Influence of rare earth metal modification on hydrodesulfurization activity of supported Ni2P/M41 catalysts

Key words:  hydrodesulfurization  modification  rare earth metals  supported catalyst

Abstract:

It is an important way to achieve deep desulfurization of oil products for the development of efficient hydrodesulfurization (HDS) catalysts. A series of rare earth metals (Nd, La, Ce, Pr, Y) modified nickel phosphide catalysts (X-Ni₂P/M41) were prepared by a temperature programmed reduction method. The structure and chemical composition of catalysts were analysed by X-ray diffraction (XRD), N₂ adsorption-desorption, CO uptake and X-ray photoelectron spectroscopy (XPS). The effect of rare earth metals on the hydrodesulfurization performance of Ni₂P / M41 catalyst was investigated by using dibenzothiophene as a model compound. The results show that the rare earth metals can affect the distribution of Ni₂P crystalline on the surface of M41 and promote the formation of the active Ni₂P crystalline phase at different levels. La and Pr can significantly increase the HDS activity of supported Ni₂P/M41 catalysts, while the addition of Nd, Ce, and Y could slightly reduces its activity. Especially, Pr-Ni₂P/M41 presents the optimal HDS preformance. After 6 h of reaction, its desulfurization conversion reaches 92.6%, which is 15.1% higher than that of the unmodified Ni₂P/M41 catalyst.