Adsorption and interaction of oxygen, carbon monoxide and certain inert gases on copper at 77°K

Abstract

By comparing oxygen adsorption on copper powders and films at 77°K with xenon, krypton and carbon monoxide adsorption at the same temperature, it is apparent that oxygen is rapidly adsorbed to form a quarter of an atomic monolayer, in which the oxygen atoms replace surface copper atoms. Carbon monoxide is adsorbed to form approximately half an atomic monolayer on the clean surface but uptake is markedly reduced by a pre-adsorbed layer of oxygen to about a quarter of an atomic monolayer. Xenon and krypton adsorb to sites to equal area. The interaction between the adsorbed gases and the anomalous behaviour of copper prepared from A.R. cupric oxide is also discussed.