UK researchers develop catalyst for cheaper hydrogen fuel cells

Hydrogen

United Kingdom – A European team led by Imperial College London researchers developed a catalyst for fuel cells using only iron, carbon, and nitrogen – low-cost, readily available materials – demonstrating that it can operate a fuel cell at high power.

Until now, fuel cells relied on a platinum catalyst to speed up the reaction that generates electricity, which is both expensive and scarce.

Lead researcher Professor Anthony Kucernak, from the Department of Chemistry at Imperial, said: “Currently, around 60% of the cost of a single fuel cell is the platinum for the catalyst. To make fuel cells a real viable alternative to fossil-fuel-powered vehicles, for example, we need to bring that cost down.”

Boost of iron

The team came up with the idea of making a catalyst with all of the iron dispersed as single atoms within an electrically conducting carbon matrix. Single-atom iron has different chemical properties than bulk iron, which is more reactive because all of the atoms are clustered together.

These properties indicate that iron enhances the reactions required in the fuel cell, making it a viable replacement for platinum. The team demonstrated in lab tests that a single-atom iron catalyst can perform similarly to platinum-based catalysts in a real 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.

Unique synthetic method

First author Dr Asad Mehmood, from the Department of Chemistry at Imperial, said: “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.

“Specifically, we used a unique synthetic 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.”

The team worked with Johnson Matthey, a UK-based fuel cell catalyst manufacturer, to test the catalyst in appropriate systems, with the goal of scaling it up for use in commercial fuel cells.

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