In Situ Studies of the Initial Atmospheric Corrosion of Copper Influence of Humidity, Sulfur Dioxide, Ozone, and Nitrogen Dioxide

Infrared reflection absorption spectroscopy and quartz crystal microbalance, integrated into a one‐surface analytical system, and complemented with tapping mode atomic force microscopy, has been used to explore the metal/atmosphere interfacial region under atmospheric pressure conditions. This unique combination of in situ techniques, all possessing submonolayer sensitivity, has revealed information on the different accelerating roles of ozone and nitrogen dioxide on the atmospheric corrosion of copper. The formation of reaction products could be followed quantitatively with respect to chemical identity and kinetics. Exposure in humidified air resulted in species, formed atop a cuprous oxide, designated , all over the copper surface. introduction resulted in an accelerated mass gain with an increased formation rate of both and of all over the surface. introduction resulted in less mass gain than observed under and , with no formation of new , an initial oxidation of and with sulfite oxidation gradually replaced by copper nitrate formation, possibly as . The formation rates of the dominating end products, in and in seemed to be limited by the supply of the gaseous constituents.