Trimetallic PtPdNi-Truncated Octahedral Nanocages with a Well-Defined Mesoporous Surface for Enhanced Oxygen Reduction Electrocatalysis.

Engineering the architectures and compositions of noble metal-based nanocrystals is an effective strategy to optimize their catalytic performance. Herein, we report the synthesis of unique trimetallic PtPdNi mesoporous-truncated octahedral nanocages (PtPdNi MTONs), which is simply performed by first constructing Pd@PtPdNi core-shell mesoporous truncated octahedra (Pd@PtPdNi MTOs) and further selective etching of the Pd cores using concentrated nitric acid. The rational combinations of polyhedral shape, mesoporous surface, and hollow structure provide sufficiently exposed active sites and efficient reactant permeability. With these unique properties, the PtPdNi MTONs show improved catalytic activity and stability toward the oxygen reduction reaction.