Nanosized HY zeolite-alumina composite support for hydrodesulfurization of FCC diesel

A series of hydrodesulfurization (HDS) NiMo catalysts supported on Al2O3-NY (denoted as ANY) composites with various amounts of nanosized H-type Y zeolite (denoted as NY) were prepared. The samples were characterized by XRD, BET, TPD, TPR, HRTEM, and FT-IR spectroscopy of pyridine adsorption. The characterization results showed that, compared with NiMo/Al2O3, the addition of NY reduced the Metal-support interaction and made the MoS2 stacking degree higher, slabs shorter and dispersion of edge and corner Mo atoms bigger. The addition of NY also enhanced the overall acidity and the ratio of Brönsted acid to Lewis acid of these catalysts. The fluidized catalytic cracking (FCC) diesel HDS activity was increased with the addition of NY in these catalysts compared with NiMo/Al2O3 catalysts. The optimal NY content was found to be 20 wt% in ANY composite support. The highest HDS activity of NiMo/ANY20 was attributed to the synergy of hydrogenation activity, acid amount and textural properties.