Hydrogen fuel cells convert hydrogen to electricity with just water vapor as a byproduct, making them a viable green option for portable power, notably in cars.
The expense of one of the major components, however, has impeded their widespread adoption. The fuel cells use a platinum catalyst, which is costly and rare, to assist the process that generates energy.
Now, a European team led by Imperial College London researchers has developed a catalyst made entirely of iron, carbon, and nitrogen – all of which are inexpensive and widely accessible – and demonstrated that it can run a high-power fuel cell. Their findings were published in Nature Catalysis today.
“Currently, roughly 60% of the cost of a single fuel cell is the platinum for the catalyst,” stated lead researcher Professor Anthony Kucernak of Imperial College’s Department of Chemistry. We need to lower the cost of fuel cells to make them a truly feasible alternative to fossil-fuel-powered automobiles, for example.
“Our less expensive catalyst design should make this a reality, allowing for the deployment of much more renewable energy systems that use hydrogen as a fuel, lowering greenhouse gas emissions and putting the world on a road to net-zero emissions.”
The researchers came up with the idea of making a catalyst with all of the iron scattered as single atoms within an electrically conducting carbon matrix. Single-atom iron has different chemical characteristics than bulk iron, which is more reactive since all of the atoms are grouped together.
These qualities indicate that iron enhances the processes required in the fuel cell, making it a viable replacement for platinum. The scientists demonstrated in lab testing that a single-atom iron catalyst may function similarly to platinum-based catalysts in a practical fuel cell system.
The method developed by the team could be adapted for other catalysts for other processes, such as chemical reactions using atmospheric oxygen as a reactant instead of expensive chemical oxidants, and wastewater treatment using air to remove harmful contaminants, in addition to producing a cheaper catalyst for fuel cells.
“We have devised a novel way to manufacture a spectrum of single atom’ catalysts that give a possibility to allow a range of new chemical and electrochemical processes,” stated first author Dr. Asad Mehmood of Imperial College’s Department of Chemistry. To prevent creating iron clusters during synthesis, we adopted a new synthetic process termed transmetallation. Other scientists attempting to make a comparable sort of catalyst might find this method useful.”
The researchers worked with Johnson Matthey, a UK-based fuel cell catalyst producer, to test the catalyst in relevant conditions, with the goal of scaling it up for usage in commercial fuel cells. Meanwhile, they’re aiming to increase the catalyst’s stability so that it can match platinum’s longevity and performance.
