Researchers from Brown University designed the world's best non-platinum catalyst, based on cobalt-graphene. This can be used to replace Platinum with a more durable and less expensive material as a fuel-cell catalyst.
To create this new material, the researchers used a self-assembly method. First, they dispersed cobalt nanoparticles and graphene in separate solutions. The two solutions were then combined and pounded with sound waves to make sure they mixed thoroughly. That caused the nanoparticles to attach evenly to the graphene in a single layer. Using a centrifuge, the material was removed from the solution, and it was then dried. Exposing it to air, the outside layers of atomic cobalt on each nanoparticle are oxidized which forms a shell of cobalt-oxide that helps protect the cobalt core.
The cobalt-graphene catalyst is a bit slower then platinum in getting the oxygen reduction reaction started, but once it was going, the oxygen reduction is actually faster than a platinum catalyst. It also degrades more slowly. After 17 hours of testing, it was performing at about 70% capacity (a platinum catalyst performed at 60% after the same amount of time).
