Electrochemical Oxygen Reduction Reaction on Ag Nanoparticles of Different Shapes

Silver electrocatalysts are an attractive alternative to platinum for electrochemical oxygen reduction reaction in alkaline fuel cells. Recent advances in the synthesis of metal nanoparticles have enabled the design of silver nanoparticles of different shapes, terminated with different surface facets that exhibit different catalytic properties. In this contribution, we prepared spherical and cubic silver nanoparticle electrocatalysts and tested their electrocatalytic oxygen reduction reaction activity in 0.1 m sodium hydroxide. Our work demonstrates that carbon‐supported silver nanospheres and nanocubes of similar size exhibit similar ORR activity with the spheres slightly outperforming the cubes. In addition, we suggest possible reasons for the slightly enhanced activity of the nanospheres. Silver ahead: Carbon‐supported 40 nm Ag spheres are slightly more catalytically active towards alkaline oxygen reduction reaction than carbon‐supported 40 nm Ag cubes. This behavior is consistent with the abundance of the Ag(1 1 1) surface facets compared to Ag(1 0 0) on the spheres.