Quantum chemical description of catalytic activation of the C-H bond

Density functional theory is presented from the point of view of its applicability in modelling catalytic reactions. Reaction paths for C-H bond scission in methane interacting with metal oxide/transition metal catalytic sites for gallium oxide in zeolitic lattice and palladium or rhodium based supported catalysts are analysed. On the basis of interdependence between the electronic structure and reactivity of the bond two mechanisms for the activation of the C-H bond are described: via electrons withdrawal from bonding states (on oxide catalysts) and via election insertion to antibonding orbitals (on metals).