Abstract

Phase engineering of nanomaterials (PEN), which focuses on the delicate regulation of atomic arrangements, has emerged as an effective strategy to synthesize novel nanostructures with fascinating physicochemical properties and enhanced performances in various important applications.1-2 Herein, we report a wet-chemical synthesis of Au@Pd core-shell nanorods (NRs) with well-defined fcc-2H-fcc heterophase (fcc: face-centered cubic; 2H: hexagonal close-packed with an atomic arrangement of “AB”), distinct phase boundary, and expanded Pd shell via seed-mediated epitaxial growth. The obtained heterophase fcc-2H-fcc Au@Pd NRs exhibit superior electrocatalytic ethanol oxidation performance. Experimental results and density functional theory calculations indicate that the enhanced performance of the Au@Pd NRs can be ascribed to the fcc-2H-fcc heterophase core-shell structure with unconventional 2H phase, 2H/fcc phase boundary, and the lattice expansion of the Pd shell. Such delicate phase engineering of nanomaterials paves a novel avenue for developing high-performance electrocatalysts and constructing model nanomaterials for mechanism study.3 

References
1. Chen, Y.; Zhang, H., et al. Nat. Rev. Chem., 2020, 4, 243-256. 

2. Ge, Y.; Zhang, H., et al. J. Am. Chem. Soc., 2020, 142, 18971-18980.
3. Zhou, X.; Zhang, H., et al. J. Am. Chem. Soc., 2022, 144, 1, 547–555.