Mild activation of methane is highly topical in catalysis. Breaking the C-H bond in CH<sub>4</sub> is generally discussed as descriptor for the ability of a catalyst to activate methane. We aim at virtual screening of metals on active supports using first principles density functional theory (DFT) simulations to study the energies involved in methane adsorption and the activation of the C-H bond on candidate catalyst materials. This contribution presents the results of DFT studies of methane activation on ceria (111) and (110) surfaces, which are modified by 1 nm diameter metal particles of Au, Ag, Cu, Ni and Pt. The ceria surfaces are described by the well-known DFT+U approach commonly used for this oxide. We present firstly results for adsorption structures of the metals on the (111) and (110) ceria surfaces and discuss their activity in terms of oxygen vacancy formation, in particular the importance of the metal-oxide interface in enhancing the formation of O vacancies. We then compare the energies of molecular and dissociative CH<sub>4</sub> adsorption at the metal-ceria structures and use nudged elastic band (NEB) calculations to compute a reaction barrier for the breaking of the C-H bond. The results are discussed in terms of the structure and the reducibility of the metal-ceria systems and we compare with previous work of methane activation on cation-doped ceria.

Methane activation on ceria surfaces modified with metal nanoparticles

249th National Meeting (2015)

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