Abstract: Temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS) were used to characterize a series of NiMo/Al2O3 catalysts prepared by impregnation method. The interaction between active component and carrier and the effect of phosphorus on the interaction of NiMo/Al2O3 catalysts was studied. Test results indicated that various interactions (week and strong) among active components Ni/Mo species and γ-Al2O3 carrier existed, and the interaction also happened between Ni species and Mo species. Adding phosphorus into NiMo/Al2O3 catalyst could weaken the interaction between active component and carrier. Catalysts samples prior and post to sulfurization were analyzed by XPS and the existence of Al species interacted with active component was verified. Furthermore, Al2p binding energies in various samples were determined, as well as the effect of phosphorus on the interaction between Mo species and the carrier could be determined quantitatively by the XPS results of sulfidized samples.

Key words: phosphorus, support, active component, interaction, Al2p binding energy