Rational Design Can Improve Fuel Cell Efficiency

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Illustration of the trimetallic sandwich-like structure. Redox reactions take place on M1, while M2 tunes the electronic structure of M1, and M3 serves as the substrate and contributes to performance by straining M2. Image credit: Stolbov and Alcántara Ortigoza.

In a new study, scientists have designed tri-metallic electrocatalysts for hydrogen fuel cells that theoretically improve both efficiency and cost-effectiveness, outperforming the best platinum-based catalysts to date.

The researchers, Sergey Stolbov and Marisol Alcántara Ortigoza from the University of Central Florida, have recently published their study on the new efficient electrocatalysts in The Journal of Physical Chemistry Letters. Stolbov and Alcántara Ortigoza focused on improving the redox reactivity of gold and palladium through the use of in-depth modeling.

This method led the researchers to a new design consisting of a three-layered sandwich-like structure. In this design, redox reactions take place on the first layer, while the second layer can tune the electronic structure of the first layer, and the third layer serves as the substrate. As an example, the researchers used gold as the first layer, then chose ruthenium as the second layer due to its ability to tune the gold layer to increase its redox reactivity. When using palladium as the first layer, their method predicted iron as a good tuning material. The ruthenium and iron do not have to come in contact with the acidic solvent, yet still contribute to the catalyst’s efficiency. In both cases, the researchers used tungsten as the substrate, which also contributed to performance in a twice-removed way by straining the middle layer.