Silica-supported nickel phosphide particles with high dispersion were obtained by treating nickel metal particles on a support with 10% PH3/H-2. Because the phosphidation occurred at relatively low temperature, the small nickel phosphide particles had the same size as the metal particles, and this size was maintained. The resulting catalysts were characterized by CO and O-2 chemisorption, XRD, and P-31 MAS NMR spectroscopy. The influence of the nickel source on the metal dispersion of the catalysts was investigated. The resulting silica-supported nickel phosphide catalysts proved to be very active in the hydrodesulfurization of dibenzothiophene and the hydrodenitrogenation of o-methylaniline in the presence and absence of H2S. (c) 2005 Elsevier Inc. All rights reserved.