Methane activation by heteronuclear diatomic AuRh + cation: comparison with homonuclear Au 2 + and Rh 2

The ability to activate methane differs appreciably for different transition metals, and it is attractive to find the most suitable metal for the direct conversion of methane to value-added chemicals. Herein, we performed a comparative study on the reactions of CH with Au , AuRh and Rh cations by mass-spectrometry based experiments and DFT-based theoretical analysis. Different reactivity has been found for these cations: Au has the lowest reactivity, and it can activate methane but only produce H-Au -CH without H release; Rh has the highest reactivity, and it can produce both carbene-type Rh -CH and carbyne-type H-Rh -CH with H release; AuRh also has high reactivity to produce only AuRh-CH with H , avoiding the excessive dehydrogenation of CH . Our theoretical results demonstrate that Rh is responsible for the high reactivity, while Au leads to selectivity, which may be caused by the unique intrinsic bonding properties of the metals.