Ni 2 P/SiO 2 , MoP/SiO 2 , and NiMoP/SiO 2 with different Ni/Mo molar ratios were prepared by temperatureprogrammed reduction (TPR). Their structural properties were characterized by N 2 sorption, X-ray diffraction (XRD), CO chemisorption, X-ray photoelectron spectroscopy (XPS), H 2 temperature-programmed desorption (H 2 -TPD), and NH 3 temperatureprogrammed desorption (NH 3 -TPD). Their performances for the hydrodeoxygenation (HDO) of anisole were tested in a fixed-bed reactor. It was found that there were mainly three reactions that occurred during the HDO, i.e., the demethylation of anisole, the hydrogenolysis of phenol, and the hydrogenation of benzene. The HDO activities decreased in the sequence of Ni 2 P/SiO 2 > NiMoP/SiO 2 > MoP/SiO 2 . The NiMoP/SiO 2 catalysts with larger Ni/Mo ratios had higher activities. In the phosphides, the Ni δþ and Mo δþ sites bearing small positive charges acted not only as Lewis acid sites for the demethylation but also as metal sites for the hydrogenolysis and hydrogenation. The Ni δþ site was more active than the Mo δþ site, and there was no synergy between the Ni δþ and Mo δþ sites. The superior activity of Ni 2 P to that of MoP is attributed to the higher d electron density in Ni 2 P. PO-H groups, which acted as Brønsted sites and provided active hydrogen species, had less activity for the three reactions compared to the metal sites. In comparison to a conventional NiMo/γ-Al 2 O 3 catalyst, the Ni phosphide-containing catalysts had much higher activities. The catalyst deactivation due to water was preliminarily discussed. The oxidation of phosphide by water might lead to the formation of metal oxide and/or phosphate, leading to the catalyst deactivation. The high stability of Ni 2 P/SiO 2 may be related to the ligand effect of P that lowers the electron density of Ni and inhibits the Ni-O combination.

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A series of phosphorus (P) modified HZSM-5 catalysts were prepared and characterized with various techniques. These catalysts were used in dehydration of ethanol to ethylene at different temperatures. It was found that not all the P-modified catalysts favor this reaction at high temperatures. Over the catalyst with 3.4 wt% P, the main product is ethylene at 573-713 K, due to the presence of weak acid sites after P modification. When the P loading is below 3.4 wt%, ethylene and higher hydrocarbons are observed at high temperatures. As P content is above 3.4 wt%, higher reaction temperature is necessary for ethanol dehydration to ethylene.

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