<P> Although catalytic converters are most commonly applied to exhaust systems in automobiles, they are also used on electrical generators, forklifts, mining equipment, trucks, buses, locomotives and motorcycles . They are also used on some wood stoves to control emissions . This is usually in response to government regulation, either through direct environmental regulation or through health and safety regulations . A catalytic converter has to be changed every 100 000 / 120 000 km in order to be efficient . It is important to recycle this part of the car . </P> <P> The catalytic converter was invented by Eugene Houdry, a French mechanical engineer and expert in catalytic oil refining, who moved to the United States in 1930 . When the results of early studies of smog in Los Angeles were published, Houdry became concerned about the role of smoke stack exhaust and automobile exhaust in air pollution and founded a company called Oxy - Catalyst . Houdry first developed catalytic converters for smoke stacks called "cats" for short, and later developed catalytic converters for warehouse forklifts that used low grade, unleaded gasoline . In the mid-1950s, he began research to develop catalytic converters for gasoline engines used on cars . He was awarded United States Patent 2,742,437 for his work . </P> <P> Widespread adoption of catalytic converters did not occur until more stringent emission control regulations forced the removal of the anti-knock agent tetraethyl lead from most types of gasoline . Lead is a "catalyst poison" and would effectively disable a catalytic converter by forming a coating on the catalyst's surface . </P> <P> Catalytic converters were further developed by a series of engineers including John J. Mooney, Carl D. Keith, Antonio Eleazar, and Phillip Messina at the Engelhard Corporation, creating the first production catalytic converter in 1973 . </P>

How does the catalyst in a catalytic converter work