Noble‐Metal‐Free Single‐Atom Catalysts CuAl4O7–9− for CO Oxidation by O2

Abstract The single copper atom doped clusters CuAl 4 O 7–9 − can catalyze CO oxidation by O 2 . The CuAl 4 O 7–9 − clusters are the first group of experimentally identified noble‐metal free single atom catalysts for such a prototypical reaction. The reactions were characterized by mass spectrometry and density functional theory calculations. The CuAl 4 O 9 CO − is much more reactive than CuAl 4 O 9 − in the reaction with CO to generate CO 2 . One adsorbed CO is crucial to stabilize Cu of CuAl 4 O 9 − around +I oxidation state and promote the oxidation of another CO. The widely emphasized correlation between the catalytic reactivity of CO oxidation and Cu oxidation state can be understood at the strictly molecular level. The remarkable difference between Cu catalysis and noble‐metal catalysis was discussed.