The clean energy future of platinum metals

Indispensable, expensive, and rare – PGMs get a green upgrade.

Back in 1950, the first catalytic converter in the United States was a box bolted onto a car's undercarriage to reduce tailpipe emissions. It was patented by French mechanical engineer Eugene Houdry, who was concerned about the effects of automobile exhaust on the good people of Los Angeles.

And it would have worked if it had not been...