CeO _{2– <i>x</i>} -Induced Interfacial Reconstruction of Fe ₃ O ₄ /Al ₂ O ₃ for the Formation of Cooperative Fe ⁰ –Fe ₃ O ₄ Dual Sites in Propane Dehydrogenation

Propane dehydrogenation (PDH) is a key process for propylene production, but conventional catalysts are often constrained by high cost, environmental impact, and limited stability under harsh reaction conditions. Fe-based catalysts offer a cost-effective and sustainable alternative due to their intrinsic ability to activate C-H bonds in alkanes. However, precise control over the oxidation state and coordination environment of Fe species to balance PDH activity and stability remains challenging. Herein, we develop a molten-salt-assisted synthesis strategy integrated with CeO_2-<i>x</i>-mediated interfacial engineering to finely tune the structural and electronic properties of Fe species supported on Al₂O₃. The molten salt medium enables uniform dispersion and controlled crystallization of Fe₃O₄, effectively mitigating its over-reduction during high-temperature H₂ treatment. The subsequent incorporation of CeO_2-<i>x</i> modulates the local electronic structure of Fe₃O₄, inducing a controlled partial reduction to metallic Fe⁰ and forming a well-defined Fe⁰-Fe₃O₄ dual-interface architecture. This interfacial electronic reconstruction enriches the electron density of low-valent Fe sites, facilitating efficient charge transfer during propane activation and promoting rapid propylene desorption. As a result, the optimized catalyst demonstrates accelerated PDH kinetics, high propylene selectivity, and enhanced resistance to coking. This work establishes a scalable route for constructing dual-interface active sites, providing a general design principle for low-cost, high-performance PDH catalysts.