TY - JOUR
T1 - Electrochemical dissolution of tin in methanesulphonic acid solutions
AU - de Greef, R.A.T.
AU - Janssen, L.J.J.
PY - 2001
Y1 - 2001
N2 - High-rate electroplating of tin on a moving steel strip is generally carried out in cells with dimensionally stable anodes. To obtain a matt tin deposit a concentrated acidic tin methanesulphonate solution containing a small concentration of sulphuric acid is used. The concentrated tin methanesulphonate solution is prepared by dissolution of tin particles with oxygen in a special column. To describe this dissolution process electrode reactions (namely, reduction of oxygen, hydrogen peroxide and hydrogen ions on a tin electrode and oxidation of tin) were studied using electrochemical techniques. It was concluded that on tin, oxygen is almost entirely reduced to water and that H2O2 cannot corrode tin directly, but its decomposition products, for instance oxygen, can. The exchange current density and the charge transfer coefficient for the investigated electrode reactions are estimated. The dissolution of tin by oxygen is determined by the kinetic parameters of the oxygen reduction reaction and by the mass transfer of (i) dissolved oxygen to and (ii) Sn2+ ions from the tin electrode surface. Hydrogen evolution can be neglected during the dissolution of tin in the presence of oxygen. Moreover, it was found that the rate of tin corrosion increases with (i) increasing H+ concentration, (ii) oxygen concentration, (iii) convection intensity and (iv) temperature. It is likely that the tin surface is not covered with oxygen during corrosion in pure methanesulphonic acid solutions, but an oxide layer may be present on the tin surface during oxygen corrosion in pure sulphuric acid solutions. This oxide layer may hinder the oxygen corrosion of tin
AB - High-rate electroplating of tin on a moving steel strip is generally carried out in cells with dimensionally stable anodes. To obtain a matt tin deposit a concentrated acidic tin methanesulphonate solution containing a small concentration of sulphuric acid is used. The concentrated tin methanesulphonate solution is prepared by dissolution of tin particles with oxygen in a special column. To describe this dissolution process electrode reactions (namely, reduction of oxygen, hydrogen peroxide and hydrogen ions on a tin electrode and oxidation of tin) were studied using electrochemical techniques. It was concluded that on tin, oxygen is almost entirely reduced to water and that H2O2 cannot corrode tin directly, but its decomposition products, for instance oxygen, can. The exchange current density and the charge transfer coefficient for the investigated electrode reactions are estimated. The dissolution of tin by oxygen is determined by the kinetic parameters of the oxygen reduction reaction and by the mass transfer of (i) dissolved oxygen to and (ii) Sn2+ ions from the tin electrode surface. Hydrogen evolution can be neglected during the dissolution of tin in the presence of oxygen. Moreover, it was found that the rate of tin corrosion increases with (i) increasing H+ concentration, (ii) oxygen concentration, (iii) convection intensity and (iv) temperature. It is likely that the tin surface is not covered with oxygen during corrosion in pure methanesulphonic acid solutions, but an oxide layer may be present on the tin surface during oxygen corrosion in pure sulphuric acid solutions. This oxide layer may hinder the oxygen corrosion of tin
U2 - 10.1023/A:1017534220761
DO - 10.1023/A:1017534220761
M3 - Article
SN - 0021-891X
VL - 31
SP - 693
EP - 702
JO - Journal of Applied Electrochemistry
JF - Journal of Applied Electrochemistry
IS - 6
ER -