CO Oxidation Promoted by Gold Atoms Loosely Attached in AuFeO<sub>3</sub><sup>–</sup> Cluster Anions YuanZhen LiXiao-Na HeSheng-Gui 2015 Time-of-flight mass spectrometry experiment shows that upon the interactions with carbon monoxide, the mass-selected AuFeO<sub>3</sub><sup>–</sup> oxide cluster anions can evaporate neutral gold atoms in a hexapole collision cell and oxidize CO into CO<sub>2</sub> in an ion trap reactor. The computational studies identify that the gold atom is loosely attached in the AuFeO<sub>3</sub><sup>–</sup> cluster, and the different reaction channels can be attributed to different cluster velocities. The structure of the AuFeO<sub>3</sub><sup>–</sup> cluster is very flexible, and the approach of CO induces significant geometrical and electronic structure changes of AuFeO<sub>3</sub><sup>–</sup>, which facilitates the exposure of the positively charged gold atom to trap and oxidize CO. The CO oxidation by the AuFeO<sub>3</sub><sup>–</sup> cluster follows the Au-assisted Mars–van Krevelen mechanism, in which the direct participation of the surface lattice oxygen (O<sup>2–</sup>) is proposed.