General synthesis of core-shell FeAlOx nanospheres based nanoreactors with enhanced catalytic performance

Abstract

Rationally designing and fabricating high-performance core-shell nanostructures for catalytic organic synthesis is significant yet challenging. Here, we report a solvothermal/calcination strategy to prepare novel core-shell iron-aluminum oxides (FeAlOx) nanosphere-based nanoreactors incorporating active heterometals (AHM = Pd, Cu, or Mn). Leveraging the synergistic benefits of their unique core-shell structure, high specific surface area (178 m²·g⁻¹), and well-dispersed heterometallic active sites, AHM/FeAlOx nanoreactors (e.g., Pd/FeAlOx, Cu/FeAlOx, Mn/FeAlOx) demonstrate outstanding catalytic performance in organic reactions such as 4-nitrophenol reduction, 2,4-dinitroaniline reduction, and benzyl alcohol selective oxidation. Notably, the Pd/FeAlOx nanoreactor achieves an unprecedented average turnover frequency of 165.8 min⁻¹ in 4-nitrophenol reduction, 8-fold higher than benchmark metal oxide-supported catalysts (typically 0.01-20.4 min⁻¹), while maintaining over 95% activity after 10 catalytic cycles. These findings establish a versatile platform for the rational design principles and scalable synthesis protocols of FeAlOx-based nanoreactors, enabling their tailored implementation in advanced organic synthesis through architecturally controlled confinement catalysis.