overall Impact

• By converting harmful emissions into less harmful substances, catalytic converters significantly reduce the environmental impact of vehicle exhaust, contributing to cleaner air and compliance with emissions regulations145.