NiMoW-O mixed oxide was obtained by calcination of the phi y layered precursor (NH4)Ni2OH(H2O)(MoO4)(2) (NiMoW-L). Unsupported catalysts were obtained from porous NiMoW-O activated ex-situ under a H2S/H-2 (15% v/v) mixture at temperatures in the range of 673-823 K. Activation temperature was crucial in catalytic activity for dibenzothiophene (DBT) hydrodesulfurization (HDS). The best temperature of activation for the trimetallic oxide was in the upper limit, with DBT conversion of 98%. X-ray diffraction (XRD), confirmed the formation of phi y, alpha oxide phase and metal sulfided phases. Hydrogen temperature-programmed reduction (H-2-TPR) provided useful information about the oxidation states of metallic species for NiMoW-O, which was related to the sulfidation step and the catalytic activity in HDS reaction. Sulfided catalysts were also characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Additional characterization was carried out using BET surface area and elemental analysis. All catalysts were tested in the HDS of DBT at 593 K and 5.5 MPa. The results indicated that the activity of the catalysts depended on the activation temperature, where the NiMoWS-823 catalyst presented the highest activity and hydrogenation capacity with values equal to 98% and 5.0, respectively. (C) 2014 Elsevier Ltd. All rights reserved.