Adsorption of carbon dioxide on Cu(110) and on hydrogen and oxygen coveredCu(110) surfaces

The interaction of CO2 with a clean Cu(110) surface and with pre-adsorbed o xygen and hydrogen on this surface has been studied in ultra-high vacuum at temperatures between 20 and 500 K with temperature programmed thermal deso rption, low-energy electron diffraction, Auger electron spectroscopy, high- resolution electron energy loss spectroscopy and work function change measu rements. CO2 adsorbs only molecularly on the clean and on the hydrogen(1x2) and oxygen(2x1) reconstructed Cu(110) surface, respectively. The initial s ticking probability of CO2 is not affected by co-adsorption of oxygen or hy drogen, although the CO2 adsorption is energetically stabilised in this cas e by 1.3 and 5.4 kJ mol(-1), respectively. On clean Cu(110), the isosteric heat of adsorption rises with coverage from similar to 13 to 25 kJ mol(-1) at saturation. High-resolution electron energy loss spectroscopy suggests t hat the isolated carbon dioxide molecule is adsorbed in a linear configurat ion on the clean and on the reconstructed surfaces, while for coverages > 0 .1 three-dimensional clustering occurs. Our experiments reveal that neither dissociation into oxygen and carbon monoxide nor hydrogenation of carbon d ioxide occurs under the experimental conditions.