| Abstract: | Copper corrosion products originated by the action of formic acid vapours at 40% and 80% relative humidity for a period of 21 days were analysed. Three formic vapour concentration levels (10, 100 and 300 ppm) were generated in laboratory tests at 30°C. The corrosion product layers were characterised using X‐ray photoelectron spectroscopy (XPS) in conjunction with Ar+‐ion sputtering. The components identified in the patina layers were cuprite (Cu2O), copper hydroxide (Cu(OH)2) and copper formate (Cu(HCOO)2). Copper formate was formed by a complex mechanism including copper hydroxide and formic acid. |
