Extending Platinum Catalysts: Platinum performs extremely well as a catalyst for the oxygen-reduction reaction that runs under highly acidic conditions in proton-exchange membrane fuel cells, but is expensive. One strategy for reducing costs is to increase the surface area of the platinum. Lim et al. (p. 1302 , published online 14 May) describe a simple chemical route, in which Pt ions in solution are reduced onto Pd seed crystals, which creates faceted Pt nanocrystals with a high area owing to their dendritic architecture. On a Pt mass basis, these catalysts are several times more active than conventional Pt catalysts.