Catalytic CO Oxidation by O2 Mediated with Single Gold Atom Doped Titanium Oxide Cluster Anions AuTi2O4-6-

Gas-phase studies on catalytic CO oxidation by O-2 mediated with gold-containing heteronuclear metal oxide clusters are vital to obtain the structure reactivity relationship of supported gold catalysts, while it is challenging to trigger the reactivity of clusters with closed-shell electronic structure in O-2 activation. Herein, we identified that CO oxidation by O-2 can be catalyzed by the AuTi2O(4)- 6 clusters, among which AuTi2O(4) with closed-shell electronic structure can effectively activate O-2. The reactions were characterized by mass spectrometry and quantum chemical calculations. Theoretical calculations showed that in the initial stage of O2 activation, the Ti2O(4) moiety in AuTi2O(4) contributes dominantly to activate O-2 into superoxide (O2 center dot) without participation of the Au atom. In subsequent steps, the intimate charge transfer interaction between Au and the Ti2O(4) moiety drives the direct dissociation of the O-2 unit.