General synthesis of core–shell FeAlOx nanosphere-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 oxide (FeAlO_x) 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/FeAlO_x nanoreactors (e.g., Pd/FeAlO_x, Cu/FeAlO_x, Mn/FeAlO_x) demonstrate outstanding catalytic performance in organic reactions such as 4-nitrophenol reduction, 2,4-dinitroaniline reduction, and benzyl alcohol selective oxidation. Notably, the Pd/FeAlO_x nanoreactor achieves an unprecedented average turnover frequency of 165.8 min⁻¹ in 4-nitrophenol reduction, 8-fold higher than those of benchmark metal oxide-supported catalysts (typically 0.01–20.4 min⁻¹), while maintaining over 95% activity after 11 catalytic cycles. These findings establish a versatile platform for rational design principles and scalable synthesis protocols for FeAlO_x-based nanoreactors, enabling their tailored implementation in advanced organic synthesis through architecturally controlled confinement catalysis.