Synthesis, characterization, and catalytic performance of NiMo catalysts supported on different crystal alumina materials in the hydrodesulfurization of diesel

- Different crystal alumina were synthesized from two sources of AlCl3 and Al(NO3)3.
- The correlation between different crystal forms with HDS efficiency was discussed.
- The NiMo/δ2-Al2O3 catalyst showed the best hydrotreating performance.
- The synergy of texture property and MSI attributed to high activity of catalysts.
- HDS and HDN efficiencies followed: NiMo/δ-Al2O3 > NiMo/γ-Al2O3 > NiMo/θ-Al2O3.

A series of alumina with different crystal structures from γ-Al2O3 to θ-Al2O3 has been synthesized by precipitation method using aluminum nitrate and aluminum chloride hexahydrate, and the corresponding NiMo/Al2O3 catalysts were prepared based on above different alumina. The typical physic-chemical properties of the supports and series catalysts were characterized with XRD, BET, UV-Vis DRS, Py-IR, Raman and XPS characterization methods, and their catalytic activities were tested for FCC diesel hydrodesulfurization. The catalytic system was tested in hydrodesulfurization reactions of FCC diesel under atmospheric and high pressure (5 MPa). The NiMo/δ-Al2O3 catalyst prepared by aluminum nitrate exhibited the highest HDS and HDN efficiencies, 99.4% and 99.3% respectively, which were mainly ascribed to the concentrated pore size distribution, moderate MSI and higher degree of sulfidation.

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