Titanium-Modified TUD-1 Mesoporous Catalysts for the Hydrotreatment of FCC Diesel

摘要

Titanium-modified pure aluminum-based TUD-1 (TiAT) mesoporous material with a highly active three-dimensional was successfully synthesized by using tetraethylene glycol (TEG) as a template through sol gel method. The series catalysts were characterized by X-ray diffraction (XRD), N-2 adsorption-desorption, Raman, pyrolysis-infrared (Py-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) technologies. The characterization results indicated that Ti was incorporated into the TUD-1. In addition, the synthesized materials had large pore size (6.4 nm), high surface area (394.0 m(2)/g), and large pore volume (0.83 cm(3)/g). It was shown that Ti acting as an electronic promoter could promote the formation of Mo7O246- precursors and more type II NiMoS phases. Furthermore, Ti incorporation could bring more Bronsted and Lewis acids into the catalysts, which were beneficial to improve the hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) reaction processes. Catalytic performances of diffierent catalysts were estimated in a high-pressure hydrotreating microreactor using FCC diesel as feedstock; moreover, the catalyst of NiMo/TiAT-25 exhibit the highest HDS (97.3%) and (HDN) (99.1%) efficiencies of FCC diesel, respectively, and the highest HDS (97.4%) of DBT, since NiMo/TiAT-25 possessed suitable acidity, pore structure, reducibility, and degree of sulfidation.