[Osmium]

For anyone interested in the science, here's a paper:

http://dx.doi.org/10.1039/C2CP40581D [subscription required]

and the Masters thesis from the PhD student mentioned in the article:

http://dspace.mit.edu/handle/1721.1/69783 [open access]

I believe they're the most relevant publications, but please correct me if I'm wrong (this isn't my area of expertise). I'm sure this specific technology is still a trade secret, but it at least shows the direction that group took to lead to the discovery. As always, these things aren't developed in a vacuum, and it's always interesting to see how they come about.