Ti- and Al-containing MCM-41 materials, with a Si/ M (M = Al(Ti)) molar ratio equal to 8, were used as supports for preparing NiMo HDS catalysts. On the surface of the MCM-41 based catalysts, agglomerations of the Mo oxo-species were observed. The incorporation of Ti and Al into the silica structure visibly enhanced the interactions between NiMo oxides phase and the mesoporous support. The results of 4,6-DMDBT HDS showed that the NiMo catalyst supported on TiMCM-41 was more efficient than that supported on Ti-free samples. From the distribution of 4,6-DMDBT HDS products we can conclude that over catalysts containing TiMCM-41 and SiMCM-41 the hydrogenation of DMBPh to MCHT occurs. (C) 2011 Elsevier B.V. All rights reserved.