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

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-FeOx nanoparticles (NPs), that exhibits notably enhanced activity and stability towards CO oxidation at relatively low temperatures (<100 °C) compared with Pt NPs. The optimized FePt-FeOx catalysts were produced by partially reducing core-shell FePt-FeOx NPs under H2 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-FeOx NPs after the post-synthesis treatment. The generation of voids, partial crystallization of the FeOx shell and increased electron density on Pt were identified as key contributors to the enhanced activity and stability towards CO oxidation in FePt-FeOx NPs. This unique structural configuration allows for CO and O2 diffusion through the FeOx shell with an increased exposure for CO and O2 adsorption onto the core as well as an enhanced activation of O2 compared with the core-shell FePt-FeOx without voids, which collectively boost the catalytic performance.

Duke Scholars

Author Miaofang Chi Thomas Lord Department of Mechanical Engineering and Materia ...