Transition metal cobalt incorporated MCM-48 mesoporous molecular sieves ( CoMCM-48) with different Co contents were synthesized hydrothermally at 120 degrees C for 24 h by directly adding fluoride ions to the initial gel. The resulting materials were characterized by means of XRD, TEM, FT-IR, UV-vis, TPR and N-2 physical adsorption, respectively. The effect of various factors, such as the Si/Co molar ratio, calcination temperature and hydrothermal treatment time, on the crystalline structure and textural properties of CoMCM-48 was investigated in detail. The results show that the CoMCM-48 mesoporous materials with high specific surface area were successfully synthesized. A small amount substitution of Co for Si in MCM-48 did not significantly change the textural properties while the higher cobalt incorporated leads to decrease of the surface area and deterioration of structural regularity. Furthermore, the resulting CoMCM-48 still retained the cubic mesoporous framework even after calcination at 800 degrees C for 4 h or hydrothermal treatment at 100 degrees C for 24 h. (C) 2010 Elsevier B.V. All rights reserved.