Mesoporosity in ETS-10 titanosilicate was generated by postsynthesis treatment with hydrogen peroxide under microwave irradiation, resulting in an increased external surface area of the materials. The influence of mesopore content, external surface area, proton-exchange conditions, and solvent on the activity of the modified ETS-10 in the Beckmann rearrangement of cyclohexanone oxime to e-caprolactam under vapor-phase conditions was investigated. Protonated mesoporous ETS-10 was catalytically active and demonstrated improved performance with increasing external surface area. (c) 2007 Elsevier Inc. All rights reserved.