The NH 3 -SCR activity of Al-MCM-41 modified with cerium dio xide (CeO 2 /Al-MCM-41) is investigated under simulated flue gas. X-ray diffractogram (XRD), Brun auer-Emmett-Teller (BET), and transmission electron microscopy (TEM) analyses are employed to character ize the samples. The effects of CeO 2 loading value, reaction temperatures, and individual flue gas components, i ncluding O 2 and SO 2 , on the NO conversion efficiency are investigated. The experimental results show that th e NO conversion efficiency can be significantly imp roved by CeO 2 and, at a reaction temperature of 350 ºC, the optim al loaded mass percentage of CeO 2 is 8 %. As the reaction temperature is increased from 200 to 350 ºC, NO con version efficiency increases markedly, but decrease s above 350 ºC. In addition, the presence of O 2 has positive effects on the NO conversion efficien cy, while the presence of SO 2 has inhibited effects