Generation of active oxygen species on solid surfaces. Opportunity for novel oxidation technologies over zeolites

Generation of surface oxygen species and their role in partial oxidation reactions catalyzed by metal oxides are discussed. Main attention is paid to a new concept related to a recent discovery of remarkable ability of Fe complexes stabilized in a ZSM-5 matrix to generate a new form of surface oxygen (alpha-oxygen) from N2O. At room temperature, alpha-oxygen exhibits a high reactivity typical for the active oxygen of monooxygenases, and mimics its unique ability to perform selective oxidation of hydrocarbons. This opens new opportunity for creating novel technologies based on biomimetic strategy. A process of direct oxidation of benzene to phenol, recently demonstrated by Solutia on a pilot plant scale, is evidence of great potential of this approach. (C) 1998 Elsevier Science B.V. All rights reserved.