Conversion of Methane at Room Temperature Mediated by the Ta–Ta σ-Bond

Metal-metal bonds constitute an important type of reactive centers for chemical transformation; however, the availability of active metal-metal bonds being capable of converting methane under mild conditions, the holy grail in catalysis, remains a serious challenge. Herein, benefiting from the systematic investigation of 36 metal clusters of tantalum by using mass spectrometric experiments complemented with quantum chemical calculations, the dehydrogenation of methane at room temperature was successfully achieved by 18 cluster species featuring σ-bonding electrons localized in single naked Ta-Ta centers. In sharp contrast, the other 18 remaining clusters, either without naked Ta-Ta σ-bond or with σ-bonding electrons delocalized over multiple Ta-Ta centers only exhibit molecular CH