What are catalytic converters

A catalytic converter is a part of a car exhaust. It is sometimes called a CAT or, worse, given the wholly non-descriptive abbreviation CC.  

A catalytic converter is a stainless steel tube located near the exhaust manifold, lined with finely divided metal salts, e.g. of platinum and palladium. 

The purpose of the catalytic converter is to oxidize some of the oxides in the gas phase. NO is reduced to elemental nitrogen. The principal reaction at the catalytic converter is oxidation of CO  

This reaction is energetically spontaneous, but it occurs quite slowly if the gases are just mixed because the activation energy to reaction is too high at 80 kJ mol-1. The reaction is much faster if the CO is burnt, but a naked flame is considered unsafe in a car exhaust. 

Although the reaction in Equation (8.64) is slow under normal conditions, it can be accelerated if performed with a catalyst hence the incorporation of a catalytic converter in the car exhaust system. 

---