Molecular O2 Activation over Cu(I)-Mediated CN Bond for Low Temperature CO Oxidation

The activation of molecular oxygen (O-2) is extremely crucial in heterogeneous oxidations for various industrial applications. Here, a charge-transfer complex CuTCNQ nanowire (CuTCNQ NW) array grown on the copper foam was first reported to show CO catalytic oxidation activity at a temperature below 200 degrees C with the activated O-2 as an oxidant. The molecular O-2 was energetically activated over the Cu(I)-mediated C N bond with a lower energy of -1.167 eV and preferentially reduced to O-center dot(2)- through one-electron transfer during the activation process by density functional theory calculations and electron paramagnetic resonance. The theoretical calculations indicated that the CO molecule was oxidized by the activated O-2 on the CuTCNQ NW surface via the Eley-Rideal mechanism, which had been further confirmed by in situ diffuse reflectance infrared Fourier transform spectra. These results indicated that the local bond electron-state engineering could effectively improve the molecular O-2 activation efficiency, which facilitates the low-temperature CO catalytic oxidation. The findings reported here enhance our understanding on the molecular oxygen activation pathway over metal organic nanocatalysts and provide a new avenue for rational design of novel low-cost, organic-based heterogeneous catalysts.