Chemistry with Methane: Concepts Rather than Recipes

Abstract

Four seemingly simple transformations related to the chemistry of methane will be addressed from mechanistic and conceptual points of view: 1) metal-mediated dehydrogenation to form metal carbene complexes, 2) the hydrogen-atom abstraction step in the oxidative dimerization of methane, 3) the mechanisms of the CH(4)→CH(3)OH conversion, and 4) the initial bond scission (C-H vs. O-H) as well as the rate-limiting step in the selective CH(3)OH→CH(2)O oxidation. State-of-the-art gas-phase experiments, in conjunction with electronic-structure calculations, permit identification of the elementary reactions at a molecular level and thus allow us to unravel detailed mechanistic aspects. Where appropriate, these results are compared with findings from related studies in solution or on surfaces.

Catalysis with Supported Size-selected Pt Clusters

“…Last, the carbon formation will be subject to further studies to better understand catalyst deactivation during hydrogenation. In a next step, the activation of methane, as future potential energy feedstock [65,357,234,358,359,360] will be probed on clusters of different metals.…”

Methane Activation by Heterogeneous Catalysis

“…The identity of the active site for methane activation on OCM catalysts remains open. According to Schwarz [68], oxygen centered radicals on metal oxides are active for homolytic hydrogen abstraction from methane (Eq. 22).…”

Fenton chemistry at aqueous interfaces

“…What is at stake is how the coordination sphere of Fe 2+ (39)(40)(41)(42)(43)(44)(45)(46) under specific conditions affects the competition between the one-electron transfer producing ·OH radicals (the Haber-Weiss mechanism) (47), reaction R1, and the two-electron oxidation via O-atom transfer (the Bray-Gorin mechanism) into Fe IV O…”