Surface reactions between CO2 and H over K-modified Cu(0 0 1)

Low temperature (115–160 K) adsorption of CO on clean Cu(0 0 1), CO2 on potassium modified Cu(0 0 1) and surface reactions between H2 and CO2 were studied. Pre-adsorption of K leads to strong interaction of the interface with arriving carbon dioxide molecules and linear CO2(phys), bent CO2-, CO and CO3- are observed as adsorbed species. Annealing of the CO2/K/Cu(0 0 1) interface causes, successively, desorption of the reaction products. Pre-adsorbed hydrogen on the alkali-modified substrate changes the surface reaction channels, mainly with no presence of CO and creation of surface formate species. Details of surface reactions are compared with results for thick potassium film on a copper substrate.