Low-Energy Electron Diffraction, Auger Electron Spectroscopy and Thermal Desorption Studies of Chemisorbed CO and O2 on the (111) and Stepped (6(111)x(100)) Iridium Surfaces.
CALIFORNIA UNIV BERKELEY
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The adsorption of CO, O2 and H2O was studied on both 111 and 6111x100 crystal faces of iridium. The techniques used are LEED, AES and thermal desorption. Marked differences were found in surface structures and heats of adsorption on these crystal faces. Oxygen is adsorbed in a single bond state on the 111 face. On the stepped iridium surface an additional bonding state with a higher heat of adsorption was detected which can be attributed to oxygen adsorbed at steps. On both 111 and stepped iridium crystal faces the adsorption of oxygen at room temperature produced a 2x1 surface structure. The influence of steps on the adsorption behavior of CO and O2 on iridium and the correlation with the results found previously on the same platinum crystal faces are discussed.
- Atomic and Molecular Physics and Spectroscopy