THE STABILIZATION OF ADSORBED CARBON-DIOXIDE BY FORMATE ON CU(100)

The adsorption and desorption of CO2 on copper has recently achieved much attention as it is expected to play an important role in the methanol synthesis and is known to take part in the water-gas-shift reaction as well as in the formate synthesis on copper. The CO2 interaction with the clean surface is known to be quite weak, 25-30 kJ mol-1 and the CO2 molecule is lying parallel to the surface. However, when formate is pre-adsorbed, the CO2 is found to be stabilized by 14 +/- 1 kJ mol-1 per monolayer formate. The bonding geometry is also heavily influenced by the formate as a new loss feature in the HREEL spectra suggests that the molecule is bent, breaking the linear symmetry.