State the function of catalytic converter in an automobile

a. Catalytic converters are recommended for vehicles. These converters have expensive metals namely platinum, palladium and rhodium as the catalysts are fitted into automobiles for the reduction of emission of poisonous gases.
b. As the exhaust passes though the catalytic converter,unburnt hydrocarbons are converted into carbon dioxide and water, and carbon monoxide and nitrogen gas. Motor vehicles equipped with catalytic converts should use unleaded petrol because lead in the petrol inactivates the catalyst.