Catalytic Converter: Description and Operation

Three-Way Catalytic Converter:

PURPOSE
The Three Way Catalytic Converter (TWC) plays a major role in the emission control system. It works as a gas reactor that initiates and speeds up the chemical reaction between components of the exhaust gases in order to reduce their pollutants.

OPERATION
As the exhaust gases come into contact with the catalyst, a thee way conversion takes place. The TWC catalyzes the oxidation reaction of unburned hydrocarbons, carbon monoxide and also, the reduction reaction of oxides of nitrogen. The TWC reduces the concentration of these emissions to acceptable levels. The three way conversion only occurs with the air fuel ratio near stoichiometry (14.7 to 1).

CONSTRUCTION
Contains a Catalyst in the form of a specially treated honeycomb structure saturated with "catalytically" active precious metals, either platinum and rhodium or palladium and rhodium.