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A Toyota hydrogen fuel cell engine at the New York International Auto Show.
Vehicles powered by hydrogen fuel cells, which emit only water vapor, are one of our best potential alternatives to pollution-spewing traditional automobile engines, which account for 30% of all carbon emissions in the United States.
The catch? The catalysts needed to make these fuel cells run with sufficient power incorporate rare and expensive metals like platinum, and there's simply not enough of these metals available to support the widespread adoption of this technology. Getting more power out of less platinum remains a challenge.
But a team led by UCLA professor Yu Huang may have turned a corner.
In a recently published study in the journal Nature Nanotechnology, they describe using a high-performing platinum-cobalt alloy that cut down on the need for platinum alone. They then broke this alloy down into miniscule particles — each about 3 nanometers long — and embedded each particle in a tiny graphene "nanopocket" in the hopes of keeping it stable and enhancing its durability.
When they integrated their new catalysts into a fuel cell, the results were surprising even to them. Their specialized system exceeded the ambitious targets set by the U.S. Department of Energy for hydrogen fuel cell stability, low platinum use and performance, generating 75 times more catalytic activity and 65% more power, among other coups.
"This has never been done before," said Professor Huang, chair of the department of materials science and engineering at the UCLA Samueli School of Engineering and a member of the California NanoSystems Institute at UCLA. "This discovery involved some serendipity. We knew we were onto something that might make smaller particles stable, but we didn't expect it to work this well.
