Novel urchin-like Pd nanostructures prepared by a simple replacement reaction and their catalytic properties

► Novel urchin-like Pd nanostructures were firstly synthesized using a simple replacement reaction. ► Numerous one-dimensional Pd nanorods radiate from the center of the aluminum templates. ► The urchin-like Pd nanostructures can accelerate the thermal decomposition of ammonium perchlorate.