Alloy Cu₃Pt nanoframes through the structure evolution in Cu-Pt nanoparticles with a core-shell construction.

Noble metal nanoparticles with hollow interiors and customizable shell compositions have immense potential for catalysis. Herein, we present an unique structure transformation phenomenon for the fabrication of alloy Cu 3 Pt nanoframes with polyhedral morphology. This strategy starts with the preparation of polyhedral Cu-Pt nanoparticles with a core-shell construction upon the anisotropic growth of Pt on multiply twinned Cu seed particles, which are subsequently transformed into alloy Cu 3 Pt nanoframes due to the Kirkendall effect between the Cu core and Pt shell. The as-prepared alloy Cu 3 Pt nanoframes possess the rhombic dodecahedral morphology of their core-shell parents after the structural evolution. In particular, the resulting alloy Cu 3 Pt nanoframes are more effective for oxygen reduction reaction but ineffective for methanol oxidation reaction in comparison with their original Cu-Pt core-shell precursors.