Communication in Angewandte Chemie provides evidence that Lunsford mechanism for the oxidative coupling of methane needs revision
A new communication paper by UniCat scientists Joachim Sauer, Raimund Horn, and Robert Schlögl, which is on early view in Angewandte Chemie Int. Ed. provides compelling evidence, both from computations and experiments, that the generally accepted Lunsford mechanism for the oxidative coupling of methane, needs revision.
They suggest a new mechanistic scenario for C-H bond activation on metal oxide surfaces that is based on heterolytic addition of the C-H bond (acid base reaction): The role of non-reducible oxides as catalysts for methane activation is not to provide and receive back electrons as with reducible oxide catalysts, but bringing together the reactants allowing them to exchange redox equivalents directly between themselves.
These new findings have general implications for the active site concept in heterogeneous catalysis.