Cooperative desorption of H₂O and CO from photo-excited cobalt oxide clusters: The evidence of photo-catalytic coupling

The cooperative desorption of H₂O and CO with 100% selectivity from the co-adsorbed cobalt oxide clusters Co_xO_yH₂OCO⁺ [(x,y) = (3,3), (5,7), (6,9), and (9,12)] upon photo excitation at 355 nm was identified by mass spectrometry. In contrast, the sole desorption of CO dominated the mass spectra of Co₃O₃H₂OCO⁺ upon collisional excitation by Xe at a wide range of center-of-mass collisional energies. The experiments and further kinetic modeling proposed the photo-catalytic coupling of H₂O and CO on the cobalt oxide clusters. Combined with theoretical studies, a mechanism for the photo-catalytic coupling of dissociatively adsorbed H₂O and CO is proposed.