Promotion of boron phosphate on the NiMoAl catalyst for hydroprocessing FCC slurry oil

Mesoporous NiMoAl catalysts with boron phosphate (BPO4) modification were synthesized through the complete liquid-phase method. X-ray diffraction (XRD) analysis evidenced the presence of BPO4-AlOOH mixed support in these BPO4-modified NiMoAl samples. The total amount of acid sites declined, but the surface acidity was strengthened by adding BPO4 into the NiMoAl catalyst. It's worth noting that the incorporation of BPO4 could increase the concentrations of Ni and Mo species on the catalyst surface and greatly improve the dispersion of (Ni)MoS2 active phases, as indicated by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) measurements. The catalytic performance of these BPO4-modified NiMoAl catalysts was investigated with the hydroprocessing of fluid catalytic cracking (FCC) slurry oil. The nitrogen-containing compounds removal from the oil was significantly enhanced with increasing the molar ratio of boron phosphate/aluminum. The NM-BPA(0.55) catalyst exhibited the best hydrodenitrogenation (HDN) activity, highlighting the significant impact of Mo sulfidation degree and the dispersion of active metals on HDN performance. The introduction of boron phosphate could also promote the hydrocracking activity of the NiMoAl catalyst, as demonstrated by SARA analysis and simulated distillation of liquid products.