Optimizing the structural configuration of FePt-FeOx nanoparticles at the atomic scale by tuning the post-synthetic conditions

Abstract Tailoring the atomic structural configuration at metal and oxide interface offers an effective route for the development of catalysts with optimized properties. Here, we report the design of a unique structural configuration of yolk-shell-like FePt-FeO x nanoparticles (NPs), that exhibits notably enhanced activity and stability towards CO oxidation at relatively low temperatures ( x catalysts were produced by partially reducing core-shell FePt-FeO x NPs under H 2 at 200 °C. The structural configuration was interrogated by advanced electron microscopy, which clearly reveals the evolution of the morphology, elemental segregation, and phase transition of FePt-FeO x NPs after the post-synthesis treatment. The generation of voids, partial crystallization of the FeO x shell and increased electron density on Pt were identified as key contributors to the enhanced activity and stability towards CO oxidation in FePt-FeO x NPs. This unique structural configuration allows for CO and O 2 diffusion through the FeO x shell with an increased exposure for CO and O 2 adsorption onto the core as well as an enhanced activation of O 2 compared with the core-shell FePt-FeO x without voids, which collectively boost the catalytic performance.