A simple and effective method is developed to synthesize flower-like platinum (Pt) nanostructures through galvanic replacement reaction between aluminum (Al) nanoparticles and PtCl2 aqueous solution at room temperature. Pt flowers exhibit an average size of approximately 1 mu m, and many thin nanosheets comprise such flower-like structure. Dendritic Pt nanostructures can be obtained by simply adding an amount of polyvinyl pyrrolidone (PVP) into the reaction solution. Nanodendrites, which are 30-100 nm in size, are rich in interconnected nanoparticles. The catalytic activity on the thermal decomposition of ammonium perchlorate (AP) was characterized by DSC/TGA. Results showed that the addition of flower-like and dendritic Pt nanostructures decrease the high decomposition temperature of AP by 96 degrees C and 114 degrees C, and increases the total DSC heat release by 1.28 and 1.36 kJ g(-1), correspondingly. The obtained Pt nanostructures demonstrate excellent catalytic activity for thermal decomposition of AP. (C) 2016 Elsevier Ltd. All rights reserved.