Two silica-containing materials, diatomite and waterglass, have been used as supports of nickel catalysts for edible oil hydrogenation. The active phase has been deposited following the precipitation-deposition method. The textural and structural characteristics of the supports and precursors have been studied by nitrogen sorption, scanning electron microscopy (SEM), infrared (IR) spectroscopy and X-ray powder diffraction (XRD). The thermogravimetric (TG) analyses have been carried out under hydrogen flow at different beating rates. Chemisorption of hydrogen has also been applied for precursor characterization and the metal particle size has been calculated from hydrogen adsorption isotherms at 25 degrees C. The catalysts have been tested in the soybean oil hydrogenation reaction. The differences in the textural and structural properties of the catalysts under study have not been found to reflect on their activity and selectivity. However, the use of water glass as the support is considered to be preferable, because of the lower economic cost of the catalyst, related to the elimination of the mechanical, chemical and thermal treatment of the crude diatomite. (c) 2005 Elsevier B.V. All rights reserved.