Lattice-strain control of the activity in dealloyed core–shell fuel cell catalysts

Abstract

Electrocatalysis will play a key role in future energy conversion and storage technologies, such as water electrolysers, fuel cells and metal–air batteries. Molecular interactions between chemical reactants and the catalytic surface control the activity and efficiency, and hence need to be optimized; however, generalized experimental strategies to do so are scarce. Here we show how lattice strain can be used experimentally to tune the catalytic activity of dealloyed bimetallic nanoparticles for the oxygen-reduction reaction, a key barrier to the application of fuel cells and metal–air batteries. We demonstrate the core–shell structure of the catalyst and clarify the mechanistic origin of its activity. The platinum-rich shell exhibits compressive strain, which results in a shift of the electronic band structure of platinum and weakening chemisorption of oxygenated species. We combine synthesis, measurements and an understanding of strain from theory to generate a reactivity–strain relationship that provides guidelines for tuning electrocatalytic activity. The rational design of catalytic materials requires synthetic control over their reactive properties. Now, the activity of dealloyed Pt–Cu bimetallic nanoparticles, which catalyse the oxygen reduction reaction, can be tuned through control of the geometric strain at their surface.

Cite this article

Strasser, P., Koh, S., Anniyev, T. et al. Lattice-strain control of the activity in dealloyed core–shell fuel cell catalysts. Nature Chem 2, 454–460 (2010). https://doi.org/10.1038/nchem.623

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