In the present investigation, Ti-HMS materials with variable Si/Ti molar ratios of 20, 40, and 80 were synthesized and employed as supports for Ni-promoted 12-molybdophosphoric acid (NiPMo) catalysts. The effect of the Ti ions and the immobilization of 12-molybdophosphoric acids on mesoporous materials were studied. Supports and catalysts were thoroughly characterized by using XRD, N-2 adsorption analysis, FT-IR, Raman, TPR, DRIFT, SEM and TEM techniques. Results from XRD and IR measurements confirm the hexagonally ordered mesoporous structure and incorporation of Ti into the HMS support, respectively. It was found that incorporation of Ti and presence of HPA into the HMS structure increased the reducibility of the catalysts. Hydrotreating experiments were conducted using coker light gas oil under industrial conditions of temperature, pressure, LHSV, and gas to oil ratio of 330-370 degrees C, 8.8 MPa, 1 h(-1), and 600 mL/mL, respectively. It was found that NiPMo catalysts prepared from heteropolyacids showed better performance in HDS and HDN of coker light gas oil (CLGO) than the NiMo catalysts prepared by conventional method using ammonium hepta molybdate (AHM) as Mo source. Crown Copyright (c) 2010 Published by Elsevier B.V. All rights reserved.