CO Oxidation by Neutral Gold-Vanadium Oxide Clusters

Oxidation of CO by gas-phase atomic clusters is being actively studied to understand the molecular-level mechanisms of heterogeneous CO oxidation over related catalytic surfaces. However, it is experimentally challenging to study CO oxidation by neutral heteronuclear metal oxide clusters because of the difficulty of cluster ionization and detection without fragmentation. Herein, the neutral AuVO_2-4 clusters were experimentally generated and their reactions with CO and O₂ were studied. The experimental results showed that CO adsorption is the dominant channel on the interactions of AuVO₄ and AuVO₃ with CO, and AuVO₂ can pick up an O₂ molecule to generate AuVO₄. Theoretical studies indicated that the oxidation of the trapped CO in AuVO_3,4CO into CO₂ is exothermic while the reaction barriers have to be overcome at the elevated temperatures. A catalytic cycle for CO oxidation by AuVO_2-4 is proposed.