Anodic passivity of glassy Ni83B17 alloy in sulphuric acid

✍ Scribed by Boguslaw Mazurkiewicz

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: German
• Weight: 424 KB
• Volume: 43
• Category: Article
• ISSN: 0947-5117
• DOI: 10.1002/maco.19920431205

✦ Synopsis

Abstract

The anodic passivation of Ni~83~B~17~ glassy was investigated in sulphuric acid solutions with respect to the degree of proton hydration and the structure of acid. The possibility of passivation in methanolic solutions of sulphuric acid was also examined. The investigations involved electrochemical measurements, XPS and sulphur dioxide analyses. When acid concentration is low, the passivity of Ni~83~B~17~ is a result of the formation of an oxide layer in the presence of “free” water molecules (i.e. not bound to protons). In concentrated sulphuric acid, the passivation may occur as a result of the oxidative ability of acid connected with S^6+^ ion reduction. At intermediate acid concentrations a mixed salt‐oxide layer is formed. The passivity of Ni~83~B~17~ was also observed in methanolic solutions of sulphuric acid, as a result of the oxidising ability of the acid.