Seminars Archive

Reactions on alkali-modified copper surfaces

Abstract
Interactions between H, CO, CO2 on alkali-modified copper surfaces have been studied by a variety of experimental techniques. The results are interpreted in terms of reactions, dissociations and site blocking. Furthermore, the reactivity of the different copper surfaces is compared. The coadsorption of CO2 and K at 120K results in weakly adsorbed molecular carbon dioxide, chemisorbed carbonate and carbon monoxide. Irradiation of the CO2/K/Cu(110) interface with photons of energy larger than a few eV causes a transformation of physisorbed CO2 to chemisorbed CO and O. It has been demonstrated that formate, HCOO-, can be synthesised by admitting CO2 to a K/Cu(110) interface with preadsorbed atomic hydrogen. The adsorption sequence of H and CO2 is decisive for the formate yield. It is concluded that when the CO2/K/Cu(110) interface is exposed to H carbonate is decomposed to CO.