Christiaen, Anne-Claire2014-03-142014-03-141994-08-04etd-11102009-020324http://hdl.handle.net/10919/45628Water and CO adsorptions were studied over the stoichiometric and the oxygen-deficient Cu₂O(111) surfaces, using thermal desorption spectroscopy (TDS), ultraviolet photoelectron spectroscopy (UPS), and X-ray photoelectron spectroscopy (XPS). Water is the only desorbing species detected in TDS and the extent of dissociation is unaffected by the surface condition: ≃ 0.25 monolayers of water dissociate on Cu₂O(111) regardless of surface condition. The local defect environment around oxygen vacancies does not play a significant role in the activity of the Cu₂O(111) surface for the dissociation of water. CO is found to bind molecularly to the surface through the carbon atom and with a heat of adsorption of 22 kcal/mol, higher value than that of CO on Cu₂O(100) (16.7 kcal/mol). This suggests that the local geometry of adsorption sites may play an important role in the way CO binds to Cu₂O surfaces. Electronic changes upon CO adsorption and the higher heat of adsorption indicate an increased σ-donor character for CO, with some π-backbonding interactions. The local defect environment around oxygen vacancies does not appear to affect CO adsorption on Cu₂O(111) surfaces.vi, 79 leavesBTDapplication/pdfenIn CopyrightLD5655.V855 1994.C575AdsorptionCarbon dioxide -- Absorption and adsorptionCopper oxide -- Absorption and adsorptionWater -- Absorption and adsorptionAdsorption of water and carbon monoxide on Cu₂O(111) single crystal surfacesThesishttp://scholar.lib.vt.edu/theses/available/etd-11102009-020324/