CO ADSORPTION ON CLEAN AND ATOMIC-LAYER-CU-COVERED ZNO(10(1)OVER-BAR-0) SURFACES

The adsorption at room temperature of CO on clean and atomic-layer-Cu- covered ZnO(101BAR0) surfaces was studied by temperature-programmed de sorption (TPD). Submonolayer amounts of Cu on the surface enhance the ability of ZnO to absorb CO drastically. A small amount of CO2 desorbe d from the surface as a result of CO reaction with surface oxygen. A d esorption order of 2 and a desorption activation energy of about 60 kJ /mol were obtained for CO desorption from the Cu-covered ZnO(101BAR0) surface, which is in good agreement with the binding energy of CO adso rbed on Cu(100) surfaces.