Nanostructured catalyst with hierarchical porosity and large surface area for on-chip fuel cells

Abstract This communication reports the synthesis of mesoporous Pd–Co dendrites with both a unique hierarchical porosity and a large surface area by the combination of electrodeposition and dealloying. The resultant mesoporous dendrites consist of microparticles with a diameter of a few hundred nanometers, and the particles have mesopores with around 10 nm width. The mesoporous dendrites are found to be Pd 8 Co 2 , to be composed of pure Pd crystalline phases and amorphous Pd–Co phases, and to be covered with Pd-skin layers. This catalyst exhibits a high activity in the oxygen reduction reaction. Thus, this novel catalyst is attractive as a catalyst for on-chip fuel cells, which require catalysts to be deposited precisely onto tiny current collectors.