Over the past decades, extensive efforts have been devoted to modulating the textural properties, morphology and microstructure of γ-Al₂O₃, since the physiochemical properties of γ-Al₂O₃ have close correlations with the performance of hydrotreating catalysts. In this work, a spongy mesoporous γ-alumina (γ-Al₂O₃) was synthesized using Al-based metal-organic frameworks (Al-MOFs) as precursor by two-step pyrolysis, and this Al-MOF-derived γ-Al₂O₃ was used as hydrodesulfurization (HDS) catalyst support, to explore the effect of support on the HDS performance. Compared with industrial γ-Al₂O₃, the spongy alumina displayed well-developed porosity with relatively high surface area, large pore volume, and abundant weak Lewis acid sites. Based on catalyst characterization and performance evaluation, sulfurized molybdenum and cobalt molecules were able to incorporate and highly disperse into channels of the spongy mesoporous alumina, increasing the dispersion of active catalytic species. The spongy γ-Al₂O₃ was also able to enhance the diffusion efficiency and mass transfer of reactant molecules due to its improved texture properties. Therefore, the corresponding catalyst presented higher activities toward HDS of dibenzothiophene (DBT) than that from industrial alumina. The spongy mesoporous γ-alumina synthesized by Al-MOFs provides a new alternative to further develop novel γ-alumina materials with different texture and various nanoporous structures, considering the diversity of MOFs with different compositions, topological structures, and morphology.
Keywords: alumina; catalyst support; hydrodesulfurization; metal-organic frameworks; microstructure.