DFG Research Grant: Mixed Metal Oxide Clusters: Model Systems for Catalytically Active Materials

We propose to combine state-of-the-art mass spectrometric and spectroscopic experiments with quantum chemical calculations to ultimately gain molecular-level insights into C-H bond activation, in general, and the mechanism of H-atom transfer operating in supported metal oxide catalysts in the context of proton-coupled electron transfer, in particular. The structure and reactivity of isolated, binary and ternary metal oxide clusters, like [MAl7O12]+ (M=Fe, Co, Cu), M2AlO4+ (M=Co, Fe) or MCoAlO4+ (M= Al, Ti, Mn, Fe, Co, Ni, Cu, Zn), which serve as gas phase models for active sites in solid catalysts, will be studied. Structures of reactants as well as products will be characterized at variable temperature using infrared photodissociation spectroscopy combined with density functional theory calculations. In critical cases multi-reference wavefunction calculations will be performed. We will focus on the stability of oxyl radicals in the vicinity of transition metal centers relative to the isomeric metal oxo species and examine their reactivity towards small hydrocarbons, in particular methane, as well as water.