Abstract:
The Ni
2P-L, Pr-Ni
2P-L and Ce-Ni
2P-L catalysts were prepared by thermal decomposition of hypophosphites and reduced at low temperature; they were characterized by X-ray diffraction (XRD), temperature programmed reduction with hydrogen (H
2-TPR), nitrogen physisorption, CO adsorption, and X-ray photoelectron spectroscopy (XPS). The effect of the rare earth praseodymium (Pr) or cerium (Ce) elements on the activity of Ni
2P-L catalyst in hydrodesulfurization (HDS) was investigated with dibenzothiophene (DBT) as a model compound. The results indicated that the addition of Pr and Ce can suppress the formation of Ni
5P
4 and other mixed crystal phases and then promote the formation of Ni
2P phase. After adding the rare earth metals, the selectivity to BP over the Ni
2P catalyst is enhanced greatly, though the total HDS activity is decreased slightly.