Tiny silver catalysts work differently when solid oxide cells generate electricity and when they produce hydrogen, revealing a potential route to more efficient clean energy systems.
Solid oxide cells can generate electricity or use electricity to split water and produce hydrogen. Silver nanocatalysts, tiny silver particles that speed up chemical reactions, can improve their performance in both modes. Researchers have now discovered for the first time that the particles’ main reaction site changes depending on which task the cell is performing.
The distinction lies at the air electrode, where the cells exchange oxygen with their surroundings. During electricity generation, silver primarily promotes oxygen reactions along the boundary where each particle meets the electrode. During hydrogen production, the silver particle’s own surface becomes the main reaction site.
