Zeolite beta synthesized with acid-treated metakaolin and its application in diesel hydrodesulfurization

A new type of zeolite beta (denoted as MB) with multi-pore system was synthesized by using in situ synthesized method from kaolin mineral in this study. NiW/Al2O3–MB and NiW/TiO2–Al2O3–MB catalysts were prepared and the hydrodesulfurization (HDS) activities of these catalysts were evaluated with FCC diesel feed. The samples were characterized by N2 physisorption, XRD, SEM, TPR, FT-IR spectroscopy of pyridine adsorption, HRTEM and XPS techniques. The HDS results showed that the MB-containing catalyst exhibited much higher HDS conversion (98.7%) than that of NiW/γ-Al2O3 (97.5%). The incorporation of TiO2 into the composite supports further increased the HDS conversion (99.3%) of NiW/TiO2–Al2O3–MB. The higher HDS activity was mainly associated with the appropriate ratio of B/L (Brönsted acid/Lewis acid) and the enhanced hydrogenation activity.