Preoxidised Cu surfaces and powdery Cu oxides were exposed to SO 2 vapour in an oxygen-deprived humid atmosphere. The reaction products were investigated by XRD and SEM-EDX. Chevreul's salt, Cu 2SO 4·CuSO 4·2H 2O results to be the only stable product. Cu(0) is detected in experiments on Cu(I) oxide. Based on the competition between Cu(I) disproportionation and Cu(II) reduction by SO 2, a reaction pathway is proposed. Initially formed Chevreul's salt exhibits orthorhombic symmetry and a phase transformation to the stable monoclinic structure occurs upon ageing at room temperature. A mechanistic analogy with bronze disease of archaeological artefacts has been pointed out. © 2012 Elsevier Ltd.
An investigation into the surface layers formed on oxidised copper exposed to SO2 in humid air under hypoxic conditions / G., Giovannelli; Natali, Stefano; Zortea, Laura; B., Bozzini. - In: CORROSION SCIENCE. - ISSN 0010-938X. - 57:(2012), pp. 104-113. [10.1016/j.corsci.2011.12.028]
An investigation into the surface layers formed on oxidised copper exposed to SO2 in humid air under hypoxic conditions
NATALI, Stefano;ZORTEA, LAURA;
2012
Abstract
Preoxidised Cu surfaces and powdery Cu oxides were exposed to SO 2 vapour in an oxygen-deprived humid atmosphere. The reaction products were investigated by XRD and SEM-EDX. Chevreul's salt, Cu 2SO 4·CuSO 4·2H 2O results to be the only stable product. Cu(0) is detected in experiments on Cu(I) oxide. Based on the competition between Cu(I) disproportionation and Cu(II) reduction by SO 2, a reaction pathway is proposed. Initially formed Chevreul's salt exhibits orthorhombic symmetry and a phase transformation to the stable monoclinic structure occurs upon ageing at room temperature. A mechanistic analogy with bronze disease of archaeological artefacts has been pointed out. © 2012 Elsevier Ltd.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
