GAS-PHASE REACTIONS OF TRANSITION-METAL CLUSTERS

The chemical reactions of isolated clusters of transition metal atoms with small molecules will be reviewed. Reactions of iron, cobalt, and nickel clusters with hydrogen, ammonia, water, and nitrogen will be considered. Experiments which determine the uptake of adsorbate molecules vs. reagent gas pressure provide information on kinetic and equilibrium processes, as well as a measure of the number of adsorbate binding sites on a cluster's surface. More detailed, quantitative determinations of reaction rate constants often show dramatic variation of reactivity with cluster size. Equilibrium studies provide measurements of cluster-adsorbate binding energies. A knowledge of the number of adsorbate binding sites often provides information about cluster geometrical structure.