Iron–lanthanum pairs improve fuel-cell reaction and durability in laboratory tests
Paired iron and lanthanum atoms improved an oxygen-reduction catalyst in acidic laboratory conditions. A single peer-reviewed study measured higher electrode activity than its platinum–carbon comparison and retained much of the starting fuel-cell performance during a 100-hour test. Spectroscopy and calculations link the change to iron’s electronic state and surrounding bonds. Commercial operating life and manufacturing scale remain untested.
Science··Midday
The paired catalyst retains activity
A fuel-cell catalyst made with iron and lanthanum retained 86 per cent of its initial performance after a 100-hour laboratory trial. This single peer-reviewed experiment addresses the difficulty of keeping a catalyst active while oxygen reacts in an acidic environment. The material uses paired atoms on carbon containing nitrogen, rather than platinum-group metals.[1]
In rotating-electrode measurements, its half-wave potential reached 0.92 V, against 0.87 V for the platinum–carbon comparator. These figures describe the tested electrolyte and material loading. Researchers also compared the paired structure with carbon carrying isolated iron sites.[1]
Lanthanum changes the iron sites
Atomic images and spectroscopy characterized the arrangement of the sites. The researchers link lanthanum’s contribution to a higher-spin iron state, an electronic configuration, and to changes in how oxygen-containing intermediate molecules attach. Measurements taken during operation were consistent with better preservation of the bonds joining iron and nitrogen. Calculations supported the proposed mechanism, while leaving individual contributions to the improvement incompletely separated.[1]
The material operates inside a test cell
The team incorporated the catalyst into a membrane electrode assembly, the structure where a fuel cell brings its reacting materials together. With hydrogen and oxygen, the cell delivered an electrical-resistance-corrected current density of 56 mA/cm² when the voltage was 0.9 V. Membrane properties, gas pressure and supply conditions affect this result. The laboratory trial measured activity and short-term durability; manufacturing at scale and service life under vehicle or power-plant conditions require separate evaluation.[1]
