CO Oxidation Promoted by the Gold Dimer in Au2VO3- and Au2VO4- Clusters

摘要

Investigations on the reactivity of atomic clusters have led to the identification of the elementary steps involved in catalytic CO oxidation, a prototypical reaction in heterogeneous catalysis. The atomic oxygen species O- and O2- bonded to early-transition-metal oxide clusters have been shown to oxidize CO. This study reports that when an Au-2 dimer is incorporated within the cluster, the molecular oxygen species O-2(2-) bonded to vanadium can be activated to oxidize CO under thermal collision conditions. The gold dimer was doped into Au2VO4- cluster ions which then reacted with CO in an ion-trap reactor to produce Au2VO3- and then Au2VO2-. The dynamic nature of gold in terms of electron storage and release promotes CO oxidation and O-O bond reduction. The oxidation of CO by atomic clusters in this study parallels similar behavior reported for the oxidation of CO by supported gold catalysts.