Mechanism of methane oxidation by transition metal oxides: A cluster model study

We present a systematic survey of C-H activation over various transition metal oxides using cluster model calculations. We find that H abstraction pathway is feasible on most oxides. Our calculations suggest that when the M = O bond possesses a high polarity such as those in tungsten oxides, (2 + 2) becomes an alternative pathway. Trends and intrinsic factors that influence the activation modes are discussed. (C) 2006 Published by Elsevier B.V.