DFT investigations on AuVO3+, a barrier-free catalyst for oxidation of CO with O2

- A single-atom, barrier-free catalyst for CO oxidation is investigated.
- The single Au atom acts as the preferred CO trapper.
- The single Au atom acts as the electron reservoir for both CO oxidation and O2 activation.

As an outstanding catalyst for CO oxidation at low temperatures, highly dispersed gold on metal oxides supports has long been the hot topic. And recently single-atom catalysts have attracted great interest. Thus here catalytic oxidation of CO with AuVO3+ was investigated with density functional theory calculations. The whole catalytic cycles can proceed naturally via the following processes: (i) AuVO3+ is subsequently reduced to AuVO2+ and AuVO+ under successive attacks from CO molecules trapped at the Au-site; (ii) AuVO+ can be oxidized by O2 trapped at the V-site, and the intermediate can be fully activated to regenerate AuVO3+; (iii) while for AuVO2+, successive attacks from a O2 molecule trapped at the V-site and a CO molecule trapped at the Au-site are required to finally regenerate AuVO3+. The single Au atom acts as both the favorable CO trapper and the electron reservoir during CO oxidation and O2 activation processes.

Single-atom, barrier-free catalyst: The cation AuVO3+ is investigated for the oxidation of CO with O2 with DFT calculations. Successive removal of two 'lattice' oxygen atoms and the subsequent regeneration can all proceed barrier-free. The single Au atom acts not only as the stronger CO trapper but also an electron reservoir in both the CO oxidation and the O2 activation processes.38