Shape-controlled core@shell nanoparticles have attracted considerable interest for their potential to minimize the use of precious metals in the shell while enhancing catalytic performance through lattice strain and shape effects. However, challenges such as core dissolution and morphological degradation during shell growth remain major obstacles to their broader applications. In this study, we successfully demonstrated core@shell CuNi@Pt-Cu nano-octahedra by leveraging a previously developed protocol based on CuNi nano-octahedra templates. Precise control of key reaction parameters, including a high reaction temperature (240 °C), a rapid heating ramp (~ 12 °C/min), and slow injection of the Pt precursor, enabled the retention of sharp-edged morphology during shell formation. The resulting nanocrystals feature (111) -facet-dominated surfaces and exhibit lattice strain at the CuNi/Pt-Cu interface, both of which contribute to their enhanced electrocatalytic performance. In the formic acid oxidation reaction, the CuNi@Pt-Cu nano-octahedra demonstrated a high specific activity of ~ 25. 2 mA/cmₓ^2, significantly outperforming CuNi@Pt-Cu nanopolyhedra/C (15. 7 mA/cmₓ^2) and commercial Pt/C catalysts (4. 36 mA/cmₓ^2). They also exhibited enhanced stability, with only a 17% loss in activity after a 1-h chronoamperometry test, compared to a ~ 44% loss observed for both the polyhedral counterpart and Pt/C. These results underscore the effectiveness of integrating shape control, interfacial strain, and multimetallic synergy within Pt-based nanostructures to improve both electrocatalytic activity and durability.
Li et al. (Fri,) studied this question.