Highly active MCM-41 supported nickel phosphide catalysts for hydrodesulfurization (HDS) were synthesized by two different phosphorus sources

in which the surface of Ni

2

P catalysts were modified by air instead of being passivated by O

2

/N

2

mixture. In addition

the catalysts need not be activated with flowing H

2

(30 ml·min

-1

) at 500℃ for 2 h prior to reaction as traditional method. X-ray diffraction (XRD)

X-ray photoelectro spectroscopy (XPS)

N

2

-adsorption specific surface area measurements and CO chemisorption were used to characterize the resulting catalysts. The effect of modification with air on the surface of the catalysts for HDS performance was investigated. Results showed that the surface modification with air can promote the formation of smaller Ni

2

P particles and more active Ni sites on surface of catalysts. At 3.0 MPa and 613 K

the dibenzothiophene (DBT) conversion of the catalysts modified with air was 98.7%

which was 7.1% higher than that of catalyst passivated by O

2

/N

2

mixture. The higher activities of Ni

2

P(x)/M41-O catalysts can be

attributed to the smaller Ni

2

P particles sizes and the increased hydrogen dissociation activity due to the surface modification.