Platinum, a metal that helps craft aesthetically pleasing jewelry, also finds use in a car's exhaust for entirely non-aesthetic reasons. The catalytic converter is required on nearly every car to ...

Introduced in 1974 by General Motors, catalytic converters were a byproduct of the 1970 Clean Air Act, which aimed at improving air quality in the U.S. by curbing smog emissions that were choking U.S.