Effect of preparation method on the HDS performance of unsupported Y-Ni₂P catalysts

The Y-Ni₂P-T and Y-Ni₂P-L were successfully prepared by temperature programmed reduction method (T) and low temperature hypophosphite method (L), respectively. The catalysts were characterized by X-ray diffraction (XRD), N₂ adsorption specific surface area measurements (BET), CO uptake, and X-ray photoelectron spectroscopy (XPS). The effect of the rare earth yttrium (Y) on the HDS activity of catalysts prepared by different method was investigated using dibenzothiophene (DBT) as the model compound. The results show that for catalyst prepared by T method, the addition of Y can suppress the formation of the Ni₅P₄ phase and thus promote the formation of the active Ni₂P phase. The addition of Y can dramatically increase the surface area and promote the formation of smaller and highly dispersed Ni₂P particles. The DBT conversion of Y-Ni₂P-T catalyst reached 91.0%, which is 29% higher than that of bulk Ni₂P-T. For catalyst prepared by L method, the addition of Y can suppress the formation of the other impure phases. And the selectivity to BP over Y-Ni₂P-T catalyst is improved, however, the total HDS activity of the catalyst decreases slightly compared with that of Ni₂P-L.