Iron and aluminum are required for the formation of active sites in MFI-type zeolites for benzene oxidation to phenol by nitrous oxide. We propose that the active species are extraframework Fe-Al-O species. These species produce characteristic IR bands around 1625 and 1635 cm(-1) after exposure to NO which are different from those found in Fe-substituted silicalite-1 and HZSM-5. While we only observe negligible benzene oxidation activities for these latter materials, a MFI zeolite containing Fe and Al shows good performance. Additionally, we found that postsynthesis dispersion of aluminum to Fe-substituted silicalite-1 offers an alternative preparation route to an active material. (C) 2003 Elsevier Inc. All rights reserved.