Metal-mediated catalysis in the gas phase: A review

This review summarizes a variety of experimentally identified gas-phase catalytic cycles, all of which are mediated by atomic metal ions, bare metal clusters, metal oxide clusters or metal complexes. Emphasis is placed on the latest advances in the unique catalytic reactivity of cluster-confined single noble metal atoms. The cycles discussed in this paper cover a wide range of inorganic and organic molecules. The use of start-of-the-art mass spectrometric instrumentation in conjunction with quantum chemistry calculations is also reported, as these techniques have determined the mechanistic details of the elementary steps of such catalytic cycles. The important role of gas-phase data in guiding the rational design of better-performing catalysts in related condensed phase reactions is also examined. In particular, this review focuses on the following three topics: (1) the catalytic oxidation of carbon monoxide, (2) the catalytic functionalization of methane, and (3) catalytic decarboxylation.