Catalytic CO Oxidation by O 2 Mediated by Noble‐Metal‐Free Cluster Anions Cu 2 VO 3 – 5 −

Catalytic CO oxidation by molecular O 2 is an important model reaction in both the condensed phase and gas‐phase studies. Available gas‐phase studies indicate that noble metal is indispensable in catalytic CO oxidation by O 2 under thermal collision conditions. Herein, we identified the first example of noble‐metal‐free heteronuclear oxide cluster catalysts, the copper–vanadium bimetallic oxide clusters Cu 2 VO 3–5 − for CO oxidation by O 2 . The reactions were characterized by mass spectrometry, photoelectron spectroscopy, and density functional calculations. The dynamic nature of the Cu−Cu unit in terms of the electron storage and release is the driving force to promote CO oxidation and O 2 activation during the catalysis.