Photoemission study of CO2 adsorbed on K/Cu(110).: Analysis of adsorbate induced structures

Using photoemission spectroscopy, adsorption and reaction of CO2 on potassium modified Cu(110) were studied. In agreement with published results of thermally programmed desorption, apart from carbonate and carbon monoxide as the disproportionation reaction products, a linear CO2 molecule and a bent active CO2(-) species were identified. The reaction paths are independent on the potassium precoverage but the number of CO3 molecules increases with the number of potassium adatoms. The presence of the CO2(-), stable up to 200 K, suitable for the reactivity of the interface in respect of the methanol synthesis, could be confirmed in the complex valence band spectra by occurrence of the characteristic peak at binding energy of 6.8 eV.