![]() We present here a study of gas-phase reactivity of cobalt sulfide cluster anions ComSn(-) with molecular oxygen. The steric protection due to the peripherally bonded Ag atoms greatly enhances the selectivity of the V-Ag bimetallic oxide clusters with respect to the corresponding pure vanadium oxide systems. The reactivity can be well-tuned gradually by controlling the number of Ag atoms. The doped Ag atoms with a valence state of +1 are highly dispersed at the periphery of the V(x)Ag(y)O(z)(+) cluster ions. The reaction mechanisms of V(2)Ag(2)O(6)(+) +C(2)H(6) are also given. DFT calculations are performed to study the structures, bonding, and reactivity. Hydrogen atom abstraction (HAA) reactions are identified over VAgO(3)(+), V(2)Ag(2)O(6)(+), V(2)Ag(4)O(7)(+), V(3)AgO(8)(+), V(3)Ag(3)O(9)(+), and V(4)Ag(2)O(11)(+) ions, in which the oxygen-centered radicals terminally bonded on V atoms are active sites for the facile HAA reactions. A reflectron time of flight (Re-TOF) mass spectrometer is used to detect the cluster distribution before and after the reactions. Vanadium-silver bimetallic oxide cluster ions (V(x)Ag(y)O(z)(+) x=1-4, y=1-4, z=3-11) are produced by laser ablation and reacted with ethane in a fast-flow reactor. This is consistent with the CID experiments. Density functional theory calculations indicate that oxidative and nonoxidative adsorption of CO takes place over Zr(3)O(7)(-) and Zr(3)O(7)(+), respectively. Loss of CO and CO(2) is observed upon the collision of the helium beam with Zr(x)O(y)CO(+) and Zr(x)O(2x+1)CO(-), respectively. The fragment ions from collision-induced dissociation (CID) are detected by a secondary TOF-MS. To study how the CO molecule is adsorbed on the clusters, the Zr(x)O(y)CO(±) products are mass-selected by a time-of-flight mass spectrometer (TOF-MS) and collided with a crossed helium beam. Zirconium oxide cluster cations and anions are produced by laser ablation and reacted with CO in a fast flow reactor.
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