Explain briefly : Catalytic converters

Explanation

These are devices developed by BHU, which are fitted in engines of vehicles. They have costly metals like platinum-palladuim and rhodium as catalysts. The exhaust gases first pass through these converters. They convert (oxidise) unburnt hydrocarbons into `CO_2, CO` into `CO_2` and Nitrogen oxide split up into `N_2` gas.