Silver Nanocatalyst Switches Reaction Sites for Power Generation and Hydrogen Production

Researchers have identified that a silver (Ag) nanocatalyst functions at distinct reaction sites within solid oxide cells depending on whether the device is operating in power‑generation mode or as a hydrogen‑producing electrolyzer. The discovery, made by a multidisciplinary team, shows that the same catalyst can adapt its active sites to the differing electrochemical demands of each mode, a behavior not previously documented for nanocatalysts in solid oxide technology.

The study demonstrates that during electricity generation the Ag nanocatalyst preferentially facilitates oxygen reduction reactions at specific lattice sites, whereas in hydrogen production it shifts to sites that favor water oxidation and hydrogen evolution. This mode‑dependent site selectivity suggests that catalyst architecture can be tuned to optimize performance for each application. By designing cells that exploit these dual‑site capabilities, engineers can potentially reduce catalyst loading, lower operating temperatures, and extend component lifetimes.

The finding introduces a new design principle for next‑generation solid oxide cells: tailoring nanocatalyst site distribution to the intended operating mode. If applied in commercial devices, this approach could improve energy efficiency and cost‑effectiveness for both power generation and hydrogen production, accelerating the deployment of solid oxide technology in the broader energy transition.