Preparation and hydrodesulfurization performance of nimo sulfide catalysts supported on mesoporous CeO₂ ⁻ Al₂O₃

To address the restricted catalytic activity caused by strong metal-support interaction (MSI) in conventional Al 2 O 3 -based systems, a novel NiMo-CeO 2 -Al 2 O 3 catalyst was synthesized via solvent evaporation-induced self-assembly and incipient wetness impregnation. Structural and acidic properties of CeO 2 -doped Al 2 O 3 supports were systematically characterized by XRD, N 2 physisorption, and FT-IR. The 5% CeO 2- Al 2 O 3 composite exhibited an ordered mesoporous structure with a high surface area (246 m²/g) and uniform pore size (9.25 nm). FT-IR analysis revealed intensified hydroxyl vibrations, indicating reduced MSI through CeO 2 incorporation. In hydrodesulfurization (HDS) tests using dibenzothiophene (DBT), the NiMo-5%CeO 2 -Al 2 O 3 catalyst achieved a 1.43-fold higher DBT conversion than conventional NiMo-Al 2 O 3 , accompanied by a lower apparent activation energy (88 kJ/mol). Mechanistic studies attributed this enhancement to the formation of Ce-O-Al bonds, which optimized active metal dispersion and promoted the direct desulfurization (DDS) pathway. The ordered mesostructure facilitated reactant diffusion, while CeO 2 ’s electronic modulation suppressed metal sintering. These synergistic effects collectively improved sulfur removal efficiency without compromising structural stability. This work demonstrates that rational design of CeO 2 -Al 2 O 3 interfaces effectively balances metal-carrier interactions and catalytic performance, providing a scalable strategy for developing advanced HDS catalysts with industrial applicability.