General synthesis of core–shell FeAlO_<i>x</i> nanosphere-based nanoreactors with enhanced catalytic performance

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_<i>x</i>) 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_<i>x</i> nanoreactors (<i>e.g.</i>, Pd/FeAlO_<i>x</i>, Cu/FeAlO_<i>x</i>, Mn/FeAlO_<i>x</i>) 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_<i>x</i> 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_<i>x</i>-based nanoreactors, enabling their tailored implementation in advanced organic synthesis through architecturally controlled confinement catalysis.