Catalytic converters are pretty expensive, owing to the platinum, palladium, or rhodium they use as catalysts. Those catalysts turn the harmful fumes into not-so-harmful gas. But researchers think they may have a better, less expensive way, and ironically, it involves gold.

The new method uses gold in nanocrystal (gold atoms bound together in crystals smaller than a strand of DNA) form.

Using a pair of scanning transmission electron microscopy (STEM) instruments, researchers at the National Institute of Standards and Technology (NIST), observed the active gold nanocrystals absorb onto iron oxide surfaces.

The research team discovered that size matters a lot – apparently the larger ones had little or no catalytic activity, while the smallest ones had nearly 100 percent efficiency.
Their results showed that the most active gold nanoclusters are 40 times smaller than the common cold virus and contains about 10 gold atoms.

This research, along with an inexpensive method for producing the nanocrystals, could pave the way for vastly less expensive catalytic converters.