- Category: Technology
19 Oct 2012
- Published on Friday, 19 October 2012 13:32
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A new catalytic material based on the element cobalt could be the key to cheaper hydrogen fuel cells by acting as an alternative to platinum.
To produce electricity, a fuel cell needs a catalyst that can oxidize the fuel – in this case hydrogen – releasing electrons which create a current. Most fuel cells use the rare metal platinum, a proven catalyst, but while this material is efficient, it is also expensive.
Brown University chemist Shouheng Sun and his students developed a new catalyst they claim is almost as efficient as platinum but is more durable and is also cheaper.
This new catalyst is created by arranging a sheet of graphene coated with cobalt and cobalt-oxide nanoparticles.
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This is said to be the first catalyst not made from a precious metal and that comes close to matching platinum’s properties.
Lab tests showed that the new graphene-cobalt material was a bit slower than platinum at triggering the oxygen reduction reaction. But once the reaction got going, it continued at a faster pace than it would have if triggered by platinum.
Aside from inducing faster reaction, the new catalyst is also more stable, degrading more slowly than platinum. Under laboratory conditions, the Brown University team found that the graphene-cobalt catalyst was still performing at around 70 percent of its initial capacity after 17 hours.
In contrast, a platinum catalyst tested under the same conditions performed at less than 60 percent after the same amount of time.
Finding a suitable non-platinum catalyst is considered key to getting fuel cells out of the laboratory phase. The cost of platinum is seen as driving up the cost of fuel cells and preventing their widespread commercialization.
Cobalt is an infinitely cheaper material that is abundantly found in nature. Mr. Sun and his team believe that with more study, their material could one day be a suitable replacement for platinum catalysts. – EcoSeed Staff