Ethylene polymerization catalysts have been prepared by grafting chromium (III) nitrate onto Al/SBA-15 and Ti/SBA-15 mesoporous materials. A combination of XRD, nitrogen adsorption, TEM, and inductively coupled plasma-atomic emission spectroscopy (ICP-AES), were used to characterize the catalysts. Polymerization activity of Cr/SBA-15 catalyst is significantly improved by Al or Ti insertion to the supports. Particularly, the chromium catalyst prepared with Ti/SBA-15 support is more active than Al/SBA-15 catalyst. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013