Hydrogen fuel cells use hydrogen to generate electricity, with water vapor being the only by-product generated in the process, making them an attractive clean alternative to batteries and other conventional portable power sources, especially for vehicles.
However, their widespread use has been hampered in large part by the cost of one of the main components: to facilitate the reaction that produces electricity, fuel cells rely on a platinum catalyst, a scarce and expensive chemical element.
Scientists have now created a hydrogen fuel cell that uses the much cheaper iron instead of expensive platinum.
This innovation opens a new path toward widespread use of hydrogen fuel cells.
The breakthrough is the work of Anthony Kucernak’s international team at Imperial College London in the United Kingdom.
Kucernak and his colleagues have created a catalyst with only iron, carbon and nitrogen, inexpensive and readily available materials, and have demonstrated that the new catalyst can be used to run a high-power fuel cell.
The team’s innovation involved producing a catalyst in which all of the iron is dispersed as individual atoms within an electrically conductive carbon matrix. Iron in the form of individual atoms has different chemical properties than iron in the form of grouped atoms.
These different properties mean that iron in single-atom form enhances the reactions needed in the fuel cell, acting as a good substitute for platinum. In laboratory tests, the team demonstrated that such an iron catalyst performs similarly to platinum-based catalysts in a real fuel cell system.
Kucernak and colleagues report the technical details of their innovation in the academic journal Nature Catalysis, under the title “High loading of single atomic iron sites in Fe-NC oxygen reduction catalysts for proton exchange membrane fuel cells.”