Metal carbonyl precursors are used to synthesize structurally unique oxide-supported organometallic and metallic catalysts including robust analogues of stable molecular metal-cluster anions and metal aggregates formed from them by removal of the carbonyl ligands. The effort concentrates on osmium, iridium, and platinum on magnesia support. Structures and stabilities of the supported species are characterized. The more stable of these aggregates are tested for catalytic activity. This effort is designed to bridge the gap between metal complexes and coordination cluster behavior (a branch of chemistry with a voluminous literature) and the behavior of supported metal catalysts (the type preferred in industrial applications). This should improve our understanding of the sensitivity of catalysis to metal structure and metal-support interactions and be a major advance in the design of practical catalysts.
