Kinetic and Mechanistic Studies of Room-Temperature Methane Activation Mediated by Free Tantalum Clusters

The selective transformation of methane, the most abundant natural gas, is an important task that requires C-H bond activation. Unraveling molecular-level mechanistics of such complex processes is facilitated in gas-phase studies of metal clusters, which serve as model catalysts. In our setup, the combination of a laser vaporization cluster source, a cryogenic ring electrode ion trap and a reflectron time-of-flight mass spectrometer is used to analyze reactions of size-selected metal clusters under well-defined multi-collision conditions. Tantalum clusters bring about dihydrogen elimination from methane and the cluster size drastically affects the reaction efficiency and final products. In addition to these size effects, changes in the reaction mechanism as well as potential C-C and C-O bond formation will be discussed.