Aerobic oxidation of alkanes on icosahedron gold nanoparticle Au55

Aerobic oxidation of cyclohexane, propane, ethane, and methane to the corresponding alcohols was investigated over an Au55 gold nanoparticle with icosahedron symmetry using density functional theory. Reaction mechanisms were elucidated and activation barriers for catalytic C–H bond cleavage and corresponding alcohols’ formation were estimated. Furthermore, on the basis of the reaction rate constants calculated for realistic reaction temperatures, the relative reaction rates for each alkane hydroxylation were discussed. The catalyst selectivity was investigated for the formation of primary and secondary alcohols. All reaction mechanisms for alkane hydroxylation are compared with the catalytic dissociation of dioxygen molecule over gold nanoparticle surface, which is an important precursor reaction for aerobic oxidation. We have further investigated overoxidation reaction mechanisms leading to formation of ketones. Our results are compared with experimental findings to provide important guidelines for the tuning of catalytic reactions towards the desired products and reaction conditions.