Electrifying our energy sources is key to saying goodbye to greenhouse gasses. But renewable electricity has its downsides: Getting it from the environment can be finicky (the sun isn’t always shining), and batteries are often made with non-renewable materials like lithium and have a limited energy storage capacity.
Enter hydrogen fuel technology, which researchers believe has a greater energy potential than conventional batteries. The fuel cells convert hydrogen, the most abundant element in our universe, into electricity without producing any carbon. While some vehicles use hydrogen fuel cells—like the Toyota Mirai—large-scale commercialization is hampered by the technology’s reliance on platinum, an expensive precious metal that the fuel cells use to speed up the electricity-making process.
But scientists are hoping to change that. In a new study published on Monday in the journal Nature Catalysis, researchers at Imperial College London and other European research institutions have developed a hydrogen fuel cell that uses iron, a much cheaper metal, as a catalyst instead. In experiments, the new fuel cell performed nearly as well as a platinum-based one. This more affordable alternative could bring down manufacturing costs, making the technology accessible and one step closer to being under the hood of your next car.
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The fuel cells work by combining hydrogen atoms with oxygen atoms in a chemical reaction that produces electricity, water, and small amounts of heat, according to the U.S. Energy Information Administration. These fuel cells typically use a catalyst, a substance (in this case platinum) that speeds up the reaction. Platinum isn’t cheap, is relatively scarce, and currently makes up 60 percent of a single fuel cell’s cost, Anthony Kucernak, a chemist at Imperial College London and lead researcher of the new study, said in a press release.
“To make fuel cells a real viable alternative to fossil-fuel-powered vehicles, for example, we need to bring that cost down,” he said.
To do that, Kucernak and his team turned to iron, a superabundant metal that’s dirt cheap. The researchers didn’t use a solid piece of iron. Instead, they broke the metal down into single atoms—which are more reactive than a whole block of metal—and placed those molecules on top of a material made of carbon and nitrogen. They found this catalyst produced nearly as much electricity as a platinum-based fuel cell, which means we might be able to get around the prohibitive costs preventing hydrogen fuel from being more commercially viable.
The iron-based hydrogen fuel cell being tested in the lab.
Imperial College LondonThe technology isn’t limited to hydrogen fuel cells either. The researchers believe it could lower costs for a wide range of commercial applications like using air to remove harmful contaminants from wastewater.
“We have developed a new approach to make a range of ‘single atom’ catalysts that offer an opportunity to allow a range of new chemical and electrochemical processes,” Asad Mehmood, a chemist at Imperial College and the study’s first author, said in the release. “Specifically, we used a unique method, called transmetallation, to avoid forming iron clusters during synthesis. This process should be beneficial to other scientists looking to prepare a similar type of catalyst.”
While this new iron catalyst for hydrogen fuel cells isn’t quite as durable as platinum, the Imperial College researchers are working on improving the system. They hope to scale it up so that one day, hydrogen fuel cells as a renewable energy source will be the norm—and not the exception.
