Synthesis of Zirconium Modified Spherical Mesostructured Cellular Silica Foams and Its Hydrodesulfurization Performance for FCC Diesel

Zr modified spherical mesostructured cellular silica foams (MCFs) with different Zr contents were successfully synthesized via an incipient wetness impregnation method. The characterization results of FTIR, SEM, and SAXS indicated that zirconium was fabricated into the silicon framework; meanwhile, the parent sphere-like morphology and topological structure were retained. Additionally, BET results showed that the as-synthesized materials possessed ultralarge pore volume (1.56 cm(3)/g), large pore size (15.9 nm), and high surface area (467 m(2)/g) when the weight percentage of Zr in the support was 12.6%, demonstrating that MCFs would be an alternative support for hydrotreating catalyst. Furthermore, the corresponding supported NiMo/Zr-MCFs catalysts were well-characterized. It was found that zirconium as an electronic promoter not only facilitated the formation of NiMoO4 precursor but also enhanced the redox ability of the catalysts as well as brought Bronsted and Lewis acid sites into MCFs, which were conducive to the hydrodesulfurization (HDS) performance. Then the catalyst activities were evaluated by using FCC diesel as feedstock, in which NiMo/Zr-MCFs-6.9 catalyst (Si/Zr = 20) had the highest hydrodesulfurization (97.3%) and hydrodenitrogenation efficiencies (98.1%); correspondingly, the main reasons could be ascribed to its desirable textural property, suitable redox ability, appropriate dispersion degree of active metals, and moderate acid property.