Corrosion in SO2 of pure and preoxidized copper at high temperature

A kinetics and morphological study of the reaction of pure SO₂ with copper over the temperature range 500–950°C showed that only Cu₂S formed despite the fact that thermodynamic ally its formation is not expected. Alternatively, the formation of Cu₂O, expected from the Cu-O-S diagram did not occur during sulfidation; however, its evaporation was observed in an atmosphere of pure SO₂ at high temperature. Thus copper differs from others metals such as nickel or cobalt by its low reactivity with SO₂ compared to the oxidation reaction; therefore, it was possible to follow the beginning of sulfidation.